1 files changed, 163 insertions, 29 deletions

diff --git a/arch/x86/kvm/kvm_cache_regs.h b/arch/x86/kvm/kvm_cache_regs.h
index f8f56a93358b..8ddb01191d6f 100644
--- a/arch/x86/kvm/kvm_cache_regs.h
+++ b/arch/x86/kvm/kvm_cache_regs.h
@@ -4,58 +4,185 @@
 
 #include <linux/kvm_host.h>
 
-#define KVM_POSSIBLE_CR0_GUEST_BITS X86_CR0_TS
+#define KVM_POSSIBLE_CR0_GUEST_BITS	(X86_CR0_TS | X86_CR0_WP)
 #define KVM_POSSIBLE_CR4_GUEST_BITS				  \
 	(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR  \
-	 | X86_CR4_OSXMMEXCPT | X86_CR4_LA57 | X86_CR4_PGE)
+	 | X86_CR4_OSXMMEXCPT | X86_CR4_PGE | X86_CR4_TSD | X86_CR4_FSGSBASE \
+	 | X86_CR4_CET)
+
+#define X86_CR0_PDPTR_BITS    (X86_CR0_CD | X86_CR0_NW | X86_CR0_PG)
+#define X86_CR4_TLBFLUSH_BITS (X86_CR4_PGE | X86_CR4_PCIDE | X86_CR4_PAE | X86_CR4_SMEP)
+#define X86_CR4_PDPTR_BITS    (X86_CR4_PGE | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_SMEP)
+
+static_assert(!(KVM_POSSIBLE_CR0_GUEST_BITS & X86_CR0_PDPTR_BITS));
+
+#define BUILD_KVM_GPR_ACCESSORS(lname, uname)				      \
+static __always_inline unsigned long kvm_##lname##_read(struct kvm_vcpu *vcpu)\
+{									      \
+	return vcpu->arch.regs[VCPU_REGS_##uname];			      \
+}									      \
+static __always_inline void kvm_##lname##_write(struct kvm_vcpu *vcpu,	      \
+						unsigned long val)	      \
+{									      \
+	vcpu->arch.regs[VCPU_REGS_##uname] = val;			      \
+}
+BUILD_KVM_GPR_ACCESSORS(rax, RAX)
+BUILD_KVM_GPR_ACCESSORS(rbx, RBX)
+BUILD_KVM_GPR_ACCESSORS(rcx, RCX)
+BUILD_KVM_GPR_ACCESSORS(rdx, RDX)
+BUILD_KVM_GPR_ACCESSORS(rbp, RBP)
+BUILD_KVM_GPR_ACCESSORS(rsi, RSI)
+BUILD_KVM_GPR_ACCESSORS(rdi, RDI)
+#ifdef CONFIG_X86_64
+BUILD_KVM_GPR_ACCESSORS(r8,  R8)
+BUILD_KVM_GPR_ACCESSORS(r9,  R9)
+BUILD_KVM_GPR_ACCESSORS(r10, R10)
+BUILD_KVM_GPR_ACCESSORS(r11, R11)
+BUILD_KVM_GPR_ACCESSORS(r12, R12)
+BUILD_KVM_GPR_ACCESSORS(r13, R13)
+BUILD_KVM_GPR_ACCESSORS(r14, R14)
+BUILD_KVM_GPR_ACCESSORS(r15, R15)
+#endif
+
+/*
+ * Using the register cache from interrupt context is generally not allowed, as
+ * caching a register and marking it available/dirty can't be done atomically,
+ * i.e. accesses from interrupt context may clobber state or read stale data if
+ * the vCPU task is in the process of updating the cache.  The exception is if
+ * KVM is handling a PMI IRQ/NMI VM-Exit, as that bound code sequence doesn't
+ * touch the cache, it runs after the cache is reset (post VM-Exit), and PMIs
+ * need to access several registers that are cacheable.
+ */
+#define kvm_assert_register_caching_allowed(vcpu)		\
+	lockdep_assert_once(in_task() || kvm_arch_pmi_in_guest(vcpu))
+
+/*
+ * avail  dirty
+ * 0	  0	  register in VMCS/VMCB
+ * 0	  1	  *INVALID*
+ * 1	  0	  register in vcpu->arch
+ * 1	  1	  register in vcpu->arch, needs to be stored back
+ */
+static inline bool kvm_register_is_available(struct kvm_vcpu *vcpu,
+					     enum kvm_reg reg)
+{
+	kvm_assert_register_caching_allowed(vcpu);
+	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+static inline bool kvm_register_is_dirty(struct kvm_vcpu *vcpu,
+					 enum kvm_reg reg)
+{
+	kvm_assert_register_caching_allowed(vcpu);
+	return test_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
 
-static inline unsigned long kvm_register_read(struct kvm_vcpu *vcpu,
-					      enum kvm_reg reg)
+static inline void kvm_register_mark_available(struct kvm_vcpu *vcpu,
+					       enum kvm_reg reg)
 {
-	if (!test_bit(reg, (unsigned long *)&vcpu->arch.regs_avail))
-		kvm_x86_ops->cache_reg(vcpu, reg);
+	kvm_assert_register_caching_allowed(vcpu);
+	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+static inline void kvm_register_mark_dirty(struct kvm_vcpu *vcpu,
+					   enum kvm_reg reg)
+{
+	kvm_assert_register_caching_allowed(vcpu);
+	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
+}
+
+/*
+ * kvm_register_test_and_mark_available() is a special snowflake that uses an
+ * arch bitop directly to avoid the explicit instrumentation that comes with
+ * the generic bitops.  This allows code that cannot be instrumented (noinstr
+ * functions), e.g. the low level VM-Enter/VM-Exit paths, to cache registers.
+ */
+static __always_inline bool kvm_register_test_and_mark_available(struct kvm_vcpu *vcpu,
+								 enum kvm_reg reg)
+{
+	kvm_assert_register_caching_allowed(vcpu);
+	return arch___test_and_set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+}
+
+/*
+ * The "raw" register helpers are only for cases where the full 64 bits of a
+ * register are read/written irrespective of current vCPU mode.  In other words,
+ * odds are good you shouldn't be using the raw variants.
+ */
+static inline unsigned long kvm_register_read_raw(struct kvm_vcpu *vcpu, int reg)
+{
+	if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
+		return 0;
+
+	if (!kvm_register_is_available(vcpu, reg))
+		kvm_x86_call(cache_reg)(vcpu, reg);
 
 	return vcpu->arch.regs[reg];
 }
 
-static inline void kvm_register_write(struct kvm_vcpu *vcpu,
-				      enum kvm_reg reg,
-				      unsigned long val)
+static inline void kvm_register_write_raw(struct kvm_vcpu *vcpu, int reg,
+					  unsigned long val)
 {
+	if (WARN_ON_ONCE((unsigned int)reg >= NR_VCPU_REGS))
+		return;
+
 	vcpu->arch.regs[reg] = val;
-	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_dirty);
-	__set_bit(reg, (unsigned long *)&vcpu->arch.regs_avail);
+	kvm_register_mark_dirty(vcpu, reg);
 }
 
 static inline unsigned long kvm_rip_read(struct kvm_vcpu *vcpu)
 {
-	return kvm_register_read(vcpu, VCPU_REGS_RIP);
+	return kvm_register_read_raw(vcpu, VCPU_REGS_RIP);
 }
 
 static inline void kvm_rip_write(struct kvm_vcpu *vcpu, unsigned long val)
 {
-	kvm_register_write(vcpu, VCPU_REGS_RIP, val);
+	kvm_register_write_raw(vcpu, VCPU_REGS_RIP, val);
+}
+
+static inline unsigned long kvm_rsp_read(struct kvm_vcpu *vcpu)
+{
+	return kvm_register_read_raw(vcpu, VCPU_REGS_RSP);
+}
+
+static inline void kvm_rsp_write(struct kvm_vcpu *vcpu, unsigned long val)
+{
+	kvm_register_write_raw(vcpu, VCPU_REGS_RSP, val);
 }
 
 static inline u64 kvm_pdptr_read(struct kvm_vcpu *vcpu, int index)
 {
 	might_sleep();  /* on svm */
 
-	if (!test_bit(VCPU_EXREG_PDPTR,
-		      (unsigned long *)&vcpu->arch.regs_avail))
-		kvm_x86_ops->cache_reg(vcpu, (enum kvm_reg)VCPU_EXREG_PDPTR);
+	if (!kvm_register_is_available(vcpu, VCPU_EXREG_PDPTR))
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_PDPTR);
 
 	return vcpu->arch.walk_mmu->pdptrs[index];
 }
 
+static inline void kvm_pdptr_write(struct kvm_vcpu *vcpu, int index, u64 value)
+{
+	vcpu->arch.walk_mmu->pdptrs[index] = value;
+}
+
 static inline ulong kvm_read_cr0_bits(struct kvm_vcpu *vcpu, ulong mask)
 {
 	ulong tmask = mask & KVM_POSSIBLE_CR0_GUEST_BITS;
-	if (tmask & vcpu->arch.cr0_guest_owned_bits)
-		kvm_x86_ops->decache_cr0_guest_bits(vcpu);
+	if ((tmask & vcpu->arch.cr0_guest_owned_bits) &&
+	    !kvm_register_is_available(vcpu, VCPU_EXREG_CR0))
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR0);
 	return vcpu->arch.cr0 & mask;
 }
 
+static __always_inline bool kvm_is_cr0_bit_set(struct kvm_vcpu *vcpu,
+					       unsigned long cr0_bit)
+{
+	BUILD_BUG_ON(!is_power_of_2(cr0_bit));
+
+	return !!kvm_read_cr0_bits(vcpu, cr0_bit);
+}
+
 static inline ulong kvm_read_cr0(struct kvm_vcpu *vcpu)
 {
 	return kvm_read_cr0_bits(vcpu, ~0UL);
@@ -64,15 +191,24 @@ static inline ulong kvm_read_cr0(struct kvm_vcpu *vcpu)
 static inline ulong kvm_read_cr4_bits(struct kvm_vcpu *vcpu, ulong mask)
 {
 	ulong tmask = mask & KVM_POSSIBLE_CR4_GUEST_BITS;
-	if (tmask & vcpu->arch.cr4_guest_owned_bits)
-		kvm_x86_ops->decache_cr4_guest_bits(vcpu);
+	if ((tmask & vcpu->arch.cr4_guest_owned_bits) &&
+	    !kvm_register_is_available(vcpu, VCPU_EXREG_CR4))
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR4);
 	return vcpu->arch.cr4 & mask;
 }
 
+static __always_inline bool kvm_is_cr4_bit_set(struct kvm_vcpu *vcpu,
+					       unsigned long cr4_bit)
+{
+	BUILD_BUG_ON(!is_power_of_2(cr4_bit));
+
+	return !!kvm_read_cr4_bits(vcpu, cr4_bit);
+}
+
 static inline ulong kvm_read_cr3(struct kvm_vcpu *vcpu)
 {
-	if (!test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_avail))
-		kvm_x86_ops->decache_cr3(vcpu);
+	if (!kvm_register_is_available(vcpu, VCPU_EXREG_CR3))
+		kvm_x86_call(cache_reg)(vcpu, VCPU_EXREG_CR3);
 	return vcpu->arch.cr3;
 }
 
@@ -83,13 +219,14 @@ static inline ulong kvm_read_cr4(struct kvm_vcpu *vcpu)
 
 static inline u64 kvm_read_edx_eax(struct kvm_vcpu *vcpu)
 {
-	return (kvm_register_read(vcpu, VCPU_REGS_RAX) & -1u)
-		| ((u64)(kvm_register_read(vcpu, VCPU_REGS_RDX) & -1u) << 32);
+	return (kvm_rax_read(vcpu) & -1u)
+		| ((u64)(kvm_rdx_read(vcpu) & -1u) << 32);
 }
 
 static inline void enter_guest_mode(struct kvm_vcpu *vcpu)
 {
 	vcpu->arch.hflags |= HF_GUEST_MASK;
+	vcpu->stat.guest_mode = 1;
 }
 
 static inline void leave_guest_mode(struct kvm_vcpu *vcpu)
@@ -100,6 +237,8 @@ static inline void leave_guest_mode(struct kvm_vcpu *vcpu)
 		vcpu->arch.load_eoi_exitmap_pending = false;
 		kvm_make_request(KVM_REQ_LOAD_EOI_EXITMAP, vcpu);
 	}
+
+	vcpu->stat.guest_mode = 0;
 }
 
 static inline bool is_guest_mode(struct kvm_vcpu *vcpu)
@@ -107,9 +246,4 @@ static inline bool is_guest_mode(struct kvm_vcpu *vcpu)
 	return vcpu->arch.hflags & HF_GUEST_MASK;
 }
 
-static inline bool is_smm(struct kvm_vcpu *vcpu)
-{
-	return vcpu->arch.hflags & HF_SMM_MASK;
-}
-
 #endif