summaryrefslogtreecommitdiff
path: root/arch/x86/kernel
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2020-10-14 10:21:34 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-10-14 10:21:34 -0700
commitda9803dfd3955bd2f9909d55e23f188ad76dbe58 (patch)
tree9e4ea42559f82bf46340d91fa3312ea555686cf6 /arch/x86/kernel
parent6873139ed078bfe0341d4cbb69e5af1b323bf532 (diff)
parent0ddfb1cf3b6b07c97cff16ea69931d986f9622ee (diff)
Merge tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 SEV-ES support from Borislav Petkov: "SEV-ES enhances the current guest memory encryption support called SEV by also encrypting the guest register state, making the registers inaccessible to the hypervisor by en-/decrypting them on world switches. Thus, it adds additional protection to Linux guests against exfiltration, control flow and rollback attacks. With SEV-ES, the guest is in full control of what registers the hypervisor can access. This is provided by a guest-host exchange mechanism based on a new exception vector called VMM Communication Exception (#VC), a new instruction called VMGEXIT and a shared Guest-Host Communication Block which is a decrypted page shared between the guest and the hypervisor. Intercepts to the hypervisor become #VC exceptions in an SEV-ES guest so in order for that exception mechanism to work, the early x86 init code needed to be made able to handle exceptions, which, in itself, brings a bunch of very nice cleanups and improvements to the early boot code like an early page fault handler, allowing for on-demand building of the identity mapping. With that, !KASLR configurations do not use the EFI page table anymore but switch to a kernel-controlled one. The main part of this series adds the support for that new exchange mechanism. The goal has been to keep this as much as possibly separate from the core x86 code by concentrating the machinery in two SEV-ES-specific files: arch/x86/kernel/sev-es-shared.c arch/x86/kernel/sev-es.c Other interaction with core x86 code has been kept at minimum and behind static keys to minimize the performance impact on !SEV-ES setups. Work by Joerg Roedel and Thomas Lendacky and others" * tag 'x86_seves_for_v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (73 commits) x86/sev-es: Use GHCB accessor for setting the MMIO scratch buffer x86/sev-es: Check required CPU features for SEV-ES x86/efi: Add GHCB mappings when SEV-ES is active x86/sev-es: Handle NMI State x86/sev-es: Support CPU offline/online x86/head/64: Don't call verify_cpu() on starting APs x86/smpboot: Load TSS and getcpu GDT entry before loading IDT x86/realmode: Setup AP jump table x86/realmode: Add SEV-ES specific trampoline entry point x86/vmware: Add VMware-specific handling for VMMCALL under SEV-ES x86/kvm: Add KVM-specific VMMCALL handling under SEV-ES x86/paravirt: Allow hypervisor-specific VMMCALL handling under SEV-ES x86/sev-es: Handle #DB Events x86/sev-es: Handle #AC Events x86/sev-es: Handle VMMCALL Events x86/sev-es: Handle MWAIT/MWAITX Events x86/sev-es: Handle MONITOR/MONITORX Events x86/sev-es: Handle INVD Events x86/sev-es: Handle RDPMC Events x86/sev-es: Handle RDTSC(P) Events ...
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/Makefile3
-rw-r--r--arch/x86/kernel/cpu/amd.c3
-rw-r--r--arch/x86/kernel/cpu/common.c25
-rw-r--r--arch/x86/kernel/cpu/scattered.c1
-rw-r--r--arch/x86/kernel/cpu/vmware.c50
-rw-r--r--arch/x86/kernel/dumpstack.c7
-rw-r--r--arch/x86/kernel/dumpstack_64.c46
-rw-r--r--arch/x86/kernel/head64.c122
-rw-r--r--arch/x86/kernel/head_64.S165
-rw-r--r--arch/x86/kernel/idt.c41
-rw-r--r--arch/x86/kernel/kvm.c35
-rw-r--r--arch/x86/kernel/nmi.c15
-rw-r--r--arch/x86/kernel/sev-es-shared.c507
-rw-r--r--arch/x86/kernel/sev-es.c1404
-rw-r--r--arch/x86/kernel/smpboot.c2
-rw-r--r--arch/x86/kernel/traps.c48
-rw-r--r--arch/x86/kernel/umip.c49
17 files changed, 2373 insertions, 150 deletions
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index de09af019e23..04ceea8f4a89 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -20,6 +20,7 @@ CFLAGS_REMOVE_kvmclock.o = -pg
CFLAGS_REMOVE_ftrace.o = -pg
CFLAGS_REMOVE_early_printk.o = -pg
CFLAGS_REMOVE_head64.o = -pg
+CFLAGS_REMOVE_sev-es.o = -pg
endif
KASAN_SANITIZE_head$(BITS).o := n
@@ -27,6 +28,7 @@ KASAN_SANITIZE_dumpstack.o := n
KASAN_SANITIZE_dumpstack_$(BITS).o := n
KASAN_SANITIZE_stacktrace.o := n
KASAN_SANITIZE_paravirt.o := n
+KASAN_SANITIZE_sev-es.o := n
# With some compiler versions the generated code results in boot hangs, caused
# by several compilation units. To be safe, disable all instrumentation.
@@ -146,6 +148,7 @@ obj-$(CONFIG_UNWINDER_ORC) += unwind_orc.o
obj-$(CONFIG_UNWINDER_FRAME_POINTER) += unwind_frame.o
obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o
+obj-$(CONFIG_AMD_MEM_ENCRYPT) += sev-es.o
###
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index dcc3d943c68f..6062ce586b95 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -614,7 +614,7 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
* If BIOS has not enabled SME then don't advertise the
* SME feature (set in scattered.c).
* For SEV: If BIOS has not enabled SEV then don't advertise the
- * SEV feature (set in scattered.c).
+ * SEV and SEV_ES feature (set in scattered.c).
*
* In all cases, since support for SME and SEV requires long mode,
* don't advertise the feature under CONFIG_X86_32.
@@ -645,6 +645,7 @@ clear_all:
setup_clear_cpu_cap(X86_FEATURE_SME);
clear_sev:
setup_clear_cpu_cap(X86_FEATURE_SEV);
+ setup_clear_cpu_cap(X86_FEATURE_SEV_ES);
}
}
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index c51158914ea2..35ad8480c464 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1876,6 +1876,8 @@ static inline void tss_setup_ist(struct tss_struct *tss)
tss->x86_tss.ist[IST_INDEX_NMI] = __this_cpu_ist_top_va(NMI);
tss->x86_tss.ist[IST_INDEX_DB] = __this_cpu_ist_top_va(DB);
tss->x86_tss.ist[IST_INDEX_MCE] = __this_cpu_ist_top_va(MCE);
+ /* Only mapped when SEV-ES is active */
+ tss->x86_tss.ist[IST_INDEX_VC] = __this_cpu_ist_top_va(VC);
}
#else /* CONFIG_X86_64 */
@@ -1908,6 +1910,29 @@ static inline void tss_setup_io_bitmap(struct tss_struct *tss)
}
/*
+ * Setup everything needed to handle exceptions from the IDT, including the IST
+ * exceptions which use paranoid_entry().
+ */
+void cpu_init_exception_handling(void)
+{
+ struct tss_struct *tss = this_cpu_ptr(&cpu_tss_rw);
+ int cpu = raw_smp_processor_id();
+
+ /* paranoid_entry() gets the CPU number from the GDT */
+ setup_getcpu(cpu);
+
+ /* IST vectors need TSS to be set up. */
+ tss_setup_ist(tss);
+ tss_setup_io_bitmap(tss);
+ set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
+
+ load_TR_desc();
+
+ /* Finally load the IDT */
+ load_current_idt();
+}
+
+/*
* cpu_init() initializes state that is per-CPU. Some data is already
* initialized (naturally) in the bootstrap process, such as the GDT
* and IDT. We reload them nevertheless, this function acts as a
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index 2eb0a8c44b35..866c9a9bcdee 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -42,6 +42,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 },
{ X86_FEATURE_SME, CPUID_EAX, 0, 0x8000001f, 0 },
{ X86_FEATURE_SEV, CPUID_EAX, 1, 0x8000001f, 0 },
+ { X86_FEATURE_SEV_ES, CPUID_EAX, 3, 0x8000001f, 0 },
{ X86_FEATURE_SME_COHERENT, CPUID_EAX, 10, 0x8000001f, 0 },
{ 0, 0, 0, 0, 0 }
};
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 9b6fafa69be9..924571fe5864 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -33,6 +33,7 @@
#include <asm/timer.h>
#include <asm/apic.h>
#include <asm/vmware.h>
+#include <asm/svm.h>
#undef pr_fmt
#define pr_fmt(fmt) "vmware: " fmt
@@ -476,10 +477,49 @@ static bool __init vmware_legacy_x2apic_available(void)
(eax & (1 << VMWARE_CMD_LEGACY_X2APIC)) != 0;
}
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+static void vmware_sev_es_hcall_prepare(struct ghcb *ghcb,
+ struct pt_regs *regs)
+{
+ /* Copy VMWARE specific Hypercall parameters to the GHCB */
+ ghcb_set_rip(ghcb, regs->ip);
+ ghcb_set_rbx(ghcb, regs->bx);
+ ghcb_set_rcx(ghcb, regs->cx);
+ ghcb_set_rdx(ghcb, regs->dx);
+ ghcb_set_rsi(ghcb, regs->si);
+ ghcb_set_rdi(ghcb, regs->di);
+ ghcb_set_rbp(ghcb, regs->bp);
+}
+
+static bool vmware_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
+{
+ if (!(ghcb_rbx_is_valid(ghcb) &&
+ ghcb_rcx_is_valid(ghcb) &&
+ ghcb_rdx_is_valid(ghcb) &&
+ ghcb_rsi_is_valid(ghcb) &&
+ ghcb_rdi_is_valid(ghcb) &&
+ ghcb_rbp_is_valid(ghcb)))
+ return false;
+
+ regs->bx = ghcb->save.rbx;
+ regs->cx = ghcb->save.rcx;
+ regs->dx = ghcb->save.rdx;
+ regs->si = ghcb->save.rsi;
+ regs->di = ghcb->save.rdi;
+ regs->bp = ghcb->save.rbp;
+
+ return true;
+}
+#endif
+
const __initconst struct hypervisor_x86 x86_hyper_vmware = {
- .name = "VMware",
- .detect = vmware_platform,
- .type = X86_HYPER_VMWARE,
- .init.init_platform = vmware_platform_setup,
- .init.x2apic_available = vmware_legacy_x2apic_available,
+ .name = "VMware",
+ .detect = vmware_platform,
+ .type = X86_HYPER_VMWARE,
+ .init.init_platform = vmware_platform_setup,
+ .init.x2apic_available = vmware_legacy_x2apic_available,
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ .runtime.sev_es_hcall_prepare = vmware_sev_es_hcall_prepare,
+ .runtime.sev_es_hcall_finish = vmware_sev_es_hcall_finish,
+#endif
};
diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index ea8d51ec251b..25c06b67e7e0 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -29,8 +29,8 @@ static int die_counter;
static struct pt_regs exec_summary_regs;
-bool in_task_stack(unsigned long *stack, struct task_struct *task,
- struct stack_info *info)
+bool noinstr in_task_stack(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info)
{
unsigned long *begin = task_stack_page(task);
unsigned long *end = task_stack_page(task) + THREAD_SIZE;
@@ -46,7 +46,8 @@ bool in_task_stack(unsigned long *stack, struct task_struct *task,
return true;
}
-bool in_entry_stack(unsigned long *stack, struct stack_info *info)
+/* Called from get_stack_info_noinstr - so must be noinstr too */
+bool noinstr in_entry_stack(unsigned long *stack, struct stack_info *info)
{
struct entry_stack *ss = cpu_entry_stack(smp_processor_id());
diff --git a/arch/x86/kernel/dumpstack_64.c b/arch/x86/kernel/dumpstack_64.c
index 4a94d38cd141..1dd851397bd9 100644
--- a/arch/x86/kernel/dumpstack_64.c
+++ b/arch/x86/kernel/dumpstack_64.c
@@ -24,11 +24,13 @@ static const char * const exception_stack_names[] = {
[ ESTACK_NMI ] = "NMI",
[ ESTACK_DB ] = "#DB",
[ ESTACK_MCE ] = "#MC",
+ [ ESTACK_VC ] = "#VC",
+ [ ESTACK_VC2 ] = "#VC2",
};
const char *stack_type_name(enum stack_type type)
{
- BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+ BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
if (type == STACK_TYPE_IRQ)
return "IRQ";
@@ -79,16 +81,18 @@ struct estack_pages estack_pages[CEA_ESTACK_PAGES] ____cacheline_aligned = {
EPAGERANGE(NMI),
EPAGERANGE(DB),
EPAGERANGE(MCE),
+ EPAGERANGE(VC),
+ EPAGERANGE(VC2),
};
-static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
+static __always_inline bool in_exception_stack(unsigned long *stack, struct stack_info *info)
{
unsigned long begin, end, stk = (unsigned long)stack;
const struct estack_pages *ep;
struct pt_regs *regs;
unsigned int k;
- BUILD_BUG_ON(N_EXCEPTION_STACKS != 4);
+ BUILD_BUG_ON(N_EXCEPTION_STACKS != 6);
begin = (unsigned long)__this_cpu_read(cea_exception_stacks);
/*
@@ -122,7 +126,7 @@ static bool in_exception_stack(unsigned long *stack, struct stack_info *info)
return true;
}
-static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
+static __always_inline bool in_irq_stack(unsigned long *stack, struct stack_info *info)
{
unsigned long *end = (unsigned long *)this_cpu_read(hardirq_stack_ptr);
unsigned long *begin = end - (IRQ_STACK_SIZE / sizeof(long));
@@ -147,32 +151,38 @@ static bool in_irq_stack(unsigned long *stack, struct stack_info *info)
return true;
}
-int get_stack_info(unsigned long *stack, struct task_struct *task,
- struct stack_info *info, unsigned long *visit_mask)
+bool noinstr get_stack_info_noinstr(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info)
{
- if (!stack)
- goto unknown;
-
- task = task ? : current;
-
if (in_task_stack(stack, task, info))
- goto recursion_check;
+ return true;
if (task != current)
- goto unknown;
+ return false;
if (in_exception_stack(stack, info))
- goto recursion_check;
+ return true;
if (in_irq_stack(stack, info))
- goto recursion_check;
+ return true;
if (in_entry_stack(stack, info))
- goto recursion_check;
+ return true;
+
+ return false;
+}
+
+int get_stack_info(unsigned long *stack, struct task_struct *task,
+ struct stack_info *info, unsigned long *visit_mask)
+{
+ task = task ? : current;
- goto unknown;
+ if (!stack)
+ goto unknown;
+
+ if (!get_stack_info_noinstr(stack, task, info))
+ goto unknown;
-recursion_check:
/*
* Make sure we don't iterate through any given stack more than once.
* If it comes up a second time then there's something wrong going on:
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index cbb71c1b574f..4199f25c0063 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -36,6 +36,11 @@
#include <asm/microcode.h>
#include <asm/kasan.h>
#include <asm/fixmap.h>
+#include <asm/realmode.h>
+#include <asm/desc.h>
+#include <asm/extable.h>
+#include <asm/trapnr.h>
+#include <asm/sev-es.h>
/*
* Manage page tables very early on.
@@ -61,6 +66,24 @@ unsigned long vmemmap_base __ro_after_init = __VMEMMAP_BASE_L4;
EXPORT_SYMBOL(vmemmap_base);
#endif
+/*
+ * GDT used on the boot CPU before switching to virtual addresses.
+ */
+static struct desc_struct startup_gdt[GDT_ENTRIES] = {
+ [GDT_ENTRY_KERNEL32_CS] = GDT_ENTRY_INIT(0xc09b, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_CS] = GDT_ENTRY_INIT(0xa09b, 0, 0xfffff),
+ [GDT_ENTRY_KERNEL_DS] = GDT_ENTRY_INIT(0xc093, 0, 0xfffff),
+};
+
+/*
+ * Address needs to be set at runtime because it references the startup_gdt
+ * while the kernel still uses a direct mapping.
+ */
+static struct desc_ptr startup_gdt_descr = {
+ .size = sizeof(startup_gdt),
+ .address = 0,
+};
+
#define __head __section(.head.text)
static void __head *fixup_pointer(void *ptr, unsigned long physaddr)
@@ -297,7 +320,7 @@ static void __init reset_early_page_tables(void)
}
/* Create a new PMD entry */
-int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
+bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
{
unsigned long physaddr = address - __PAGE_OFFSET;
pgdval_t pgd, *pgd_p;
@@ -307,7 +330,7 @@ int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
/* Invalid address or early pgt is done ? */
if (physaddr >= MAXMEM || read_cr3_pa() != __pa_nodebug(early_top_pgt))
- return -1;
+ return false;
again:
pgd_p = &early_top_pgt[pgd_index(address)].pgd;
@@ -364,10 +387,10 @@ again:
}
pmd_p[pmd_index(address)] = pmd;
- return 0;
+ return true;
}
-int __init early_make_pgtable(unsigned long address)
+static bool __init early_make_pgtable(unsigned long address)
{
unsigned long physaddr = address - __PAGE_OFFSET;
pmdval_t pmd;
@@ -377,6 +400,19 @@ int __init early_make_pgtable(unsigned long address)
return __early_make_pgtable(address, pmd);
}
+void __init do_early_exception(struct pt_regs *regs, int trapnr)
+{
+ if (trapnr == X86_TRAP_PF &&
+ early_make_pgtable(native_read_cr2()))
+ return;
+
+ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT) &&
+ trapnr == X86_TRAP_VC && handle_vc_boot_ghcb(regs))
+ return;
+
+ early_fixup_exception(regs, trapnr);
+}
+
/* Don't add a printk in there. printk relies on the PDA which is not initialized
yet. */
static void __init clear_bss(void)
@@ -489,3 +525,81 @@ void __init x86_64_start_reservations(char *real_mode_data)
start_kernel();
}
+
+/*
+ * Data structures and code used for IDT setup in head_64.S. The bringup-IDT is
+ * used until the idt_table takes over. On the boot CPU this happens in
+ * x86_64_start_kernel(), on secondary CPUs in start_secondary(). In both cases
+ * this happens in the functions called from head_64.S.
+ *
+ * The idt_table can't be used that early because all the code modifying it is
+ * in idt.c and can be instrumented by tracing or KASAN, which both don't work
+ * during early CPU bringup. Also the idt_table has the runtime vectors
+ * configured which require certain CPU state to be setup already (like TSS),
+ * which also hasn't happened yet in early CPU bringup.
+ */
+static gate_desc bringup_idt_table[NUM_EXCEPTION_VECTORS] __page_aligned_data;
+
+static struct desc_ptr bringup_idt_descr = {
+ .size = (NUM_EXCEPTION_VECTORS * sizeof(gate_desc)) - 1,
+ .address = 0, /* Set at runtime */
+};
+
+static void set_bringup_idt_handler(gate_desc *idt, int n, void *handler)
+{
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ struct idt_data data;
+ gate_desc desc;
+
+ init_idt_data(&data, n, handler);
+ idt_init_desc(&desc, &data);
+ native_write_idt_entry(idt, n, &desc);
+#endif
+}
+
+/* This runs while still in the direct mapping */
+static void startup_64_load_idt(unsigned long physbase)
+{
+ struct desc_ptr *desc = fixup_pointer(&bringup_idt_descr, physbase);
+ gate_desc *idt = fixup_pointer(bringup_idt_table, physbase);
+
+
+ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT)) {
+ void *handler;
+
+ /* VMM Communication Exception */
+ handler = fixup_pointer(vc_no_ghcb, physbase);
+ set_bringup_idt_handler(idt, X86_TRAP_VC, handler);
+ }
+
+ desc->address = (unsigned long)idt;
+ native_load_idt(desc);
+}
+
+/* This is used when running on kernel addresses */
+void early_setup_idt(void)
+{
+ /* VMM Communication Exception */
+ if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
+ set_bringup_idt_handler(bringup_idt_table, X86_TRAP_VC, vc_boot_ghcb);
+
+ bringup_idt_descr.address = (unsigned long)bringup_idt_table;
+ native_load_idt(&bringup_idt_descr);
+}
+
+/*
+ * Setup boot CPU state needed before kernel switches to virtual addresses.
+ */
+void __head startup_64_setup_env(unsigned long physbase)
+{
+ /* Load GDT */
+ startup_gdt_descr.address = (unsigned long)fixup_pointer(startup_gdt, physbase);
+ native_load_gdt(&startup_gdt_descr);
+
+ /* New GDT is live - reload data segment registers */
+ asm volatile("movl %%eax, %%ds\n"
+ "movl %%eax, %%ss\n"
+ "movl %%eax, %%es\n" : : "a"(__KERNEL_DS) : "memory");
+
+ startup_64_load_idt(physbase);
+}
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 16da4ac01597..7eb2a1c87969 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -73,6 +73,20 @@ SYM_CODE_START_NOALIGN(startup_64)
/* Set up the stack for verify_cpu(), similar to initial_stack below */
leaq (__end_init_task - SIZEOF_PTREGS)(%rip), %rsp
+ leaq _text(%rip), %rdi
+ pushq %rsi
+ call startup_64_setup_env
+ popq %rsi
+
+ /* Now switch to __KERNEL_CS so IRET works reliably */
+ pushq $__KERNEL_CS
+ leaq .Lon_kernel_cs(%rip), %rax
+ pushq %rax
+ lretq
+
+.Lon_kernel_cs:
+ UNWIND_HINT_EMPTY
+
/* Sanitize CPU configuration */
call verify_cpu
@@ -112,6 +126,18 @@ SYM_CODE_START(secondary_startup_64)
call verify_cpu
/*
+ * The secondary_startup_64_no_verify entry point is only used by
+ * SEV-ES guests. In those guests the call to verify_cpu() would cause
+ * #VC exceptions which can not be handled at this stage of secondary
+ * CPU bringup.
+ *
+ * All non SEV-ES systems, especially Intel systems, need to execute
+ * verify_cpu() above to make sure NX is enabled.
+ */
+SYM_INNER_LABEL(secondary_startup_64_no_verify, SYM_L_GLOBAL)
+ UNWIND_HINT_EMPTY
+
+ /*
* Retrieve the modifier (SME encryption mask if SME is active) to be
* added to the initial pgdir entry that will be programmed into CR3.
*/
@@ -144,33 +170,6 @@ SYM_CODE_START(secondary_startup_64)
1:
UNWIND_HINT_EMPTY
- /* Check if nx is implemented */
- movl $0x80000001, %eax
- cpuid
- movl %edx,%edi
-
- /* Setup EFER (Extended Feature Enable Register) */
- movl $MSR_EFER, %ecx
- rdmsr
- btsl $_EFER_SCE, %eax /* Enable System Call */
- btl $20,%edi /* No Execute supported? */
- jnc 1f
- btsl $_EFER_NX, %eax
- btsq $_PAGE_BIT_NX,early_pmd_flags(%rip)
-1: wrmsr /* Make changes effective */
-
- /* Setup cr0 */
- movl $CR0_STATE, %eax
- /* Make changes effective */
- movq %rax, %cr0
-
- /* Setup a boot time stack */
- movq initial_stack(%rip), %rsp
-
- /* zero EFLAGS after setting rsp */
- pushq $0
- popfq
-
/*
* We must switch to a new descriptor in kernel space for the GDT
* because soon the kernel won't have access anymore to the userspace
@@ -205,6 +204,41 @@ SYM_CODE_START(secondary_startup_64)
movl initial_gs+4(%rip),%edx
wrmsr
+ /*
+ * Setup a boot time stack - Any secondary CPU will have lost its stack
+ * by now because the cr3-switch above unmaps the real-mode stack
+ */
+ movq initial_stack(%rip), %rsp
+
+ /* Setup and Load IDT */
+ pushq %rsi
+ call early_setup_idt
+ popq %rsi
+
+ /* Check if nx is implemented */
+ movl $0x80000001, %eax
+ cpuid
+ movl %edx,%edi
+
+ /* Setup EFER (Extended Feature Enable Register) */
+ movl $MSR_EFER, %ecx
+ rdmsr
+ btsl $_EFER_SCE, %eax /* Enable System Call */
+ btl $20,%edi /* No Execute supported? */
+ jnc 1f
+ btsl $_EFER_NX, %eax
+ btsq $_PAGE_BIT_NX,early_pmd_flags(%rip)
+1: wrmsr /* Make changes effective */
+
+ /* Setup cr0 */
+ movl $CR0_STATE, %eax
+ /* Make changes effective */
+ movq %rax, %cr0
+
+ /* zero EFLAGS after setting rsp */
+ pushq $0
+ popfq
+
/* rsi is pointer to real mode structure with interesting info.
pass it to C */
movq %rsi, %rdi
@@ -259,11 +293,47 @@ SYM_CODE_START(start_cpu0)
SYM_CODE_END(start_cpu0)
#endif
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+/*
+ * VC Exception handler used during early boot when running on kernel
+ * addresses, but before the switch to the idt_table can be made.
+ * The early_idt_handler_array can't be used here because it calls into a lot
+ * of __init code and this handler is also used during CPU offlining/onlining.
+ * Therefore this handler ends up in the .text section so that it stays around
+ * when .init.text is freed.
+ */
+SYM_CODE_START_NOALIGN(vc_boot_ghcb)
+ UNWIND_HINT_IRET_REGS offset=8
+
+ /* Build pt_regs */
+ PUSH_AND_CLEAR_REGS
+
+ /* Call C handler */
+ movq %rsp, %rdi
+ movq ORIG_RAX(%rsp), %rsi
+ movq initial_vc_handler(%rip), %rax
+ ANNOTATE_RETPOLINE_SAFE
+ call *%rax
+
+ /* Unwind pt_regs */
+ POP_REGS
+
+ /* Remove Error Code */
+ addq $8, %rsp
+
+ /* Pure iret required here - don't use INTERRUPT_RETURN */
+ iretq
+SYM_CODE_END(vc_boot_ghcb)
+#endif
+
/* Both SMP bootup and ACPI suspend change these variables */
__REFDATA
.balign 8
SYM_DATA(initial_code, .quad x86_64_start_kernel)
SYM_DATA(initial_gs, .quad INIT_PER_CPU_VAR(fixed_percpu_data))
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+SYM_DATA(initial_vc_handler, .quad handle_vc_boot_ghcb)
+#endif
/*
* The SIZEOF_PTREGS gap is a convention which helps the in-kernel unwinder
@@ -319,22 +389,43 @@ SYM_CODE_START_LOCAL(early_idt_handler_common)
pushq %r15 /* pt_regs->r15 */
UNWIND_HINT_REGS
- cmpq $14,%rsi /* Page fault? */
- jnz 10f
- GET_CR2_INTO(%rdi) /* can clobber %rax if pv */
- call early_make_pgtable
- andl %eax,%eax
- jz 20f /* All good */
-
-10:
movq %rsp,%rdi /* RDI = pt_regs; RSI is already trapnr */
- call early_fixup_exception
+ call do_early_exception
-20:
decl early_recursion_flag(%rip)
jmp restore_regs_and_return_to_kernel
SYM_CODE_END(early_idt_handler_common)
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+/*
+ * VC Exception handler used during very early boot. The
+ * early_idt_handler_array can't be used because it returns via the
+ * paravirtualized INTERRUPT_RETURN and pv-ops don't work that early.
+ *
+ * This handler will end up in the .init.text section and not be
+ * available to boot secondary CPUs.
+ */
+SYM_CODE_START_NOALIGN(vc_no_ghcb)
+ UNWIND_HINT_IRET_REGS offset=8
+
+ /* Build pt_regs */
+ PUSH_AND_CLEAR_REGS
+
+ /* Call C handler */
+ movq %rsp, %rdi
+ movq ORIG_RAX(%rsp), %rsi
+ call do_vc_no_ghcb
+
+ /* Unwind pt_regs */
+ POP_REGS
+
+ /* Remove Error Code */
+ addq $8, %rsp
+
+ /* Pure iret required here - don't use INTERRUPT_RETURN */
+ iretq
+SYM_CODE_END(vc_no_ghcb)
+#endif
#define SYM_DATA_START_PAGE_ALIGNED(name) \
SYM_START(name, SYM_L_GLOBAL, .balign PAGE_SIZE)
diff --git a/arch/x86/kernel/idt.c b/arch/x86/kernel/idt.c
index 1bffb87dcfdc..ee1a283f8e96 100644
--- a/arch/x86/kernel/idt.c
+++ b/arch/x86/kernel/idt.c
@@ -11,13 +11,6 @@
#include <asm/desc.h>
#include <asm/hw_irq.h>
-struct idt_data {
- unsigned int vector;
- unsigned int segment;
- struct idt_bits bits;
- const void *addr;
-};
-
#define DPL0 0x0
#define DPL3 0x3
@@ -175,20 +168,6 @@ bool idt_is_f00f_address(unsigned long address)
}
#endif
-static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d)
-{
- unsigned long addr = (unsigned long) d->addr;
-
- gate->offset_low = (u16) addr;
- gate->segment = (u16) d->segment;
- gate->bits = d->bits;
- gate->offset_middle = (u16) (addr >> 16);
-#ifdef CONFIG_X86_64
- gate->offset_high = (u32) (addr >> 32);
- gate->reserved = 0;
-#endif
-}
-
static __init void
idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size, bool sys)
{
@@ -206,14 +185,7 @@ static __init void set_intr_gate(unsigned int n, const void *addr)
{
struct idt_data data;
- BUG_ON(n > 0xFF);
-
- memset(&data, 0, sizeof(data));
- data.vector = n;
- data.addr = addr;
- data.segment = __KERNEL_CS;
- data.bits.type = GATE_INTERRUPT;
- data.bits.p = 1;
+ init_idt_data(&data, n, addr);
idt_setup_from_table(idt_table, &data, 1, false);
}
@@ -254,11 +226,14 @@ static const __initconst struct idt_data early_pf_idts[] = {
* cpu_init() when the TSS has been initialized.
*/
static const __initconst struct idt_data ist_idts[] = {
- ISTG(X86_TRAP_DB, asm_exc_debug, IST_INDEX_DB),
- ISTG(X86_TRAP_NMI, asm_exc_nmi, IST_INDEX_NMI),
- ISTG(X86_TRAP_DF, asm_exc_double_fault, IST_INDEX_DF),
+ ISTG(X86_TRAP_DB, asm_exc_debug, IST_INDEX_DB),
+ ISTG(X86_TRAP_NMI, asm_exc_nmi, IST_INDEX_NMI),
+ ISTG(X86_TRAP_DF, asm_exc_double_fault, IST_INDEX_DF),
#ifdef CONFIG_X86_MCE
- ISTG(X86_TRAP_MC, asm_exc_machine_check, IST_INDEX_MCE),
+ ISTG(X86_TRAP_MC, asm_exc_machine_check, IST_INDEX_MCE),
+#endif
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+ ISTG(X86_TRAP_VC, asm_exc_vmm_communication, IST_INDEX_VC),
#endif
};
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index 9663ba31347c..1c0f2560a41c 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -36,6 +36,8 @@
#include <asm/hypervisor.h>
#include <asm/tlb.h>
#include <asm/cpuidle_haltpoll.h>
+#include <asm/ptrace.h>
+#include <asm/svm.h>
DEFINE_STATIC_KEY_FALSE(kvm_async_pf_enabled);
@@ -744,13 +746,34 @@ static void __init kvm_init_platform(void)
x86_platform.apic_post_init = kvm_apic_init;
}
+#if defined(CONFIG_AMD_MEM_ENCRYPT)
+static void kvm_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs)
+{
+ /* RAX and CPL are already in the GHCB */
+ ghcb_set_rbx(ghcb, regs->bx);
+ ghcb_set_rcx(ghcb, regs->cx);
+ ghcb_set_rdx(ghcb, regs->dx);
+ ghcb_set_rsi(ghcb, regs->si);
+}
+
+static bool kvm_sev_es_hcall_finish(struct ghcb *ghcb, struct pt_regs *regs)
+{
+ /* No checking of the return state needed */
+ return true;
+}
+#endif
+
const __initconst struct hypervisor_x86 x86_hyper_kvm = {
- .name = "KVM",
- .detect = kvm_detect,
- .type = X86_HYPER_KVM,
- .init.guest_late_init = kvm_guest_init,
- .init.x2apic_available = kvm_para_available,
- .init.init_platform = kvm_init_platform,
+ .name = "KVM",
+ .detect = kvm_detect,
+ .type = X86_HYPER_KVM,
+ .init.guest_late_init = kvm_guest_init,
+ .init.x2apic_available = kvm_para_available,
+ .init.init_platform = kvm_init_platform,
+#if defined(CONFIG_AMD_MEM_ENCRYPT)
+ .runtime.sev_es_hcall_prepare = kvm_sev_es_hcall_prepare,
+ .runtime.sev_es_hcall_finish = kvm_sev_es_hcall_finish,
+#endif
};
static __init int activate_jump_labels(void)
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 47381666d6a5..4bc77aaf1303 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -33,6 +33,7 @@
#include <asm/reboot.h>
#include <asm/cache.h>
#include <asm/nospec-branch.h>
+#include <asm/sev-es.h>
#define CREATE_TRACE_POINTS
#include <trace/events/nmi.h>
@@ -476,6 +477,12 @@ DEFINE_IDTENTRY_RAW(exc_nmi)
{
bool irq_state;
+ /*
+ * Re-enable NMIs right here when running as an SEV-ES guest. This might
+ * cause nested NMIs, but those can be handled safely.
+ */
+ sev_es_nmi_complete();
+
if (IS_ENABLED(CONFIG_SMP) && arch_cpu_is_offline(smp_processor_id()))
return;
@@ -487,6 +494,12 @@ DEFINE_IDTENTRY_RAW(exc_nmi)
this_cpu_write(nmi_cr2, read_cr2());
nmi_restart:
+ /*
+ * Needs to happen before DR7 is accessed, because the hypervisor can
+ * intercept DR7 reads/writes, turning those into #VC exceptions.
+ */
+ sev_es_ist_enter(regs);
+
this_cpu_write(nmi_dr7, local_db_save());
irq_state = idtentry_enter_nmi(regs);
@@ -500,6 +513,8 @@ nmi_restart:
local_db_restore(this_cpu_read(nmi_dr7));
+ sev_es_ist_exit();
+
if (unlikely(this_cpu_read(nmi_cr2) != read_cr2()))
write_cr2(this_cpu_read(nmi_cr2));
if (this_cpu_dec_return(nmi_state))
diff --git a/arch/x86/kernel/sev-es-shared.c b/arch/x86/kernel/sev-es-shared.c
new file mode 100644
index 000000000000..5f83ccaab877
--- /dev/null
+++ b/arch/x86/kernel/sev-es-shared.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Encrypted Register State Support
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ *
+ * This file is not compiled stand-alone. It contains code shared
+ * between the pre-decompression boot code and the running Linux kernel
+ * and is included directly into both code-bases.
+ */
+
+#ifndef __BOOT_COMPRESSED
+#define error(v) pr_err(v)
+#define has_cpuflag(f) boot_cpu_has(f)
+#endif
+
+static bool __init sev_es_check_cpu_features(void)
+{
+ if (!has_cpuflag(X86_FEATURE_RDRAND)) {
+ error("RDRAND instruction not supported - no trusted source of randomness available\n");
+ return false;
+ }
+
+ return true;
+}
+
+static void sev_es_terminate(unsigned int reason)
+{
+ u64 val = GHCB_SEV_TERMINATE;
+
+ /*
+ * Tell the hypervisor what went wrong - only reason-set 0 is
+ * currently supported.
+ */
+ val |= GHCB_SEV_TERMINATE_REASON(0, reason);
+
+ /* Request Guest Termination from Hypvervisor */
+ sev_es_wr_ghcb_msr(val);
+ VMGEXIT();
+
+ while (true)
+ asm volatile("hlt\n" : : : "memory");
+}
+
+static bool sev_es_negotiate_protocol(void)
+{
+ u64 val;
+
+ /* Do the GHCB protocol version negotiation */
+ sev_es_wr_ghcb_msr(GHCB_SEV_INFO_REQ);
+ VMGEXIT();
+ val = sev_es_rd_ghcb_msr();
+
+ if (GHCB_INFO(val) != GHCB_SEV_INFO)
+ return false;
+
+ if (GHCB_PROTO_MAX(val) < GHCB_PROTO_OUR ||
+ GHCB_PROTO_MIN(val) > GHCB_PROTO_OUR)
+ return false;
+
+ return true;
+}
+
+static __always_inline void vc_ghcb_invalidate(struct ghcb *ghcb)
+{
+ memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
+}
+
+static bool vc_decoding_needed(unsigned long exit_code)
+{
+ /* Exceptions don't require to decode the instruction */
+ return !(exit_code >= SVM_EXIT_EXCP_BASE &&
+ exit_code <= SVM_EXIT_LAST_EXCP);
+}
+
+static enum es_result vc_init_em_ctxt(struct es_em_ctxt *ctxt,
+ struct pt_regs *regs,
+ unsigned long exit_code)
+{
+ enum es_result ret = ES_OK;
+
+ memset(ctxt, 0, sizeof(*ctxt));
+ ctxt->regs = regs;
+
+ if (vc_decoding_needed(exit_code))
+ ret = vc_decode_insn(ctxt);
+
+ return ret;
+}
+
+static void vc_finish_insn(struct es_em_ctxt *ctxt)
+{
+ ctxt->regs->ip += ctxt->insn.length;
+}
+
+static enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2)
+{
+ enum es_result ret;
+
+ /* Fill in protocol and format specifiers */
+ ghcb->protocol_version = GHCB_PROTOCOL_MAX;
+ ghcb->ghcb_usage = GHCB_DEFAULT_USAGE;
+
+ ghcb_set_sw_exit_code(ghcb, exit_code);
+ ghcb_set_sw_exit_info_1(ghcb, exit_info_1);
+ ghcb_set_sw_exit_info_2(ghcb, exit_info_2);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ if ((ghcb->save.sw_exit_info_1 & 0xffffffff) == 1) {
+ u64 info = ghcb->save.sw_exit_info_2;
+ unsigned long v;
+
+ info = ghcb->save.sw_exit_info_2;
+ v = info & SVM_EVTINJ_VEC_MASK;
+
+ /* Check if exception information from hypervisor is sane. */
+ if ((info & SVM_EVTINJ_VALID) &&
+ ((v == X86_TRAP_GP) || (v == X86_TRAP_UD)) &&
+ ((info & SVM_EVTINJ_TYPE_MASK) == SVM_EVTINJ_TYPE_EXEPT)) {
+ ctxt->fi.vector = v;
+ if (info & SVM_EVTINJ_VALID_ERR)
+ ctxt->fi.error_code = info >> 32;
+ ret = ES_EXCEPTION;
+ } else {
+ ret = ES_VMM_ERROR;
+ }
+ } else {
+ ret = ES_OK;
+ }
+
+ return ret;
+}
+
+/*
+ * Boot VC Handler - This is the first VC handler during boot, there is no GHCB
+ * page yet, so it only supports the MSR based communication with the
+ * hypervisor and only the CPUID exit-code.
+ */
+void __init do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code)
+{
+ unsigned int fn = lower_bits(regs->ax, 32);
+ unsigned long val;
+
+ /* Only CPUID is supported via MSR protocol */
+ if (exit_code != SVM_EXIT_CPUID)
+ goto fail;
+
+ sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_EAX));
+ VMGEXIT();
+ val = sev_es_rd_ghcb_msr();
+ if (GHCB_SEV_GHCB_RESP_CODE(val) != GHCB_SEV_CPUID_RESP)
+ goto fail;
+ regs->ax = val >> 32;
+
+ sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_EBX));
+ VMGEXIT();
+ val = sev_es_rd_ghcb_msr();
+ if (GHCB_SEV_GHCB_RESP_CODE(val) != GHCB_SEV_CPUID_RESP)
+ goto fail;
+ regs->bx = val >> 32;
+
+ sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_ECX));
+ VMGEXIT();
+ val = sev_es_rd_ghcb_msr();
+ if (GHCB_SEV_GHCB_RESP_CODE(val) != GHCB_SEV_CPUID_RESP)
+ goto fail;
+ regs->cx = val >> 32;
+
+ sev_es_wr_ghcb_msr(GHCB_CPUID_REQ(fn, GHCB_CPUID_REQ_EDX));
+ VMGEXIT();
+ val = sev_es_rd_ghcb_msr();
+ if (GHCB_SEV_GHCB_RESP_CODE(val) != GHCB_SEV_CPUID_RESP)
+ goto fail;
+ regs->dx = val >> 32;
+
+ /* Skip over the CPUID two-byte opcode */
+ regs->ip += 2;
+
+ return;
+
+fail:
+ sev_es_wr_ghcb_msr(GHCB_SEV_TERMINATE);
+ VMGEXIT();
+
+ /* Shouldn't get here - if we do halt the machine */
+ while (true)
+ asm volatile("hlt\n");
+}
+
+static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
+ void *src, char *buf,
+ unsigned int data_size,
+ unsigned int count,
+ bool backwards)
+{
+ int i, b = backwards ? -1 : 1;
+ enum es_result ret = ES_OK;
+
+ for (i = 0; i < count; i++) {
+ void *s = src + (i * data_size * b);
+ char *d = buf + (i * data_size);
+
+ ret = vc_read_mem(ctxt, s, d, data_size);
+ if (ret != ES_OK)
+ break;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_insn_string_write(struct es_em_ctxt *ctxt,
+ void *dst, char *buf,
+ unsigned int data_size,
+ unsigned int count,
+ bool backwards)
+{
+ int i, s = backwards ? -1 : 1;
+ enum es_result ret = ES_OK;
+
+ for (i = 0; i < count; i++) {
+ void *d = dst + (i * data_size * s);
+ char *b = buf + (i * data_size);
+
+ ret = vc_write_mem(ctxt, d, b, data_size);
+ if (ret != ES_OK)
+ break;
+ }
+
+ return ret;
+}
+
+#define IOIO_TYPE_STR BIT(2)
+#define IOIO_TYPE_IN 1
+#define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR)
+#define IOIO_TYPE_OUT 0
+#define IOIO_TYPE_OUTS (IOIO_TYPE_OUT | IOIO_TYPE_STR)
+
+#define IOIO_REP BIT(3)
+
+#define IOIO_ADDR_64 BIT(9)
+#define IOIO_ADDR_32 BIT(8)
+#define IOIO_ADDR_16 BIT(7)
+
+#define IOIO_DATA_32 BIT(6)
+#define IOIO_DATA_16 BIT(5)
+#define IOIO_DATA_8 BIT(4)
+
+#define IOIO_SEG_ES (0 << 10)
+#define IOIO_SEG_DS (3 << 10)
+
+static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo)
+{
+ struct insn *insn = &ctxt->insn;
+ *exitinfo = 0;
+
+ switch (insn->opcode.bytes[0]) {
+ /* INS opcodes */
+ case 0x6c:
+ case 0x6d:
+ *exitinfo |= IOIO_TYPE_INS;
+ *exitinfo |= IOIO_SEG_ES;
+ *exitinfo |= (ctxt->regs->dx & 0xffff) << 16;
+ break;
+
+ /* OUTS opcodes */
+ case 0x6e:
+ case 0x6f:
+ *exitinfo |= IOIO_TYPE_OUTS;
+ *exitinfo |= IOIO_SEG_DS;
+ *exitinfo |= (ctxt->regs->dx & 0xffff) << 16;
+ break;
+
+ /* IN immediate opcodes */
+ case 0xe4:
+ case 0xe5:
+ *exitinfo |= IOIO_TYPE_IN;
+ *exitinfo |= (u64)insn->immediate.value << 16;
+ break;
+
+ /* OUT immediate opcodes */
+ case 0xe6:
+ case 0xe7:
+ *exitinfo |= IOIO_TYPE_OUT;
+ *exitinfo |= (u64)insn->immediate.value << 16;
+ break;
+
+ /* IN register opcodes */
+ case 0xec:
+ case 0xed:
+ *exitinfo |= IOIO_TYPE_IN;
+ *exitinfo |= (ctxt->regs->dx & 0xffff) << 16;
+ break;
+
+ /* OUT register opcodes */
+ case 0xee:
+ case 0xef:
+ *exitinfo |= IOIO_TYPE_OUT;
+ *exitinfo |= (ctxt->regs->dx & 0xffff) << 16;
+ break;
+
+ default:
+ return ES_DECODE_FAILED;
+ }
+
+ switch (insn->opcode.bytes[0]) {
+ case 0x6c:
+ case 0x6e:
+ case 0xe4:
+ case 0xe6:
+ case 0xec:
+ case 0xee:
+ /* Single byte opcodes */
+ *exitinfo |= IOIO_DATA_8;
+ break;
+ default:
+ /* Length determined by instruction parsing */
+ *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16
+ : IOIO_DATA_32;
+ }
+ switch (insn->addr_bytes) {
+ case 2:
+ *exitinfo |= IOIO_ADDR_16;
+ break;
+ case 4:
+ *exitinfo |= IOIO_ADDR_32;
+ break;
+ case 8:
+ *exitinfo |= IOIO_ADDR_64;
+ break;
+ }
+
+ if (insn_has_rep_prefix(insn))
+ *exitinfo |= IOIO_REP;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u64 exit_info_1, exit_info_2;
+ enum es_result ret;
+
+ ret = vc_ioio_exitinfo(ctxt, &exit_info_1);
+ if (ret != ES_OK)
+ return ret;
+
+ if (exit_info_1 & IOIO_TYPE_STR) {
+
+ /* (REP) INS/OUTS */
+
+ bool df = ((regs->flags & X86_EFLAGS_DF) == X86_EFLAGS_DF);
+ unsigned int io_bytes, exit_bytes;
+ unsigned int ghcb_count, op_count;
+ unsigned long es_base;
+ u64 sw_scratch;
+
+ /*
+ * For the string variants with rep prefix the amount of in/out
+ * operations per #VC exception is limited so that the kernel
+ * has a chance to take interrupts and re-schedule while the
+ * instruction is emulated.
+ */
+ io_bytes = (exit_info_1 >> 4) & 0x7;
+ ghcb_count = sizeof(ghcb->shared_buffer) / io_bytes;
+
+ op_count = (exit_info_1 & IOIO_REP) ? regs->cx : 1;
+ exit_info_2 = min(op_count, ghcb_count);
+ exit_bytes = exit_info_2 * io_bytes;
+
+ es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
+
+ /* Read bytes of OUTS into the shared buffer */
+ if (!(exit_info_1 & IOIO_TYPE_IN)) {
+ ret = vc_insn_string_read(ctxt,
+ (void *)(es_base + regs->si),
+ ghcb->shared_buffer, io_bytes,
+ exit_info_2, df);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Issue an VMGEXIT to the HV to consume the bytes from the
+ * shared buffer or to have it write them into the shared buffer
+ * depending on the instruction: OUTS or INS.
+ */
+ sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
+ ghcb_set_sw_scratch(ghcb, sw_scratch);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+ exit_info_1, exit_info_2);
+ if (ret != ES_OK)
+ return ret;
+
+ /* Read bytes from shared buffer into the guest's destination. */
+ if (exit_info_1 & IOIO_TYPE_IN) {
+ ret = vc_insn_string_write(ctxt,
+ (void *)(es_base + regs->di),
+ ghcb->shared_buffer, io_bytes,
+ exit_info_2, df);
+ if (ret)
+ return ret;
+
+ if (df)
+ regs->di -= exit_bytes;
+ else
+ regs->di += exit_bytes;
+ } else {
+ if (df)
+ regs->si -= exit_bytes;
+ else
+ regs->si += exit_bytes;
+ }
+
+ if (exit_info_1 & IOIO_REP)
+ regs->cx -= exit_info_2;
+
+ ret = regs->cx ? ES_RETRY : ES_OK;
+
+ } else {
+
+ /* IN/OUT into/from rAX */
+
+ int bits = (exit_info_1 & 0x70) >> 1;
+ u64 rax = 0;
+
+ if (!(exit_info_1 & IOIO_TYPE_IN))
+ rax = lower_bits(regs->ax, bits);
+
+ ghcb_set_rax(ghcb, rax);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (exit_info_1 & IOIO_TYPE_IN) {
+ if (!ghcb_rax_is_valid(ghcb))
+ return ES_VMM_ERROR;
+ regs->ax = lower_bits(ghcb->save.rax, bits);
+ }
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u32 cr4 = native_read_cr4();
+ enum es_result ret;
+
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rcx(ghcb, regs->cx);
+
+ if (cr4 & X86_CR4_OSXSAVE)
+ /* Safe to read xcr0 */
+ ghcb_set_xcr0(ghcb, xgetbv(XCR_XFEATURE_ENABLED_MASK));
+ else
+ /* xgetbv will cause #GP - use reset value for xcr0 */
+ ghcb_set_xcr0(ghcb, 1);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) &&
+ ghcb_rbx_is_valid(ghcb) &&
+ ghcb_rcx_is_valid(ghcb) &&
+ ghcb_rdx_is_valid(ghcb)))
+ return ES_VMM_ERROR;
+
+ regs->ax = ghcb->save.rax;
+ regs->bx = ghcb->save.rbx;
+ regs->cx = ghcb->save.rcx;
+ regs->dx = ghcb->save.rdx;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
+{
+ bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
+ enum es_result ret;
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) &&
+ (!rdtscp || ghcb_rcx_is_valid(ghcb))))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+ ctxt->regs->dx = ghcb->save.rdx;
+ if (rdtscp)
+ ctxt->regs->cx = ghcb->save.rcx;
+
+ return ES_OK;
+}
diff --git a/arch/x86/kernel/sev-es.c b/arch/x86/kernel/sev-es.c
new file mode 100644
index 000000000000..4a96726fbaf8
--- /dev/null
+++ b/arch/x86/kernel/sev-es.c
@@ -0,0 +1,1404 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#define pr_fmt(fmt) "SEV-ES: " fmt
+
+#include <linux/sched/debug.h> /* For show_regs() */
+#include <linux/percpu-defs.h>
+#include <linux/mem_encrypt.h>
+#include <linux/lockdep.h>
+#include <linux/printk.h>
+#include <linux/mm_types.h>
+#include <linux/set_memory.h>
+#include <linux/memblock.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include <asm/cpu_entry_area.h>
+#include <asm/stacktrace.h>
+#include <asm/sev-es.h>
+#include <asm/insn-eval.h>
+#include <asm/fpu/internal.h>
+#include <asm/processor.h>
+#include <asm/realmode.h>
+#include <asm/traps.h>
+#include <asm/svm.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+
+#define DR7_RESET_VALUE 0x400
+
+/* For early boot hypervisor communication in SEV-ES enabled guests */
+static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE);
+
+/*
+ * Needs to be in the .data section because we need it NULL before bss is
+ * cleared
+ */
+static struct ghcb __initdata *boot_ghcb;
+
+/* #VC handler runtime per-CPU data */
+struct sev_es_runtime_data {
+ struct ghcb ghcb_page;
+
+ /* Physical storage for the per-CPU IST stack of the #VC handler */
+ char ist_stack[EXCEPTION_STKSZ] __aligned(PAGE_SIZE);
+
+ /*
+ * Physical storage for the per-CPU fall-back stack of the #VC handler.
+ * The fall-back stack is used when it is not safe to switch back to the
+ * interrupted stack in the #VC entry code.
+ */
+ char fallback_stack[EXCEPTION_STKSZ] __aligned(PAGE_SIZE);
+
+ /*
+ * Reserve one page per CPU as backup storage for the unencrypted GHCB.
+ * It is needed when an NMI happens while the #VC handler uses the real
+ * GHCB, and the NMI handler itself is causing another #VC exception. In
+ * that case the GHCB content of the first handler needs to be backed up
+ * and restored.
+ */
+ struct ghcb backup_ghcb;
+
+ /*
+ * Mark the per-cpu GHCBs as in-use to detect nested #VC exceptions.
+ * There is no need for it to be atomic, because nothing is written to
+ * the GHCB between the read and the write of ghcb_active. So it is safe
+ * to use it when a nested #VC exception happens before the write.
+ *
+ * This is necessary for example in the #VC->NMI->#VC case when the NMI
+ * happens while the first #VC handler uses the GHCB. When the NMI code
+ * raises a second #VC handler it might overwrite the contents of the
+ * GHCB written by the first handler. To avoid this the content of the
+ * GHCB is saved and restored when the GHCB is detected to be in use
+ * already.
+ */
+ bool ghcb_active;
+ bool backup_ghcb_active;
+
+ /*
+ * Cached DR7 value - write it on DR7 writes and return it on reads.
+ * That value will never make it to the real hardware DR7 as debugging
+ * is currently unsupported in SEV-ES guests.
+ */
+ unsigned long dr7;
+};
+
+struct ghcb_state {
+ struct ghcb *ghcb;
+};
+
+static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
+DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
+
+/* Needed in vc_early_forward_exception */
+void do_early_exception(struct pt_regs *regs, int trapnr);
+
+static void __init setup_vc_stacks(int cpu)
+{
+ struct sev_es_runtime_data *data;
+ struct cpu_entry_area *cea;
+ unsigned long vaddr;
+ phys_addr_t pa;
+
+ data = per_cpu(runtime_data, cpu);
+ cea = get_cpu_entry_area(cpu);
+
+ /* Map #VC IST stack */
+ vaddr = CEA_ESTACK_BOT(&cea->estacks, VC);
+ pa = __pa(data->ist_stack);
+ cea_set_pte((void *)vaddr, pa, PAGE_KERNEL);
+
+ /* Map VC fall-back stack */
+ vaddr = CEA_ESTACK_BOT(&cea->estacks, VC2);
+ pa = __pa(data->fallback_stack);
+ cea_set_pte((void *)vaddr, pa, PAGE_KERNEL);
+}
+
+static __always_inline bool on_vc_stack(unsigned long sp)
+{
+ return ((sp >= __this_cpu_ist_bottom_va(VC)) && (sp < __this_cpu_ist_top_va(VC)));
+}
+
+/*
+ * This function handles the case when an NMI is raised in the #VC exception
+ * handler entry code. In this case, the IST entry for #VC must be adjusted, so
+ * that any subsequent #VC exception will not overwrite the stack contents of the
+ * interrupted #VC handler.
+ *
+ * The IST entry is adjusted unconditionally so that it can be also be
+ * unconditionally adjusted back in sev_es_ist_exit(). Otherwise a nested
+ * sev_es_ist_exit() call may adjust back the IST entry too early.
+ */
+void noinstr __sev_es_ist_enter(struct pt_regs *regs)
+{
+ unsigned long old_ist, new_ist;
+
+ /* Read old IST entry */
+ old_ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
+
+ /* Make room on the IST stack */
+ if (on_vc_stack(regs->sp))
+ new_ist = ALIGN_DOWN(regs->sp, 8) - sizeof(old_ist);
+ else
+ new_ist = old_ist - sizeof(old_ist);
+
+ /* Store old IST entry */
+ *(unsigned long *)new_ist = old_ist;
+
+ /* Set new IST entry */
+ this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], new_ist);
+}
+
+void noinstr __sev_es_ist_exit(void)
+{
+ unsigned long ist;
+
+ /* Read IST entry */
+ ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
+
+ if (WARN_ON(ist == __this_cpu_ist_top_va(VC)))
+ return;
+
+ /* Read back old IST entry and write it to the TSS */
+ this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], *(unsigned long *)ist);
+}
+
+static __always_inline struct ghcb *sev_es_get_ghcb(struct ghcb_state *state)
+{
+ struct sev_es_runtime_data *data;
+ struct ghcb *ghcb;
+
+ data = this_cpu_read(runtime_data);
+ ghcb = &data->ghcb_page;
+
+ if (unlikely(data->ghcb_active)) {
+ /* GHCB is already in use - save its contents */
+
+ if (unlikely(data->backup_ghcb_active))
+ return NULL;
+
+ /* Mark backup_ghcb active before writing to it */
+ data->backup_ghcb_active = true;
+
+ state->ghcb = &data->backup_ghcb;
+
+ /* Backup GHCB content */
+ *state->ghcb = *ghcb;
+ } else {
+ state->ghcb = NULL;
+ data->ghcb_active = true;
+ }
+
+ return ghcb;
+}
+
+static __always_inline void sev_es_put_ghcb(struct ghcb_state *state)
+{
+ struct sev_es_runtime_data *data;
+ struct ghcb *ghcb;
+
+ data = this_cpu_read(runtime_data);
+ ghcb = &data->ghcb_page;
+
+ if (state->ghcb) {
+ /* Restore GHCB from Backup */
+ *ghcb = *state->ghcb;
+ data->backup_ghcb_active = false;
+ state->ghcb = NULL;
+ } else {
+ data->ghcb_active = false;
+ }
+}
+
+/* Needed in vc_early_forward_exception */
+void do_early_exception(struct pt_regs *regs, int trapnr);
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+ return __rdmsr(MSR_AMD64_SEV_ES_GHCB);
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+ u32 low, high;
+
+ low = (u32)(val);
+ high = (u32)(val >> 32);
+
+ native_wrmsr(MSR_AMD64_SEV_ES_GHCB, low, high);
+}
+
+static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
+ unsigned char *buffer)
+{
+ return copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
+}
+
+static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+ char buffer[MAX_INSN_SIZE];
+ enum es_result ret;
+ int res;
+
+ if (user_mode(ctxt->regs)) {
+ res = insn_fetch_from_user(ctxt->regs, buffer);
+ if (!res) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER;
+ ctxt->fi.cr2 = ctxt->regs->ip;
+ return ES_EXCEPTION;
+ }
+
+ if (!insn_decode(&ctxt->insn, ctxt->regs, buffer, res))
+ return ES_DECODE_FAILED;
+ } else {
+ res = vc_fetch_insn_kernel(ctxt, buffer);
+ if (res) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_INSTR;
+ ctxt->fi.cr2 = ctxt->regs->ip;
+ return ES_EXCEPTION;
+ }
+
+ insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1);
+ insn_get_length(&ctxt->insn);
+ }
+
+ ret = ctxt->insn.immediate.got ? ES_OK : ES_DECODE_FAILED;
+
+ return ret;
+}
+
+static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
+ char *dst, char *buf, size_t size)
+{
+ unsigned long error_code = X86_PF_PROT | X86_PF_WRITE;
+ char __user *target = (char __user *)dst;
+ u64 d8;
+ u32 d4;
+ u16 d2;
+ u8 d1;
+
+ switch (size) {
+ case 1:
+ memcpy(&d1, buf, 1);
+ if (put_user(d1, target))
+ goto fault;
+ break;
+ case 2:
+ memcpy(&d2, buf, 2);
+ if (put_user(d2, target))
+ goto fault;
+ break;
+ case 4:
+ memcpy(&d4, buf, 4);
+ if (put_user(d4, target))
+ goto fault;
+ break;
+ case 8:
+ memcpy(&d8, buf, 8);
+ if (put_user(d8, target))
+ goto fault;
+ break;
+ default:
+ WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
+ return ES_UNSUPPORTED;
+ }
+
+ return ES_OK;
+
+fault:
+ if (user_mode(ctxt->regs))
+ error_code |= X86_PF_USER;
+
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = error_code;
+ ctxt->fi.cr2 = (unsigned long)dst;
+
+ return ES_EXCEPTION;
+}
+
+static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
+ char *src, char *buf, size_t size)
+{
+ unsigned long error_code = X86_PF_PROT;
+ char __user *s = (char __user *)src;
+ u64 d8;
+ u32 d4;
+ u16 d2;
+ u8 d1;
+
+ switch (size) {
+ case 1:
+ if (get_user(d1, s))
+ goto fault;
+ memcpy(buf, &d1, 1);
+ break;
+ case 2:
+ if (get_user(d2, s))
+ goto fault;
+ memcpy(buf, &d2, 2);
+ break;
+ case 4:
+ if (get_user(d4, s))
+ goto fault;
+ memcpy(buf, &d4, 4);
+ break;
+ case 8:
+ if (get_user(d8, s))
+ goto fault;
+ memcpy(buf, &d8, 8);
+ break;
+ default:
+ WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
+ return ES_UNSUPPORTED;
+ }
+
+ return ES_OK;
+
+fault:
+ if (user_mode(ctxt->regs))
+ error_code |= X86_PF_USER;
+
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = error_code;
+ ctxt->fi.cr2 = (unsigned long)src;
+
+ return ES_EXCEPTION;
+}
+
+static bool vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
+ unsigned long vaddr, phys_addr_t *paddr)
+{
+ unsigned long va = (unsigned long)vaddr;
+ unsigned int level;
+ phys_addr_t pa;
+ pgd_t *pgd;
+ pte_t *pte;
+
+ pgd = __va(read_cr3_pa());
+ pgd = &pgd[pgd_index(va)];
+ pte = lookup_address_in_pgd(pgd, va, &level);
+ if (!pte) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.cr2 = vaddr;
+ ctxt->fi.error_code = 0;
+
+ if (user_mode(ctxt->regs))
+ ctxt->fi.error_code |= X86_PF_USER;
+
+ return false;
+ }
+
+ pa = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
+ pa |= va & ~page_level_mask(level);
+
+ *paddr = pa;
+
+ return true;
+}
+
+/* Include code shared with pre-decompression boot stage */
+#include "sev-es-shared.c"
+
+void noinstr __sev_es_nmi_complete(void)
+{
+ struct ghcb_state state;
+ struct ghcb *ghcb;
+
+ ghcb = sev_es_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_NMI_COMPLETE);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa_nodebug(ghcb));
+ VMGEXIT();
+
+ sev_es_put_ghcb(&state);
+}
+
+static u64 get_jump_table_addr(void)
+{
+ struct ghcb_state state;
+ unsigned long flags;
+ struct ghcb *ghcb;
+ u64 ret = 0;
+
+ local_irq_save(flags);
+
+ ghcb = sev_es_get_ghcb(&state);
+
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_JUMP_TABLE);
+ ghcb_set_sw_exit_info_1(ghcb, SVM_VMGEXIT_GET_AP_JUMP_TABLE);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ if (ghcb_sw_exit_info_1_is_valid(ghcb) &&
+ ghcb_sw_exit_info_2_is_valid(ghcb))
+ ret = ghcb->save.sw_exit_info_2;
+
+ sev_es_put_ghcb(&state);
+
+ local_irq_restore(flags);
+
+ return ret;
+}
+
+int sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
+{
+ u16 startup_cs, startup_ip;
+ phys_addr_t jump_table_pa;
+ u64 jump_table_addr;
+ u16 __iomem *jump_table;
+
+ jump_table_addr = get_jump_table_addr();
+
+ /* On UP guests there is no jump table so this is not a failure */
+ if (!jump_table_addr)
+ return 0;
+
+ /* Check if AP Jump Table is page-aligned */
+ if (jump_table_addr & ~PAGE_MASK)
+ return -EINVAL;
+
+ jump_table_pa = jump_table_addr & PAGE_MASK;
+
+ startup_cs = (u16)(rmh->trampoline_start >> 4);
+ startup_ip = (u16)(rmh->sev_es_trampoline_start -
+ rmh->trampoline_start);
+
+ jump_table = ioremap_encrypted(jump_table_pa, PAGE_SIZE);
+ if (!jump_table)
+ return -EIO;
+
+ writew(startup_ip, &jump_table[0]);
+ writew(startup_cs, &jump_table[1]);
+
+ iounmap(jump_table);
+
+ return 0;
+}
+
+/*
+ * This is needed by the OVMF UEFI firmware which will use whatever it finds in
+ * the GHCB MSR as its GHCB to talk to the hypervisor. So make sure the per-cpu
+ * runtime GHCBs used by the kernel are also mapped in the EFI page-table.
+ */
+int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
+{
+ struct sev_es_runtime_data *data;
+ unsigned long address, pflags;
+ int cpu;
+ u64 pfn;
+
+ if (!sev_es_active())
+ return 0;
+
+ pflags = _PAGE_NX | _PAGE_RW;
+
+ for_each_possible_cpu(cpu) {
+ data = per_cpu(runtime_data, cpu);
+
+ address = __pa(&data->ghcb_page);
+ pfn = address >> PAGE_SHIFT;
+
+ if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags))
+ return 1;
+ }
+
+ return 0;
+}
+
+static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ enum es_result ret;
+ u64 exit_info_1;
+
+ /* Is it a WRMSR? */
+ exit_info_1 = (ctxt->insn.opcode.bytes[1] == 0x30) ? 1 : 0;
+
+ ghcb_set_rcx(ghcb, regs->cx);
+ if (exit_info_1) {
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rdx(ghcb, regs->dx);
+ }
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+
+ if ((ret == ES_OK) && (!exit_info_1)) {
+ regs->ax = ghcb->save.rax;
+ regs->dx = ghcb->save.rdx;
+ }
+
+ return ret;
+}
+
+/*
+ * This function runs on the first #VC exception after the kernel
+ * switched to virtual addresses.
+ */
+static bool __init sev_es_setup_ghcb(void)
+{
+ /* First make sure the hypervisor talks a supported protocol. */
+ if (!sev_es_negotiate_protocol())
+ return false;
+
+ /*
+ * Clear the boot_ghcb. The first exception comes in before the bss
+ * section is cleared.
+ */
+ memset(&boot_ghcb_page, 0, PAGE_SIZE);
+
+ /* Alright - Make the boot-ghcb public */
+ boot_ghcb = &boot_ghcb_page;
+
+ return true;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void sev_es_ap_hlt_loop(void)
+{
+ struct ghcb_state state;
+ struct ghcb *ghcb;
+
+ ghcb = sev_es_get_ghcb(&state);
+
+ while (true) {
+ vc_ghcb_invalidate(ghcb);
+ ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_HLT_LOOP);
+ ghcb_set_sw_exit_info_1(ghcb, 0);
+ ghcb_set_sw_exit_info_2(ghcb, 0);
+
+ sev_es_wr_ghcb_msr(__pa(ghcb));
+ VMGEXIT();
+
+ /* Wakeup signal? */
+ if (ghcb_sw_exit_info_2_is_valid(ghcb) &&
+ ghcb->save.sw_exit_info_2)
+ break;
+ }
+
+ sev_es_put_ghcb(&state);
+}
+
+/*
+ * Play_dead handler when running under SEV-ES. This is needed because
+ * the hypervisor can't deliver an SIPI request to restart the AP.
+ * Instead the kernel has to issue a VMGEXIT to halt the VCPU until the
+ * hypervisor wakes it up again.
+ */
+static void sev_es_play_dead(void)
+{
+ play_dead_common();
+
+ /* IRQs now disabled */
+
+ sev_es_ap_hlt_loop();
+
+ /*
+ * If we get here, the VCPU was woken up again. Jump to CPU
+ * startup code to get it back online.
+ */
+ start_cpu0();
+}
+#else /* CONFIG_HOTPLUG_CPU */
+#define sev_es_play_dead native_play_dead
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#ifdef CONFIG_SMP
+static void __init sev_es_setup_play_dead(void)
+{
+ smp_ops.play_dead = sev_es_play_dead;
+}
+#else
+static inline void sev_es_setup_play_dead(void) { }
+#endif
+
+static void __init alloc_runtime_data(int cpu)
+{
+ struct sev_es_runtime_data *data;
+
+ data = memblock_alloc(sizeof(*data), PAGE_SIZE);
+ if (!data)
+ panic("Can't allocate SEV-ES runtime data");
+
+ per_cpu(runtime_data, cpu) = data;
+}
+
+static void __init init_ghcb(int cpu)
+{
+ struct sev_es_runtime_data *data;
+ int err;
+
+ data = per_cpu(runtime_data, cpu);
+
+ err = early_set_memory_decrypted((unsigned long)&data->ghcb_page,
+ sizeof(data->ghcb_page));
+ if (err)
+ panic("Can't map GHCBs unencrypted");
+
+ memset(&data->ghcb_page, 0, sizeof(data->ghcb_page));
+
+ data->ghcb_active = false;
+ data->backup_ghcb_active = false;
+}
+
+void __init sev_es_init_vc_handling(void)
+{
+ int cpu;
+
+ BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
+
+ if (!sev_es_active())
+ return;
+
+ if (!sev_es_check_cpu_features())
+ panic("SEV-ES CPU Features missing");
+
+ /* Enable SEV-ES special handling */
+ static_branch_enable(&sev_es_enable_key);
+
+ /* Initialize per-cpu GHCB pages */
+ for_each_possible_cpu(cpu) {
+ alloc_runtime_data(cpu);
+ init_ghcb(cpu);
+ setup_vc_stacks(cpu);
+ }
+
+ sev_es_setup_play_dead();
+
+ /* Secondary CPUs use the runtime #VC handler */
+ initial_vc_handler = (unsigned long)safe_stack_exc_vmm_communication;
+}
+
+static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt)
+{
+ int trapnr = ctxt->fi.vector;
+
+ if (trapnr == X86_TRAP_PF)
+ native_write_cr2(ctxt->fi.cr2);
+
+ ctxt->regs->orig_ax = ctxt->fi.error_code;
+ do_early_exception(ctxt->regs, trapnr);
+}
+
+static long *vc_insn_get_reg(struct es_em_ctxt *ctxt)
+{
+ long *reg_array;
+ int offset;
+
+ reg_array = (long *)ctxt->regs;
+ offset = insn_get_modrm_reg_off(&ctxt->insn, ctxt->regs);
+
+ if (offset < 0)
+ return NULL;
+
+ offset /= sizeof(long);
+
+ return reg_array + offset;
+}
+
+static long *vc_insn_get_rm(struct es_em_ctxt *ctxt)
+{
+ long *reg_array;
+ int offset;
+
+ reg_array = (long *)ctxt->regs;
+ offset = insn_get_modrm_rm_off(&ctxt->insn, ctxt->regs);
+
+ if (offset < 0)
+ return NULL;
+
+ offset /= sizeof(long);
+
+ return reg_array + offset;
+}
+static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
+ unsigned int bytes, bool read)
+{
+ u64 exit_code, exit_info_1, exit_info_2;
+ unsigned long ghcb_pa = __pa(ghcb);
+ phys_addr_t paddr;
+ void __user *ref;
+
+ ref = insn_get_addr_ref(&ctxt->insn, ctxt->regs);
+ if (ref == (void __user *)-1L)
+ return ES_UNSUPPORTED;
+
+ exit_code = read ? SVM_VMGEXIT_MMIO_READ : SVM_VMGEXIT_MMIO_WRITE;
+
+ if (!vc_slow_virt_to_phys(ghcb, ctxt, (unsigned long)ref, &paddr)) {
+ if (!read)
+ ctxt->fi.error_code |= X86_PF_WRITE;
+
+ return ES_EXCEPTION;
+ }
+
+ exit_info_1 = paddr;
+ /* Can never be greater than 8 */
+ exit_info_2 = bytes;
+
+ ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
+
+ return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+}
+
+static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct insn *insn = &ctxt->insn;
+ unsigned int bytes = 0;
+ enum es_result ret;
+ int sign_byte;
+ long *reg_data;
+
+ switch (insn->opcode.bytes[1]) {
+ /* MMIO Read w/ zero-extension */
+ case 0xb6:
+ bytes = 1;
+ fallthrough;
+ case 0xb7:
+ if (!bytes)
+ bytes = 2;
+
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ /* Zero extend based on operand size */
+ reg_data = vc_insn_get_reg(ctxt);
+ if (!reg_data)
+ return ES_DECODE_FAILED;
+
+ memset(reg_data, 0, insn->opnd_bytes);
+
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+
+ /* MMIO Read w/ sign-extension */
+ case 0xbe:
+ bytes = 1;
+ fallthrough;
+ case 0xbf:
+ if (!bytes)
+ bytes = 2;
+
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ /* Sign extend based on operand size */
+ reg_data = vc_insn_get_reg(ctxt);
+ if (!reg_data)
+ return ES_DECODE_FAILED;
+
+ if (bytes == 1) {
+ u8 *val = (u8 *)ghcb->shared_buffer;
+
+ sign_byte = (*val & 0x80) ? 0xff : 0x00;
+ } else {
+ u16 *val = (u16 *)ghcb->shared_buffer;
+
+ sign_byte = (*val & 0x8000) ? 0xff : 0x00;
+ }
+ memset(reg_data, sign_byte, insn->opnd_bytes);
+
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+
+ default:
+ ret = ES_UNSUPPORTED;
+ }
+
+ return ret;
+}
+
+/*
+ * The MOVS instruction has two memory operands, which raises the
+ * problem that it is not known whether the access to the source or the
+ * destination caused the #VC exception (and hence whether an MMIO read
+ * or write operation needs to be emulated).
+ *
+ * Instead of playing games with walking page-tables and trying to guess
+ * whether the source or destination is an MMIO range, split the move
+ * into two operations, a read and a write with only one memory operand.
+ * This will cause a nested #VC exception on the MMIO address which can
+ * then be handled.
+ *
+ * This implementation has the benefit that it also supports MOVS where
+ * source _and_ destination are MMIO regions.
+ *
+ * It will slow MOVS on MMIO down a lot, but in SEV-ES guests it is a
+ * rare operation. If it turns out to be a performance problem the split
+ * operations can be moved to memcpy_fromio() and memcpy_toio().
+ */
+static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt,
+ unsigned int bytes)
+{
+ unsigned long ds_base, es_base;
+ unsigned char *src, *dst;
+ unsigned char buffer[8];
+ enum es_result ret;
+ bool rep;
+ int off;
+
+ ds_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_DS);
+ es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
+
+ if (ds_base == -1L || es_base == -1L) {
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+ }
+
+ src = ds_base + (unsigned char *)ctxt->regs->si;
+ dst = es_base + (unsigned char *)ctxt->regs->di;
+
+ ret = vc_read_mem(ctxt, src, buffer, bytes);
+ if (ret != ES_OK)
+ return ret;
+
+ ret = vc_write_mem(ctxt, dst, buffer, bytes);
+ if (ret != ES_OK)
+ return ret;
+
+ if (ctxt->regs->flags & X86_EFLAGS_DF)
+ off = -bytes;
+ else
+ off = bytes;
+
+ ctxt->regs->si += off;
+ ctxt->regs->di += off;
+
+ rep = insn_has_rep_prefix(&ctxt->insn);
+ if (rep)
+ ctxt->regs->cx -= 1;
+
+ if (!rep || ctxt->regs->cx == 0)
+ return ES_OK;
+ else
+ return ES_RETRY;
+}
+
+static enum es_result vc_handle_mmio(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct insn *insn = &ctxt->insn;
+ unsigned int bytes = 0;
+ enum es_result ret;
+ long *reg_data;
+
+ switch (insn->opcode.bytes[0]) {
+ /* MMIO Write */
+ case 0x88:
+ bytes = 1;
+ fallthrough;
+ case 0x89:
+ if (!bytes)
+ bytes = insn->opnd_bytes;
+
+ reg_data = vc_insn_get_reg(ctxt);
+ if (!reg_data)
+ return ES_DECODE_FAILED;
+
+ memcpy(ghcb->shared_buffer, reg_data, bytes);
+
+ ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+ break;
+
+ case 0xc6:
+ bytes = 1;
+ fallthrough;
+ case 0xc7:
+ if (!bytes)
+ bytes = insn->opnd_bytes;
+
+ memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);
+
+ ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+ break;
+
+ /* MMIO Read */
+ case 0x8a:
+ bytes = 1;
+ fallthrough;
+ case 0x8b:
+ if (!bytes)
+ bytes = insn->opnd_bytes;
+
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ reg_data = vc_insn_get_reg(ctxt);
+ if (!reg_data)
+ return ES_DECODE_FAILED;
+
+ /* Zero-extend for 32-bit operation */
+ if (bytes == 4)
+ *reg_data = 0;
+
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+
+ /* MOVS instruction */
+ case 0xa4:
+ bytes = 1;
+ fallthrough;
+ case 0xa5:
+ if (!bytes)
+ bytes = insn->opnd_bytes;
+
+ ret = vc_handle_mmio_movs(ctxt, bytes);
+ break;
+ /* Two-Byte Opcodes */
+ case 0x0f:
+ ret = vc_handle_mmio_twobyte_ops(ghcb, ctxt);
+ break;
+ default:
+ ret = ES_UNSUPPORTED;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+ long val, *reg = vc_insn_get_rm(ctxt);
+ enum es_result ret;
+
+ if (!reg)
+ return ES_DECODE_FAILED;
+
+ val = *reg;
+
+ /* Upper 32 bits must be written as zeroes */
+ if (val >> 32) {
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+ }
+
+ /* Clear out other reserved bits and set bit 10 */
+ val = (val & 0xffff23ffL) | BIT(10);
+
+ /* Early non-zero writes to DR7 are not supported */
+ if (!data && (val & ~DR7_RESET_VALUE))
+ return ES_UNSUPPORTED;
+
+ /* Using a value of 0 for ExitInfo1 means RAX holds the value */
+ ghcb_set_rax(ghcb, val);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (data)
+ data->dr7 = val;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+ long *reg = vc_insn_get_rm(ctxt);
+
+ if (!reg)
+ return ES_DECODE_FAILED;
+
+ if (data)
+ *reg = data->dr7;
+ else
+ *reg = DR7_RESET_VALUE;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+}
+
+static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ enum es_result ret;
+
+ ghcb_set_rcx(ghcb, ctxt->regs->cx);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb)))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+ ctxt->regs->dx = ghcb->save.rdx;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_monitor(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /*
+ * Treat it as a NOP and do not leak a physical address to the
+ * hypervisor.
+ */
+ return ES_OK;
+}
+
+static enum es_result vc_handle_mwait(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /* Treat the same as MONITOR/MONITORX */
+ return ES_OK;
+}
+
+static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ enum es_result ret;
+
+ ghcb_set_rax(ghcb, ctxt->regs->ax);
+ ghcb_set_cpl(ghcb, user_mode(ctxt->regs) ? 3 : 0);
+
+ if (x86_platform.hyper.sev_es_hcall_prepare)
+ x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!ghcb_rax_is_valid(ghcb))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+
+ /*
+ * Call sev_es_hcall_finish() after regs->ax is already set.
+ * This allows the hypervisor handler to overwrite it again if
+ * necessary.
+ */
+ if (x86_platform.hyper.sev_es_hcall_finish &&
+ !x86_platform.hyper.sev_es_hcall_finish(ghcb, ctxt->regs))
+ return ES_VMM_ERROR;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_trap_ac(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ /*
+ * Calling ecx_alignment_check() directly does not work, because it
+ * enables IRQs and the GHCB is active. Forward the exception and call
+ * it later from vc_forward_exception().
+ */
+ ctxt->fi.vector = X86_TRAP_AC;
+ ctxt->fi.error_code = 0;
+ return ES_EXCEPTION;
+}
+
+static __always_inline void vc_handle_trap_db(struct pt_regs *regs)
+{
+ if (user_mode(regs))
+ noist_exc_debug(regs);
+ else
+ exc_debug(regs);
+}
+
+static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
+ struct ghcb *ghcb,
+ unsigned long exit_code)
+{
+ enum es_result result;
+
+ switch (exit_code) {
+ case SVM_EXIT_READ_DR7:
+ result = vc_handle_dr7_read(ghcb, ctxt);
+ break;
+ case SVM_EXIT_WRITE_DR7:
+ result = vc_handle_dr7_write(ghcb, ctxt);
+ break;
+ case SVM_EXIT_EXCP_BASE + X86_TRAP_AC:
+ result = vc_handle_trap_ac(ghcb, ctxt);
+ break;
+ case SVM_EXIT_RDTSC:
+ case SVM_EXIT_RDTSCP:
+ result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
+ break;
+ case SVM_EXIT_RDPMC:
+ result = vc_handle_rdpmc(ghcb, ctxt);
+ break;
+ case SVM_EXIT_INVD:
+ pr_err_ratelimited("#VC exception for INVD??? Seriously???\n");
+ result = ES_UNSUPPORTED;
+ break;
+ case SVM_EXIT_CPUID:
+ result = vc_handle_cpuid(ghcb, ctxt);
+ break;
+ case SVM_EXIT_IOIO:
+ result = vc_handle_ioio(ghcb, ctxt);
+ break;
+ case SVM_EXIT_MSR:
+ result = vc_handle_msr(ghcb, ctxt);
+ break;
+ case SVM_EXIT_VMMCALL:
+ result = vc_handle_vmmcall(ghcb, ctxt);
+ break;
+ case SVM_EXIT_WBINVD:
+ result = vc_handle_wbinvd(ghcb, ctxt);
+ break;
+ case SVM_EXIT_MONITOR:
+ result = vc_handle_monitor(ghcb, ctxt);
+ break;
+ case SVM_EXIT_MWAIT:
+ result = vc_handle_mwait(ghcb, ctxt);
+ break;
+ case SVM_EXIT_NPF:
+ result = vc_handle_mmio(ghcb, ctxt);
+ break;
+ default:
+ /*
+ * Unexpected #VC exception
+ */
+ result = ES_UNSUPPORTED;
+ }
+
+ return result;
+}
+
+static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
+{
+ long error_code = ctxt->fi.error_code;
+ int trapnr = ctxt->fi.vector;
+
+ ctxt->regs->orig_ax = ctxt->fi.error_code;
+
+ switch (trapnr) {
+ case X86_TRAP_GP:
+ exc_general_protection(ctxt->regs, error_code);
+ break;
+ case X86_TRAP_UD:
+ exc_invalid_op(ctxt->regs);
+ break;
+ case X86_TRAP_AC:
+ exc_alignment_check(ctxt->regs, error_code);
+ break;
+ default:
+ pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
+ BUG();
+ }
+}
+
+static __always_inline bool on_vc_fallback_stack(struct pt_regs *regs)
+{
+ unsigned long sp = (unsigned long)regs;
+
+ return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
+}
+
+/*
+ * Main #VC exception handler. It is called when the entry code was able to
+ * switch off the IST to a safe kernel stack.
+ *
+ * With the current implementation it is always possible to switch to a safe
+ * stack because #VC exceptions only happen at known places, like intercepted
+ * instructions or accesses to MMIO areas/IO ports. They can also happen with
+ * code instrumentation when the hypervisor intercepts #DB, but the critical
+ * paths are forbidden to be instrumented, so #DB exceptions currently also
+ * only happen in safe places.
+ */
+DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)
+{
+ struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+ struct ghcb_state state;
+ struct es_em_ctxt ctxt;
+ enum es_result result;
+ struct ghcb *ghcb;
+
+ lockdep_assert_irqs_disabled();
+
+ /*
+ * Handle #DB before calling into !noinstr code to avoid recursive #DB.
+ */
+ if (error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB) {
+ vc_handle_trap_db(regs);
+ return;
+ }
+
+ instrumentation_begin();
+
+ /*
+ * This is invoked through an interrupt gate, so IRQs are disabled. The
+ * code below might walk page-tables for user or kernel addresses, so
+ * keep the IRQs disabled to protect us against concurrent TLB flushes.
+ */
+
+ ghcb = sev_es_get_ghcb(&state);
+ if (!ghcb) {
+ /*
+ * Mark GHCBs inactive so that panic() is able to print the
+ * message.
+ */
+ data->ghcb_active = false;
+ data->backup_ghcb_active = false;
+
+ panic("Unable to handle #VC exception! GHCB and Backup GHCB are already in use");
+ }
+
+ vc_ghcb_invalidate(ghcb);
+ result = vc_init_em_ctxt(&ctxt, regs, error_code);
+
+ if (result == ES_OK)
+ result = vc_handle_exitcode(&ctxt, ghcb, error_code);
+
+ sev_es_put_ghcb(&state);
+
+ /* Done - now check the result */
+ switch (result) {
+ case ES_OK:
+ vc_finish_insn(&ctxt);
+ break;
+ case ES_UNSUPPORTED:
+ pr_err_ratelimited("Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
+ error_code, regs->ip);
+ goto fail;
+ case ES_VMM_ERROR:
+ pr_err_ratelimited("Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+ error_code, regs->ip);
+ goto fail;
+ case ES_DECODE_FAILED:
+ pr_err_ratelimited("Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+ error_code, regs->ip);
+ goto fail;
+ case ES_EXCEPTION:
+ vc_forward_exception(&ctxt);
+ break;
+ case ES_RETRY:
+ /* Nothing to do */
+ break;
+ default:
+ pr_emerg("Unknown result in %s():%d\n", __func__, result);
+ /*
+ * Emulating the instruction which caused the #VC exception
+ * failed - can't continue so print debug information
+ */
+ BUG();
+ }
+
+out:
+ instrumentation_end();
+
+ return;
+
+fail:
+ if (user_mode(regs)) {
+ /*
+ * Do not kill the machine if user-space triggered the
+ * exception. Send SIGBUS instead and let user-space deal with
+ * it.
+ */
+ force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)0);
+ } else {
+ pr_emerg("PANIC: Unhandled #VC exception in kernel space (result=%d)\n",
+ result);
+
+ /* Show some debug info */
+ show_regs(regs);
+
+ /* Ask hypervisor to sev_es_terminate */
+ sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+
+ /* If that fails and we get here - just panic */
+ panic("Returned from Terminate-Request to Hypervisor\n");
+ }
+
+ goto out;
+}
+
+/* This handler runs on the #VC fall-back stack. It can cause further #VC exceptions */
+DEFINE_IDTENTRY_VC_IST(exc_vmm_communication)
+{
+ instrumentation_begin();
+ panic("Can't handle #VC exception from unsupported context\n");
+ instrumentation_end();
+}
+
+DEFINE_IDTENTRY_VC(exc_vmm_communication)
+{
+ if (likely(!on_vc_fallback_stack(regs)))
+ safe_stack_exc_vmm_communication(regs, error_code);
+ else
+ ist_exc_vmm_communication(regs, error_code);
+}
+
+bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
+{
+ unsigned long exit_code = regs->orig_ax;
+ struct es_em_ctxt ctxt;
+ enum es_result result;
+
+ /* Do initial setup or terminate the guest */
+ if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb()))
+ sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+
+ vc_ghcb_invalidate(boot_ghcb);
+
+ result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+ if (result == ES_OK)
+ result = vc_handle_exitcode(&ctxt, boot_ghcb, exit_code);
+
+ /* Done - now check the result */
+ switch (result) {
+ case ES_OK:
+ vc_finish_insn(&ctxt);
+ break;
+ case ES_UNSUPPORTED:
+ early_printk("PANIC: Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_VMM_ERROR:
+ early_printk("PANIC: Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_DECODE_FAILED:
+ early_printk("PANIC: Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+ exit_code, regs->ip);
+ goto fail;
+ case ES_EXCEPTION:
+ vc_early_forward_exception(&ctxt);
+ break;
+ case ES_RETRY:
+ /* Nothing to do */
+ break;
+ default:
+ BUG();
+ }
+
+ return true;
+
+fail:
+ show_regs(regs);
+
+ while (true)
+ halt();
+}
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f5ef689dd62a..de776b2e6046 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -227,7 +227,7 @@ static void notrace start_secondary(void *unused)
load_cr3(swapper_pg_dir);
__flush_tlb_all();
#endif
- load_current_idt();
+ cpu_init_exception_handling();
cpu_init();
x86_cpuinit.early_percpu_clock_init();
preempt_disable();
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index ec3a2572843f..3c70fb34028b 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -43,6 +43,7 @@
#include <asm/stacktrace.h>
#include <asm/processor.h>
#include <asm/debugreg.h>
+#include <asm/realmode.h>
#include <asm/text-patching.h>
#include <asm/ftrace.h>
#include <asm/traps.h>
@@ -673,6 +674,50 @@ asmlinkage __visible noinstr struct pt_regs *sync_regs(struct pt_regs *eregs)
return regs;
}
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *regs)
+{
+ unsigned long sp, *stack;
+ struct stack_info info;
+ struct pt_regs *regs_ret;
+
+ /*
+ * In the SYSCALL entry path the RSP value comes from user-space - don't
+ * trust it and switch to the current kernel stack
+ */
+ if (regs->ip >= (unsigned long)entry_SYSCALL_64 &&
+ regs->ip < (unsigned long)entry_SYSCALL_64_safe_stack) {
+ sp = this_cpu_read(cpu_current_top_of_stack);
+ goto sync;
+ }
+
+ /*
+ * From here on the RSP value is trusted. Now check whether entry
+ * happened from a safe stack. Not safe are the entry or unknown stacks,
+ * use the fall-back stack instead in this case.
+ */
+ sp = regs->sp;
+ stack = (unsigned long *)sp;
+
+ if (!get_stack_info_noinstr(stack, current, &info) || info.type == STACK_TYPE_ENTRY ||
+ info.type >= STACK_TYPE_EXCEPTION_LAST)
+ sp = __this_cpu_ist_top_va(VC2);
+
+sync:
+ /*
+ * Found a safe stack - switch to it as if the entry didn't happen via
+ * IST stack. The code below only copies pt_regs, the real switch happens
+ * in assembly code.
+ */
+ sp = ALIGN_DOWN(sp, 8) - sizeof(*regs_ret);
+
+ regs_ret = (struct pt_regs *)sp;
+ *regs_ret = *regs;
+
+ return regs_ret;
+}
+#endif
+
struct bad_iret_stack {
void *error_entry_ret;
struct pt_regs regs;
@@ -1082,6 +1127,9 @@ void __init trap_init(void)
/* Init cpu_entry_area before IST entries are set up */
setup_cpu_entry_areas();
+ /* Init GHCB memory pages when running as an SEV-ES guest */
+ sev_es_init_vc_handling();
+
idt_setup_traps();
/*
diff --git a/arch/x86/kernel/umip.c b/arch/x86/kernel/umip.c
index 2c304fd0bb1a..f6225bf22c02 100644
--- a/arch/x86/kernel/umip.c
+++ b/arch/x86/kernel/umip.c
@@ -335,63 +335,28 @@ static void force_sig_info_umip_fault(void __user *addr, struct pt_regs *regs)
*/
bool fixup_umip_exception(struct pt_regs *regs)
{
- int not_copied, nr_copied, reg_offset, dummy_data_size, umip_inst;
- unsigned long seg_base = 0, *reg_addr;
+ int nr_copied, reg_offset, dummy_data_size, umip_inst;
/* 10 bytes is the maximum size of the result of UMIP instructions */
unsigned char dummy_data[10] = { 0 };
unsigned char buf[MAX_INSN_SIZE];
+ unsigned long *reg_addr;
void __user *uaddr;
struct insn insn;
- int seg_defs;
if (!regs)
return false;
- /*
- * If not in user-space long mode, a custom code segment could be in
- * use. This is true in protected mode (if the process defined a local
- * descriptor table), or virtual-8086 mode. In most of the cases
- * seg_base will be zero as in USER_CS.
- */
- if (!user_64bit_mode(regs))
- seg_base = insn_get_seg_base(regs, INAT_SEG_REG_CS);
-
- if (seg_base == -1L)
- return false;
-
- not_copied = copy_from_user(buf, (void __user *)(seg_base + regs->ip),
- sizeof(buf));
- nr_copied = sizeof(buf) - not_copied;
+ nr_copied = insn_fetch_from_user(regs, buf);
/*
- * The copy_from_user above could have failed if user code is protected
- * by a memory protection key. Give up on emulation in such a case.
- * Should we issue a page fault?
+ * The insn_fetch_from_user above could have failed if user code
+ * is protected by a memory protection key. Give up on emulation
+ * in such a case. Should we issue a page fault?
*/
if (!nr_copied)
return false;
- insn_init(&insn, buf, nr_copied, user_64bit_mode(regs));
-
- /*
- * Override the default operand and address sizes with what is specified
- * in the code segment descriptor. The instruction decoder only sets
- * the address size it to either 4 or 8 address bytes and does nothing
- * for the operand bytes. This OK for most of the cases, but we could
- * have special cases where, for instance, a 16-bit code segment
- * descriptor is used.
- * If there is an address override prefix, the instruction decoder
- * correctly updates these values, even for 16-bit defaults.
- */
- seg_defs = insn_get_code_seg_params(regs);
- if (seg_defs == -EINVAL)
- return false;
-
- insn.addr_bytes = INSN_CODE_SEG_ADDR_SZ(seg_defs);
- insn.opnd_bytes = INSN_CODE_SEG_OPND_SZ(seg_defs);
-
- insn_get_length(&insn);
- if (nr_copied < insn.length)
+ if (!insn_decode(&insn, regs, buf, nr_copied))
return false;
umip_inst = identify_insn(&insn);
generated by cgit (git 2.34.1) at 2024-06-03 09:49:43 +0000