Merge branch 'kvm-hw-enable-refactor' into HEAD

The main theme of this series is to kill off kvm_arch_init(),
kvm_arch_hardware_(un)setup(), and kvm_arch_check_processor_compat(), which
all originated in x86 code from way back when, and needlessly complicate
both common KVM code and architecture code.  E.g. many architectures don't
mark functions/data as __init/__ro_after_init purely because kvm_init()
isn't marked __init to support x86's separate vendor modules.

The idea/hope is that with those hooks gone (moved to arch code), it will
be easier for x86 (and other architectures) to modify their module init
sequences as needed without having to fight common KVM code.  E.g. I'm
hoping that ARM can build on this to simplify its hardware enabling logic,
especially the pKVM side of things.

There are bug fixes throughout this series.  They are more scattered than
I would usually prefer, but getting the sequencing correct was a gigantic
pain for many of the x86 fixes due to needing to fix common code in order
for the x86 fix to have any meaning.  And while the bugs are often fatal,
they aren't all that interesting for most users as they either require a
malicious admin or broken hardware, i.e. aren't likely to be encountered
by the vast majority of KVM users.  So unless someone _really_ wants a
particular fix isolated for backporting, I'm not planning on shuffling
patches.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

82 files changed, 861 insertions, 816 deletions

diff --git a/Documentation/virt/kvm/locking.rst b/Documentation/virt/kvm/locking.rst
index a3ca76f9be75..1147836742cc 100644
--- a/Documentation/virt/kvm/locking.rst
+++ b/Documentation/virt/kvm/locking.rst
@@ -9,6 +9,8 @@ KVM Lock Overview
 
 The acquisition orders for mutexes are as follows:
 
+- cpus_read_lock() is taken outside kvm_lock
+
 - kvm->lock is taken outside vcpu->mutex
 
 - kvm->lock is taken outside kvm->slots_lock and kvm->irq_lock
@@ -225,15 +227,10 @@ time it will be set using the Dirty tracking mechanism described above.
 :Type:		mutex
 :Arch:		any
 :Protects:	- vm_list
-
-``kvm_count_lock``
-^^^^^^^^^^^^^^^^^^
-
-:Type:		raw_spinlock_t
-:Arch:		any
-:Protects:	- hardware virtualization enable/disable
-:Comment:	'raw' because hardware enabling/disabling must be atomic /wrt
-		migration.
+		- kvm_usage_count
+		- hardware virtualization enable/disable
+:Comment:	KVM also disables CPU hotplug via cpus_read_lock() during
+		enable/disable.
 
 ``kvm->mn_invalidate_lock``
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -291,3 +288,13 @@ time it will be set using the Dirty tracking mechanism described above.
 		wakeup notification event since external interrupts from the
 		assigned devices happens, we will find the vCPU on the list to
 		wakeup.
+
+``vendor_module_lock``
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+:Type:		mutex
+:Arch:		x86
+:Protects:	loading a vendor module (kvm_amd or kvm_intel)
+:Comment:	Exists because using kvm_lock leads to deadlock.  cpu_hotplug_lock is
+    taken outside of kvm_lock, e.g. in KVM's CPU online/offline callbacks, and
+    many operations need to take cpu_hotplug_lock when loading a vendor module,
+    e.g. updating static calls.
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 35a159d131b5..113e20fdbb56 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -66,8 +66,8 @@ enum kvm_mode kvm_get_mode(void);
 
 DECLARE_STATIC_KEY_FALSE(userspace_irqchip_in_use);
 
-extern unsigned int kvm_sve_max_vl;
-int kvm_arm_init_sve(void);
+extern unsigned int __ro_after_init kvm_sve_max_vl;
+int __init kvm_arm_init_sve(void);
 
 u32 __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
@@ -877,7 +877,7 @@ int kvm_handle_cp10_id(struct kvm_vcpu *vcpu);
 
 void kvm_reset_sys_regs(struct kvm_vcpu *vcpu);
 
-int kvm_sys_reg_table_init(void);
+int __init kvm_sys_reg_table_init(void);
 
 /* MMIO helpers */
 void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);
@@ -908,9 +908,9 @@ int kvm_arm_pvtime_get_attr(struct kvm_vcpu *vcpu,
 int kvm_arm_pvtime_has_attr(struct kvm_vcpu *vcpu,
 			    struct kvm_device_attr *attr);
 
-extern unsigned int kvm_arm_vmid_bits;
-int kvm_arm_vmid_alloc_init(void);
-void kvm_arm_vmid_alloc_free(void);
+extern unsigned int __ro_after_init kvm_arm_vmid_bits;
+int __init kvm_arm_vmid_alloc_init(void);
+void __init kvm_arm_vmid_alloc_free(void);
 void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid);
 void kvm_arm_vmid_clear_active(void);
 
@@ -943,7 +943,6 @@ static inline bool kvm_system_needs_idmapped_vectors(void)
 
 void kvm_arm_vcpu_ptrauth_trap(struct kvm_vcpu *vcpu);
 
-static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
@@ -994,7 +993,7 @@ static inline void kvm_clr_pmu_events(u32 clr) {}
 void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu);
 void kvm_vcpu_put_sysregs_vhe(struct kvm_vcpu *vcpu);
 
-int kvm_set_ipa_limit(void);
+int __init kvm_set_ipa_limit(void);
 
 #define __KVM_HAVE_ARCH_VM_ALLOC
 struct kvm *kvm_arch_alloc_vm(void);
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index e4a7e6369499..7f7c1231679e 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -163,7 +163,7 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size,
 			   void __iomem **haddr);
 int create_hyp_exec_mappings(phys_addr_t phys_addr, size_t size,
 			     void **haddr);
-void free_hyp_pgds(void);
+void __init free_hyp_pgds(void);
 
 void stage2_unmap_vm(struct kvm *kvm);
 int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu, unsigned long type);
@@ -175,7 +175,7 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu);
 
 phys_addr_t kvm_mmu_get_httbr(void);
 phys_addr_t kvm_get_idmap_vector(void);
-int kvm_mmu_init(u32 *hyp_va_bits);
+int __init kvm_mmu_init(u32 *hyp_va_bits);
 
 static inline void *__kvm_vector_slot2addr(void *base,
 					   enum arm64_hyp_spectre_vector slot)
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 05da3c8f7e88..ca6eadeb7d1a 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -21,6 +21,7 @@ if VIRTUALIZATION
 menuconfig KVM
 	bool "Kernel-based Virtual Machine (KVM) support"
 	depends on HAVE_KVM
+	select KVM_GENERIC_HARDWARE_ENABLING
 	select MMU_NOTIFIER
 	select PREEMPT_NOTIFIERS
 	select HAVE_KVM_CPU_RELAX_INTERCEPT
diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index bb24a76b4224..23346585a294 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -811,10 +811,18 @@ void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu)
 	ptimer->host_timer_irq_flags = host_ptimer_irq_flags;
 }
 
-static void kvm_timer_init_interrupt(void *info)
+void kvm_timer_cpu_up(void)
 {
 	enable_percpu_irq(host_vtimer_irq, host_vtimer_irq_flags);
-	enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags);
+	if (host_ptimer_irq)
+		enable_percpu_irq(host_ptimer_irq, host_ptimer_irq_flags);
+}
+
+void kvm_timer_cpu_down(void)
+{
+	disable_percpu_irq(host_vtimer_irq);
+	if (host_ptimer_irq)
+		disable_percpu_irq(host_ptimer_irq);
 }
 
 int kvm_arm_timer_set_reg(struct kvm_vcpu *vcpu, u64 regid, u64 value)
@@ -976,18 +984,6 @@ void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
 	preempt_enable();
 }
 
-static int kvm_timer_starting_cpu(unsigned int cpu)
-{
-	kvm_timer_init_interrupt(NULL);
-	return 0;
-}
-
-static int kvm_timer_dying_cpu(unsigned int cpu)
-{
-	disable_percpu_irq(host_vtimer_irq);
-	return 0;
-}
-
 static int timer_irq_set_vcpu_affinity(struct irq_data *d, void *vcpu)
 {
 	if (vcpu)
@@ -1117,7 +1113,7 @@ static int kvm_irq_init(struct arch_timer_kvm_info *info)
 	return 0;
 }
 
-int kvm_timer_hyp_init(bool has_gic)
+int __init kvm_timer_hyp_init(bool has_gic)
 {
 	struct arch_timer_kvm_info *info;
 	int err;
@@ -1185,9 +1181,6 @@ int kvm_timer_hyp_init(bool has_gic)
 		goto out_free_irq;
 	}
 
-	cpuhp_setup_state(CPUHP_AP_KVM_ARM_TIMER_STARTING,
-			  "kvm/arm/timer:starting", kvm_timer_starting_cpu,
-			  kvm_timer_dying_cpu);
 	return 0;
 out_free_irq:
 	free_percpu_irq(host_vtimer_irq, kvm_get_running_vcpus());
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9c5573bc4614..698787ed87e9 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -63,16 +63,6 @@ int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
 }
 
-int kvm_arch_hardware_setup(void *opaque)
-{
-	return 0;
-}
-
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 			    struct kvm_enable_cap *cap)
 {
@@ -1539,7 +1529,7 @@ static int kvm_init_vector_slots(void)
 	return 0;
 }
 
-static void cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits)
+static void __init cpu_prepare_hyp_mode(int cpu, u32 hyp_va_bits)
 {
 	struct kvm_nvhe_init_params *params = per_cpu_ptr_nvhe_sym(kvm_init_params, cpu);
 	unsigned long tcr;
@@ -1682,7 +1672,15 @@ static void _kvm_arch_hardware_enable(void *discard)
 
 int kvm_arch_hardware_enable(void)
 {
+	int was_enabled = __this_cpu_read(kvm_arm_hardware_enabled);
+
 	_kvm_arch_hardware_enable(NULL);
+
+	if (!was_enabled) {
+		kvm_vgic_cpu_up();
+		kvm_timer_cpu_up();
+	}
+
 	return 0;
 }
 
@@ -1696,6 +1694,11 @@ static void _kvm_arch_hardware_disable(void *discard)
 
 void kvm_arch_hardware_disable(void)
 {
+	if (__this_cpu_read(kvm_arm_hardware_enabled)) {
+		kvm_timer_cpu_down();
+		kvm_vgic_cpu_down();
+	}
+
 	if (!is_protected_kvm_enabled())
 		_kvm_arch_hardware_disable(NULL);
 }
@@ -1738,26 +1741,26 @@ static struct notifier_block hyp_init_cpu_pm_nb = {
 	.notifier_call = hyp_init_cpu_pm_notifier,
 };
 
-static void hyp_cpu_pm_init(void)
+static void __init hyp_cpu_pm_init(void)
 {
 	if (!is_protected_kvm_enabled())
 		cpu_pm_register_notifier(&hyp_init_cpu_pm_nb);
 }
-static void hyp_cpu_pm_exit(void)
+static void __init hyp_cpu_pm_exit(void)
 {
 	if (!is_protected_kvm_enabled())
 		cpu_pm_unregister_notifier(&hyp_init_cpu_pm_nb);
 }
 #else
-static inline void hyp_cpu_pm_init(void)
+static inline void __init hyp_cpu_pm_init(void)
 {
 }
-static inline void hyp_cpu_pm_exit(void)
+static inline void __init hyp_cpu_pm_exit(void)
 {
 }
 #endif
 
-static void init_cpu_logical_map(void)
+static void __init init_cpu_logical_map(void)
 {
 	unsigned int cpu;
 
@@ -1774,7 +1777,7 @@ static void init_cpu_logical_map(void)
 #define init_psci_0_1_impl_state(config, what)	\
 	config.psci_0_1_ ## what ## _implemented = psci_ops.what
 
-static bool init_psci_relay(void)
+static bool __init init_psci_relay(void)
 {
 	/*
 	 * If PSCI has not been initialized, protected KVM cannot install
@@ -1797,7 +1800,7 @@ static bool init_psci_relay(void)
 	return true;
 }
 
-static int init_subsystems(void)
+static int __init init_subsystems(void)
 {
 	int err = 0;
 
@@ -1838,13 +1841,22 @@ static int init_subsystems(void)
 	kvm_register_perf_callbacks(NULL);
 
 out:
+	if (err)
+		hyp_cpu_pm_exit();
+
 	if (err || !is_protected_kvm_enabled())
 		on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);
 
 	return err;
 }
 
-static void teardown_hyp_mode(void)
+static void __init teardown_subsystems(void)
+{
+	kvm_unregister_perf_callbacks();
+	hyp_cpu_pm_exit();
+}
+
+static void __init teardown_hyp_mode(void)
 {
 	int cpu;
 
@@ -1855,7 +1867,7 @@ static void teardown_hyp_mode(void)
 	}
 }
 
-static int do_pkvm_init(u32 hyp_va_bits)
+static int __init do_pkvm_init(u32 hyp_va_bits)
 {
 	void *per_cpu_base = kvm_ksym_ref(kvm_nvhe_sym(kvm_arm_hyp_percpu_base));
 	int ret;
@@ -1891,7 +1903,7 @@ static void kvm_hyp_init_symbols(void)
 	kvm_nvhe_sym(kvm_arm_vmid_bits) = kvm_arm_vmid_bits;
 }
 
-static int kvm_hyp_init_protection(u32 hyp_va_bits)
+static int __init kvm_hyp_init_protection(u32 hyp_va_bits)
 {
 	void *addr = phys_to_virt(hyp_mem_base);
 	int ret;
@@ -1912,7 +1924,7 @@ static int kvm_hyp_init_protection(u32 hyp_va_bits)
 /**
  * Inits Hyp-mode on all online CPUs
  */
-static int init_hyp_mode(void)
+static int __init init_hyp_mode(void)
 {
 	u32 hyp_va_bits;
 	int cpu;
@@ -2094,7 +2106,7 @@ out_err:
 	return err;
 }
 
-static void _kvm_host_prot_finalize(void *arg)
+static void __init _kvm_host_prot_finalize(void *arg)
 {
 	int *err = arg;
 
@@ -2102,7 +2114,7 @@ static void _kvm_host_prot_finalize(void *arg)
 		WRITE_ONCE(*err, -EINVAL);
 }
 
-static int pkvm_drop_host_privileges(void)
+static int __init pkvm_drop_host_privileges(void)
 {
 	int ret = 0;
 
@@ -2115,7 +2127,7 @@ static int pkvm_drop_host_privileges(void)
 	return ret;
 }
 
-static int finalize_hyp_mode(void)
+static int __init finalize_hyp_mode(void)
 {
 	if (!is_protected_kvm_enabled())
 		return 0;
@@ -2190,7 +2202,7 @@ void kvm_arch_irq_bypass_start(struct irq_bypass_consumer *cons)
 /**
  * Initialize Hyp-mode and memory mappings on all CPUs.
  */
-int kvm_arch_init(void *opaque)
+static __init int kvm_arm_init(void)
 {
 	int err;
 	bool in_hyp_mode;
@@ -2241,7 +2253,7 @@ int kvm_arch_init(void *opaque)
 	err = kvm_init_vector_slots();
 	if (err) {
 		kvm_err("Cannot initialise vector slots\n");
-		goto out_err;
+		goto out_hyp;
 	}
 
 	err = init_subsystems();
@@ -2252,7 +2264,7 @@ int kvm_arch_init(void *opaque)
 		err = finalize_hyp_mode();
 		if (err) {
 			kvm_err("Failed to finalize Hyp protection\n");
-			goto out_hyp;
+			goto out_subs;
 		}
 	}
 
@@ -2264,10 +2276,19 @@ int kvm_arch_init(void *opaque)
 		kvm_info("Hyp mode initialized successfully\n");
 	}
 
+	/*
+	 * FIXME: Do something reasonable if kvm_init() fails after pKVM
+	 * hypervisor protection is finalized.
+	 */
+	err = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	if (err)
+		goto out_subs;
+
 	return 0;
 
+out_subs:
+	teardown_subsystems();
 out_hyp:
-	hyp_cpu_pm_exit();
 	if (!in_hyp_mode)
 		teardown_hyp_mode();
 out_err:
@@ -2275,12 +2296,6 @@ out_err:
 	return err;
 }
 
-/* NOP: Compiling as a module not supported */
-void kvm_arch_exit(void)
-{
-	kvm_unregister_perf_callbacks();
-}
-
 static int __init early_kvm_mode_cfg(char *arg)
 {
 	if (!arg)
@@ -2319,10 +2334,4 @@ enum kvm_mode kvm_get_mode(void)
 	return kvm_mode;
 }
 
-static int arm_init(void)
-{
-	int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
-	return rc;
-}
-
-module_init(arm_init);
+module_init(kvm_arm_init);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index 31d7fa4c7c14..d6c41043b5af 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -25,11 +25,11 @@
 static struct kvm_pgtable *hyp_pgtable;
 static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
 
-static unsigned long hyp_idmap_start;
-static unsigned long hyp_idmap_end;
-static phys_addr_t hyp_idmap_vector;
+static unsigned long __ro_after_init hyp_idmap_start;
+static unsigned long __ro_after_init hyp_idmap_end;
+static phys_addr_t __ro_after_init hyp_idmap_vector;
 
-static unsigned long io_map_base;
+static unsigned long __ro_after_init io_map_base;
 
 static phys_addr_t stage2_range_addr_end(phys_addr_t addr, phys_addr_t end)
 {
@@ -280,7 +280,7 @@ static void stage2_flush_vm(struct kvm *kvm)
 /**
  * free_hyp_pgds - free Hyp-mode page tables
  */
-void free_hyp_pgds(void)
+void __init free_hyp_pgds(void)
 {
 	mutex_lock(&kvm_hyp_pgd_mutex);
 	if (hyp_pgtable) {
@@ -1665,7 +1665,7 @@ static struct kvm_pgtable_mm_ops kvm_hyp_mm_ops = {
 	.virt_to_phys		= kvm_host_pa,
 };
 
-int kvm_mmu_init(u32 *hyp_va_bits)
+int __init kvm_mmu_init(u32 *hyp_va_bits)
 {
 	int err;
 	u32 idmap_bits;
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index e0267f672b8a..2bc74739a6df 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -30,7 +30,7 @@
 #include <asm/virt.h>
 
 /* Maximum phys_shift supported for any VM on this host */
-static u32 kvm_ipa_limit;
+static u32 __ro_after_init kvm_ipa_limit;
 
 /*
  * ARMv8 Reset Values
@@ -41,9 +41,9 @@ static u32 kvm_ipa_limit;
 #define VCPU_RESET_PSTATE_SVC	(PSR_AA32_MODE_SVC | PSR_AA32_A_BIT | \
 				 PSR_AA32_I_BIT | PSR_AA32_F_BIT)
 
-unsigned int kvm_sve_max_vl;
+unsigned int __ro_after_init kvm_sve_max_vl;
 
-int kvm_arm_init_sve(void)
+int __init kvm_arm_init_sve(void)
 {
 	if (system_supports_sve()) {
 		kvm_sve_max_vl = sve_max_virtualisable_vl();
@@ -352,7 +352,7 @@ u32 get_kvm_ipa_limit(void)
 	return kvm_ipa_limit;
 }
 
-int kvm_set_ipa_limit(void)
+int __init kvm_set_ipa_limit(void)
 {
 	unsigned int parange;
 	u64 mmfr0;
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index d5ee52d6bf73..1225e9faac06 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -82,7 +82,7 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg)
 }
 
 /* 3 bits per cache level, as per CLIDR, but non-existent caches always 0 */
-static u32 cache_levels;
+static u32 __ro_after_init cache_levels;
 
 /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */
 #define CSSELR_MAX 14
@@ -2733,7 +2733,7 @@ static void get_ctr_el0(struct kvm_vcpu *v, const struct sys_reg_desc *r)
 }
 
 /* ->val is filled in by kvm_sys_reg_table_init() */
-static struct sys_reg_desc invariant_sys_regs[] = {
+static struct sys_reg_desc invariant_sys_regs[] __ro_after_init = {
 	{ SYS_DESC(SYS_MIDR_EL1), NULL, get_midr_el1 },
 	{ SYS_DESC(SYS_REVIDR_EL1), NULL, get_revidr_el1 },
 	{ SYS_DESC(SYS_CLIDR_EL1), NULL, get_clidr_el1 },
@@ -3057,7 +3057,7 @@ int kvm_arm_copy_sys_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
 	return write_demux_regids(uindices);
 }
 
-int kvm_sys_reg_table_init(void)
+int __init kvm_sys_reg_table_init(void)
 {
 	bool valid = true;
 	unsigned int i;
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index f6d4f4052555..6c7f6ae21ec0 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -465,17 +465,15 @@ out:
 
 /* GENERIC PROBE */
 
-static int vgic_init_cpu_starting(unsigned int cpu)
+void kvm_vgic_cpu_up(void)
 {
 	enable_percpu_irq(kvm_vgic_global_state.maint_irq, 0);
-	return 0;
 }
 
 
-static int vgic_init_cpu_dying(unsigned int cpu)
+void kvm_vgic_cpu_down(void)
 {
 	disable_percpu_irq(kvm_vgic_global_state.maint_irq);
-	return 0;
 }
 
 static irqreturn_t vgic_maintenance_handler(int irq, void *data)
@@ -584,19 +582,6 @@ int kvm_vgic_hyp_init(void)
 		return ret;
 	}
 
-	ret = cpuhp_setup_state(CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
-				"kvm/arm/vgic:starting",
-				vgic_init_cpu_starting, vgic_init_cpu_dying);
-	if (ret) {
-		kvm_err("Cannot register vgic CPU notifier\n");
-		goto out_free_irq;
-	}
-
 	kvm_info("vgic interrupt IRQ%d\n", kvm_vgic_global_state.maint_irq);
 	return 0;
-
-out_free_irq:
-	free_percpu_irq(kvm_vgic_global_state.maint_irq,
-			kvm_get_running_vcpus());
-	return ret;
 }
diff --git a/arch/arm64/kvm/vmid.c b/arch/arm64/kvm/vmid.c
index d78ae63d7c15..08978d0672e7 100644
--- a/arch/arm64/kvm/vmid.c
+++ b/arch/arm64/kvm/vmid.c
@@ -16,7 +16,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmu.h>
 
-unsigned int kvm_arm_vmid_bits;
+unsigned int __ro_after_init kvm_arm_vmid_bits;
 static DEFINE_RAW_SPINLOCK(cpu_vmid_lock);
 
 static atomic64_t vmid_generation;
@@ -172,7 +172,7 @@ void kvm_arm_vmid_update(struct kvm_vmid *kvm_vmid)
 /*
  * Initialize the VMID allocator
  */
-int kvm_arm_vmid_alloc_init(void)
+int __init kvm_arm_vmid_alloc_init(void)
 {
 	kvm_arm_vmid_bits = kvm_get_vmid_bits();
 
@@ -190,7 +190,7 @@ int kvm_arm_vmid_alloc_init(void)
 	return 0;
 }
 
-void kvm_arm_vmid_alloc_free(void)
+void __init kvm_arm_vmid_alloc_free(void)
 {
 	kfree(vmid_map);
 }
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 5cedb28e8a40..2803c9c21ef9 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -758,7 +758,7 @@ struct kvm_mips_callbacks {
 	void (*vcpu_reenter)(struct kvm_vcpu *vcpu);
 };
 extern struct kvm_mips_callbacks *kvm_mips_callbacks;
-int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks);
+int kvm_mips_emulation_init(void);
 
 /* Debug: dump vcpu state */
 int kvm_arch_vcpu_dump_regs(struct kvm_vcpu *vcpu);
@@ -888,7 +888,6 @@ extern unsigned long kvm_mips_get_ramsize(struct kvm *kvm);
 extern int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
 			     struct kvm_mips_interrupt *irq);
 
-static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_free_memslot(struct kvm *kvm,
 					 struct kvm_memory_slot *slot) {}
diff --git a/arch/mips/kvm/Kconfig b/arch/mips/kvm/Kconfig
index 91d197bee9c0..29e51649203b 100644
--- a/arch/mips/kvm/Kconfig
+++ b/arch/mips/kvm/Kconfig
@@ -28,6 +28,7 @@ config KVM
 	select MMU_NOTIFIER
 	select SRCU
 	select INTERVAL_TREE
+	select KVM_GENERIC_HARDWARE_ENABLING
 	help
 	  Support for hosting Guest kernels.
 
diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
index 21ff75bcdbc4..805aeea2166e 100644
--- a/arch/mips/kvm/Makefile
+++ b/arch/mips/kvm/Makefile
@@ -17,4 +17,4 @@ kvm-$(CONFIG_CPU_LOONGSON64) += loongson_ipi.o
 
 kvm-y		+= vz.o
 obj-$(CONFIG_KVM)	+= kvm.o
-obj-y			+= callback.o tlb.o
+obj-y			+= tlb.o
diff --git a/arch/mips/kvm/callback.c b/arch/mips/kvm/callback.c
deleted file mode 100644
index d88aa2173fb0..000000000000
--- a/arch/mips/kvm/callback.c
+++ /dev/null
@@ -1,14 +0,0 @@
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
- * Authors: Yann Le Du <ledu@kymasys.com>
- */
-
-#include <linux/export.h>
-#include <linux/kvm_host.h>
-
-struct kvm_mips_callbacks *kvm_mips_callbacks;
-EXPORT_SYMBOL_GPL(kvm_mips_callbacks);
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index a25e0b73ee70..36c8991b5d39 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -135,16 +135,6 @@ void kvm_arch_hardware_disable(void)
 	kvm_mips_callbacks->hardware_disable();
 }
 
-int kvm_arch_hardware_setup(void *opaque)
-{
-	return 0;
-}
-
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 extern void kvm_init_loongson_ipi(struct kvm *kvm);
 
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
@@ -1015,21 +1005,6 @@ long kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
 	return r;
 }
 
-int kvm_arch_init(void *opaque)
-{
-	if (kvm_mips_callbacks) {
-		kvm_err("kvm: module already exists\n");
-		return -EEXIST;
-	}
-
-	return kvm_mips_emulation_init(&kvm_mips_callbacks);
-}
-
-void kvm_arch_exit(void)
-{
-	kvm_mips_callbacks = NULL;
-}
-
 int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
 				  struct kvm_sregs *sregs)
 {
@@ -1646,16 +1621,21 @@ static int __init kvm_mips_init(void)
 	if (ret)
 		return ret;
 
-	ret = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
-
+	ret = kvm_mips_emulation_init();
 	if (ret)
 		return ret;
 
+
 	if (boot_cpu_type() == CPU_LOONGSON64)
 		kvm_priority_to_irq = kvm_loongson3_priority_to_irq;
 
 	register_die_notifier(&kvm_mips_csr_die_notifier);
 
+	ret = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	if (ret) {
+		unregister_die_notifier(&kvm_mips_csr_die_notifier);
+		return ret;
+	}
 	return 0;
 }
 
diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index c706f5890a05..dafab003ea0d 100644
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -3304,7 +3304,10 @@ static struct kvm_mips_callbacks kvm_vz_callbacks = {
 	.vcpu_reenter = kvm_vz_vcpu_reenter,
 };
 
-int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
+/* FIXME: Get rid of the callbacks now that trap-and-emulate is gone. */
+struct kvm_mips_callbacks *kvm_mips_callbacks = &kvm_vz_callbacks;
+
+int kvm_mips_emulation_init(void)
 {
 	if (!cpu_has_vz)
 		return -ENODEV;
@@ -3318,7 +3321,5 @@ int kvm_mips_emulation_init(struct kvm_mips_callbacks **install_callbacks)
 		return -ENODEV;
 
 	pr_info("Starting KVM with MIPS VZ extensions\n");
-
-	*install_callbacks = &kvm_vz_callbacks;
 	return 0;
 }
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index caea15dcb91d..959f566a455c 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -876,13 +876,10 @@ struct kvm_vcpu_arch {
 #define __KVM_HAVE_ARCH_WQP
 #define __KVM_HAVE_CREATE_DEVICE
 
-static inline void kvm_arch_hardware_disable(void) {}
-static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
 static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
-static inline void kvm_arch_exit(void) {}
 static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
 
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index eae9619b6190..6bef23d6d0e3 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -118,7 +118,6 @@ extern int kvmppc_xlate(struct kvm_vcpu *vcpu, ulong eaddr,
 extern int kvmppc_core_vcpu_create(struct kvm_vcpu *vcpu);
 extern void kvmppc_core_vcpu_free(struct kvm_vcpu *vcpu);
 extern int kvmppc_core_vcpu_setup(struct kvm_vcpu *vcpu);
-extern int kvmppc_core_check_processor_compat(void);
 extern int kvmppc_core_vcpu_translate(struct kvm_vcpu *vcpu,
                                       struct kvm_translation *tr);
 
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 6d525285dbe8..57f4e7896d67 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -999,16 +999,6 @@ int kvmppc_h_logical_ci_store(struct kvm_vcpu *vcpu)
 }
 EXPORT_SYMBOL_GPL(kvmppc_h_logical_ci_store);
 
-int kvmppc_core_check_processor_compat(void)
-{
-	/*
-	 * We always return 0 for book3s. We check
-	 * for compatibility while loading the HV
-	 * or PR module
-	 */
-	return 0;
-}
-
 int kvmppc_book3s_hcall_implemented(struct kvm *kvm, unsigned long hcall)
 {
 	return kvm->arch.kvm_ops->hcall_implemented(hcall);
@@ -1062,7 +1052,7 @@ static int kvmppc_book3s_init(void)
 {
 	int r;
 
-	r = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 	if (r)
 		return r;
 #ifdef CONFIG_KVM_BOOK3S_32_HANDLER
diff --git a/arch/powerpc/kvm/e500.c b/arch/powerpc/kvm/e500.c
index c8b2b4478545..b0f695428733 100644
--- a/arch/powerpc/kvm/e500.c
+++ b/arch/powerpc/kvm/e500.c
@@ -314,7 +314,7 @@ static void kvmppc_core_vcpu_put_e500(struct kvm_vcpu *vcpu)
 	kvmppc_booke_vcpu_put(vcpu);
 }
 
-int kvmppc_core_check_processor_compat(void)
+static int kvmppc_e500_check_processor_compat(void)
 {
 	int r;
 
@@ -507,7 +507,7 @@ static int __init kvmppc_e500_init(void)
 	unsigned long handler_len;
 	unsigned long max_ivor = 0;
 
-	r = kvmppc_core_check_processor_compat();
+	r = kvmppc_e500_check_processor_compat();
 	if (r)
 		goto err_out;
 
@@ -531,7 +531,7 @@ static int __init kvmppc_e500_init(void)
 	flush_icache_range(kvmppc_booke_handlers, kvmppc_booke_handlers +
 			   ivor[max_ivor] + handler_len);
 
-	r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
 	if (r)
 		goto err_out;
 	kvm_ops_e500.owner = THIS_MODULE;
diff --git a/arch/powerpc/kvm/e500mc.c b/arch/powerpc/kvm/e500mc.c
index 57e0ad6a2ca3..611532a0dedc 100644
--- a/arch/powerpc/kvm/e500mc.c
+++ b/arch/powerpc/kvm/e500mc.c
@@ -388,6 +388,10 @@ static int __init kvmppc_e500mc_init(void)
 {
 	int r;
 
+	r = kvmppc_e500mc_check_processor_compat();
+	if (r)
+		return kvmppc_e500mc;
+
 	r = kvmppc_booke_init();
 	if (r)
 		goto err_out;
@@ -400,7 +404,7 @@ static int __init kvmppc_e500mc_init(void)
 	 */
 	kvmppc_init_lpid(KVMPPC_NR_LPIDS/threads_per_core);
 
-	r = kvm_init(NULL, sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
+	r = kvm_init(sizeof(struct kvmppc_vcpu_e500), 0, THIS_MODULE);
 	if (r)
 		goto err_out;
 	kvm_ops_e500mc.owner = THIS_MODULE;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 04494a4fb37a..4c5405fc5538 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -435,21 +435,6 @@ int kvmppc_ld(struct kvm_vcpu *vcpu, ulong *eaddr, int size, void *ptr,
 }
 EXPORT_SYMBOL_GPL(kvmppc_ld);
 
-int kvm_arch_hardware_enable(void)
-{
-	return 0;
-}
-
-int kvm_arch_hardware_setup(void *opaque)
-{
-	return 0;
-}
-
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return kvmppc_core_check_processor_compat();
-}
-
 int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
 {
 	struct kvmppc_ops *kvm_ops = NULL;
@@ -2544,11 +2529,6 @@ void kvmppc_init_lpid(unsigned long nr_lpids_param)
 }
 EXPORT_SYMBOL_GPL(kvmppc_init_lpid);
 
-int kvm_arch_init(void *opaque)
-{
-	return 0;
-}
-
 EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ppc_instr);
 
 void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_dentry)
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 93f43a3e7886..cf24da85b13c 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -230,7 +230,6 @@ struct kvm_vcpu_arch {
 	bool pause;
 };
 
-static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
@@ -297,11 +296,11 @@ int kvm_riscv_gstage_map(struct kvm_vcpu *vcpu,
 int kvm_riscv_gstage_alloc_pgd(struct kvm *kvm);
 void kvm_riscv_gstage_free_pgd(struct kvm *kvm);
 void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu);
-void kvm_riscv_gstage_mode_detect(void);
-unsigned long kvm_riscv_gstage_mode(void);
+void __init kvm_riscv_gstage_mode_detect(void);
+unsigned long __init kvm_riscv_gstage_mode(void);
 int kvm_riscv_gstage_gpa_bits(void);
 
-void kvm_riscv_gstage_vmid_detect(void);
+void __init kvm_riscv_gstage_vmid_detect(void);
 unsigned long kvm_riscv_gstage_vmid_bits(void);
 int kvm_riscv_gstage_vmid_init(struct kvm *kvm);
 bool kvm_riscv_gstage_vmid_ver_changed(struct kvm_vmid *vmid);
diff --git a/arch/riscv/kvm/Kconfig b/arch/riscv/kvm/Kconfig
index f36a737d5f96..d5a658a047a7 100644
--- a/arch/riscv/kvm/Kconfig
+++ b/arch/riscv/kvm/Kconfig
@@ -20,6 +20,7 @@ if VIRTUALIZATION
 config KVM
 	tristate "Kernel-based Virtual Machine (KVM) support (EXPERIMENTAL)"
 	depends on RISCV_SBI && MMU
+	select KVM_GENERIC_HARDWARE_ENABLING
 	select MMU_NOTIFIER
 	select PREEMPT_NOTIFIERS
 	select KVM_MMIO
diff --git a/arch/riscv/kvm/main.c b/arch/riscv/kvm/main.c
index 58c5489d3031..e2da56ed9069 100644
--- a/arch/riscv/kvm/main.c
+++ b/arch/riscv/kvm/main.c
@@ -20,16 +20,6 @@ long kvm_arch_dev_ioctl(struct file *filp,
 	return -EINVAL;
 }
 
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
-int kvm_arch_hardware_setup(void *opaque)
-{
-	return 0;
-}
-
 int kvm_arch_hardware_enable(void)
 {
 	unsigned long hideleg, hedeleg;
@@ -70,7 +60,7 @@ void kvm_arch_hardware_disable(void)
 	csr_write(CSR_HIDELEG, 0);
 }
 
-int kvm_arch_init(void *opaque)
+static int __init riscv_kvm_init(void)
 {
 	const char *str;
 
@@ -115,16 +105,7 @@ int kvm_arch_init(void *opaque)
 
 	kvm_info("VMID %ld bits available\n", kvm_riscv_gstage_vmid_bits());
 
-	return 0;
-}
-
-void kvm_arch_exit(void)
-{
-}
-
-static int __init riscv_kvm_init(void)
-{
-	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	return kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
 }
 module_init(riscv_kvm_init);
 
diff --git a/arch/riscv/kvm/mmu.c b/arch/riscv/kvm/mmu.c
index 34b57e0be2ef..66ef19676fe4 100644
--- a/arch/riscv/kvm/mmu.c
+++ b/arch/riscv/kvm/mmu.c
@@ -20,12 +20,12 @@
 #include <asm/pgtable.h>
 
 #ifdef CONFIG_64BIT
-static unsigned long gstage_mode = (HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
-static unsigned long gstage_pgd_levels = 3;
+static unsigned long gstage_mode __ro_after_init = (HGATP_MODE_SV39X4 << HGATP_MODE_SHIFT);
+static unsigned long gstage_pgd_levels __ro_after_init = 3;
 #define gstage_index_bits	9
 #else
-static unsigned long gstage_mode = (HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
-static unsigned long gstage_pgd_levels = 2;
+static unsigned long gstage_mode __ro_after_init = (HGATP_MODE_SV32X4 << HGATP_MODE_SHIFT);
+static unsigned long gstage_pgd_levels __ro_after_init = 2;
 #define gstage_index_bits	10
 #endif
 
@@ -758,7 +758,7 @@ void kvm_riscv_gstage_update_hgatp(struct kvm_vcpu *vcpu)
 		kvm_riscv_local_hfence_gvma_all();
 }
 
-void kvm_riscv_gstage_mode_detect(void)
+void __init kvm_riscv_gstage_mode_detect(void)
 {
 #ifdef CONFIG_64BIT
 	/* Try Sv57x4 G-stage mode */
@@ -782,7 +782,7 @@ skip_sv48x4_test:
 #endif
 }
 
-unsigned long kvm_riscv_gstage_mode(void)
+unsigned long __init kvm_riscv_gstage_mode(void)
 {
 	return gstage_mode >> HGATP_MODE_SHIFT;
 }
diff --git a/arch/riscv/kvm/vmid.c b/arch/riscv/kvm/vmid.c
index 6cd93995fb65..5246da1c9167 100644
--- a/arch/riscv/kvm/vmid.c
+++ b/arch/riscv/kvm/vmid.c
@@ -17,10 +17,10 @@
 
 static unsigned long vmid_version = 1;
 static unsigned long vmid_next;
-static unsigned long vmid_bits;
+static unsigned long vmid_bits __ro_after_init;
 static DEFINE_SPINLOCK(vmid_lock);
 
-void kvm_riscv_gstage_vmid_detect(void)
+void __init kvm_riscv_gstage_vmid_detect(void)
 {
 	unsigned long old;
 
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index d67ce719d16a..2bbc3d54959d 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -1031,7 +1031,6 @@ extern char sie_exit;
 extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc);
 extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc);
 
-static inline void kvm_arch_hardware_disable(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 static inline void kvm_arch_free_memslot(struct kvm *kvm,
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 1dae78deddf2..3754d7937530 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -3411,7 +3411,7 @@ void kvm_s390_gib_destroy(void)
 	gib = NULL;
 }
 
-int kvm_s390_gib_init(u8 nisc)
+int __init kvm_s390_gib_init(u8 nisc)
 {
 	int rc = 0;
 
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e4890e04b210..bd25076aa19b 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -256,17 +256,6 @@ debug_info_t *kvm_s390_dbf;
 debug_info_t *kvm_s390_dbf_uv;
 
 /* Section: not file related */
-int kvm_arch_hardware_enable(void)
-{
-	/* every s390 is virtualization enabled ;-) */
-	return 0;
-}
-
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	return 0;
-}
-
 /* forward declarations */
 static void kvm_gmap_notifier(struct gmap *gmap, unsigned long start,
 			      unsigned long end);
@@ -329,25 +318,6 @@ static struct notifier_block kvm_clock_notifier = {
 	.notifier_call = kvm_clock_sync,
 };
 
-int kvm_arch_hardware_setup(void *opaque)
-{
-	gmap_notifier.notifier_call = kvm_gmap_notifier;
-	gmap_register_pte_notifier(&gmap_notifier);
-	vsie_gmap_notifier.notifier_call = kvm_s390_vsie_gmap_notifier;
-	gmap_register_pte_notifier(&vsie_gmap_notifier);
-	atomic_notifier_chain_register(&s390_epoch_delta_notifier,
-				       &kvm_clock_notifier);
-	return 0;
-}
-
-void kvm_arch_hardware_unsetup(void)
-{
-	gmap_unregister_pte_notifier(&gmap_notifier);
-	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
-	atomic_notifier_chain_unregister(&s390_epoch_delta_notifier,
-					 &kvm_clock_notifier);
-}
-
 static void allow_cpu_feat(unsigned long nr)
 {
 	set_bit_inv(nr, kvm_s390_available_cpu_feat);
@@ -385,7 +355,7 @@ static __always_inline void __insn32_query(unsigned int opcode, u8 *query)
 #define INSN_SORTL 0xb938
 #define INSN_DFLTCC 0xb939
 
-static void kvm_s390_cpu_feat_init(void)
+static void __init kvm_s390_cpu_feat_init(void)
 {
 	int i;
 
@@ -488,7 +458,7 @@ static void kvm_s390_cpu_feat_init(void)
 	 */
 }
 
-int kvm_arch_init(void *opaque)
+static int __init __kvm_s390_init(void)
 {
 	int rc = -ENOMEM;
 
@@ -498,11 +468,11 @@ int kvm_arch_init(void *opaque)
 
 	kvm_s390_dbf_uv = debug_register("kvm-uv", 32, 1, 7 * sizeof(long));
 	if (!kvm_s390_dbf_uv)
-		goto out;
+		goto err_kvm_uv;
 
 	if (debug_register_view(kvm_s390_dbf, &debug_sprintf_view) ||
 	    debug_register_view(kvm_s390_dbf_uv, &debug_sprintf_view))
-		goto out;
+		goto err_debug_view;
 
 	kvm_s390_cpu_feat_init();
 
@@ -510,30 +480,49 @@ int kvm_arch_init(void *opaque)
 	rc = kvm_register_device_ops(&kvm_flic_ops, KVM_DEV_TYPE_FLIC);
 	if (rc) {
 		pr_err("A FLIC registration call failed with rc=%d\n", rc);
-		goto out;
+		goto err_flic;
 	}
 
 	if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM)) {
 		rc = kvm_s390_pci_init();
 		if (rc) {
 			pr_err("Unable to allocate AIFT for PCI\n");
-			goto out;
+			goto err_pci;
 		}
 	}
 
 	rc = kvm_s390_gib_init(GAL_ISC);
 	if (rc)
-		goto out;
+		goto err_gib;
+
+	gmap_notifier.notifier_call = kvm_gmap_notifier;
+	gmap_register_pte_notifier(&gmap_notifier);
+	vsie_gmap_notifier.notifier_call = kvm_s390_vsie_gmap_notifier;
+	gmap_register_pte_notifier(&vsie_gmap_notifier);
+	atomic_notifier_chain_register(&s390_epoch_delta_notifier,
+				       &kvm_clock_notifier);
 
 	return 0;
 
-out:
-	kvm_arch_exit();
+err_gib:
+	if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM))
+		kvm_s390_pci_exit();
+err_pci:
+err_flic:
+err_debug_view:
+	debug_unregister(kvm_s390_dbf_uv);
+err_kvm_uv:
+	debug_unregister(kvm_s390_dbf);
 	return rc;
 }
 
-void kvm_arch_exit(void)
+static void __kvm_s390_exit(void)
 {
+	gmap_unregister_pte_notifier(&gmap_notifier);
+	gmap_unregister_pte_notifier(&vsie_gmap_notifier);
+	atomic_notifier_chain_unregister(&s390_epoch_delta_notifier,
+					 &kvm_clock_notifier);
+
 	kvm_s390_gib_destroy();
 	if (IS_ENABLED(CONFIG_VFIO_PCI_ZDEV_KVM))
 		kvm_s390_pci_exit();
@@ -5696,7 +5685,7 @@ static inline unsigned long nonhyp_mask(int i)
 
 static int __init kvm_s390_init(void)
 {
-	int i;
+	int i, r;
 
 	if (!sclp.has_sief2) {
 		pr_info("SIE is not available\n");
@@ -5712,12 +5701,23 @@ static int __init kvm_s390_init(void)
 		kvm_s390_fac_base[i] |=
 			stfle_fac_list[i] & nonhyp_mask(i);
 
-	return kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	r = __kvm_s390_init();
+	if (r)
+		return r;
+
+	r = kvm_init(sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	if (r) {
+		__kvm_s390_exit();
+		return r;
+	}
+	return 0;
 }
 
 static void __exit kvm_s390_exit(void)
 {
 	kvm_exit();
+
+	__kvm_s390_exit();
 }
 
 module_init(kvm_s390_init);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index d48588c207d8..0261d42c7d01 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -470,7 +470,7 @@ void kvm_s390_gisa_clear(struct kvm *kvm);
 void kvm_s390_gisa_destroy(struct kvm *kvm);
 void kvm_s390_gisa_disable(struct kvm *kvm);
 void kvm_s390_gisa_enable(struct kvm *kvm);
-int kvm_s390_gib_init(u8 nisc);
+int __init kvm_s390_gib_init(u8 nisc);
 void kvm_s390_gib_destroy(void);
 
 /* implemented in guestdbg.c */
diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
index ec51e810e381..b124d586db55 100644
--- a/arch/s390/kvm/pci.c
+++ b/arch/s390/kvm/pci.c
@@ -672,7 +672,7 @@ out:
 	return r;
 }
 
-int kvm_s390_pci_init(void)
+int __init kvm_s390_pci_init(void)
 {
 	zpci_kvm_hook.kvm_register = kvm_s390_pci_register_kvm;
 	zpci_kvm_hook.kvm_unregister = kvm_s390_pci_unregister_kvm;
diff --git a/arch/s390/kvm/pci.h b/arch/s390/kvm/pci.h
index 486d06ef563f..ff0972dd5e71 100644
--- a/arch/s390/kvm/pci.h
+++ b/arch/s390/kvm/pci.h
@@ -60,7 +60,7 @@ void kvm_s390_pci_clear_list(struct kvm *kvm);
 
 int kvm_s390_pci_zpci_op(struct kvm *kvm, struct kvm_s390_zpci_op *args);
 
-int kvm_s390_pci_init(void);
+int __init kvm_s390_pci_init(void);
 void kvm_s390_pci_exit(void);
 
 static inline bool kvm_s390_pci_interp_allowed(void)
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index abccd51dcfca..dba2909e5ae2 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -14,6 +14,7 @@ BUILD_BUG_ON(1)
  * to make a definition optional, but in this case the default will
  * be __static_call_return0.
  */
+KVM_X86_OP(check_processor_compatibility)
 KVM_X86_OP(hardware_enable)
 KVM_X86_OP(hardware_disable)
 KVM_X86_OP(hardware_unsetup)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c70690b2c82d..6a9d6f99d0d3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1511,6 +1511,8 @@ static inline u16 kvm_lapic_irq_dest_mode(bool dest_mode_logical)
 struct kvm_x86_ops {
 	const char *name;
 
+	int (*check_processor_compatibility)(void);
+
 	int (*hardware_enable)(void);
 	void (*hardware_disable)(void);
 	void (*hardware_unsetup)(void);
@@ -1722,9 +1724,6 @@ struct kvm_x86_nested_ops {
 };
 
 struct kvm_x86_init_ops {
-	int (*cpu_has_kvm_support)(void);
-	int (*disabled_by_bios)(void);
-	int (*check_processor_compatibility)(void);
 	int (*hardware_setup)(void);
 	unsigned int (*handle_intel_pt_intr)(void);
 
@@ -1751,6 +1750,9 @@ extern struct kvm_x86_ops kvm_x86_ops;
 #define KVM_X86_OP_OPTIONAL_RET0 KVM_X86_OP
 #include <asm/kvm-x86-ops.h>
 
+int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops);
+void kvm_x86_vendor_exit(void);
+
 #define __KVM_HAVE_ARCH_VM_ALLOC
 static inline struct kvm *kvm_arch_alloc_vm(void)
 {
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index fbeaa9ddef59..8e578311ca9d 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -49,6 +49,7 @@ config KVM
 	select SRCU
 	select INTERVAL_TREE
 	select HAVE_KVM_PM_NOTIFIER if PM
+	select KVM_GENERIC_HARDWARE_ENABLING
 	help
 	  Support hosting fully virtualized guest machines using hardware
 	  virtualization extensions.  You will need a fairly recent
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 69768e4d53a6..4ca16b18a086 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -8,6 +8,7 @@
  * Copyright 2011 Red Hat, Inc. and/or its affiliates.
  * Copyright IBM Corporation, 2008
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/export.h>
diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c
index c1390357126a..ee8c4c3496ed 100644
--- a/arch/x86/kvm/debugfs.c
+++ b/arch/x86/kvm/debugfs.c
@@ -4,6 +4,8 @@
  *
  * Copyright 2016 Red Hat, Inc. and/or its affiliates.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kvm_host.h>
 #include <linux/debugfs.h>
 #include "lapic.h"
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 5cc3efa0e21c..c3443045cd93 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -17,6 +17,7 @@
  *
  * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include "kvm_cache_regs.h"
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index 80d082ecd5c5..71aff0edc0ed 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -17,6 +17,7 @@
  *   Ben-Ami Yassour <benami@il.ibm.com>
  *   Andrey Smetanin <asmetanin@virtuozzo.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "x86.h"
 #include "lapic.h"
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index e0a7a0e7a73c..cd57a517d04a 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -30,7 +30,7 @@
  *   Based on QEMU and Xen.
  */
 
-#define pr_fmt(fmt) "pit: " fmt
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/slab.h>
@@ -351,7 +351,7 @@ static void create_pit_timer(struct kvm_pit *pit, u32 val, int is_period)
 
 		if (ps->period < min_period) {
 			pr_info_ratelimited(
-			    "kvm: requested %lld ns "
+			    "requested %lld ns "
 			    "i8254 timer period limited to %lld ns\n",
 			    ps->period, min_period);
 			ps->period = min_period;
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index e1bb6218bb96..4756bcb5724f 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -26,6 +26,8 @@
  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
  *   Port from Qemu.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/bitops.h>
@@ -35,7 +37,7 @@
 #include "trace.h"
 
 #define pr_pic_unimpl(fmt, ...)	\
-	pr_err_ratelimited("kvm: pic: " fmt, ## __VA_ARGS__)
+	pr_err_ratelimited("pic: " fmt, ## __VA_ARGS__)
 
 static void pic_irq_request(struct kvm *kvm, int level);
 
diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index 765943d7cfa5..042dee556125 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -26,6 +26,7 @@
  *  Yaozu (Eddie) Dong <eddie.dong@intel.com>
  *  Based on Xen 3.1 code.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/kvm.h>
diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index a70952eca905..b2c397dd2bc6 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -7,6 +7,7 @@
  * Authors:
  *   Yaozu (Eddie) Dong <Eddie.dong@intel.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/export.h>
 #include <linux/kvm_host.h>
diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
index 3742d9adacfc..16d076a1b91a 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -8,6 +8,7 @@
  *
  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/slab.h>
@@ -56,7 +57,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
 
 	if (irq->dest_mode == APIC_DEST_PHYSICAL &&
 	    irq->dest_id == 0xff && kvm_lowest_prio_delivery(irq)) {
-		printk(KERN_INFO "kvm: apic: phys broadcast and lowest prio\n");
+		pr_info("apic: phys broadcast and lowest prio\n");
 		irq->delivery_mode = APIC_DM_FIXED;
 	}
 
@@ -199,7 +200,7 @@ int kvm_request_irq_source_id(struct kvm *kvm)
 	irq_source_id = find_first_zero_bit(bitmap, BITS_PER_LONG);
 
 	if (irq_source_id >= BITS_PER_LONG) {
-		printk(KERN_WARNING "kvm: exhaust allocatable IRQ sources!\n");
+		pr_warn("exhausted allocatable IRQ sources!\n");
 		irq_source_id = -EFAULT;
 		goto unlock;
 	}
@@ -221,7 +222,7 @@ void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id)
 	mutex_lock(&kvm->irq_lock);
 	if (irq_source_id < 0 ||
 	    irq_source_id >= BITS_PER_LONG) {
-		printk(KERN_ERR "kvm: IRQ source ID out of range!\n");
+		pr_err("IRQ source ID out of range!\n");
 		goto unlock;
 	}
 	clear_bit(irq_source_id, &kvm->arch.irq_sources_bitmap);
diff --git a/arch/x86/kvm/kvm_onhyperv.c b/arch/x86/kvm/kvm_onhyperv.c
index ee4f696a0782..482d6639ef88 100644
--- a/arch/x86/kvm/kvm_onhyperv.c
+++ b/arch/x86/kvm/kvm_onhyperv.c
@@ -2,6 +2,7 @@
 /*
  * KVM L1 hypervisor optimizations on Hyper-V.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <asm/mshyperv.h>
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index 4efdb4a4d72c..cfaf1d8c64ca 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -15,6 +15,7 @@
  *
  * Based on Xen 3.1 code, Copyright (c) 2004, Intel Corporation.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/kvm.h>
@@ -941,8 +942,7 @@ static void kvm_apic_disabled_lapic_found(struct kvm *kvm)
 {
 	if (!kvm->arch.disabled_lapic_found) {
 		kvm->arch.disabled_lapic_found = true;
-		printk(KERN_INFO
-		       "Disabled LAPIC found during irq injection\n");
+		pr_info("Disabled LAPIC found during irq injection\n");
 	}
 }
 
@@ -1560,7 +1560,7 @@ static void limit_periodic_timer_frequency(struct kvm_lapic *apic)
 
 		if (apic->lapic_timer.period < min_period) {
 			pr_info_ratelimited(
-			    "kvm: vcpu %i: requested %lld ns "
+			    "vcpu %i: requested %lld ns "
 			    "lapic timer period limited to %lld ns\n",
 			    apic->vcpu->vcpu_id,
 			    apic->lapic_timer.period, min_period);
@@ -1845,7 +1845,7 @@ static bool set_target_expiration(struct kvm_lapic *apic, u32 count_reg)
 				deadline = apic->lapic_timer.period;
 			else if (unlikely(deadline > apic->lapic_timer.period)) {
 				pr_info_ratelimited(
-				    "kvm: vcpu %i: requested lapic timer restore with "
+				    "vcpu %i: requested lapic timer restore with "
 				    "starting count register %#x=%u (%lld ns) > initial count (%lld ns). "
 				    "Using initial count to start timer.\n",
 				    apic->vcpu->vcpu_id,
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 9c7198544195..aeb240b339f5 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -14,6 +14,7 @@
  *   Yaniv Kamay  <yaniv@qumranet.com>
  *   Avi Kivity   <avi@qumranet.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "irq.h"
 #include "ioapic.h"
@@ -3456,8 +3457,7 @@ static int fast_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 		}
 
 		if (++retry_count > 4) {
-			printk_once(KERN_WARNING
-				"kvm: Fast #PF retrying more than 4 times.\n");
+			pr_warn_once("Fast #PF retrying more than 4 times.\n");
 			break;
 		}
 
@@ -6647,7 +6647,7 @@ void kvm_mmu_invalidate_mmio_sptes(struct kvm *kvm, u64 gen)
 	 * zap all shadow pages.
 	 */
 	if (unlikely(gen == 0)) {
-		kvm_debug_ratelimited("kvm: zapping shadow pages for mmio generation wraparound\n");
+		kvm_debug_ratelimited("zapping shadow pages for mmio generation wraparound\n");
 		kvm_mmu_zap_all_fast(kvm);
 	}
 }
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index 2e09d1b6249f..0a2ac438d647 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -10,6 +10,7 @@
  * Author:
  *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <linux/rculist.h>
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index c0fd7e049b4e..fce6f047399f 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -7,7 +7,7 @@
  * Copyright (C) 2006 Qumranet, Inc.
  * Copyright 2020 Red Hat, Inc. and/or its affiliates.
  */
-
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include "mmu.h"
@@ -352,7 +352,7 @@ u64 mark_spte_for_access_track(u64 spte)
 
 	WARN_ONCE(spte & (SHADOW_ACC_TRACK_SAVED_BITS_MASK <<
 			  SHADOW_ACC_TRACK_SAVED_BITS_SHIFT),
-		  "kvm: Access Tracking saved bit locations are not zero\n");
+		  "Access Tracking saved bit locations are not zero\n");
 
 	spte |= (spte & SHADOW_ACC_TRACK_SAVED_BITS_MASK) <<
 		SHADOW_ACC_TRACK_SAVED_BITS_SHIFT;
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 6f54dc9409c9..0d8deefee66c 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -435,11 +435,11 @@ static inline void check_spte_writable_invariants(u64 spte)
 {
 	if (spte & shadow_mmu_writable_mask)
 		WARN_ONCE(!(spte & shadow_host_writable_mask),
-			  "kvm: MMU-writable SPTE is not Host-writable: %llx",
+			  KBUILD_MODNAME ": MMU-writable SPTE is not Host-writable: %llx",
 			  spte);
 	else
 		WARN_ONCE(is_writable_pte(spte),
-			  "kvm: Writable SPTE is not MMU-writable: %llx", spte);
+			  KBUILD_MODNAME ": Writable SPTE is not MMU-writable: %llx", spte);
 }
 
 static inline bool is_mmu_writable_spte(u64 spte)
diff --git a/arch/x86/kvm/mmu/tdp_iter.c b/arch/x86/kvm/mmu/tdp_iter.c
index 39b48e7d7d1a..e26e744df1d1 100644
--- a/arch/x86/kvm/mmu/tdp_iter.c
+++ b/arch/x86/kvm/mmu/tdp_iter.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "mmu_internal.h"
 #include "tdp_iter.h"
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index cc1fb9a65620..bba33aea0fb0 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "mmu.h"
 #include "mmu_internal.h"
diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index a8502e02f479..9fac1ec03463 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -13,6 +13,7 @@
  *   Paolo Bonzini <pbonzini@redhat.com>
  *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include <asm/mtrr.h>
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index eb594620dd75..d939d3b84e6f 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -9,6 +9,7 @@
  *   Gleb Natapov <gleb@redhat.com>
  *   Wei Huang    <wei@redhat.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/types.h>
 #include <linux/kvm_host.h>
diff --git a/arch/x86/kvm/smm.c b/arch/x86/kvm/smm.c
index a9c1c2af8d94..cc43638d48a3 100644
--- a/arch/x86/kvm/smm.c
+++ b/arch/x86/kvm/smm.c
@@ -1,4 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0 */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include "x86.h"
diff --git a/arch/x86/kvm/svm/avic.c b/arch/x86/kvm/svm/avic.c
index 6919dee69f18..f52f5e0dd465 100644
--- a/arch/x86/kvm/svm/avic.c
+++ b/arch/x86/kvm/svm/avic.c
@@ -12,7 +12,7 @@
  *   Avi Kivity   <avi@qumranet.com>
  */
 
-#define pr_fmt(fmt) "SVM: " fmt
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_types.h>
 #include <linux/hashtable.h>
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index bc9cd7086fa9..3bfbcb607d80 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -12,7 +12,7 @@
  *   Avi Kivity   <avi@qumranet.com>
  */
 
-#define pr_fmt(fmt) "SVM: " fmt
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_types.h>
 #include <linux/kvm_host.h>
diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c
index 0e313fbae055..1ff068f23841 100644
--- a/arch/x86/kvm/svm/pmu.c
+++ b/arch/x86/kvm/svm/pmu.c
@@ -9,6 +9,8 @@
  *
  * Implementation is based on pmu_intel.c file
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/types.h>
 #include <linux/kvm_host.h>
 #include <linux/perf_event.h>
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 86d6897f4806..273cba809328 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -6,6 +6,7 @@
  *
  * Copyright 2010 Red Hat, Inc. and/or its affiliates.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_types.h>
 #include <linux/kvm_host.h>
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 9a194aa1a75a..799b24801d31 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1,4 +1,4 @@
-#define pr_fmt(fmt) "SVM: " fmt
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 
@@ -519,21 +519,37 @@ static void svm_init_osvw(struct kvm_vcpu *vcpu)
 		vcpu->arch.osvw.status |= 1;
 }
 
-static int has_svm(void)
+static bool kvm_is_svm_supported(void)
 {
+	int cpu = raw_smp_processor_id();
 	const char *msg;
+	u64 vm_cr;
 
 	if (!cpu_has_svm(&msg)) {
-		printk(KERN_INFO "has_svm: %s\n", msg);
-		return 0;
+		pr_err("SVM not supported by CPU %d, %s\n", cpu, msg);
+		return false;
 	}
 
 	if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT)) {
 		pr_info("KVM is unsupported when running as an SEV guest\n");
-		return 0;
+		return false;
 	}
 
-	return 1;
+	rdmsrl(MSR_VM_CR, vm_cr);
+	if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE)) {
+		pr_err("SVM disabled (by BIOS) in MSR_VM_CR on CPU %d\n", cpu);
+		return false;
+	}
+
+	return true;
+}
+
+static int svm_check_processor_compat(void)
+{
+	if (!kvm_is_svm_supported())
+		return -EIO;
+
+	return 0;
 }
 
 void __svm_write_tsc_multiplier(u64 multiplier)
@@ -572,10 +588,6 @@ static int svm_hardware_enable(void)
 	if (efer & EFER_SVME)
 		return -EBUSY;
 
-	if (!has_svm()) {
-		pr_err("%s: err EOPNOTSUPP on %d\n", __func__, me);
-		return -EINVAL;
-	}
 	sd = per_cpu_ptr(&svm_data, me);
 	sd->asid_generation = 1;
 	sd->max_asid = cpuid_ebx(SVM_CPUID_FUNC) - 1;
@@ -2076,7 +2088,7 @@ static void svm_handle_mce(struct kvm_vcpu *vcpu)
 		 * Erratum 383 triggered. Guest state is corrupt so kill the
 		 * guest.
 		 */
-		pr_err("KVM: Guest triggered AMD Erratum 383\n");
+		pr_err("Guest triggered AMD Erratum 383\n");
 
 		kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
 
@@ -4076,17 +4088,6 @@ static void svm_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
 	vmcb_mark_dirty(svm->vmcb, VMCB_CR);
 }
 
-static int is_disabled(void)
-{
-	u64 vm_cr;
-
-	rdmsrl(MSR_VM_CR, vm_cr);
-	if (vm_cr & (1 << SVM_VM_CR_SVM_DISABLE))
-		return 1;
-
-	return 0;
-}
-
 static void
 svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
 {
@@ -4098,11 +4099,6 @@ svm_patch_hypercall(struct kvm_vcpu *vcpu, unsigned char *hypercall)
 	hypercall[2] = 0xd9;
 }
 
-static int __init svm_check_processor_compat(void)
-{
-	return 0;
-}
-
 /*
  * The kvm parameter can be NULL (module initialization, or invocation before
  * VM creation). Be sure to check the kvm parameter before using it.
@@ -4629,7 +4625,7 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, int emul_type,
 	smap = cr4 & X86_CR4_SMAP;
 	is_user = svm_get_cpl(vcpu) == 3;
 	if (smap && (!smep || is_user)) {
-		pr_err_ratelimited("KVM: SEV Guest triggered AMD Erratum 1096\n");
+		pr_err_ratelimited("SEV Guest triggered AMD Erratum 1096\n");
 
 		/*
 		 * If the fault occurred in userspace, arbitrarily inject #GP
@@ -4701,7 +4697,9 @@ static int svm_vm_init(struct kvm *kvm)
 }
 
 static struct kvm_x86_ops svm_x86_ops __initdata = {
-	.name = "kvm_amd",
+	.name = KBUILD_MODNAME,
+
+	.check_processor_compatibility = svm_check_processor_compat,
 
 	.hardware_unsetup = svm_hardware_unsetup,
 	.hardware_enable = svm_hardware_enable,
@@ -4978,7 +4976,7 @@ static __init int svm_hardware_setup(void)
 	}
 
 	if (nested) {
-		printk(KERN_INFO "kvm: Nested Virtualization enabled\n");
+		pr_info("Nested Virtualization enabled\n");
 		kvm_enable_efer_bits(EFER_SVME | EFER_LMSLE);
 	}
 
@@ -4996,7 +4994,7 @@ static __init int svm_hardware_setup(void)
 	/* Force VM NPT level equal to the host's paging level */
 	kvm_configure_mmu(npt_enabled, get_npt_level(),
 			  get_npt_level(), PG_LEVEL_1G);
-	pr_info("kvm: Nested Paging %sabled\n", npt_enabled ? "en" : "dis");
+	pr_info("Nested Paging %sabled\n", npt_enabled ? "en" : "dis");
 
 	/* Setup shadow_me_value and shadow_me_mask */
 	kvm_mmu_set_me_spte_mask(sme_me_mask, sme_me_mask);
@@ -5086,10 +5084,7 @@ err:
 
 
 static struct kvm_x86_init_ops svm_init_ops __initdata = {
-	.cpu_has_kvm_support = has_svm,
-	.disabled_by_bios = is_disabled,
 	.hardware_setup = svm_hardware_setup,
-	.check_processor_compatibility = svm_check_processor_compat,
 
 	.runtime_ops = &svm_x86_ops,
 	.pmu_ops = &amd_pmu_ops,
@@ -5097,15 +5092,37 @@ static struct kvm_x86_init_ops svm_init_ops __initdata = {
 
 static int __init svm_init(void)
 {
+	int r;
+
 	__unused_size_checks();
 
-	return kvm_init(&svm_init_ops, sizeof(struct vcpu_svm),
-			__alignof__(struct vcpu_svm), THIS_MODULE);
+	if (!kvm_is_svm_supported())
+		return -EOPNOTSUPP;
+
+	r = kvm_x86_vendor_init(&svm_init_ops);
+	if (r)
+		return r;
+
+	/*
+	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
+	 * exposed to userspace!
+	 */
+	r = kvm_init(sizeof(struct vcpu_svm), __alignof__(struct vcpu_svm),
+		     THIS_MODULE);
+	if (r)
+		goto err_kvm_init;
+
+	return 0;
+
+err_kvm_init:
+	kvm_x86_vendor_exit();
+	return r;
 }
 
 static void __exit svm_exit(void)
 {
 	kvm_exit();
+	kvm_x86_vendor_exit();
 }
 
 module_init(svm_init)
diff --git a/arch/x86/kvm/svm/svm_onhyperv.c b/arch/x86/kvm/svm/svm_onhyperv.c
index 26a89d0da93e..7af8422d3382 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.c
+++ b/arch/x86/kvm/svm/svm_onhyperv.c
@@ -2,6 +2,7 @@
 /*
  * KVM L1 hypervisor optimizations on Hyper-V for SVM.
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 
diff --git a/arch/x86/kvm/svm/svm_onhyperv.h b/arch/x86/kvm/svm/svm_onhyperv.h
index 45faf84476ce..6981c1e9a809 100644
--- a/arch/x86/kvm/svm/svm_onhyperv.h
+++ b/arch/x86/kvm/svm/svm_onhyperv.h
@@ -34,7 +34,7 @@ static inline void svm_hv_hardware_setup(void)
 {
 	if (npt_enabled &&
 	    ms_hyperv.nested_features & HV_X64_NESTED_ENLIGHTENED_TLB) {
-		pr_info("kvm: Hyper-V enlightened NPT TLB flush enabled\n");
+		pr_info(KBUILD_MODNAME ": Hyper-V enlightened NPT TLB flush enabled\n");
 		svm_x86_ops.tlb_remote_flush = hv_remote_flush_tlb;
 		svm_x86_ops.tlb_remote_flush_with_range =
 				hv_remote_flush_tlb_with_range;
@@ -43,7 +43,7 @@ static inline void svm_hv_hardware_setup(void)
 	if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH) {
 		int cpu;
 
-		pr_info("kvm: Hyper-V Direct TLB Flush enabled\n");
+		pr_info(KBUILD_MODNAME ": Hyper-V Direct TLB Flush enabled\n");
 		for_each_online_cpu(cpu) {
 			struct hv_vp_assist_page *vp_ap =
 				hv_get_vp_assist_page(cpu);
diff --git a/arch/x86/kvm/vmx/capabilities.h b/arch/x86/kvm/vmx/capabilities.h
index cd2ac9536c99..45162c1bcd8f 100644
--- a/arch/x86/kvm/vmx/capabilities.h
+++ b/arch/x86/kvm/vmx/capabilities.h
@@ -66,13 +66,13 @@ struct vmcs_config {
 	u64 misc;
 	struct nested_vmx_msrs nested;
 };
-extern struct vmcs_config vmcs_config;
+extern struct vmcs_config vmcs_config __ro_after_init;
 
 struct vmx_capability {
 	u32 ept;
 	u32 vpid;
 };
-extern struct vmx_capability vmx_capability;
+extern struct vmx_capability vmx_capability __ro_after_init;
 
 static inline bool cpu_has_vmx_basic_inout(void)
 {
diff --git a/arch/x86/kvm/vmx/hyperv.c b/arch/x86/kvm/vmx/hyperv.c
index f773450fba6e..22daca752797 100644
--- a/arch/x86/kvm/vmx/hyperv.c
+++ b/arch/x86/kvm/vmx/hyperv.c
@@ -1,6 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-
-#define pr_fmt(fmt) "kvm/hyper-v: " fmt
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/errno.h>
 #include <linux/smp.h>
@@ -527,7 +526,7 @@ int nested_evmcs_check_controls(struct vmcs12 *vmcs12)
 	}									\
 	while (0)
 
-__init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
+void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf)
 {
 	evmcs_check_vmcs_conf(cpu_based_exec_ctrl, EXEC_CTRL);
 	evmcs_check_vmcs_conf(pin_based_exec_ctrl, PINCTRL);
diff --git a/arch/x86/kvm/vmx/hyperv.h b/arch/x86/kvm/vmx/hyperv.h
index 883102d567c3..ab08a9b9ab7d 100644
--- a/arch/x86/kvm/vmx/hyperv.h
+++ b/arch/x86/kvm/vmx/hyperv.h
@@ -179,9 +179,7 @@ static __always_inline int get_evmcs_offset(unsigned long field,
 {
 	int offset = evmcs_field_offset(field, clean_field);
 
-	WARN_ONCE(offset < 0, "KVM: accessing unsupported EVMCS field %lx\n",
-		  field);
-
+	WARN_ONCE(offset < 0, "accessing unsupported EVMCS field %lx\n", field);
 	return offset;
 }
 
@@ -273,7 +271,7 @@ static inline void evmcs_load(u64 phys_addr)
 	vp_ap->enlighten_vmentry = 1;
 }
 
-__init void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf);
+void evmcs_sanitize_exec_ctrls(struct vmcs_config *vmcs_conf);
 #else /* !IS_ENABLED(CONFIG_HYPERV) */
 static __always_inline void evmcs_write64(unsigned long field, u64 value) {}
 static inline void evmcs_write32(unsigned long field, u32 value) {}
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index d93c715cda6a..557b9c468734 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/objtool.h>
 #include <linux/percpu.h>
@@ -203,7 +204,7 @@ static void nested_vmx_abort(struct kvm_vcpu *vcpu, u32 indicator)
 {
 	/* TODO: not to reset guest simply here. */
 	kvm_make_request(KVM_REQ_TRIPLE_FAULT, vcpu);
-	pr_debug_ratelimited("kvm: nested vmx abort, indicator %d\n", indicator);
+	pr_debug_ratelimited("nested vmx abort, indicator %d\n", indicator);
 }
 
 static inline bool vmx_control_verify(u32 control, u32 low, u32 high)
diff --git a/arch/x86/kvm/vmx/pmu_intel.c b/arch/x86/kvm/vmx/pmu_intel.c
index e5cec07ca8d9..efce9ad70e4e 100644
--- a/arch/x86/kvm/vmx/pmu_intel.c
+++ b/arch/x86/kvm/vmx/pmu_intel.c
@@ -8,6 +8,8 @@
  *   Avi Kivity   <avi@redhat.com>
  *   Gleb Natapov <gleb@redhat.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/types.h>
 #include <linux/kvm_host.h>
 #include <linux/perf_event.h>
@@ -762,8 +764,7 @@ void vmx_passthrough_lbr_msrs(struct kvm_vcpu *vcpu)
 	return;
 
 warn:
-	pr_warn_ratelimited("kvm: vcpu-%d: fail to passthrough LBR.\n",
-		vcpu->vcpu_id);
+	pr_warn_ratelimited("vcpu-%d: fail to passthrough LBR.\n", vcpu->vcpu_id);
 }
 
 static void intel_pmu_cleanup(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index 1b56c5e5c9fb..94c38bea60e7 100644
--- a/arch/x86/kvm/vmx/posted_intr.c
+++ b/arch/x86/kvm/vmx/posted_intr.c
@@ -1,4 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/kvm_host.h>
 
 #include <asm/irq_remapping.h>
diff --git a/arch/x86/kvm/vmx/sgx.c b/arch/x86/kvm/vmx/sgx.c
index b12da2a6dec9..aa53c98034bf 100644
--- a/arch/x86/kvm/vmx/sgx.c
+++ b/arch/x86/kvm/vmx/sgx.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0
 /*  Copyright(c) 2021 Intel Corporation. */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <asm/sgx.h>
 
@@ -164,7 +165,7 @@ static int __handle_encls_ecreate(struct kvm_vcpu *vcpu,
 	if (!vcpu->kvm->arch.sgx_provisioning_allowed &&
 	    (attributes & SGX_ATTR_PROVISIONKEY)) {
 		if (sgx_12_1->eax & SGX_ATTR_PROVISIONKEY)
-			pr_warn_once("KVM: SGX PROVISIONKEY advertised but not allowed\n");
+			pr_warn_once("SGX PROVISIONKEY advertised but not allowed\n");
 		kvm_inject_gp(vcpu, 0);
 		return 1;
 	}
@@ -381,7 +382,7 @@ int handle_encls(struct kvm_vcpu *vcpu)
 			return handle_encls_ecreate(vcpu);
 		if (leaf == EINIT)
 			return handle_encls_einit(vcpu);
-		WARN(1, "KVM: unexpected exit on ENCLS[%u]", leaf);
+		WARN_ONCE(1, "unexpected exit on ENCLS[%u]", leaf);
 		vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
 		vcpu->run->hw.hardware_exit_reason = EXIT_REASON_ENCLS;
 		return 0;
diff --git a/arch/x86/kvm/vmx/vmcs12.c b/arch/x86/kvm/vmx/vmcs12.c
index 2251b60920f8..106a72c923ca 100644
--- a/arch/x86/kvm/vmx/vmcs12.c
+++ b/arch/x86/kvm/vmx/vmcs12.c
@@ -1,4 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "vmcs12.h"
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 0220e22b89ca..73005d7e4e43 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -12,6 +12,7 @@
  *   Avi Kivity   <avi@qumranet.com>
  *   Yaniv Kamay  <yaniv@qumranet.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/highmem.h>
 #include <linux/hrtimer.h>
@@ -444,36 +445,36 @@ void vmread_error(unsigned long field, bool fault)
 	if (fault)
 		kvm_spurious_fault();
 	else
-		vmx_insn_failed("kvm: vmread failed: field=%lx\n", field);
+		vmx_insn_failed("vmread failed: field=%lx\n", field);
 }
 
 noinline void vmwrite_error(unsigned long field, unsigned long value)
 {
-	vmx_insn_failed("kvm: vmwrite failed: field=%lx val=%lx err=%u\n",
+	vmx_insn_failed("vmwrite failed: field=%lx val=%lx err=%u\n",
 			field, value, vmcs_read32(VM_INSTRUCTION_ERROR));
 }
 
 noinline void vmclear_error(struct vmcs *vmcs, u64 phys_addr)
 {
-	vmx_insn_failed("kvm: vmclear failed: %p/%llx err=%u\n",
+	vmx_insn_failed("vmclear failed: %p/%llx err=%u\n",
 			vmcs, phys_addr, vmcs_read32(VM_INSTRUCTION_ERROR));
 }
 
 noinline void vmptrld_error(struct vmcs *vmcs, u64 phys_addr)
 {
-	vmx_insn_failed("kvm: vmptrld failed: %p/%llx err=%u\n",
+	vmx_insn_failed("vmptrld failed: %p/%llx err=%u\n",
 			vmcs, phys_addr, vmcs_read32(VM_INSTRUCTION_ERROR));
 }
 
 noinline void invvpid_error(unsigned long ext, u16 vpid, gva_t gva)
 {
-	vmx_insn_failed("kvm: invvpid failed: ext=0x%lx vpid=%u gva=0x%lx\n",
+	vmx_insn_failed("invvpid failed: ext=0x%lx vpid=%u gva=0x%lx\n",
 			ext, vpid, gva);
 }
 
 noinline void invept_error(unsigned long ext, u64 eptp, gpa_t gpa)
 {
-	vmx_insn_failed("kvm: invept failed: ext=0x%lx eptp=%llx gpa=0x%llx\n",
+	vmx_insn_failed("invept failed: ext=0x%lx eptp=%llx gpa=0x%llx\n",
 			ext, eptp, gpa);
 }
 
@@ -488,8 +489,8 @@ static DEFINE_PER_CPU(struct list_head, loaded_vmcss_on_cpu);
 static DECLARE_BITMAP(vmx_vpid_bitmap, VMX_NR_VPIDS);
 static DEFINE_SPINLOCK(vmx_vpid_lock);
 
-struct vmcs_config vmcs_config;
-struct vmx_capability vmx_capability;
+struct vmcs_config vmcs_config __ro_after_init;
+struct vmx_capability vmx_capability __ro_after_init;
 
 #define VMX_SEGMENT_FIELD(seg)					\
 	[VCPU_SREG_##seg] = {                                   \
@@ -523,6 +524,8 @@ static inline void vmx_segment_cache_clear(struct vcpu_vmx *vmx)
 static unsigned long host_idt_base;
 
 #if IS_ENABLED(CONFIG_HYPERV)
+static struct kvm_x86_ops vmx_x86_ops __initdata;
+
 static bool __read_mostly enlightened_vmcs = true;
 module_param(enlightened_vmcs, bool, 0444);
 
@@ -551,6 +554,71 @@ static int hv_enable_l2_tlb_flush(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static __init void hv_init_evmcs(void)
+{
+	int cpu;
+
+	if (!enlightened_vmcs)
+		return;
+
+	/*
+	 * Enlightened VMCS usage should be recommended and the host needs
+	 * to support eVMCS v1 or above.
+	 */
+	if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED &&
+	    (ms_hyperv.nested_features & HV_X64_ENLIGHTENED_VMCS_VERSION) >=
+	     KVM_EVMCS_VERSION) {
+
+		/* Check that we have assist pages on all online CPUs */
+		for_each_online_cpu(cpu) {
+			if (!hv_get_vp_assist_page(cpu)) {
+				enlightened_vmcs = false;
+				break;
+			}
+		}
+
+		if (enlightened_vmcs) {
+			pr_info("Using Hyper-V Enlightened VMCS\n");
+			static_branch_enable(&enable_evmcs);
+		}
+
+		if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)
+			vmx_x86_ops.enable_l2_tlb_flush
+				= hv_enable_l2_tlb_flush;
+
+	} else {
+		enlightened_vmcs = false;
+	}
+}
+
+static void hv_reset_evmcs(void)
+{
+	struct hv_vp_assist_page *vp_ap;
+
+	if (!static_branch_unlikely(&enable_evmcs))
+		return;
+
+	/*
+	 * KVM should enable eVMCS if and only if all CPUs have a VP assist
+	 * page, and should reject CPU onlining if eVMCS is enabled the CPU
+	 * doesn't have a VP assist page allocated.
+	 */
+	vp_ap = hv_get_vp_assist_page(smp_processor_id());
+	if (WARN_ON_ONCE(!vp_ap))
+		return;
+
+	/*
+	 * Reset everything to support using non-enlightened VMCS access later
+	 * (e.g. when we reload the module with enlightened_vmcs=0)
+	 */
+	vp_ap->nested_control.features.directhypercall = 0;
+	vp_ap->current_nested_vmcs = 0;
+	vp_ap->enlighten_vmentry = 0;
+}
+
+#else /* IS_ENABLED(CONFIG_HYPERV) */
+static void hv_init_evmcs(void) {}
+static void hv_reset_evmcs(void) {}
 #endif /* IS_ENABLED(CONFIG_HYPERV) */
 
 /*
@@ -1613,8 +1681,8 @@ static int skip_emulated_instruction(struct kvm_vcpu *vcpu)
 		if (!instr_len)
 			goto rip_updated;
 
-		WARN(exit_reason.enclave_mode,
-		     "KVM: skipping instruction after SGX enclave VM-Exit");
+		WARN_ONCE(exit_reason.enclave_mode,
+			  "skipping instruction after SGX enclave VM-Exit");
 
 		orig_rip = kvm_rip_read(vcpu);
 		rip = orig_rip + instr_len;
@@ -2448,88 +2516,6 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
 	}
 }
 
-static __init int cpu_has_kvm_support(void)
-{
-	return cpu_has_vmx();
-}
-
-static __init int vmx_disabled_by_bios(void)
-{
-	return !boot_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
-	       !boot_cpu_has(X86_FEATURE_VMX);
-}
-
-static int kvm_cpu_vmxon(u64 vmxon_pointer)
-{
-	u64 msr;
-
-	cr4_set_bits(X86_CR4_VMXE);
-
-	asm_volatile_goto("1: vmxon %[vmxon_pointer]\n\t"
-			  _ASM_EXTABLE(1b, %l[fault])
-			  : : [vmxon_pointer] "m"(vmxon_pointer)
-			  : : fault);
-	return 0;
-
-fault:
-	WARN_ONCE(1, "VMXON faulted, MSR_IA32_FEAT_CTL (0x3a) = 0x%llx\n",
-		  rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr) ? 0xdeadbeef : msr);
-	cr4_clear_bits(X86_CR4_VMXE);
-
-	return -EFAULT;
-}
-
-static int vmx_hardware_enable(void)
-{
-	int cpu = raw_smp_processor_id();
-	u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
-	int r;
-
-	if (cr4_read_shadow() & X86_CR4_VMXE)
-		return -EBUSY;
-
-	/*
-	 * This can happen if we hot-added a CPU but failed to allocate
-	 * VP assist page for it.
-	 */
-	if (static_branch_unlikely(&enable_evmcs) &&
-	    !hv_get_vp_assist_page(cpu))
-		return -EFAULT;
-
-	intel_pt_handle_vmx(1);
-
-	r = kvm_cpu_vmxon(phys_addr);
-	if (r) {
-		intel_pt_handle_vmx(0);
-		return r;
-	}
-
-	if (enable_ept)
-		ept_sync_global();
-
-	return 0;
-}
-
-static void vmclear_local_loaded_vmcss(void)
-{
-	int cpu = raw_smp_processor_id();
-	struct loaded_vmcs *v, *n;
-
-	list_for_each_entry_safe(v, n, &per_cpu(loaded_vmcss_on_cpu, cpu),
-				 loaded_vmcss_on_cpu_link)
-		__loaded_vmcs_clear(v);
-}
-
-static void vmx_hardware_disable(void)
-{
-	vmclear_local_loaded_vmcss();
-
-	if (cpu_vmxoff())
-		kvm_spurious_fault();
-
-	intel_pt_handle_vmx(0);
-}
-
 /*
  * There is no X86_FEATURE for SGX yet, but anyway we need to query CPUID
  * directly instead of going through cpu_has(), to ensure KVM is trapping
@@ -2565,8 +2551,7 @@ static bool cpu_has_perf_global_ctrl_bug(void)
 	return false;
 }
 
-static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
-				      u32 msr, u32 *result)
+static int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt, u32 msr, u32 *result)
 {
 	u32 vmx_msr_low, vmx_msr_high;
 	u32 ctl = ctl_min | ctl_opt;
@@ -2584,7 +2569,7 @@ static __init int adjust_vmx_controls(u32 ctl_min, u32 ctl_opt,
 	return 0;
 }
 
-static __init u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
+static u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
 {
 	u64 allowed;
 
@@ -2593,8 +2578,8 @@ static __init u64 adjust_vmx_controls64(u64 ctl_opt, u32 msr)
 	return  ctl_opt & allowed;
 }
 
-static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
-				    struct vmx_capability *vmx_cap)
+static int setup_vmcs_config(struct vmcs_config *vmcs_conf,
+			     struct vmx_capability *vmx_cap)
 {
 	u32 vmx_msr_low, vmx_msr_high;
 	u32 _pin_based_exec_control = 0;
@@ -2760,6 +2745,119 @@ static __init int setup_vmcs_config(struct vmcs_config *vmcs_conf,
 	return 0;
 }
 
+static bool kvm_is_vmx_supported(void)
+{
+	int cpu = raw_smp_processor_id();
+
+	if (!cpu_has_vmx()) {
+		pr_err("VMX not supported by CPU %d\n", cpu);
+		return false;
+	}
+
+	if (!this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
+	    !this_cpu_has(X86_FEATURE_VMX)) {
+		pr_err("VMX not enabled (by BIOS) in MSR_IA32_FEAT_CTL on CPU %d\n", cpu);
+		return false;
+	}
+
+	return true;
+}
+
+static int vmx_check_processor_compat(void)
+{
+	int cpu = raw_smp_processor_id();
+	struct vmcs_config vmcs_conf;
+	struct vmx_capability vmx_cap;
+
+	if (!kvm_is_vmx_supported())
+		return -EIO;
+
+	if (setup_vmcs_config(&vmcs_conf, &vmx_cap) < 0) {
+		pr_err("Failed to setup VMCS config on CPU %d\n", cpu);
+		return -EIO;
+	}
+	if (nested)
+		nested_vmx_setup_ctls_msrs(&vmcs_conf, vmx_cap.ept);
+	if (memcmp(&vmcs_config, &vmcs_conf, sizeof(struct vmcs_config))) {
+		pr_err("Inconsistent VMCS config on CPU %d\n", cpu);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int kvm_cpu_vmxon(u64 vmxon_pointer)
+{
+	u64 msr;
+
+	cr4_set_bits(X86_CR4_VMXE);
+
+	asm_volatile_goto("1: vmxon %[vmxon_pointer]\n\t"
+			  _ASM_EXTABLE(1b, %l[fault])
+			  : : [vmxon_pointer] "m"(vmxon_pointer)
+			  : : fault);
+	return 0;
+
+fault:
+	WARN_ONCE(1, "VMXON faulted, MSR_IA32_FEAT_CTL (0x3a) = 0x%llx\n",
+		  rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr) ? 0xdeadbeef : msr);
+	cr4_clear_bits(X86_CR4_VMXE);
+
+	return -EFAULT;
+}
+
+static int vmx_hardware_enable(void)
+{
+	int cpu = raw_smp_processor_id();
+	u64 phys_addr = __pa(per_cpu(vmxarea, cpu));
+	int r;
+
+	if (cr4_read_shadow() & X86_CR4_VMXE)
+		return -EBUSY;
+
+	/*
+	 * This can happen if we hot-added a CPU but failed to allocate
+	 * VP assist page for it.
+	 */
+	if (static_branch_unlikely(&enable_evmcs) &&
+	    !hv_get_vp_assist_page(cpu))
+		return -EFAULT;
+
+	intel_pt_handle_vmx(1);
+
+	r = kvm_cpu_vmxon(phys_addr);
+	if (r) {
+		intel_pt_handle_vmx(0);
+		return r;
+	}
+
+	if (enable_ept)
+		ept_sync_global();
+
+	return 0;
+}
+
+static void vmclear_local_loaded_vmcss(void)
+{
+	int cpu = raw_smp_processor_id();
+	struct loaded_vmcs *v, *n;
+
+	list_for_each_entry_safe(v, n, &per_cpu(loaded_vmcss_on_cpu, cpu),
+				 loaded_vmcss_on_cpu_link)
+		__loaded_vmcs_clear(v);
+}
+
+static void vmx_hardware_disable(void)
+{
+	vmclear_local_loaded_vmcss();
+
+	if (cpu_vmxoff())
+		kvm_spurious_fault();
+
+	hv_reset_evmcs();
+
+	intel_pt_handle_vmx(0);
+}
+
 struct vmcs *alloc_vmcs_cpu(bool shadow, int cpu, gfp_t flags)
 {
 	int node = cpu_to_node(cpu);
@@ -2955,9 +3053,8 @@ static void fix_rmode_seg(int seg, struct kvm_segment *save)
 		var.type = 0x3;
 		var.avl = 0;
 		if (save->base & 0xf)
-			printk_once(KERN_WARNING "kvm: segment base is not "
-					"paragraph aligned when entering "
-					"protected mode (seg=%d)", seg);
+			pr_warn_once("segment base is not paragraph aligned "
+				     "when entering protected mode (seg=%d)", seg);
 	}
 
 	vmcs_write16(sf->selector, var.selector);
@@ -2987,8 +3084,7 @@ static void enter_rmode(struct kvm_vcpu *vcpu)
 	 * vcpu. Warn the user that an update is overdue.
 	 */
 	if (!kvm_vmx->tss_addr)
-		printk_once(KERN_WARNING "kvm: KVM_SET_TSS_ADDR need to be "
-			     "called before entering vcpu\n");
+		pr_warn_once("KVM_SET_TSS_ADDR needs to be called before running vCPU\n");
 
 	vmx_segment_cache_clear(vmx);
 
@@ -6856,7 +6952,7 @@ static void handle_external_interrupt_irqoff(struct kvm_vcpu *vcpu)
 	gate_desc *desc = (gate_desc *)host_idt_base + vector;
 
 	if (KVM_BUG(!is_external_intr(intr_info), vcpu->kvm,
-	    "KVM: unexpected VM-Exit interrupt info: 0x%x", intr_info))
+	    "unexpected VM-Exit interrupt info: 0x%x", intr_info))
 		return;
 
 	handle_interrupt_nmi_irqoff(vcpu, gate_offset(desc));
@@ -7454,29 +7550,6 @@ static int vmx_vm_init(struct kvm *kvm)
 	return 0;
 }
 
-static int __init vmx_check_processor_compat(void)
-{
-	struct vmcs_config vmcs_conf;
-	struct vmx_capability vmx_cap;
-
-	if (!this_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
-	    !this_cpu_has(X86_FEATURE_VMX)) {
-		pr_err("kvm: VMX is disabled on CPU %d\n", smp_processor_id());
-		return -EIO;
-	}
-
-	if (setup_vmcs_config(&vmcs_conf, &vmx_cap) < 0)
-		return -EIO;
-	if (nested)
-		nested_vmx_setup_ctls_msrs(&vmcs_conf, vmx_cap.ept);
-	if (memcmp(&vmcs_config, &vmcs_conf, sizeof(struct vmcs_config)) != 0) {
-		printk(KERN_ERR "kvm: CPU %d feature inconsistency!\n",
-				smp_processor_id());
-		return -EIO;
-	}
-	return 0;
-}
-
 static u8 vmx_get_mt_mask(struct kvm_vcpu *vcpu, gfn_t gfn, bool is_mmio)
 {
 	u8 cache;
@@ -8076,7 +8149,9 @@ static void vmx_vm_destroy(struct kvm *kvm)
 }
 
 static struct kvm_x86_ops vmx_x86_ops __initdata = {
-	.name = "kvm_intel",
+	.name = KBUILD_MODNAME,
+
+	.check_processor_compatibility = vmx_check_processor_compat,
 
 	.hardware_unsetup = vmx_hardware_unsetup,
 
@@ -8296,7 +8371,7 @@ static __init int hardware_setup(void)
 		return -EIO;
 
 	if (cpu_has_perf_global_ctrl_bug())
-		pr_warn_once("kvm: VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL "
+		pr_warn_once("VM_EXIT_LOAD_IA32_PERF_GLOBAL_CTRL "
 			     "does not work properly. Using workaround\n");
 
 	if (boot_cpu_has(X86_FEATURE_NX))
@@ -8304,7 +8379,7 @@ static __init int hardware_setup(void)
 
 	if (boot_cpu_has(X86_FEATURE_MPX)) {
 		rdmsrl(MSR_IA32_BNDCFGS, host_bndcfgs);
-		WARN_ONCE(host_bndcfgs, "KVM: BNDCFGS in host will be lost");
+		WARN_ONCE(host_bndcfgs, "BNDCFGS in host will be lost");
 	}
 
 	if (!cpu_has_vmx_mpx())
@@ -8323,7 +8398,7 @@ static __init int hardware_setup(void)
 
 	/* NX support is required for shadow paging. */
 	if (!enable_ept && !boot_cpu_has(X86_FEATURE_NX)) {
-		pr_err_ratelimited("kvm: NX (Execute Disable) not supported\n");
+		pr_err_ratelimited("NX (Execute Disable) not supported\n");
 		return -EOPNOTSUPP;
 	}
 
@@ -8475,9 +8550,6 @@ static __init int hardware_setup(void)
 }
 
 static struct kvm_x86_init_ops vmx_init_ops __initdata = {
-	.cpu_has_kvm_support = cpu_has_kvm_support,
-	.disabled_by_bios = vmx_disabled_by_bios,
-	.check_processor_compatibility = vmx_check_processor_compat,
 	.hardware_setup = hardware_setup,
 	.handle_intel_pt_intr = NULL,
 
@@ -8495,41 +8567,23 @@ static void vmx_cleanup_l1d_flush(void)
 	l1tf_vmx_mitigation = VMENTER_L1D_FLUSH_AUTO;
 }
 
-static void vmx_exit(void)
+static void __vmx_exit(void)
 {
+	allow_smaller_maxphyaddr = false;
+
 #ifdef CONFIG_KEXEC_CORE
 	RCU_INIT_POINTER(crash_vmclear_loaded_vmcss, NULL);
 	synchronize_rcu();
 #endif
+	vmx_cleanup_l1d_flush();
+}
 
+static void vmx_exit(void)
+{
 	kvm_exit();
+	kvm_x86_vendor_exit();
 
-#if IS_ENABLED(CONFIG_HYPERV)
-	if (static_branch_unlikely(&enable_evmcs)) {
-		int cpu;
-		struct hv_vp_assist_page *vp_ap;
-		/*
-		 * Reset everything to support using non-enlightened VMCS
-		 * access later (e.g. when we reload the module with
-		 * enlightened_vmcs=0)
-		 */
-		for_each_online_cpu(cpu) {
-			vp_ap =	hv_get_vp_assist_page(cpu);
-
-			if (!vp_ap)
-				continue;
-
-			vp_ap->nested_control.features.directhypercall = 0;
-			vp_ap->current_nested_vmcs = 0;
-			vp_ap->enlighten_vmentry = 0;
-		}
-
-		static_branch_disable(&enable_evmcs);
-	}
-#endif
-	vmx_cleanup_l1d_flush();
-
-	allow_smaller_maxphyaddr = false;
+	__vmx_exit();
 }
 module_exit(vmx_exit);
 
@@ -8537,56 +8591,29 @@ static int __init vmx_init(void)
 {
 	int r, cpu;
 
-#if IS_ENABLED(CONFIG_HYPERV)
+	if (!kvm_is_vmx_supported())
+		return -EOPNOTSUPP;
+
 	/*
-	 * Enlightened VMCS usage should be recommended and the host needs
-	 * to support eVMCS v1 or above. We can also disable eVMCS support
-	 * with module parameter.
+	 * Note, hv_init_evmcs() touches only VMX knobs, i.e. there's nothing
+	 * to unwind if a later step fails.
 	 */
-	if (enlightened_vmcs &&
-	    ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED &&
-	    (ms_hyperv.nested_features & HV_X64_ENLIGHTENED_VMCS_VERSION) >=
-	    KVM_EVMCS_VERSION) {
+	hv_init_evmcs();
 
-		/* Check that we have assist pages on all online CPUs */
-		for_each_online_cpu(cpu) {
-			if (!hv_get_vp_assist_page(cpu)) {
-				enlightened_vmcs = false;
-				break;
-			}
-		}
-
-		if (enlightened_vmcs) {
-			pr_info("KVM: vmx: using Hyper-V Enlightened VMCS\n");
-			static_branch_enable(&enable_evmcs);
-		}
-
-		if (ms_hyperv.nested_features & HV_X64_NESTED_DIRECT_FLUSH)
-			vmx_x86_ops.enable_l2_tlb_flush
-				= hv_enable_l2_tlb_flush;
-
-	} else {
-		enlightened_vmcs = false;
-	}
-#endif
-
-	r = kvm_init(&vmx_init_ops, sizeof(struct vcpu_vmx),
-		     __alignof__(struct vcpu_vmx), THIS_MODULE);
+	r = kvm_x86_vendor_init(&vmx_init_ops);
 	if (r)
 		return r;
 
 	/*
-	 * Must be called after kvm_init() so enable_ept is properly set
+	 * Must be called after common x86 init so enable_ept is properly set
 	 * up. Hand the parameter mitigation value in which was stored in
 	 * the pre module init parser. If no parameter was given, it will
 	 * contain 'auto' which will be turned into the default 'cond'
 	 * mitigation mode.
 	 */
 	r = vmx_setup_l1d_flush(vmentry_l1d_flush_param);
-	if (r) {
-		vmx_exit();
-		return r;
-	}
+	if (r)
+		goto err_l1d_flush;
 
 	vmx_setup_fb_clear_ctrl();
 
@@ -8610,6 +8637,21 @@ static int __init vmx_init(void)
 	if (!enable_ept)
 		allow_smaller_maxphyaddr = true;
 
+	/*
+	 * Common KVM initialization _must_ come last, after this, /dev/kvm is
+	 * exposed to userspace!
+	 */
+	r = kvm_init(sizeof(struct vcpu_vmx), __alignof__(struct vcpu_vmx),
+		     THIS_MODULE);
+	if (r)
+		goto err_kvm_init;
+
 	return 0;
+
+err_kvm_init:
+	__vmx_exit();
+err_l1d_flush:
+	kvm_x86_vendor_exit();
+	return r;
 }
 module_init(vmx_init);
diff --git a/arch/x86/kvm/vmx/vmx_ops.h b/arch/x86/kvm/vmx/vmx_ops.h
index 842dc898c972..a5282014616c 100644
--- a/arch/x86/kvm/vmx/vmx_ops.h
+++ b/arch/x86/kvm/vmx/vmx_ops.h
@@ -100,8 +100,8 @@ static __always_inline unsigned long __vmcs_readl(unsigned long field)
 	return value;
 
 do_fail:
-	WARN_ONCE(1, "kvm: vmread failed: field=%lx\n", field);
-	pr_warn_ratelimited("kvm: vmread failed: field=%lx\n", field);
+	WARN_ONCE(1, KBUILD_MODNAME ": vmread failed: field=%lx\n", field);
+	pr_warn_ratelimited(KBUILD_MODNAME ": vmread failed: field=%lx\n", field);
 	return 0;
 
 do_exception:
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index f6ef44dc8a0e..c3ac88036b52 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -15,6 +15,7 @@
  *   Amit Shah    <amit.shah@qumranet.com>
  *   Ben-Ami Yassour <benami@il.ibm.com>
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/kvm_host.h>
 #include "irq.h"
@@ -128,6 +129,7 @@ static int kvm_vcpu_do_singlestep(struct kvm_vcpu *vcpu);
 static int __set_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2);
 static void __get_sregs2(struct kvm_vcpu *vcpu, struct kvm_sregs2 *sregs2);
 
+static DEFINE_MUTEX(vendor_module_lock);
 struct kvm_x86_ops kvm_x86_ops __read_mostly;
 
 #define KVM_X86_OP(func)					     \
@@ -2086,7 +2088,7 @@ static int kvm_emulate_monitor_mwait(struct kvm_vcpu *vcpu, const char *insn)
 	    !guest_cpuid_has(vcpu, X86_FEATURE_MWAIT))
 		return kvm_handle_invalid_op(vcpu);
 
-	pr_warn_once("kvm: %s instruction emulated as NOP!\n", insn);
+	pr_warn_once("%s instruction emulated as NOP!\n", insn);
 	return kvm_emulate_as_nop(vcpu);
 }
 int kvm_emulate_mwait(struct kvm_vcpu *vcpu)
@@ -2433,7 +2435,8 @@ static int kvm_set_tsc_khz(struct kvm_vcpu *vcpu, u32 user_tsc_khz)
 	thresh_lo = adjust_tsc_khz(tsc_khz, -tsc_tolerance_ppm);
 	thresh_hi = adjust_tsc_khz(tsc_khz, tsc_tolerance_ppm);
 	if (user_tsc_khz < thresh_lo || user_tsc_khz > thresh_hi) {
-		pr_debug("kvm: requested TSC rate %u falls outside tolerance [%u,%u]\n", user_tsc_khz, thresh_lo, thresh_hi);
+		pr_debug("requested TSC rate %u falls outside tolerance [%u,%u]\n",
+			 user_tsc_khz, thresh_lo, thresh_hi);
 		use_scaling = 1;
 	}
 	return set_tsc_khz(vcpu, user_tsc_khz, use_scaling);
@@ -7701,7 +7704,7 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
 	return X86EMUL_CONTINUE;
 
 emul_write:
-	printk_once(KERN_WARNING "kvm: emulating exchange as write\n");
+	pr_warn_once("emulating exchange as write\n");
 
 	return emulator_write_emulated(ctxt, addr, new, bytes, exception);
 }
@@ -8262,7 +8265,7 @@ static struct x86_emulate_ctxt *alloc_emulate_ctxt(struct kvm_vcpu *vcpu)
 
 	ctxt = kmem_cache_zalloc(x86_emulator_cache, GFP_KERNEL_ACCOUNT);
 	if (!ctxt) {
-		pr_err("kvm: failed to allocate vcpu's emulator\n");
+		pr_err("failed to allocate vcpu's emulator\n");
 		return NULL;
 	}
 
@@ -9273,35 +9276,66 @@ static struct notifier_block pvclock_gtod_notifier = {
 };
 #endif
 
-int kvm_arch_init(void *opaque)
+static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
+{
+	memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops));
+
+#define __KVM_X86_OP(func) \
+	static_call_update(kvm_x86_##func, kvm_x86_ops.func);
+#define KVM_X86_OP(func) \
+	WARN_ON(!kvm_x86_ops.func); __KVM_X86_OP(func)
+#define KVM_X86_OP_OPTIONAL __KVM_X86_OP
+#define KVM_X86_OP_OPTIONAL_RET0(func) \
+	static_call_update(kvm_x86_##func, (void *)kvm_x86_ops.func ? : \
+					   (void *)__static_call_return0);
+#include <asm/kvm-x86-ops.h>
+#undef __KVM_X86_OP
+
+	kvm_pmu_ops_update(ops->pmu_ops);
+}
+
+static int kvm_x86_check_processor_compatibility(void)
+{
+	int cpu = smp_processor_id();
+	struct cpuinfo_x86 *c = &cpu_data(cpu);
+
+	/*
+	 * Compatibility checks are done when loading KVM and when enabling
+	 * hardware, e.g. during CPU hotplug, to ensure all online CPUs are
+	 * compatible, i.e. KVM should never perform a compatibility check on
+	 * an offline CPU.
+	 */
+	WARN_ON(!cpu_online(cpu));
+
+	if (__cr4_reserved_bits(cpu_has, c) !=
+	    __cr4_reserved_bits(cpu_has, &boot_cpu_data))
+		return -EIO;
+
+	return static_call(kvm_x86_check_processor_compatibility)();
+}
+
+static void kvm_x86_check_cpu_compat(void *ret)
+{
+	*(int *)ret = kvm_x86_check_processor_compatibility();
+}
+
+static int __kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
 {
-	struct kvm_x86_init_ops *ops = opaque;
 	u64 host_pat;
-	int r;
+	int r, cpu;
 
 	if (kvm_x86_ops.hardware_enable) {
-		pr_err("kvm: already loaded vendor module '%s'\n", kvm_x86_ops.name);
+		pr_err("already loaded vendor module '%s'\n", kvm_x86_ops.name);
 		return -EEXIST;
 	}
 
-	if (!ops->cpu_has_kvm_support()) {
-		pr_err_ratelimited("kvm: no hardware support for '%s'\n",
-				   ops->runtime_ops->name);
-		return -EOPNOTSUPP;
-	}
-	if (ops->disabled_by_bios()) {
-		pr_err_ratelimited("kvm: support for '%s' disabled by bios\n",
-				   ops->runtime_ops->name);
-		return -EOPNOTSUPP;
-	}
-
 	/*
 	 * KVM explicitly assumes that the guest has an FPU and
 	 * FXSAVE/FXRSTOR. For example, the KVM_GET_FPU explicitly casts the
 	 * vCPU's FPU state as a fxregs_state struct.
 	 */
 	if (!boot_cpu_has(X86_FEATURE_FPU) || !boot_cpu_has(X86_FEATURE_FXSR)) {
-		printk(KERN_ERR "kvm: inadequate fpu\n");
+		pr_err("inadequate fpu\n");
 		return -EOPNOTSUPP;
 	}
 
@@ -9319,19 +9353,19 @@ int kvm_arch_init(void *opaque)
 	 */
 	if (rdmsrl_safe(MSR_IA32_CR_PAT, &host_pat) ||
 	    (host_pat & GENMASK(2, 0)) != 6) {
-		pr_err("kvm: host PAT[0] is not WB\n");
+		pr_err("host PAT[0] is not WB\n");
 		return -EIO;
 	}
 
 	x86_emulator_cache = kvm_alloc_emulator_cache();
 	if (!x86_emulator_cache) {
-		pr_err("kvm: failed to allocate cache for x86 emulator\n");
+		pr_err("failed to allocate cache for x86 emulator\n");
 		return -ENOMEM;
 	}
 
 	user_return_msrs = alloc_percpu(struct kvm_user_return_msrs);
 	if (!user_return_msrs) {
-		printk(KERN_ERR "kvm: failed to allocate percpu kvm_user_return_msrs\n");
+		pr_err("failed to allocate percpu kvm_user_return_msrs\n");
 		r = -ENOMEM;
 		goto out_free_x86_emulator_cache;
 	}
@@ -9341,13 +9375,37 @@ int kvm_arch_init(void *opaque)
 	if (r)
 		goto out_free_percpu;
 
-	kvm_timer_init();
-
 	if (boot_cpu_has(X86_FEATURE_XSAVE)) {
 		host_xcr0 = xgetbv(XCR_XFEATURE_ENABLED_MASK);
 		kvm_caps.supported_xcr0 = host_xcr0 & KVM_SUPPORTED_XCR0;
 	}
 
+	rdmsrl_safe(MSR_EFER, &host_efer);
+
+	if (boot_cpu_has(X86_FEATURE_XSAVES))
+		rdmsrl(MSR_IA32_XSS, host_xss);
+
+	kvm_init_pmu_capability();
+
+	r = ops->hardware_setup();
+	if (r != 0)
+		goto out_mmu_exit;
+
+	kvm_ops_update(ops);
+
+	for_each_online_cpu(cpu) {
+		smp_call_function_single(cpu, kvm_x86_check_cpu_compat, &r, 1);
+		if (r < 0)
+			goto out_unwind_ops;
+	}
+
+	/*
+	 * Point of no return!  DO NOT add error paths below this point unless
+	 * absolutely necessary, as most operations from this point forward
+	 * require unwinding.
+	 */
+	kvm_timer_init();
+
 	if (pi_inject_timer == -1)
 		pi_inject_timer = housekeeping_enabled(HK_TYPE_TIMER);
 #ifdef CONFIG_X86_64
@@ -9357,8 +9415,35 @@ int kvm_arch_init(void *opaque)
 		set_hv_tscchange_cb(kvm_hyperv_tsc_notifier);
 #endif
 
+	kvm_register_perf_callbacks(ops->handle_intel_pt_intr);
+
+	if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
+		kvm_caps.supported_xss = 0;
+
+#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
+	cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
+#undef __kvm_cpu_cap_has
+
+	if (kvm_caps.has_tsc_control) {
+		/*
+		 * Make sure the user can only configure tsc_khz values that
+		 * fit into a signed integer.
+		 * A min value is not calculated because it will always
+		 * be 1 on all machines.
+		 */
+		u64 max = min(0x7fffffffULL,
+			      __scale_tsc(kvm_caps.max_tsc_scaling_ratio, tsc_khz));
+		kvm_caps.max_guest_tsc_khz = max;
+	}
+	kvm_caps.default_tsc_scaling_ratio = 1ULL << kvm_caps.tsc_scaling_ratio_frac_bits;
+	kvm_init_msr_list();
 	return 0;
 
+out_unwind_ops:
+	kvm_x86_ops.hardware_enable = NULL;
+	static_call(kvm_x86_hardware_unsetup)();
+out_mmu_exit:
+	kvm_mmu_vendor_module_exit();
 out_free_percpu:
 	free_percpu(user_return_msrs);
 out_free_x86_emulator_cache:
@@ -9366,8 +9451,22 @@ out_free_x86_emulator_cache:
 	return r;
 }
 
-void kvm_arch_exit(void)
+int kvm_x86_vendor_init(struct kvm_x86_init_ops *ops)
+{
+	int r;
+
+	mutex_lock(&vendor_module_lock);
+	r = __kvm_x86_vendor_init(ops);
+	mutex_unlock(&vendor_module_lock);
+
+	return r;
+}
+EXPORT_SYMBOL_GPL(kvm_x86_vendor_init);
+
+void kvm_x86_vendor_exit(void)
 {
+	kvm_unregister_perf_callbacks();
+
 #ifdef CONFIG_X86_64
 	if (hypervisor_is_type(X86_HYPER_MS_HYPERV))
 		clear_hv_tscchange_cb();
@@ -9384,7 +9483,7 @@ void kvm_arch_exit(void)
 	irq_work_sync(&pvclock_irq_work);
 	cancel_work_sync(&pvclock_gtod_work);
 #endif
-	kvm_x86_ops.hardware_enable = NULL;
+	static_call(kvm_x86_hardware_unsetup)();
 	kvm_mmu_vendor_module_exit();
 	free_percpu(user_return_msrs);
 	kmem_cache_destroy(x86_emulator_cache);
@@ -9392,7 +9491,11 @@ void kvm_arch_exit(void)
 	static_key_deferred_flush(&kvm_xen_enabled);
 	WARN_ON(static_branch_unlikely(&kvm_xen_enabled.key));
 #endif
+	mutex_lock(&vendor_module_lock);
+	kvm_x86_ops.hardware_enable = NULL;
+	mutex_unlock(&vendor_module_lock);
 }
+EXPORT_SYMBOL_GPL(kvm_x86_vendor_exit);
 
 static int __kvm_emulate_halt(struct kvm_vcpu *vcpu, int state, int reason)
 {
@@ -11533,7 +11636,7 @@ static int sync_regs(struct kvm_vcpu *vcpu)
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 {
 	if (kvm_check_tsc_unstable() && kvm->created_vcpus)
-		pr_warn_once("kvm: SMP vm created on host with unstable TSC; "
+		pr_warn_once("SMP vm created on host with unstable TSC; "
 			     "guest TSC will not be reliable\n");
 
 	if (!kvm->arch.max_vcpu_ids)
@@ -11610,7 +11713,7 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
 		goto free_wbinvd_dirty_mask;
 
 	if (!fpu_alloc_guest_fpstate(&vcpu->arch.guest_fpu)) {
-		pr_err("kvm: failed to allocate vcpu's fpu\n");
+		pr_err("failed to allocate vcpu's fpu\n");
 		goto free_emulate_ctxt;
 	}
 
@@ -11884,6 +11987,11 @@ int kvm_arch_hardware_enable(void)
 	bool stable, backwards_tsc = false;
 
 	kvm_user_return_msr_cpu_online();
+
+	ret = kvm_x86_check_processor_compatibility();
+	if (ret)
+		return ret;
+
 	ret = static_call(kvm_x86_hardware_enable)();
 	if (ret != 0)
 		return ret;
@@ -11970,88 +12078,6 @@ void kvm_arch_hardware_disable(void)
 	drop_user_return_notifiers();
 }
 
-static inline void kvm_ops_update(struct kvm_x86_init_ops *ops)
-{
-	memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops));
-
-#define __KVM_X86_OP(func) \
-	static_call_update(kvm_x86_##func, kvm_x86_ops.func);
-#define KVM_X86_OP(func) \
-	WARN_ON(!kvm_x86_ops.func); __KVM_X86_OP(func)
-#define KVM_X86_OP_OPTIONAL __KVM_X86_OP
-#define KVM_X86_OP_OPTIONAL_RET0(func) \
-	static_call_update(kvm_x86_##func, (void *)kvm_x86_ops.func ? : \
-					   (void *)__static_call_return0);
-#include <asm/kvm-x86-ops.h>
-#undef __KVM_X86_OP
-
-	kvm_pmu_ops_update(ops->pmu_ops);
-}
-
-int kvm_arch_hardware_setup(void *opaque)
-{
-	struct kvm_x86_init_ops *ops = opaque;
-	int r;
-
-	rdmsrl_safe(MSR_EFER, &host_efer);
-
-	if (boot_cpu_has(X86_FEATURE_XSAVES))
-		rdmsrl(MSR_IA32_XSS, host_xss);
-
-	kvm_init_pmu_capability();
-
-	r = ops->hardware_setup();
-	if (r != 0)
-		return r;
-
-	kvm_ops_update(ops);
-
-	kvm_register_perf_callbacks(ops->handle_intel_pt_intr);
-
-	if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
-		kvm_caps.supported_xss = 0;
-
-#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
-	cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
-#undef __kvm_cpu_cap_has
-
-	if (kvm_caps.has_tsc_control) {
-		/*
-		 * Make sure the user can only configure tsc_khz values that
-		 * fit into a signed integer.
-		 * A min value is not calculated because it will always
-		 * be 1 on all machines.
-		 */
-		u64 max = min(0x7fffffffULL,
-			      __scale_tsc(kvm_caps.max_tsc_scaling_ratio, tsc_khz));
-		kvm_caps.max_guest_tsc_khz = max;
-	}
-	kvm_caps.default_tsc_scaling_ratio = 1ULL << kvm_caps.tsc_scaling_ratio_frac_bits;
-	kvm_init_msr_list();
-	return 0;
-}
-
-void kvm_arch_hardware_unsetup(void)
-{
-	kvm_unregister_perf_callbacks();
-
-	static_call(kvm_x86_hardware_unsetup)();
-}
-
-int kvm_arch_check_processor_compat(void *opaque)
-{
-	struct cpuinfo_x86 *c = &cpu_data(smp_processor_id());
-	struct kvm_x86_init_ops *ops = opaque;
-
-	WARN_ON(!irqs_disabled());
-
-	if (__cr4_reserved_bits(cpu_has, c) !=
-	    __cr4_reserved_bits(cpu_has, &boot_cpu_data))
-		return -EIO;
-
-	return ops->check_processor_compatibility();
-}
-
 bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu)
 {
 	return vcpu->kvm->arch.bsp_vcpu_id == vcpu->vcpu_id;
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 2e29bdc2949c..0bd5d171df57 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -5,6 +5,7 @@
  *
  * KVM Xen emulation
  */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include "x86.h"
 #include "xen.h"
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index cd6d8f260eab..71916de7c6c4 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -60,7 +60,7 @@ struct arch_timer_cpu {
 	bool			enabled;
 };
 
-int kvm_timer_hyp_init(bool);
+int __init kvm_timer_hyp_init(bool has_gic);
 int kvm_timer_enable(struct kvm_vcpu *vcpu);
 int kvm_timer_vcpu_reset(struct kvm_vcpu *vcpu);
 void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu);
@@ -104,4 +104,8 @@ void kvm_arm_timer_write_sysreg(struct kvm_vcpu *vcpu,
 u32 timer_get_ctl(struct arch_timer_context *ctxt);
 u64 timer_get_cval(struct arch_timer_context *ctxt);
 
+/* CPU HP callbacks */
+void kvm_timer_cpu_up(void);
+void kvm_timer_cpu_down(void);
+
 #endif
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 9270cd87da3f..0629e3532ad0 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -432,4 +432,8 @@ int vgic_v4_load(struct kvm_vcpu *vcpu);
 void vgic_v4_commit(struct kvm_vcpu *vcpu);
 int vgic_v4_put(struct kvm_vcpu *vcpu, bool need_db);
 
+/* CPU HP callbacks */
+void kvm_vgic_cpu_up(void);
+void kvm_vgic_cpu_down(void);
+
 #endif /* __KVM_ARM_VGIC_H */
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 6c6859bfc454..5b2f8147d1ae 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -187,10 +187,6 @@ enum cpuhp_state {
 	CPUHP_AP_CSKY_TIMER_STARTING,
 	CPUHP_AP_TI_GP_TIMER_STARTING,
 	CPUHP_AP_HYPERV_TIMER_STARTING,
-	CPUHP_AP_KVM_STARTING,
-	CPUHP_AP_KVM_ARM_VGIC_INIT_STARTING,
-	CPUHP_AP_KVM_ARM_VGIC_STARTING,
-	CPUHP_AP_KVM_ARM_TIMER_STARTING,
 	/* Must be the last timer callback */
 	CPUHP_AP_DUMMY_TIMER_STARTING,
 	CPUHP_AP_ARM_XEN_STARTING,
@@ -205,6 +201,7 @@ enum cpuhp_state {
 
 	/* Online section invoked on the hotplugged CPU from the hotplug thread */
 	CPUHP_AP_ONLINE_IDLE,
+	CPUHP_AP_KVM_ONLINE,
 	CPUHP_AP_SCHED_WAIT_EMPTY,
 	CPUHP_AP_SMPBOOT_THREADS,
 	CPUHP_AP_X86_VDSO_VMA_ONLINE,
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 4f26b244f6d0..109b18e2789c 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -956,8 +956,7 @@ static inline void kvm_irqfd_exit(void)
 {
 }
 #endif
-int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
-		  struct module *module);
+int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module);
 void kvm_exit(void);
 
 void kvm_get_kvm(struct kvm *kvm);
@@ -1423,9 +1422,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
 					struct kvm_guest_debug *dbg);
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu);
 
-int kvm_arch_init(void *opaque);
-void kvm_arch_exit(void);
-
 void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);
 
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
@@ -1445,11 +1441,10 @@ void kvm_arch_create_vcpu_debugfs(struct kvm_vcpu *vcpu, struct dentry *debugfs_
 static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
 #endif
 
+#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
 int kvm_arch_hardware_enable(void);
 void kvm_arch_hardware_disable(void);
-int kvm_arch_hardware_setup(void *opaque);
-void kvm_arch_hardware_unsetup(void);
-int kvm_arch_check_processor_compat(void *opaque);
+#endif
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu);
 bool kvm_arch_vcpu_in_kernel(struct kvm_vcpu *vcpu);
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu);
@@ -2081,7 +2076,9 @@ static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
 	}
 }
 
+#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
 extern bool kvm_rebooting;
+#endif
 
 extern unsigned int halt_poll_ns;
 extern unsigned int halt_poll_ns_grow;
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 9fb1ff6f19e5..b74916de5183 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -92,3 +92,6 @@ config KVM_XFER_TO_GUEST_WORK
 
 config HAVE_KVM_PM_NOTIFIER
        bool
+
+config KVM_GENERIC_HARDWARE_ENABLING
+       bool
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 13e88297f999..0f17b8786792 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -100,13 +100,8 @@ EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
  */
 
 DEFINE_MUTEX(kvm_lock);
-static DEFINE_RAW_SPINLOCK(kvm_count_lock);
 LIST_HEAD(vm_list);
 
-static cpumask_var_t cpus_hardware_enabled;
-static int kvm_usage_count;
-static atomic_t hardware_enable_failed;
-
 static struct kmem_cache *kvm_vcpu_cache;
 
 static __read_mostly struct preempt_ops kvm_preempt_ops;
@@ -148,9 +143,6 @@ static void hardware_disable_all(void);
 
 static void kvm_io_bus_destroy(struct kvm_io_bus *bus);
 
-__visible bool kvm_rebooting;
-EXPORT_SYMBOL_GPL(kvm_rebooting);
-
 #define KVM_EVENT_CREATE_VM 0
 #define KVM_EVENT_DESTROY_VM 1
 static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm);
@@ -5095,50 +5087,70 @@ static struct miscdevice kvm_dev = {
 	&kvm_chardev_ops,
 };
 
-static void hardware_enable_nolock(void *junk)
-{
-	int cpu = raw_smp_processor_id();
-	int r;
-
-	if (cpumask_test_cpu(cpu, cpus_hardware_enabled))
-		return;
+#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
+__visible bool kvm_rebooting;
+EXPORT_SYMBOL_GPL(kvm_rebooting);
 
-	cpumask_set_cpu(cpu, cpus_hardware_enabled);
+static DEFINE_PER_CPU(bool, hardware_enabled);
+static int kvm_usage_count;
 
-	r = kvm_arch_hardware_enable();
+static int __hardware_enable_nolock(void)
+{
+	if (__this_cpu_read(hardware_enabled))
+		return 0;
 
-	if (r) {
-		cpumask_clear_cpu(cpu, cpus_hardware_enabled);
-		atomic_inc(&hardware_enable_failed);
-		pr_info("kvm: enabling virtualization on CPU%d failed\n", cpu);
+	if (kvm_arch_hardware_enable()) {
+		pr_info("kvm: enabling virtualization on CPU%d failed\n",
+			raw_smp_processor_id());
+		return -EIO;
 	}
+
+	__this_cpu_write(hardware_enabled, true);
+	return 0;
 }
 
-static int kvm_starting_cpu(unsigned int cpu)
+static void hardware_enable_nolock(void *failed)
 {
-	raw_spin_lock(&kvm_count_lock);
+	if (__hardware_enable_nolock())
+		atomic_inc(failed);
+}
+
+static int kvm_online_cpu(unsigned int cpu)
+{
+	int ret = 0;
+
+	/*
+	 * Abort the CPU online process if hardware virtualization cannot
+	 * be enabled. Otherwise running VMs would encounter unrecoverable
+	 * errors when scheduled to this CPU.
+	 */
+	mutex_lock(&kvm_lock);
 	if (kvm_usage_count)
-		hardware_enable_nolock(NULL);
-	raw_spin_unlock(&kvm_count_lock);
-	return 0;
+		ret = __hardware_enable_nolock();
+	mutex_unlock(&kvm_lock);
+	return ret;
 }
 
 static void hardware_disable_nolock(void *junk)
 {
-	int cpu = raw_smp_processor_id();
-
-	if (!cpumask_test_cpu(cpu, cpus_hardware_enabled))
+	/*
+	 * Note, hardware_disable_all_nolock() tells all online CPUs to disable
+	 * hardware, not just CPUs that successfully enabled hardware!
+	 */
+	if (!__this_cpu_read(hardware_enabled))
 		return;
-	cpumask_clear_cpu(cpu, cpus_hardware_enabled);
+
 	kvm_arch_hardware_disable();
+
+	__this_cpu_write(hardware_enabled, false);
 }
 
-static int kvm_dying_cpu(unsigned int cpu)
+static int kvm_offline_cpu(unsigned int cpu)
 {
-	raw_spin_lock(&kvm_count_lock);
+	mutex_lock(&kvm_lock);
 	if (kvm_usage_count)
 		hardware_disable_nolock(NULL);
-	raw_spin_unlock(&kvm_count_lock);
+	mutex_unlock(&kvm_lock);
 	return 0;
 }
 
@@ -5153,29 +5165,41 @@ static void hardware_disable_all_nolock(void)
 
 static void hardware_disable_all(void)
 {
-	raw_spin_lock(&kvm_count_lock);
+	cpus_read_lock();
+	mutex_lock(&kvm_lock);
 	hardware_disable_all_nolock();
-	raw_spin_unlock(&kvm_count_lock);
+	mutex_unlock(&kvm_lock);
+	cpus_read_unlock();
 }
 
 static int hardware_enable_all(void)
 {
+	atomic_t failed = ATOMIC_INIT(0);
 	int r = 0;
 
-	raw_spin_lock(&kvm_count_lock);
+	/*
+	 * When onlining a CPU, cpu_online_mask is set before kvm_online_cpu()
+	 * is called, and so on_each_cpu() between them includes the CPU that
+	 * is being onlined.  As a result, hardware_enable_nolock() may get
+	 * invoked before kvm_online_cpu(), which also enables hardware if the
+	 * usage count is non-zero.  Disable CPU hotplug to avoid attempting to
+	 * enable hardware multiple times.
+	 */
+	cpus_read_lock();
+	mutex_lock(&kvm_lock);
 
 	kvm_usage_count++;
 	if (kvm_usage_count == 1) {
-		atomic_set(&hardware_enable_failed, 0);
-		on_each_cpu(hardware_enable_nolock, NULL, 1);
+		on_each_cpu(hardware_enable_nolock, &failed, 1);
 
-		if (atomic_read(&hardware_enable_failed)) {
+		if (atomic_read(&failed)) {
 			hardware_disable_all_nolock();
 			r = -EBUSY;
 		}
 	}
 
-	raw_spin_unlock(&kvm_count_lock);
+	mutex_unlock(&kvm_lock);
+	cpus_read_unlock();
 
 	return r;
 }
@@ -5200,6 +5224,49 @@ static struct notifier_block kvm_reboot_notifier = {
 	.priority = 0,
 };
 
+static int kvm_suspend(void)
+{
+	/*
+	 * Secondary CPUs and CPU hotplug are disabled across the suspend/resume
+	 * callbacks, i.e. no need to acquire kvm_lock to ensure the usage count
+	 * is stable.  Assert that kvm_lock is not held to ensure the system
+	 * isn't suspended while KVM is enabling hardware.  Hardware enabling
+	 * can be preempted, but the task cannot be frozen until it has dropped
+	 * all locks (userspace tasks are frozen via a fake signal).
+	 */
+	lockdep_assert_not_held(&kvm_lock);
+	lockdep_assert_irqs_disabled();
+
+	if (kvm_usage_count)
+		hardware_disable_nolock(NULL);
+	return 0;
+}
+
+static void kvm_resume(void)
+{
+	lockdep_assert_not_held(&kvm_lock);
+	lockdep_assert_irqs_disabled();
+
+	if (kvm_usage_count)
+		WARN_ON_ONCE(__hardware_enable_nolock());
+}
+
+static struct syscore_ops kvm_syscore_ops = {
+	.suspend = kvm_suspend,
+	.resume = kvm_resume,
+};
+#else /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
+static int hardware_enable_all(void)
+{
+	return 0;
+}
+
+static void hardware_disable_all(void)
+{
+
+}
+#endif /* CONFIG_KVM_GENERIC_HARDWARE_ENABLING */
+
 static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
 {
 	int i;
@@ -5778,26 +5845,6 @@ static void kvm_init_debug(void)
 	}
 }
 
-static int kvm_suspend(void)
-{
-	if (kvm_usage_count)
-		hardware_disable_nolock(NULL);
-	return 0;
-}
-
-static void kvm_resume(void)
-{
-	if (kvm_usage_count) {
-		lockdep_assert_not_held(&kvm_count_lock);
-		hardware_enable_nolock(NULL);
-	}
-}
-
-static struct syscore_ops kvm_syscore_ops = {
-	.suspend = kvm_suspend,
-	.resume = kvm_resume,
-};
-
 static inline
 struct kvm_vcpu *preempt_notifier_to_vcpu(struct preempt_notifier *pn)
 {
@@ -5902,62 +5949,20 @@ void kvm_unregister_perf_callbacks(void)
 }
 #endif
 
-struct kvm_cpu_compat_check {
-	void *opaque;
-	int *ret;
-};
-
-static void check_processor_compat(void *data)
-{
-	struct kvm_cpu_compat_check *c = data;
-
-	*c->ret = kvm_arch_check_processor_compat(c->opaque);
-}
-
-int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
-		  struct module *module)
+int kvm_init(unsigned vcpu_size, unsigned vcpu_align, struct module *module)
 {
-	struct kvm_cpu_compat_check c;
 	int r;
 	int cpu;
 
-	r = kvm_arch_init(opaque);
-	if (r)
-		goto out_fail;
-
-	/*
-	 * kvm_arch_init makes sure there's at most one caller
-	 * for architectures that support multiple implementations,
-	 * like intel and amd on x86.
-	 * kvm_arch_init must be called before kvm_irqfd_init to avoid creating
-	 * conflicts in case kvm is already setup for another implementation.
-	 */
-	r = kvm_irqfd_init();
+#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
+	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_ONLINE, "kvm/cpu:online",
+				      kvm_online_cpu, kvm_offline_cpu);
 	if (r)
-		goto out_irqfd;
-
-	if (!zalloc_cpumask_var(&cpus_hardware_enabled, GFP_KERNEL)) {
-		r = -ENOMEM;
-		goto out_free_0;
-	}
-
-	r = kvm_arch_hardware_setup(opaque);
-	if (r < 0)
-		goto out_free_1;
-
-	c.ret = &r;
-	c.opaque = opaque;
-	for_each_online_cpu(cpu) {
-		smp_call_function_single(cpu, check_processor_compat, &c, 1);
-		if (r < 0)
-			goto out_free_2;
-	}
+		return r;
 
-	r = cpuhp_setup_state_nocalls(CPUHP_AP_KVM_STARTING, "kvm/cpu:starting",
-				      kvm_starting_cpu, kvm_dying_cpu);
-	if (r)
-		goto out_free_2;
 	register_reboot_notifier(&kvm_reboot_notifier);
+	register_syscore_ops(&kvm_syscore_ops);
+#endif
 
 	/* A kmem cache lets us meet the alignment requirements of fx_save. */
 	if (!vcpu_align)
@@ -5971,59 +5976,65 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 					   NULL);
 	if (!kvm_vcpu_cache) {
 		r = -ENOMEM;
-		goto out_free_3;
+		goto err_vcpu_cache;
 	}
 
 	for_each_possible_cpu(cpu) {
 		if (!alloc_cpumask_var_node(&per_cpu(cpu_kick_mask, cpu),
 					    GFP_KERNEL, cpu_to_node(cpu))) {
 			r = -ENOMEM;
-			goto out_free_4;
+			goto err_cpu_kick_mask;
 		}
 	}
 
+	r = kvm_irqfd_init();
+	if (r)
+		goto err_irqfd;
+
 	r = kvm_async_pf_init();
 	if (r)
-		goto out_free_4;
+		goto err_async_pf;
 
 	kvm_chardev_ops.owner = module;
 
-	r = misc_register(&kvm_dev);
-	if (r) {
-		pr_err("kvm: misc device register failed\n");
-		goto out_unreg;
-	}
-
-	register_syscore_ops(&kvm_syscore_ops);
-
 	kvm_preempt_ops.sched_in = kvm_sched_in;
 	kvm_preempt_ops.sched_out = kvm_sched_out;
 
 	kvm_init_debug();
 
 	r = kvm_vfio_ops_init();
-	WARN_ON(r);
+	if (WARN_ON_ONCE(r))
+		goto err_vfio;
+
+	/*
+	 * Registration _must_ be the very last thing done, as this exposes
+	 * /dev/kvm to userspace, i.e. all infrastructure must be setup!
+	 */
+	r = misc_register(&kvm_dev);
+	if (r) {
+		pr_err("kvm: misc device register failed\n");
+		goto err_register;
+	}
 
 	return 0;
 
-out_unreg:
+err_register:
+	kvm_vfio_ops_exit();
+err_vfio:
 	kvm_async_pf_deinit();
-out_free_4:
+err_async_pf:
+	kvm_irqfd_exit();
+err_irqfd:
+err_cpu_kick_mask:
 	for_each_possible_cpu(cpu)
 		free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
 	kmem_cache_destroy(kvm_vcpu_cache);
-out_free_3:
+err_vcpu_cache:
+#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
+	unregister_syscore_ops(&kvm_syscore_ops);
 	unregister_reboot_notifier(&kvm_reboot_notifier);
-	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
-out_free_2:
-	kvm_arch_hardware_unsetup();
-out_free_1:
-	free_cpumask_var(cpus_hardware_enabled);
-out_free_0:
-	kvm_irqfd_exit();
-out_irqfd:
-	kvm_arch_exit();
-out_fail:
+	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE);
+#endif
 	return r;
 }
 EXPORT_SYMBOL_GPL(kvm_init);
@@ -6032,21 +6043,25 @@ void kvm_exit(void)
 {
 	int cpu;
 
-	debugfs_remove_recursive(kvm_debugfs_dir);
+	/*
+	 * Note, unregistering /dev/kvm doesn't strictly need to come first,
+	 * fops_get(), a.k.a. try_module_get(), prevents acquiring references
+	 * to KVM while the module is being stopped.
+	 */
 	misc_deregister(&kvm_dev);
+
+	debugfs_remove_recursive(kvm_debugfs_dir);
 	for_each_possible_cpu(cpu)
 		free_cpumask_var(per_cpu(cpu_kick_mask, cpu));
 	kmem_cache_destroy(kvm_vcpu_cache);
+	kvm_vfio_ops_exit();
 	kvm_async_pf_deinit();
+#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
 	unregister_syscore_ops(&kvm_syscore_ops);
 	unregister_reboot_notifier(&kvm_reboot_notifier);
-	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_STARTING);
-	on_each_cpu(hardware_disable_nolock, NULL, 1);
-	kvm_arch_hardware_unsetup();
-	kvm_arch_exit();
+	cpuhp_remove_state_nocalls(CPUHP_AP_KVM_ONLINE);
+#endif
 	kvm_irqfd_exit();
-	free_cpumask_var(cpus_hardware_enabled);
-	kvm_vfio_ops_exit();
 }
 EXPORT_SYMBOL_GPL(kvm_exit);