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
  ...

arch/x86/Kconfig

@@ -1523,6 +1523,7 @@ config AMD_MEM_ENCRYPT
 	select DYNAMIC_PHYSICAL_MASK
 	select ARCH_USE_MEMREMAP_PROT
 	select ARCH_HAS_FORCE_DMA_UNENCRYPTED
+	select INSTRUCTION_DECODER
 	help
 	  Say yes to enable support for the encryption of system memory.
 	  This requires an AMD processor that supports Secure Memory

arch/x86/boot/compressed/Makefile

@@ -32,7 +32,7 @@ KBUILD_CFLAGS := -m$(BITS) -O2
 KBUILD_CFLAGS += -fno-strict-aliasing -fPIE
 KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING
 cflags-$(CONFIG_X86_32) := -march=i386
-cflags-$(CONFIG_X86_64) := -mcmodel=small
+cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone
 KBUILD_CFLAGS += $(cflags-y)
 KBUILD_CFLAGS += -mno-mmx -mno-sse
 KBUILD_CFLAGS += -ffreestanding
@@ -47,6 +47,11 @@ KBUILD_CFLAGS += -D__DISABLE_EXPORTS
 KBUILD_CFLAGS += $(call as-option,-Wa$(comma)-mrelax-relocations=no)
 KBUILD_CFLAGS += -include $(srctree)/include/linux/hidden.h
 
+# sev-es.c indirectly inludes inat-table.h which is generated during
+# compilation and stored in $(objtree). Add the directory to the includes so
+# that the compiler finds it even with out-of-tree builds (make O=/some/path).
+CFLAGS_sev-es.o += -I$(objtree)/arch/x86/lib/
+
 KBUILD_AFLAGS  := $(KBUILD_CFLAGS) -D__ASSEMBLY__
 GCOV_PROFILE := n
 UBSAN_SANITIZE :=n
@@ -81,9 +86,11 @@ vmlinux-objs-y := $(obj)/vmlinux.lds $(obj)/kernel_info.o $(obj)/head_$(BITS).o
 vmlinux-objs-$(CONFIG_EARLY_PRINTK) += $(obj)/early_serial_console.o
 vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr.o
 ifdef CONFIG_X86_64
-	vmlinux-objs-$(CONFIG_RANDOMIZE_BASE) += $(obj)/kaslr_64.o
+	vmlinux-objs-y += $(obj)/ident_map_64.o
+	vmlinux-objs-y += $(obj)/idt_64.o $(obj)/idt_handlers_64.o
 	vmlinux-objs-y += $(obj)/mem_encrypt.o
 	vmlinux-objs-y += $(obj)/pgtable_64.o
+	vmlinux-objs-$(CONFIG_AMD_MEM_ENCRYPT) += $(obj)/sev-es.o
 endif
 
 vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o

arch/x86/boot/compressed/cpuflags.c

 // SPDX-License-Identifier: GPL-2.0
-#ifdef CONFIG_RANDOMIZE_BASE
-
 #include "../cpuflags.c"
 
 bool has_cpuflag(int flag)
@@ -9,5 +7,3 @@ bool has_cpuflag(int flag)
 
 	return test_bit(flag, cpu.flags);
 }
-
-#endif

arch/x86/boot/compressed/head_64.S

@@ -33,6 +33,7 @@
 #include <asm/processor-flags.h>
 #include <asm/asm-offsets.h>
 #include <asm/bootparam.h>
+#include <asm/desc_defs.h>
 #include "pgtable.h"
 
 /*
@@ -415,6 +416,10 @@ SYM_CODE_START(startup_64)
 
 .Lon_kernel_cs:
 
+	pushq	%rsi
+	call	load_stage1_idt
+	popq	%rsi
+
 	/*
 	 * paging_prepare() sets up the trampoline and checks if we need to
 	 * enable 5-level paging.
@@ -527,6 +532,21 @@ SYM_FUNC_START_LOCAL_NOALIGN(.Lrelocated)
 	shrq	$3, %rcx
 	rep	stosq
 
+/*
+ * If running as an SEV guest, the encryption mask is required in the
+ * page-table setup code below. When the guest also has SEV-ES enabled
+ * set_sev_encryption_mask() will cause #VC exceptions, but the stage2
+ * handler can't map its GHCB because the page-table is not set up yet.
+ * So set up the encryption mask here while still on the stage1 #VC
+ * handler. Then load stage2 IDT and switch to the kernel's own
+ * page-table.
+ */
+	pushq	%rsi
+	call	set_sev_encryption_mask
+	call	load_stage2_idt
+	call	initialize_identity_maps
+	popq	%rsi
+
 /*
  * Do the extraction, and jump to the new kernel..
  */
@@ -659,10 +679,21 @@ SYM_DATA_START_LOCAL(gdt)
 	.quad   0x0000000000000000	/* TS continued */
 SYM_DATA_END_LABEL(gdt, SYM_L_LOCAL, gdt_end)
 
+SYM_DATA_START(boot_idt_desc)
+	.word	boot_idt_end - boot_idt - 1
+	.quad	0
+SYM_DATA_END(boot_idt_desc)
+	.balign 8
+SYM_DATA_START(boot_idt)
+	.rept	BOOT_IDT_ENTRIES
+	.quad	0
+	.quad	0
+	.endr
+SYM_DATA_END_LABEL(boot_idt, SYM_L_GLOBAL, boot_idt_end)
+
 #ifdef CONFIG_EFI_STUB
 SYM_DATA(image_offset, .long 0)
 #endif
-
 #ifdef CONFIG_EFI_MIXED
 SYM_DATA_LOCAL(efi32_boot_args, .long 0, 0, 0)
 SYM_DATA(efi_is64, .byte 1)

arch/x86/boot/compressed/kaslr_64.c → arch/x86/boot/compressed/ident_map_64.c

@@ -19,16 +19,29 @@
 /* No PAGE_TABLE_ISOLATION support needed either: */
 #undef CONFIG_PAGE_TABLE_ISOLATION
 
+#include "error.h"
 #include "misc.h"
 
 /* These actually do the work of building the kernel identity maps. */
 #include <linux/pgtable.h>
+#include <asm/cmpxchg.h>
+#include <asm/trap_pf.h>
+#include <asm/trapnr.h>
 #include <asm/init.h>
 /* Use the static base for this part of the boot process */
 #undef __PAGE_OFFSET
 #define __PAGE_OFFSET __PAGE_OFFSET_BASE
 #include "../../mm/ident_map.c"
 
+#ifdef CONFIG_X86_5LEVEL
+unsigned int __pgtable_l5_enabled;
+unsigned int pgdir_shift = 39;
+unsigned int ptrs_per_p4d = 1;
+#endif
+
+/* Used by PAGE_KERN* macros: */
+pteval_t __default_kernel_pte_mask __read_mostly = ~0;
+
 /* Used to track our page table allocation area. */
 struct alloc_pgt_data {
 	unsigned char *pgt_buf;
@@ -74,12 +87,28 @@ phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
  */
 static struct x86_mapping_info mapping_info;
 
+/*
+ * Adds the specified range to the identity mappings.
+ */
+static void add_identity_map(unsigned long start, unsigned long end)
+{
+	int ret;
+
+	/* Align boundary to 2M. */
+	start = round_down(start, PMD_SIZE);
+	end = round_up(end, PMD_SIZE);
+	if (start >= end)
+		return;
+
+	/* Build the mapping. */
+	ret = kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt, start, end);
+	if (ret)
+		error("Error: kernel_ident_mapping_init() failed\n");
+}
+
 /* Locates and clears a region for a new top level page table. */
 void initialize_identity_maps(void)
 {
-	/* If running as an SEV guest, the encryption mask is required. */
-	set_sev_encryption_mask();
-
 	/* Exclude the encryption mask from __PHYSICAL_MASK */
 	physical_mask &= ~sme_me_mask;
 
@@ -109,37 +138,22 @@ void initialize_identity_maps(void)
 	 */
 	top_level_pgt = read_cr3_pa();
 	if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) {
-		debug_putstr("booted via startup_32()\n");
 		pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE;
 		pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE;
 		memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
 	} else {
-		debug_putstr("booted via startup_64()\n");
 		pgt_data.pgt_buf = _pgtable;
 		pgt_data.pgt_buf_size = BOOT_PGT_SIZE;
 		memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
 		top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data);
 	}
-}
-
-/*
- * Adds the specified range to what will become the new identity mappings.
- * Once all ranges have been added, the new mapping is activated by calling
- * finalize_identity_maps() below.
- */
-void add_identity_map(unsigned long start, unsigned long size)
-{
-	unsigned long end = start + size;
 
-	/* Align boundary to 2M. */
-	start = round_down(start, PMD_SIZE);
-	end = round_up(end, PMD_SIZE);
-	if (start >= end)
-		return;
-
-	/* Build the mapping. */
-	kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt,
-				  start, end);
+	/*
+	 * New page-table is set up - map the kernel image and load it
+	 * into cr3.
+	 */
+	add_identity_map((unsigned long)_head, (unsigned long)_end);
+	write_cr3(top_level_pgt);
 }
 
 /*
@@ -151,3 +165,185 @@ void finalize_identity_maps(void)
 {
 	write_cr3(top_level_pgt);
 }
+
+static pte_t *split_large_pmd(struct x86_mapping_info *info,
+			      pmd_t *pmdp, unsigned long __address)
+{
+	unsigned long page_flags;
+	unsigned long address;
+	pte_t *pte;
+	pmd_t pmd;
+	int i;
+
+	pte = (pte_t *)info->alloc_pgt_page(info->context);
+	if (!pte)
+		return NULL;
+
+	address     = __address & PMD_MASK;
+	/* No large page - clear PSE flag */
+	page_flags  = info->page_flag & ~_PAGE_PSE;
+
+	/* Populate the PTEs */
+	for (i = 0; i < PTRS_PER_PMD; i++) {
+		set_pte(&pte[i], __pte(address | page_flags));
+		address += PAGE_SIZE;
+	}
+
+	/*
+	 * Ideally we need to clear the large PMD first and do a TLB
+	 * flush before we write the new PMD. But the 2M range of the
+	 * PMD might contain the code we execute and/or the stack
+	 * we are on, so we can't do that. But that should be safe here
+	 * because we are going from large to small mappings and we are
+	 * also the only user of the page-table, so there is no chance
+	 * of a TLB multihit.
+	 */
+	pmd = __pmd((unsigned long)pte | info->kernpg_flag);
+	set_pmd(pmdp, pmd);
+	/* Flush TLB to establish the new PMD */
+	write_cr3(top_level_pgt);
+
+	return pte + pte_index(__address);
+}
+
+static void clflush_page(unsigned long address)
+{
+	unsigned int flush_size;
+	char *cl, *start, *end;
+
+	/*
+	 * Hardcode cl-size to 64 - CPUID can't be used here because that might
+	 * cause another #VC exception and the GHCB is not ready to use yet.
+	 */
+	flush_size = 64;
+	start      = (char *)(address & PAGE_MASK);
+	end        = start + PAGE_SIZE;
+
+	/*
+	 * First make sure there are no pending writes on the cache-lines to
+	 * flush.
+	 */
+	asm volatile("mfence" : : : "memory");
+
+	for (cl = start; cl != end; cl += flush_size)
+		clflush(cl);
+}
+
+static int set_clr_page_flags(struct x86_mapping_info *info,
+			      unsigned long address,
+			      pteval_t set, pteval_t clr)
+{
+	pgd_t *pgdp = (pgd_t *)top_level_pgt;
+	p4d_t *p4dp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep, pte;
+
+	/*
+	 * First make sure there is a PMD mapping for 'address'.
+	 * It should already exist, but keep things generic.
+	 *
+	 * To map the page just read from it and fault it in if there is no
+	 * mapping yet. add_identity_map() can't be called here because that
+	 * would unconditionally map the address on PMD level, destroying any
+	 * PTE-level mappings that might already exist. Use assembly here so
+	 * the access won't be optimized away.
+	 */
+	asm volatile("mov %[address], %%r9"
+		     :: [address] "g" (*(unsigned long *)address)
+		     : "r9", "memory");
+
+	/*
+	 * The page is mapped at least with PMD size - so skip checks and walk
+	 * directly to the PMD.
+	 */
+	p4dp = p4d_offset(pgdp, address);
+	pudp = pud_offset(p4dp, address);
+	pmdp = pmd_offset(pudp, address);
+
+	if (pmd_large(*pmdp))
+		ptep = split_large_pmd(info, pmdp, address);
+	else
+		ptep = pte_offset_kernel(pmdp, address);
+
+	if (!ptep)
+		return -ENOMEM;
+
+	/*
+	 * Changing encryption attributes of a page requires to flush it from
+	 * the caches.
+	 */
+	if ((set | clr) & _PAGE_ENC)
+		clflush_page(address);
+
+	/* Update PTE */
+	pte = *ptep;
+	pte = pte_set_flags(pte, set);
+	pte = pte_clear_flags(pte, clr);
+	set_pte(ptep, pte);
+
+	/* Flush TLB after changing encryption attribute */
+	write_cr3(top_level_pgt);
+
+	return 0;
+}
+
+int set_page_decrypted(unsigned long address)
+{
+	return set_clr_page_flags(&mapping_info, address, 0, _PAGE_ENC);
+}
+
+int set_page_encrypted(unsigned long address)
+{
+	return set_clr_page_flags(&mapping_info, address, _PAGE_ENC, 0);
+}
+
+int set_page_non_present(unsigned long address)
+{
+	return set_clr_page_flags(&mapping_info, address, 0, _PAGE_PRESENT);
+}
+
+static void do_pf_error(const char *msg, unsigned long error_code,
+			unsigned long address, unsigned long ip)
+{
+	error_putstr(msg);
+
+	error_putstr("\nError Code: ");
+	error_puthex(error_code);
+	error_putstr("\nCR2: 0x");
+	error_puthex(address);
+	error_putstr("\nRIP relative to _head: 0x");
+	error_puthex(ip - (unsigned long)_head);
+	error_putstr("\n");
+
+	error("Stopping.\n");
+}
+
+void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
+{
+	unsigned long address = native_read_cr2();
+	unsigned long end;
+	bool ghcb_fault;
+
+	ghcb_fault = sev_es_check_ghcb_fault(address);
+
+	address   &= PMD_MASK;
+	end        = address + PMD_SIZE;
+
+	/*
+	 * Check for unexpected error codes. Unexpected are:
+	 *	- Faults on present pages
+	 *	- User faults
+	 *	- Reserved bits set
+	 */
+	if (error_code & (X86_PF_PROT | X86_PF_USER | X86_PF_RSVD))
+		do_pf_error("Unexpected page-fault:", error_code, address, regs->ip);
+	else if (ghcb_fault)
+		do_pf_error("Page-fault on GHCB page:", error_code, address, regs->ip);
+
+	/*
+	 * Error code is sane - now identity map the 2M region around
+	 * the faulting address.
+	 */
+	add_identity_map(address, end);
+}

arch/x86/boot/compressed/idt_64.c

+// SPDX-License-Identifier: GPL-2.0-only
+#include <asm/trap_pf.h>
+#include <asm/segment.h>
+#include <asm/trapnr.h>
+#include "misc.h"
+
+static void set_idt_entry(int vector, void (*handler)(void))
+{
+	unsigned long address = (unsigned long)handler;
+	gate_desc entry;
+
+	memset(&entry, 0, sizeof(entry));
+
+	entry.offset_low    = (u16)(address & 0xffff);
+	entry.segment       = __KERNEL_CS;
+	entry.bits.type     = GATE_TRAP;
+	entry.bits.p        = 1;
+	entry.offset_middle = (u16)((address >> 16) & 0xffff);
+	entry.offset_high   = (u32)(address >> 32);
+
+	memcpy(&boot_idt[vector], &entry, sizeof(entry));
+}
+
+/* Have this here so we don't need to include <asm/desc.h> */
+static void load_boot_idt(const struct desc_ptr *dtr)
+{
+	asm volatile("lidt %0"::"m" (*dtr));
+}
+
+/* Setup IDT before kernel jumping to  .Lrelocated */
+void load_stage1_idt(void)
+{
+	boot_idt_desc.address = (unsigned long)boot_idt;
+
+
+	if (IS_ENABLED(CONFIG_AMD_MEM_ENCRYPT))
+		set_idt_entry(X86_TRAP_VC, boot_stage1_vc);
+
+	load_boot_idt(&boot_idt_desc);
+}
+
+/* Setup IDT after kernel jumping to  .Lrelocated */
+void load_stage2_idt(void)
+{
+	boot_idt_desc.address = (unsigned long)boot_idt;
+
+	set_idt_entry(X86_TRAP_PF, boot_page_fault);
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	set_idt_entry(X86_TRAP_VC, boot_stage2_vc);
+#endif
+
+	load_boot_idt(&boot_idt_desc);
+}

arch/x86/boot/compressed/idt_handlers_64.S

+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Early IDT handler entry points
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#include <asm/segment.h>
+
+/* For ORIG_RAX */
+#include "../../entry/calling.h"
+
+.macro EXCEPTION_HANDLER name function error_code=0
+SYM_FUNC_START(\name)
+
+	/* Build pt_regs */
+	.if \error_code == 0
+	pushq   $0
+	.endif
+
+	pushq   %rdi
+	pushq   %rsi
+	pushq   %rdx
+	pushq   %rcx
+	pushq   %rax
+	pushq   %r8
+	pushq   %r9
+	pushq   %r10
+	pushq   %r11
+	pushq   %rbx
+	pushq   %rbp
+	pushq   %r12
+	pushq   %r13
+	pushq   %r14
+	pushq   %r15
+
+	/* Call handler with pt_regs */
+	movq    %rsp, %rdi
+	/* Error code is second parameter */
+	movq	ORIG_RAX(%rsp), %rsi
+	call    \function
+
+	/* Restore regs */
+	popq    %r15
+	popq    %r14
+	popq    %r13
+	popq    %r12
+	popq    %rbp
+	popq    %rbx
+	popq    %r11
+	popq    %r10
+	popq    %r9
+	popq    %r8
+	popq    %rax
+	popq    %rcx
+	popq    %rdx
+	popq    %rsi
+	popq    %rdi
+
+	/* Remove error code and return */
+	addq    $8, %rsp
+
+	iretq
+SYM_FUNC_END(\name)
+	.endm
+
+	.text
+	.code64
+
+EXCEPTION_HANDLER	boot_page_fault do_boot_page_fault error_code=1
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+EXCEPTION_HANDLER	boot_stage1_vc do_vc_no_ghcb		error_code=1
+EXCEPTION_HANDLER	boot_stage2_vc do_boot_stage2_vc	error_code=1
+#endif

arch/x86/boot/compressed/kaslr.c

@@ -40,17 +40,8 @@
 #include <asm/setup.h>	/* For COMMAND_LINE_SIZE */
 #undef _SETUP
 
-#ifdef CONFIG_X86_5LEVEL
-unsigned int __pgtable_l5_enabled;
-unsigned int pgdir_shift __ro_after_init = 39;
-unsigned int ptrs_per_p4d __ro_after_init = 1;
-#endif
-
 extern unsigned long get_cmd_line_ptr(void);
 
-/* Used by PAGE_KERN* macros: */
-pteval_t __default_kernel_pte_mask __read_mostly = ~0;
-
 /* Simplified build-specific string for starting entropy. */
 static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@"
 		LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION;
@@ -406,8 +397,6 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 	 */
 	mem_avoid[MEM_AVOID_ZO_RANGE].start = input;
 	mem_avoid[MEM_AVOID_ZO_RANGE].size = (output + init_size) - input;
-	add_identity_map(mem_avoid[MEM_AVOID_ZO_RANGE].start,
-			 mem_avoid[MEM_AVOID_ZO_RANGE].size);
 
 	/* Avoid initrd. */
 	initrd_start  = (u64)boot_params->ext_ramdisk_image << 32;
@@ -425,15 +414,11 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 		cmd_line_size = strnlen((char *)cmd_line, COMMAND_LINE_SIZE-1) + 1;
 		mem_avoid[MEM_AVOID_CMDLINE].start = cmd_line;
 		mem_avoid[MEM_AVOID_CMDLINE].size = cmd_line_size;
-		add_identity_map(mem_avoid[MEM_AVOID_CMDLINE].start,
-				 mem_avoid[MEM_AVOID_CMDLINE].size);
 	}
 
 	/* Avoid boot parameters. */
 	mem_avoid[MEM_AVOID_BOOTPARAMS].start = (unsigned long)boot_params;
 	mem_avoid[MEM_AVOID_BOOTPARAMS].size = sizeof(*boot_params);
-	add_identity_map(mem_avoid[MEM_AVOID_BOOTPARAMS].start,
-			 mem_avoid[MEM_AVOID_BOOTPARAMS].size);
 
 	/* We don't need to set a mapping for setup_data. */
 
@@ -442,11 +427,6 @@ static void mem_avoid_init(unsigned long input, unsigned long input_size,
 
 	/* Enumerate the immovable memory regions */
 	num_immovable_mem = count_immovable_mem_regions();
-
-#ifdef CONFIG_X86_VERBOSE_BOOTUP
-	/* Make sure video RAM can be used. */
-	add_identity_map(0, PMD_SIZE);
-#endif
 }
 
 /*
@@ -870,9 +850,6 @@ void choose_random_location(unsigned long input,
 
 	boot_params->hdr.loadflags |= KASLR_FLAG;
 
-	/* Prepare to add new identity pagetables on demand. */
-	initialize_identity_maps();
-
 	if (IS_ENABLED(CONFIG_X86_32))
 		mem_limit = KERNEL_IMAGE_SIZE;
 	else
@@ -896,19 +873,8 @@ void choose_random_location(unsigned long input,
 		warn("Physical KASLR disabled: no suitable memory region!");
 	} else {
 		/* Update the new physical address location. */
-		if (*output != random_addr) {
-			add_identity_map(random_addr, output_size);
+		if (*output != random_addr)
 			*output = random_addr;
-		}
-
-		/*
-		 * This loads the identity mapping page table.
-		 * This should only be done if a new physical address
-		 * is found for the kernel, otherwise we should keep
-		 * the old page table to make it be like the "nokaslr"
-		 * case.
-		 */
-		finalize_identity_maps();
 	}
 
 

arch/x86/boot/compressed/misc.c

@@ -442,6 +442,13 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap,
 	parse_elf(output);
 	handle_relocations(output, output_len, virt_addr);
 	debug_putstr("done.\nBooting the kernel.\n");
+
+	/*
+	 * Flush GHCB from cache and map it encrypted again when running as
+	 * SEV-ES guest.
+	 */
+	sev_es_shutdown_ghcb();
+
 	return output;
 }
 

arch/x86/boot/compressed/misc.h

@@ -23,6 +23,7 @@
 #include <asm/page.h>
 #include <asm/boot.h>
 #include <asm/bootparam.h>
+#include <asm/desc_defs.h>
 
 #define BOOT_CTYPE_H
 #include <linux/acpi.h>
@@ -36,6 +37,9 @@
 #define memptr unsigned
 #endif
 
+/* boot/compressed/vmlinux start and end markers */
+extern char _head[], _end[];
+
 /* misc.c */
 extern memptr free_mem_ptr;
 extern memptr free_mem_end_ptr;
@@ -81,8 +85,6 @@ void choose_random_location(unsigned long input,
 			    unsigned long *output,
 			    unsigned long output_size,
 			    unsigned long *virt_addr);
-/* cpuflags.c */
-bool has_cpuflag(int flag);
 #else
 static inline void choose_random_location(unsigned long input,
 					  unsigned long input_size,
@@ -93,18 +95,14 @@ static inline void choose_random_location(unsigned long input,
 }
 #endif
 
+/* cpuflags.c */
+bool has_cpuflag(int flag);
+
 #ifdef CONFIG_X86_64
-void initialize_identity_maps(void);
-void add_identity_map(unsigned long start, unsigned long size);
-void finalize_identity_maps(void);
+extern int set_page_decrypted(unsigned long address);
+extern int set_page_encrypted(unsigned long address);
+extern int set_page_non_present(unsigned long address);
 extern unsigned char _pgtable[];
-#else
-static inline void initialize_identity_maps(void)
-{ }
-static inline void add_identity_map(unsigned long start, unsigned long size)
-{ }
-static inline void finalize_identity_maps(void)
-{ }
 #endif
 
 #ifdef CONFIG_EARLY_PRINTK
@@ -119,6 +117,17 @@ static inline void console_init(void)
 
 void set_sev_encryption_mask(void);
 
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+void sev_es_shutdown_ghcb(void);
+extern bool sev_es_check_ghcb_fault(unsigned long address);
+#else
+static inline void sev_es_shutdown_ghcb(void) { }
+static inline bool sev_es_check_ghcb_fault(unsigned long address)
+{
+	return false;
+}
+#endif
+
 /* acpi.c */
 #ifdef CONFIG_ACPI
 acpi_physical_address get_rsdp_addr(void);
@@ -133,4 +142,21 @@ int count_immovable_mem_regions(void);
 static inline int count_immovable_mem_regions(void) { return 0; }
 #endif
 
+/* ident_map_64.c */
+#ifdef CONFIG_X86_5LEVEL
+extern unsigned int __pgtable_l5_enabled, pgdir_shift, ptrs_per_p4d;
+#endif
+
+/* Used by PAGE_KERN* macros: */
+extern pteval_t __default_kernel_pte_mask;
+
+/* idt_64.c */
+extern gate_desc boot_idt[BOOT_IDT_ENTRIES];
+extern struct desc_ptr boot_idt_desc;
+
+/* IDT Entry Points */
+void boot_page_fault(void);
+void boot_stage1_vc(void);
+void boot_stage2_vc(void);
+
 #endif /* BOOT_COMPRESSED_MISC_H */

arch/x86/boot/compressed/sev-es.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * AMD Encrypted Register State Support
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+/*
+ * misc.h needs to be first because it knows how to include the other kernel
+ * headers in the pre-decompression code in a way that does not break
+ * compilation.
+ */
+#include "misc.h"
+
+#include <asm/pgtable_types.h>
+#include <asm/sev-es.h>
+#include <asm/trapnr.h>
+#include <asm/trap_pf.h>
+#include <asm/msr-index.h>
+#include <asm/fpu/xcr.h>
+#include <asm/ptrace.h>
+#include <asm/svm.h>
+
+#include "error.h"
+
+struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);
+struct ghcb *boot_ghcb;
+
+/*
+ * Copy a version of this function here - insn-eval.c can't be used in
+ * pre-decompression code.
+ */
+static bool insn_has_rep_prefix(struct insn *insn)
+{
+	int i;
+
+	insn_get_prefixes(insn);
+
+	for (i = 0; i < insn->prefixes.nbytes; i++) {
+		insn_byte_t p = insn->prefixes.bytes[i];
+
+		if (p == 0xf2 || p == 0xf3)
+			return true;
+	}
+
+	return false;
+}
+
+/*
+ * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and
+ * doesn't use segments.
+ */
+static unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx)
+{
+	return 0UL;
+}
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+	unsigned long low, high;
+
+	asm volatile("rdmsr" : "=a" (low), "=d" (high) :
+			"c" (MSR_AMD64_SEV_ES_GHCB));
+
+	return ((high << 32) | low);
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+	u32 low, high;
+
+	low  = val & 0xffffffffUL;
+	high = val >> 32;
+
+	asm volatile("wrmsr" : : "c" (MSR_AMD64_SEV_ES_GHCB),
+			"a"(low), "d" (high) : "memory");
+}
+
+static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+	char buffer[MAX_INSN_SIZE];
+	enum es_result ret;
+
+	memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
+
+	insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE, 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,
+				   void *dst, char *buf, size_t size)
+{
+	memcpy(dst, buf, size);
+
+	return ES_OK;
+}
+
+static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
+				  void *src, char *buf, size_t size)
+{
+	memcpy(buf, src, size);
+
+	return ES_OK;
+}
+
+#undef __init
+#undef __pa
+#define __init
+#define __pa(x)	((unsigned long)(x))
+
+#define __BOOT_COMPRESSED
+
+/* Basic instruction decoding support needed */
+#include "../../lib/inat.c"
+#include "../../lib/insn.c"
+
+/* Include code for early handlers */
+#include "../../kernel/sev-es-shared.c"
+
+static bool early_setup_sev_es(void)
+{
+	if (!sev_es_negotiate_protocol())
+		sev_es_terminate(GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED);
+
+	if (set_page_decrypted((unsigned long)&boot_ghcb_page))
+		return false;
+
+	/* Page is now mapped decrypted, clear it */
+	memset(&boot_ghcb_page, 0, sizeof(boot_ghcb_page));
+
+	boot_ghcb = &boot_ghcb_page;
+
+	/* Initialize lookup tables for the instruction decoder */
+	inat_init_tables();
+
+	return true;
+}
+
+void sev_es_shutdown_ghcb(void)
+{
+	if (!boot_ghcb)
+		return;
+
+	if (!sev_es_check_cpu_features())
+		error("SEV-ES CPU Features missing.");
+
+	/*
+	 * GHCB Page must be flushed from the cache and mapped encrypted again.
+	 * Otherwise the running kernel will see strange cache effects when
+	 * trying to use that page.
+	 */
+	if (set_page_encrypted((unsigned long)&boot_ghcb_page))
+		error("Can't map GHCB page encrypted");
+
+	/*
+	 * GHCB page is mapped encrypted again and flushed from the cache.
+	 * Mark it non-present now to catch bugs when #VC exceptions trigger
+	 * after this point.
+	 */
+	if (set_page_non_present((unsigned long)&boot_ghcb_page))
+		error("Can't unmap GHCB page");
+}
+
+bool sev_es_check_ghcb_fault(unsigned long address)
+{
+	/* Check whether the fault was on the GHCB page */
+	return ((address & PAGE_MASK) == (unsigned long)&boot_ghcb_page);
+}
+
+void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)
+{
+	struct es_em_ctxt ctxt;
+	enum es_result result;
+
+	if (!boot_ghcb && !early_setup_sev_es())
+		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)
+		goto finish;
+
+	switch (exit_code) {
+	case SVM_EXIT_RDTSC:
+	case SVM_EXIT_RDTSCP:
+		result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code);
+		break;
+	case SVM_EXIT_IOIO:
+		result = vc_handle_ioio(boot_ghcb, &ctxt);
+		break;
+	case SVM_EXIT_CPUID:
+		result = vc_handle_cpuid(boot_ghcb, &ctxt);
+		break;
+	default:
+		result = ES_UNSUPPORTED;
+		break;
+	}
+
+finish:
+	if (result == ES_OK) {
+		vc_finish_insn(&ctxt);
+	} else if (result != ES_RETRY) {
+		/*
+		 * For now, just halt the machine. That makes debugging easier,
+		 * later we just call sev_es_terminate() here.
+		 */
+		while (true)
+			asm volatile("hlt\n");
+	}
+}

arch/x86/entry/entry_64.S

@@ -101,6 +101,8 @@ SYM_CODE_START(entry_SYSCALL_64)
 	SWITCH_TO_KERNEL_CR3 scratch_reg=%rsp
 	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rsp
 
+SYM_INNER_LABEL(entry_SYSCALL_64_safe_stack, SYM_L_GLOBAL)
+
 	/* Construct struct pt_regs on stack */
 	pushq	$__USER_DS				/* pt_regs->ss */
 	pushq	PER_CPU_VAR(cpu_tss_rw + TSS_sp2)	/* pt_regs->sp */
@@ -446,6 +448,84 @@ _ASM_NOKPROBE(\asmsym)
 SYM_CODE_END(\asmsym)
 .endm
 
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+/**
+ * idtentry_vc - Macro to generate entry stub for #VC
+ * @vector:		Vector number
+ * @asmsym:		ASM symbol for the entry point
+ * @cfunc:		C function to be called
+ *
+ * The macro emits code to set up the kernel context for #VC. The #VC handler
+ * runs on an IST stack and needs to be able to cause nested #VC exceptions.
+ *
+ * To make this work the #VC entry code tries its best to pretend it doesn't use
+ * an IST stack by switching to the task stack if coming from user-space (which
+ * includes early SYSCALL entry path) or back to the stack in the IRET frame if
+ * entered from kernel-mode.
+ *
+ * If entered from kernel-mode the return stack is validated first, and if it is
+ * not safe to use (e.g. because it points to the entry stack) the #VC handler
+ * will switch to a fall-back stack (VC2) and call a special handler function.
+ *
+ * The macro is only used for one vector, but it is planned to be extended in
+ * the future for the #HV exception.
+ */
+.macro idtentry_vc vector asmsym cfunc
+SYM_CODE_START(\asmsym)
+	UNWIND_HINT_IRET_REGS
+	ASM_CLAC
+
+	/*
+	 * If the entry is from userspace, switch stacks and treat it as
+	 * a normal entry.
+	 */
+	testb	$3, CS-ORIG_RAX(%rsp)
+	jnz	.Lfrom_usermode_switch_stack_\@
+
+	/*
+	 * paranoid_entry returns SWAPGS flag for paranoid_exit in EBX.
+	 * EBX == 0 -> SWAPGS, EBX == 1 -> no SWAPGS
+	 */
+	call	paranoid_entry
+
+	UNWIND_HINT_REGS
+
+	/*
+	 * Switch off the IST stack to make it free for nested exceptions. The
+	 * vc_switch_off_ist() function will switch back to the interrupted
+	 * stack if it is safe to do so. If not it switches to the VC fall-back
+	 * stack.
+	 */
+	movq	%rsp, %rdi		/* pt_regs pointer */
+	call	vc_switch_off_ist
+	movq	%rax, %rsp		/* Switch to new stack */
+
+	UNWIND_HINT_REGS
+
+	/* Update pt_regs */
+	movq	ORIG_RAX(%rsp), %rsi	/* get error code into 2nd argument*/
+	movq	$-1, ORIG_RAX(%rsp)	/* no syscall to restart */
+
+	movq	%rsp, %rdi		/* pt_regs pointer */
+
+	call	\cfunc
+
+	/*
+	 * No need to switch back to the IST stack. The current stack is either
+	 * identical to the stack in the IRET frame or the VC fall-back stack,
+	 * so it is definitly mapped even with PTI enabled.
+	 */
+	jmp	paranoid_exit
+
+	/* Switch to the regular task stack */
+.Lfrom_usermode_switch_stack_\@:
+	idtentry_body safe_stack_\cfunc, has_error_code=1
+
+_ASM_NOKPROBE(\asmsym)
+SYM_CODE_END(\asmsym)
+.endm
+#endif
+
 /*
  * Double fault entry. Straight paranoid. No checks from which context
  * this comes because for the espfix induced #DF this would do the wrong

arch/x86/include/asm/cpu_entry_area.h

@@ -11,25 +11,29 @@
 #ifdef CONFIG_X86_64
 
 /* Macro to enforce the same ordering and stack sizes */
-#define ESTACKS_MEMBERS(guardsize)		\
-	char	DF_stack_guard[guardsize];	\
-	char	DF_stack[EXCEPTION_STKSZ];	\
-	char	NMI_stack_guard[guardsize];	\
-	char	NMI_stack[EXCEPTION_STKSZ];	\
-	char	DB_stack_guard[guardsize];	\
-	char	DB_stack[EXCEPTION_STKSZ];	\
-	char	MCE_stack_guard[guardsize];	\
-	char	MCE_stack[EXCEPTION_STKSZ];	\
-	char	IST_top_guard[guardsize];	\
+#define ESTACKS_MEMBERS(guardsize, optional_stack_size)		\
+	char	DF_stack_guard[guardsize];			\
+	char	DF_stack[EXCEPTION_STKSZ];			\
+	char	NMI_stack_guard[guardsize];			\
+	char	NMI_stack[EXCEPTION_STKSZ];			\
+	char	DB_stack_guard[guardsize];			\
+	char	DB_stack[EXCEPTION_STKSZ];			\
+	char	MCE_stack_guard[guardsize];			\
+	char	MCE_stack[EXCEPTION_STKSZ];			\
+	char	VC_stack_guard[guardsize];			\
+	char	VC_stack[optional_stack_size];			\
+	char	VC2_stack_guard[guardsize];			\
+	char	VC2_stack[optional_stack_size];			\
+	char	IST_top_guard[guardsize];			\
 
 /* The exception stacks' physical storage. No guard pages required */
 struct exception_stacks {
-	ESTACKS_MEMBERS(0)
+	ESTACKS_MEMBERS(0, 0)
 };
 
 /* The effective cpu entry area mapping with guard pages. */
 struct cea_exception_stacks {
-	ESTACKS_MEMBERS(PAGE_SIZE)
+	ESTACKS_MEMBERS(PAGE_SIZE, EXCEPTION_STKSZ)
 };
 
 /*
@@ -40,6 +44,8 @@ enum exception_stack_ordering {
 	ESTACK_NMI,
 	ESTACK_DB,
 	ESTACK_MCE,
+	ESTACK_VC,
+	ESTACK_VC2,
 	N_EXCEPTION_STACKS
 };
 
@@ -139,4 +145,7 @@ static inline struct entry_stack *cpu_entry_stack(int cpu)
 #define __this_cpu_ist_top_va(name)					\
 	CEA_ESTACK_TOP(__this_cpu_read(cea_exception_stacks), name)
 
+#define __this_cpu_ist_bottom_va(name)					\
+	CEA_ESTACK_BOT(__this_cpu_read(cea_exception_stacks), name)
+
 #endif

arch/x86/include/asm/cpufeatures.h

@@ -236,6 +236,7 @@
 #define X86_FEATURE_EPT_AD		( 8*32+17) /* Intel Extended Page Table access-dirty bit */
 #define X86_FEATURE_VMCALL		( 8*32+18) /* "" Hypervisor supports the VMCALL instruction */
 #define X86_FEATURE_VMW_VMMCALL		( 8*32+19) /* "" VMware prefers VMMCALL hypercall instruction */
+#define X86_FEATURE_SEV_ES		( 8*32+20) /* AMD Secure Encrypted Virtualization - Encrypted State */
 
 /* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */
 #define X86_FEATURE_FSGSBASE		( 9*32+ 0) /* RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/

arch/x86/include/asm/desc.h

@@ -383,6 +383,33 @@ static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit)
 
 void alloc_intr_gate(unsigned int n, const void *addr);
 
+static inline void init_idt_data(struct idt_data *data, unsigned int n,
+				 const void *addr)
+{
+	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;
+}
+
+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
+}
+
 extern unsigned long system_vectors[];
 
 extern void load_current_idt(void);

arch/x86/include/asm/desc_defs.h

@@ -74,6 +74,13 @@ struct idt_bits {
 			p	: 1;
 } __attribute__((packed));
 
+struct idt_data {
+	unsigned int	vector;
+	unsigned int	segment;
+	struct idt_bits	bits;
+	const void	*addr;
+};
+
 struct gate_struct {
 	u16		offset_low;
 	u16		segment;
@@ -109,6 +116,9 @@ struct desc_ptr {
 
 #endif /* !__ASSEMBLY__ */
 
+/* Boot IDT definitions */
+#define	BOOT_IDT_ENTRIES	32
+
 /* Access rights as returned by LAR */
 #define AR_TYPE_RODATA		(0 * (1 << 9))
 #define AR_TYPE_RWDATA		(1 * (1 << 9))

arch/x86/include/asm/fpu/internal.h

@@ -19,6 +19,7 @@
 #include <asm/user.h>
 #include <asm/fpu/api.h>
 #include <asm/fpu/xstate.h>
+#include <asm/fpu/xcr.h>
 #include <asm/cpufeature.h>
 #include <asm/trace/fpu.h>
 
@@ -592,33 +593,4 @@ static inline void switch_fpu_finish(struct fpu *new_fpu)
 	update_pasid();
 }
 
-/*
- * MXCSR and XCR definitions:
- */
-
-static inline void ldmxcsr(u32 mxcsr)
-{
-	asm volatile("ldmxcsr %0" :: "m" (mxcsr));
-}
-
-extern unsigned int mxcsr_feature_mask;
-
-#define XCR_XFEATURE_ENABLED_MASK	0x00000000
-
-static inline u64 xgetbv(u32 index)
-{
-	u32 eax, edx;
-
-	asm volatile("xgetbv" : "=a" (eax), "=d" (edx) : "c" (index));
-	return eax + ((u64)edx << 32);
-}
-
-static inline void xsetbv(u32 index, u64 value)
-{
-	u32 eax = value;
-	u32 edx = value >> 32;
-
-	asm volatile("xsetbv" :: "a" (eax), "d" (edx), "c" (index));
-}
-
 #endif /* _ASM_X86_FPU_INTERNAL_H */

arch/x86/include/asm/fpu/xcr.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_FPU_XCR_H
+#define _ASM_X86_FPU_XCR_H
+
+/*
+ * MXCSR and XCR definitions:
+ */
+
+static inline void ldmxcsr(u32 mxcsr)
+{
+	asm volatile("ldmxcsr %0" :: "m" (mxcsr));
+}
+
+extern unsigned int mxcsr_feature_mask;
+
+#define XCR_XFEATURE_ENABLED_MASK	0x00000000
+
+static inline u64 xgetbv(u32 index)
+{
+	u32 eax, edx;
+
+	asm volatile("xgetbv" : "=a" (eax), "=d" (edx) : "c" (index));
+	return eax + ((u64)edx << 32);
+}
+
+static inline void xsetbv(u32 index, u64 value)
+{
+	u32 eax = value;
+	u32 edx = value >> 32;
+
+	asm volatile("xsetbv" :: "a" (eax), "d" (edx), "c" (index));
+}
+
+#endif /* _ASM_X86_FPU_XCR_H */

arch/x86/include/asm/idtentry.h

@@ -308,6 +308,19 @@ static __always_inline void __##func(struct pt_regs *regs)
 	DECLARE_IDTENTRY_RAW(vector, func);				\
 	__visible void noist_##func(struct pt_regs *regs)
 
+/**
+ * DECLARE_IDTENTRY_VC - Declare functions for the VC entry point
+ * @vector:	Vector number (ignored for C)
+ * @func:	Function name of the entry point
+ *
+ * Maps to DECLARE_IDTENTRY_RAW_ERRORCODE, but declares also the
+ * safe_stack C handler.
+ */
+#define DECLARE_IDTENTRY_VC(vector, func)				\
+	DECLARE_IDTENTRY_RAW_ERRORCODE(vector, func);			\
+	__visible noinstr void ist_##func(struct pt_regs *regs, unsigned long error_code);	\
+	__visible noinstr void safe_stack_##func(struct pt_regs *regs, unsigned long error_code)
+
 /**
  * DEFINE_IDTENTRY_IST - Emit code for IST entry points
  * @func:	Function name of the entry point
@@ -347,6 +360,35 @@ static __always_inline void __##func(struct pt_regs *regs)
 #define DEFINE_IDTENTRY_DF(func)					\
 	DEFINE_IDTENTRY_RAW_ERRORCODE(func)
 
+/**
+ * DEFINE_IDTENTRY_VC_SAFE_STACK - Emit code for VMM communication handler
+				   which runs on a safe stack.
+ * @func:	Function name of the entry point
+ *
+ * Maps to DEFINE_IDTENTRY_RAW_ERRORCODE
+ */
+#define DEFINE_IDTENTRY_VC_SAFE_STACK(func)				\
+	DEFINE_IDTENTRY_RAW_ERRORCODE(safe_stack_##func)
+
+/**
+ * DEFINE_IDTENTRY_VC_IST - Emit code for VMM communication handler
+			    which runs on the VC fall-back stack
+ * @func:	Function name of the entry point
+ *
+ * Maps to DEFINE_IDTENTRY_RAW_ERRORCODE
+ */
+#define DEFINE_IDTENTRY_VC_IST(func)				\
+	DEFINE_IDTENTRY_RAW_ERRORCODE(ist_##func)
+
+/**
+ * DEFINE_IDTENTRY_VC - Emit code for VMM communication handler
+ * @func:	Function name of the entry point
+ *
+ * Maps to DEFINE_IDTENTRY_RAW_ERRORCODE
+ */
+#define DEFINE_IDTENTRY_VC(func)					\
+	DEFINE_IDTENTRY_RAW_ERRORCODE(func)
+
 #else	/* CONFIG_X86_64 */
 
 /**
@@ -433,6 +475,9 @@ __visible noinstr void func(struct pt_regs *regs,			\
 # define DECLARE_IDTENTRY_XENCB(vector, func)				\
 	DECLARE_IDTENTRY(vector, func)
 
+# define DECLARE_IDTENTRY_VC(vector, func)				\
+	idtentry_vc vector asm_##func func
+
 #else
 # define DECLARE_IDTENTRY_MCE(vector, func)				\
 	DECLARE_IDTENTRY(vector, func)
@@ -564,6 +609,11 @@ DECLARE_IDTENTRY_RAW(X86_TRAP_DB,	xenpv_exc_debug);
 /* #DF */
 DECLARE_IDTENTRY_DF(X86_TRAP_DF,	exc_double_fault);
 
+/* #VC */
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+DECLARE_IDTENTRY_VC(X86_TRAP_VC,	exc_vmm_communication);
+#endif
+
 #ifdef CONFIG_XEN_PV
 DECLARE_IDTENTRY_XENCB(X86_TRAP_OTHER,	exc_xen_hypervisor_callback);
 #endif

arch/x86/include/asm/insn-eval.h

@@ -15,9 +15,15 @@
 #define INSN_CODE_SEG_OPND_SZ(params) (params & 0xf)
 #define INSN_CODE_SEG_PARAMS(oper_sz, addr_sz) (oper_sz | (addr_sz << 4))
 
+bool insn_has_rep_prefix(struct insn *insn);
 void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs);
 int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs);
+int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs);
 unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx);
 int insn_get_code_seg_params(struct pt_regs *regs);
+int insn_fetch_from_user(struct pt_regs *regs,
+			 unsigned char buf[MAX_INSN_SIZE]);
+bool insn_decode(struct insn *insn, struct pt_regs *regs,
+		 unsigned char buf[MAX_INSN_SIZE], int buf_size);
 
 #endif /* _ASM_X86_INSN_EVAL_H */

arch/x86/include/asm/mem_encrypt.h

@@ -19,6 +19,7 @@
 #ifdef CONFIG_AMD_MEM_ENCRYPT
 
 extern u64 sme_me_mask;
+extern u64 sev_status;
 extern bool sev_enabled;
 
 void sme_encrypt_execute(unsigned long encrypted_kernel_vaddr,
@@ -48,8 +49,10 @@ void __init mem_encrypt_free_decrypted_mem(void);
 /* Architecture __weak replacement functions */
 void __init mem_encrypt_init(void);
 
+void __init sev_es_init_vc_handling(void);
 bool sme_active(void);
 bool sev_active(void);
+bool sev_es_active(void);
 
 #define __bss_decrypted __attribute__((__section__(".bss..decrypted")))
 
@@ -70,8 +73,10 @@ static inline void __init sme_early_init(void) { }
 static inline void __init sme_encrypt_kernel(struct boot_params *bp) { }
 static inline void __init sme_enable(struct boot_params *bp) { }
 
+static inline void sev_es_init_vc_handling(void) { }
 static inline bool sme_active(void) { return false; }
 static inline bool sev_active(void) { return false; }
+static inline bool sev_es_active(void) { return false; }
 
 static inline int __init
 early_set_memory_decrypted(unsigned long vaddr, unsigned long size) { return 0; }

arch/x86/include/asm/msr-index.h

@@ -470,9 +470,12 @@
 #define MSR_AMD64_ICIBSEXTDCTL		0xc001103c
 #define MSR_AMD64_IBSOPDATA4		0xc001103d
 #define MSR_AMD64_IBS_REG_COUNT_MAX	8 /* includes MSR_AMD64_IBSBRTARGET */
+#define MSR_AMD64_SEV_ES_GHCB		0xc0010130
 #define MSR_AMD64_SEV			0xc0010131
 #define MSR_AMD64_SEV_ENABLED_BIT	0
+#define MSR_AMD64_SEV_ES_ENABLED_BIT	1
 #define MSR_AMD64_SEV_ENABLED		BIT_ULL(MSR_AMD64_SEV_ENABLED_BIT)
+#define MSR_AMD64_SEV_ES_ENABLED	BIT_ULL(MSR_AMD64_SEV_ES_ENABLED_BIT)
 
 #define MSR_AMD64_VIRT_SPEC_CTRL	0xc001011f
 

arch/x86/include/asm/page_64_types.h

@@ -28,6 +28,7 @@
 #define	IST_INDEX_NMI		1
 #define	IST_INDEX_DB		2
 #define	IST_INDEX_MCE		3
+#define	IST_INDEX_VC		4
 
 /*
  * Set __PAGE_OFFSET to the most negative possible address +

arch/x86/include/asm/pgtable.h

@@ -28,7 +28,7 @@
 #include <asm-generic/pgtable_uffd.h>
 
 extern pgd_t early_top_pgt[PTRS_PER_PGD];
-int __init __early_make_pgtable(unsigned long address, pmdval_t pmd);
+bool __init __early_make_pgtable(unsigned long address, pmdval_t pmd);
 
 void ptdump_walk_pgd_level(struct seq_file *m, struct mm_struct *mm);
 void ptdump_walk_pgd_level_debugfs(struct seq_file *m, struct mm_struct *mm,

arch/x86/include/asm/processor.h

@@ -696,6 +696,7 @@ extern void load_direct_gdt(int);
 extern void load_fixmap_gdt(int);
 extern void load_percpu_segment(int);
 extern void cpu_init(void);
+extern void cpu_init_exception_handling(void);
 extern void cr4_init(void);
 
 static inline unsigned long get_debugctlmsr(void)

arch/x86/include/asm/proto.h

@@ -10,6 +10,7 @@ void syscall_init(void);
 
 #ifdef CONFIG_X86_64
 void entry_SYSCALL_64(void);
+void entry_SYSCALL_64_safe_stack(void);
 long do_arch_prctl_64(struct task_struct *task, int option, unsigned long arg2);
 #endif
 

arch/x86/include/asm/realmode.h

@@ -21,6 +21,9 @@ struct real_mode_header {
 	/* SMP trampoline */
 	u32	trampoline_start;
 	u32	trampoline_header;
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+	u32	sev_es_trampoline_start;
+#endif
 #ifdef CONFIG_X86_64
 	u32	trampoline_pgd;
 #endif
@@ -57,6 +60,9 @@ extern unsigned char real_mode_blob_end[];
 extern unsigned long initial_code;
 extern unsigned long initial_gs;
 extern unsigned long initial_stack;
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+extern unsigned long initial_vc_handler;
+#endif
 
 extern unsigned char real_mode_blob[];
 extern unsigned char real_mode_relocs[];
@@ -66,6 +72,7 @@ extern unsigned char startup_32_smp[];
 extern unsigned char boot_gdt[];
 #else
 extern unsigned char secondary_startup_64[];
+extern unsigned char secondary_startup_64_no_verify[];
 #endif
 
 static inline size_t real_mode_size_needed(void)

arch/x86/include/asm/segment.h

@@ -226,7 +226,7 @@
 #define NUM_EXCEPTION_VECTORS		32
 
 /* Bitmask of exception vectors which push an error code on the stack: */
-#define EXCEPTION_ERRCODE_MASK		0x00027d00
+#define EXCEPTION_ERRCODE_MASK		0x20027d00
 
 #define GDT_SIZE			(GDT_ENTRIES*8)
 #define GDT_ENTRY_TLS_ENTRIES		3

arch/x86/include/asm/setup.h

@@ -39,6 +39,8 @@ void vsmp_init(void);
 static inline void vsmp_init(void) { }
 #endif
 
+struct pt_regs;
+
 void setup_bios_corruption_check(void);
 void early_platform_quirks(void);
 
@@ -48,7 +50,9 @@ extern void reserve_standard_io_resources(void);
 extern void i386_reserve_resources(void);
 extern unsigned long __startup_64(unsigned long physaddr, struct boot_params *bp);
 extern unsigned long __startup_secondary_64(void);
-extern int early_make_pgtable(unsigned long address);
+extern void startup_64_setup_env(unsigned long physbase);
+extern void early_setup_idt(void);
+extern void __init do_early_exception(struct pt_regs *regs, int trapnr);
 
 #ifdef CONFIG_X86_INTEL_MID
 extern void x86_intel_mid_early_setup(void);

arch/x86/include/asm/sev-es.h

+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * AMD Encrypted Register State Support
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#ifndef __ASM_ENCRYPTED_STATE_H
+#define __ASM_ENCRYPTED_STATE_H
+
+#include <linux/types.h>
+#include <asm/insn.h>
+
+#define GHCB_SEV_INFO		0x001UL
+#define GHCB_SEV_INFO_REQ	0x002UL
+#define		GHCB_INFO(v)		((v) & 0xfffUL)
+#define		GHCB_PROTO_MAX(v)	(((v) >> 48) & 0xffffUL)
+#define		GHCB_PROTO_MIN(v)	(((v) >> 32) & 0xffffUL)
+#define		GHCB_PROTO_OUR		0x0001UL
+#define GHCB_SEV_CPUID_REQ	0x004UL
+#define		GHCB_CPUID_REQ_EAX	0
+#define		GHCB_CPUID_REQ_EBX	1
+#define		GHCB_CPUID_REQ_ECX	2
+#define		GHCB_CPUID_REQ_EDX	3
+#define		GHCB_CPUID_REQ(fn, reg) (GHCB_SEV_CPUID_REQ | \
+					(((unsigned long)reg & 3) << 30) | \
+					(((unsigned long)fn) << 32))
+
+#define	GHCB_PROTOCOL_MAX	0x0001UL
+#define GHCB_DEFAULT_USAGE	0x0000UL
+
+#define GHCB_SEV_CPUID_RESP	0x005UL
+#define GHCB_SEV_TERMINATE	0x100UL
+#define		GHCB_SEV_TERMINATE_REASON(reason_set, reason_val)	\
+			(((((u64)reason_set) &  0x7) << 12) |		\
+			 ((((u64)reason_val) & 0xff) << 16))
+#define		GHCB_SEV_ES_REASON_GENERAL_REQUEST	0
+#define		GHCB_SEV_ES_REASON_PROTOCOL_UNSUPPORTED	1
+
+#define	GHCB_SEV_GHCB_RESP_CODE(v)	((v) & 0xfff)
+#define	VMGEXIT()			{ asm volatile("rep; vmmcall\n\r"); }
+
+enum es_result {
+	ES_OK,			/* All good */
+	ES_UNSUPPORTED,		/* Requested operation not supported */
+	ES_VMM_ERROR,		/* Unexpected state from the VMM */
+	ES_DECODE_FAILED,	/* Instruction decoding failed */
+	ES_EXCEPTION,		/* Instruction caused exception */
+	ES_RETRY,		/* Retry instruction emulation */
+};
+
+struct es_fault_info {
+	unsigned long vector;
+	unsigned long error_code;
+	unsigned long cr2;
+};
+
+struct pt_regs;
+
+/* ES instruction emulation context */
+struct es_em_ctxt {
+	struct pt_regs *regs;
+	struct insn insn;
+	struct es_fault_info fi;
+};
+
+void do_vc_no_ghcb(struct pt_regs *regs, unsigned long exit_code);
+
+static inline u64 lower_bits(u64 val, unsigned int bits)
+{
+	u64 mask = (1ULL << bits) - 1;
+
+	return (val & mask);
+}
+
+struct real_mode_header;
+enum stack_type;
+
+/* Early IDT entry points for #VC handler */
+extern void vc_no_ghcb(void);
+extern void vc_boot_ghcb(void);
+extern bool handle_vc_boot_ghcb(struct pt_regs *regs);
+
+#ifdef CONFIG_AMD_MEM_ENCRYPT
+extern struct static_key_false sev_es_enable_key;
+extern void __sev_es_ist_enter(struct pt_regs *regs);
+extern void __sev_es_ist_exit(void);
+static __always_inline void sev_es_ist_enter(struct pt_regs *regs)
+{
+	if (static_branch_unlikely(&sev_es_enable_key))
+		__sev_es_ist_enter(regs);
+}
+static __always_inline void sev_es_ist_exit(void)
+{
+	if (static_branch_unlikely(&sev_es_enable_key))
+		__sev_es_ist_exit();
+}
+extern int sev_es_setup_ap_jump_table(struct real_mode_header *rmh);
+extern void __sev_es_nmi_complete(void);
+static __always_inline void sev_es_nmi_complete(void)
+{
+	if (static_branch_unlikely(&sev_es_enable_key))
+		__sev_es_nmi_complete();
+}
+extern int __init sev_es_efi_map_ghcbs(pgd_t *pgd);
+#else
+static inline void sev_es_ist_enter(struct pt_regs *regs) { }
+static inline void sev_es_ist_exit(void) { }
+static inline int sev_es_setup_ap_jump_table(struct real_mode_header *rmh) { return 0; }
+static inline void sev_es_nmi_complete(void) { }
+static inline int sev_es_efi_map_ghcbs(pgd_t *pgd) { return 0; }
+#endif
+
+#endif

arch/x86/include/asm/stacktrace.h

@@ -35,6 +35,8 @@ bool in_entry_stack(unsigned long *stack, struct stack_info *info);
 
 int get_stack_info(unsigned long *stack, struct task_struct *task,
 		   struct stack_info *info, unsigned long *visit_mask);
+bool get_stack_info_noinstr(unsigned long *stack, struct task_struct *task,
+			    struct stack_info *info);
 
 const char *stack_type_name(enum stack_type type);
 

arch/x86/include/asm/svm.h

@@ -150,14 +150,14 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
 #define SVM_NESTED_CTL_NP_ENABLE	BIT(0)
 #define SVM_NESTED_CTL_SEV_ENABLE	BIT(1)
 
-struct __attribute__ ((__packed__)) vmcb_seg {
+struct vmcb_seg {
 	u16 selector;
 	u16 attrib;
 	u32 limit;
 	u64 base;
-};
+} __packed;
 
-struct __attribute__ ((__packed__)) vmcb_save_area {
+struct vmcb_save_area {
 	struct vmcb_seg es;
 	struct vmcb_seg cs;
 	struct vmcb_seg ss;
@@ -200,20 +200,67 @@ struct __attribute__ ((__packed__)) vmcb_save_area {
 	u64 br_to;
 	u64 last_excp_from;
 	u64 last_excp_to;
-};
 
+	/*
+	 * The following part of the save area is valid only for
+	 * SEV-ES guests when referenced through the GHCB.
+	 */
+	u8 reserved_7[104];
+	u64 reserved_8;		/* rax already available at 0x01f8 */
+	u64 rcx;
+	u64 rdx;
+	u64 rbx;
+	u64 reserved_9;		/* rsp already available at 0x01d8 */
+	u64 rbp;
+	u64 rsi;
+	u64 rdi;
+	u64 r8;
+	u64 r9;
+	u64 r10;
+	u64 r11;
+	u64 r12;
+	u64 r13;
+	u64 r14;
+	u64 r15;
+	u8 reserved_10[16];
+	u64 sw_exit_code;
+	u64 sw_exit_info_1;
+	u64 sw_exit_info_2;
+	u64 sw_scratch;
+	u8 reserved_11[56];
+	u64 xcr0;
+	u8 valid_bitmap[16];
+	u64 x87_state_gpa;
+} __packed;
+
+struct ghcb {
+	struct vmcb_save_area save;
+	u8 reserved_save[2048 - sizeof(struct vmcb_save_area)];
+
+	u8 shared_buffer[2032];
+
+	u8 reserved_1[10];
+	u16 protocol_version;	/* negotiated SEV-ES/GHCB protocol version */
+	u32 ghcb_usage;
+} __packed;
+
+
+#define EXPECTED_VMCB_SAVE_AREA_SIZE		1032
+#define EXPECTED_VMCB_CONTROL_AREA_SIZE		256
+#define EXPECTED_GHCB_SIZE			PAGE_SIZE
 
 static inline void __unused_size_checks(void)
 {
-	BUILD_BUG_ON(sizeof(struct vmcb_save_area) != 0x298);
-	BUILD_BUG_ON(sizeof(struct vmcb_control_area) != 256);
+	BUILD_BUG_ON(sizeof(struct vmcb_save_area)	!= EXPECTED_VMCB_SAVE_AREA_SIZE);
+	BUILD_BUG_ON(sizeof(struct vmcb_control_area)	!= EXPECTED_VMCB_CONTROL_AREA_SIZE);
+	BUILD_BUG_ON(sizeof(struct ghcb)		!= EXPECTED_GHCB_SIZE);
 }
 
-struct __attribute__ ((__packed__)) vmcb {
+struct vmcb {
 	struct vmcb_control_area control;
 	u8 reserved_control[1024 - sizeof(struct vmcb_control_area)];
 	struct vmcb_save_area save;
-};
+} __packed;
 
 #define SVM_CPUID_FUNC 0x8000000a
 
@@ -298,4 +345,47 @@ struct __attribute__ ((__packed__)) vmcb {
 
 #define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)
 
+/* GHCB Accessor functions */
+
+#define GHCB_BITMAP_IDX(field)							\
+	(offsetof(struct vmcb_save_area, field) / sizeof(u64))
+
+#define DEFINE_GHCB_ACCESSORS(field)						\
+	static inline bool ghcb_##field##_is_valid(const struct ghcb *ghcb)	\
+	{									\
+		return test_bit(GHCB_BITMAP_IDX(field),				\
+				(unsigned long *)&ghcb->save.valid_bitmap);	\
+	}									\
+										\
+	static inline void ghcb_set_##field(struct ghcb *ghcb, u64 value)	\
+	{									\
+		__set_bit(GHCB_BITMAP_IDX(field),				\
+			  (unsigned long *)&ghcb->save.valid_bitmap);		\
+		ghcb->save.field = value;					\
+	}
+
+DEFINE_GHCB_ACCESSORS(cpl)
+DEFINE_GHCB_ACCESSORS(rip)
+DEFINE_GHCB_ACCESSORS(rsp)
+DEFINE_GHCB_ACCESSORS(rax)
+DEFINE_GHCB_ACCESSORS(rcx)
+DEFINE_GHCB_ACCESSORS(rdx)
+DEFINE_GHCB_ACCESSORS(rbx)
+DEFINE_GHCB_ACCESSORS(rbp)
+DEFINE_GHCB_ACCESSORS(rsi)
+DEFINE_GHCB_ACCESSORS(rdi)
+DEFINE_GHCB_ACCESSORS(r8)
+DEFINE_GHCB_ACCESSORS(r9)
+DEFINE_GHCB_ACCESSORS(r10)
+DEFINE_GHCB_ACCESSORS(r11)
+DEFINE_GHCB_ACCESSORS(r12)
+DEFINE_GHCB_ACCESSORS(r13)
+DEFINE_GHCB_ACCESSORS(r14)
+DEFINE_GHCB_ACCESSORS(r15)
+DEFINE_GHCB_ACCESSORS(sw_exit_code)
+DEFINE_GHCB_ACCESSORS(sw_exit_info_1)
+DEFINE_GHCB_ACCESSORS(sw_exit_info_2)
+DEFINE_GHCB_ACCESSORS(sw_scratch)
+DEFINE_GHCB_ACCESSORS(xcr0)
+
 #endif

arch/x86/include/asm/trap_pf.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_TRAP_PF_H
+#define _ASM_X86_TRAP_PF_H
+
+/*
+ * Page fault error code bits:
+ *
+ *   bit 0 ==	 0: no page found	1: protection fault
+ *   bit 1 ==	 0: read access		1: write access
+ *   bit 2 ==	 0: kernel-mode access	1: user-mode access
+ *   bit 3 ==				1: use of reserved bit detected
+ *   bit 4 ==				1: fault was an instruction fetch
+ *   bit 5 ==				1: protection keys block access
+ */
+enum x86_pf_error_code {
+	X86_PF_PROT	=		1 << 0,
+	X86_PF_WRITE	=		1 << 1,
+	X86_PF_USER	=		1 << 2,
+	X86_PF_RSVD	=		1 << 3,
+	X86_PF_INSTR	=		1 << 4,
+	X86_PF_PK	=		1 << 5,
+};
+
+#endif /* _ASM_X86_TRAP_PF_H */

arch/x86/include/asm/trapnr.h

@@ -26,6 +26,7 @@
 #define X86_TRAP_XF		19	/* SIMD Floating-Point Exception */
 #define X86_TRAP_VE		20	/* Virtualization Exception */
 #define X86_TRAP_CP		21	/* Control Protection Exception */
+#define X86_TRAP_VC		29	/* VMM Communication Exception */
 #define X86_TRAP_IRET		32	/* IRET Exception */
 
 #endif

arch/x86/include/asm/traps.h

@@ -8,12 +8,14 @@
 #include <asm/debugreg.h>
 #include <asm/idtentry.h>
 #include <asm/siginfo.h>			/* TRAP_TRACE, ... */
+#include <asm/trap_pf.h>
 
 #ifdef CONFIG_X86_64
 asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs);
 asmlinkage __visible notrace
 struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s);
 void __init trap_init(void);
+asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *eregs);
 #endif
 
 #ifdef CONFIG_X86_F00F_BUG
@@ -43,22 +45,4 @@ void __noreturn handle_stack_overflow(const char *message,
 				      unsigned long fault_address);
 #endif
 
-/*
- * Page fault error code bits:
- *
- *   bit 0 ==	 0: no page found	1: protection fault
- *   bit 1 ==	 0: read access		1: write access
- *   bit 2 ==	 0: kernel-mode access	1: user-mode access
- *   bit 3 ==				1: use of reserved bit detected
- *   bit 4 ==				1: fault was an instruction fetch
- *   bit 5 ==				1: protection keys block access
- */
-enum x86_pf_error_code {
-	X86_PF_PROT	=		1 << 0,
-	X86_PF_WRITE	=		1 << 1,
-	X86_PF_USER	=		1 << 2,
-	X86_PF_RSVD	=		1 << 3,
-	X86_PF_INSTR	=		1 << 4,
-	X86_PF_PK	=		1 << 5,
-};
 #endif /* _ASM_X86_TRAPS_H */

arch/x86/include/asm/x86_init.h

@@ -4,8 +4,10 @@
 
 #include <asm/bootparam.h>
 
+struct ghcb;
 struct mpc_bus;
 struct mpc_cpu;
+struct pt_regs;
 struct mpc_table;
 struct cpuinfo_x86;
 struct irq_domain;
@@ -229,10 +231,22 @@ struct x86_legacy_features {
 /**
  * struct x86_hyper_runtime - x86 hypervisor specific runtime callbacks
  *
- * @pin_vcpu:		pin current vcpu to specified physical cpu (run rarely)
+ * @pin_vcpu:			pin current vcpu to specified physical
+ *				cpu (run rarely)
+ * @sev_es_hcall_prepare:	Load additional hypervisor-specific
+ *				state into the GHCB when doing a VMMCALL under
+ *				SEV-ES. Called from the #VC exception handler.
+ * @sev_es_hcall_finish:	Copies state from the GHCB back into the
+ *				processor (or pt_regs). Also runs checks on the
+ *				state returned from the hypervisor after a
+ *				VMMCALL under SEV-ES.  Needs to return 'false'
+ *				if the checks fail.  Called from the #VC
+ *				exception handler.
  */
 struct x86_hyper_runtime {
 	void (*pin_vcpu)(int cpu);
+	void (*sev_es_hcall_prepare)(struct ghcb *ghcb, struct pt_regs *regs);
+	bool (*sev_es_hcall_finish)(struct ghcb *ghcb, struct pt_regs *regs);
 };
 
 /**

arch/x86/include/uapi/asm/svm.h

@@ -29,6 +29,7 @@
 #define SVM_EXIT_WRITE_DR6     0x036
 #define SVM_EXIT_WRITE_DR7     0x037
 #define SVM_EXIT_EXCP_BASE     0x040
+#define SVM_EXIT_LAST_EXCP     0x05f
 #define SVM_EXIT_INTR          0x060
 #define SVM_EXIT_NMI           0x061
 #define SVM_EXIT_SMI           0x062
@@ -80,6 +81,16 @@
 #define SVM_EXIT_AVIC_INCOMPLETE_IPI		0x401
 #define SVM_EXIT_AVIC_UNACCELERATED_ACCESS	0x402
 
+/* SEV-ES software-defined VMGEXIT events */
+#define SVM_VMGEXIT_MMIO_READ			0x80000001
+#define SVM_VMGEXIT_MMIO_WRITE			0x80000002
+#define SVM_VMGEXIT_NMI_COMPLETE		0x80000003
+#define SVM_VMGEXIT_AP_HLT_LOOP			0x80000004
+#define SVM_VMGEXIT_AP_JUMP_TABLE		0x80000005
+#define SVM_VMGEXIT_SET_AP_JUMP_TABLE		0
+#define SVM_VMGEXIT_GET_AP_JUMP_TABLE		1
+#define SVM_VMGEXIT_UNSUPPORTED_EVENT		0x8000ffff
+
 #define SVM_EXIT_ERR           -1
 
 #define SVM_EXIT_REASONS \

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)

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 @@ static void early_detect_mem_encrypt(struct cpuinfo_x86 *c)
 		setup_clear_cpu_cap(X86_FEATURE_SME);
 clear_sev:
 		setup_clear_cpu_cap(X86_FEATURE_SEV);
+		setup_clear_cpu_cap(X86_FEATURE_SEV_ES);
 	}
 }
 

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 */
@@ -1907,6 +1909,29 @@ static inline void tss_setup_io_bitmap(struct tss_struct *tss)
 #endif
 }
 
+/*
+ * 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

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 }
 };

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
 };

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());
 

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:

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 @@ int __init __early_make_pgtable(unsigned long address, pmdval_t pmd)
 	}
 	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);
+}

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
 
@@ -111,6 +125,18 @@ SYM_CODE_START(secondary_startup_64)
 	/* Sanitize CPU configuration */
 	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
@@ -257,6 +291,39 @@ SYM_CODE_START(start_cpu0)
 	movq	initial_stack(%rip), %rsp
 	jmp	.Ljump_to_C_code
 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 */
@@ -264,6 +331,9 @@ SYM_CODE_END(start_cpu0)
 	.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)

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
 };
 

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)

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 @@ DEFINE_IDTENTRY_RAW(exc_nmi)
 
 	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))

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();

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();
 
 	/*

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);

arch/x86/kvm/svm/nested.c

@@ -1062,10 +1062,14 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 	struct vmcb *hsave = svm->nested.hsave;
 	struct vmcb __user *user_vmcb = (struct vmcb __user *)
 		&user_kvm_nested_state->data.svm[0];
-	struct vmcb_control_area ctl;
-	struct vmcb_save_area save;
+	struct vmcb_control_area *ctl;
+	struct vmcb_save_area *save;
+	int ret;
 	u32 cr0;
 
+	BUILD_BUG_ON(sizeof(struct vmcb_control_area) + sizeof(struct vmcb_save_area) >
+		     KVM_STATE_NESTED_SVM_VMCB_SIZE);
+
 	if (kvm_state->format != KVM_STATE_NESTED_FORMAT_SVM)
 		return -EINVAL;
 
@@ -1097,13 +1101,22 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 	if (kvm_state->size < sizeof(*kvm_state) + KVM_STATE_NESTED_SVM_VMCB_SIZE)
 		return -EINVAL;
-	if (copy_from_user(&ctl, &user_vmcb->control, sizeof(ctl)))
-		return -EFAULT;
-	if (copy_from_user(&save, &user_vmcb->save, sizeof(save)))
-		return -EFAULT;
 
-	if (!nested_vmcb_check_controls(&ctl))
-		return -EINVAL;
+	ret  = -ENOMEM;
+	ctl  = kzalloc(sizeof(*ctl),  GFP_KERNEL);
+	save = kzalloc(sizeof(*save), GFP_KERNEL);
+	if (!ctl || !save)
+		goto out_free;
+
+	ret = -EFAULT;
+	if (copy_from_user(ctl, &user_vmcb->control, sizeof(*ctl)))
+		goto out_free;
+	if (copy_from_user(save, &user_vmcb->save, sizeof(*save)))
+		goto out_free;
+
+	ret = -EINVAL;
+	if (!nested_vmcb_check_controls(ctl))
+		goto out_free;
 
 	/*
 	 * Processor state contains L2 state.  Check that it is
@@ -1111,15 +1124,15 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 	 */
 	cr0 = kvm_read_cr0(vcpu);
         if (((cr0 & X86_CR0_CD) == 0) && (cr0 & X86_CR0_NW))
-                return -EINVAL;
+		goto out_free;
 
 	/*
 	 * Validate host state saved from before VMRUN (see
 	 * nested_svm_check_permissions).
 	 * TODO: validate reserved bits for all saved state.
 	 */
-	if (!(save.cr0 & X86_CR0_PG))
-		return -EINVAL;
+	if (!(save->cr0 & X86_CR0_PG))
+		goto out_free;
 
 	/*
 	 * All checks done, we can enter guest mode.  L1 control fields
@@ -1128,10 +1141,10 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 	 * contains saved L1 state.
 	 */
 	copy_vmcb_control_area(&hsave->control, &svm->vmcb->control);
-	hsave->save = save;
+	hsave->save = *save;
 
 	svm->nested.vmcb = kvm_state->hdr.svm.vmcb_pa;
-	load_nested_vmcb_control(svm, &ctl);
+	load_nested_vmcb_control(svm, ctl);
 	nested_prepare_vmcb_control(svm);
 
 	if (!nested_svm_vmrun_msrpm(svm))
@@ -1139,7 +1152,13 @@ static int svm_set_nested_state(struct kvm_vcpu *vcpu,
 
 out_set_gif:
 	svm_set_gif(svm, !!(kvm_state->flags & KVM_STATE_NESTED_GIF_SET));
-	return 0;
+
+	ret = 0;
+out_free:
+	kfree(save);
+	kfree(ctl);
+
+	return ret;
 }
 
 struct kvm_x86_nested_ops svm_nested_ops = {

arch/x86/kvm/svm/svm.c

@@ -4176,6 +4176,8 @@ static struct kvm_x86_init_ops svm_init_ops __initdata = {
 
 static int __init svm_init(void)
 {
+	__unused_size_checks();
+
 	return kvm_init(&svm_init_ops, sizeof(struct vcpu_svm),
 			__alignof__(struct vcpu_svm), THIS_MODULE);
 }

arch/x86/lib/insn-eval.c

@@ -20,6 +20,7 @@
 
 enum reg_type {
 	REG_TYPE_RM = 0,
+	REG_TYPE_REG,
 	REG_TYPE_INDEX,
 	REG_TYPE_BASE,
 };
@@ -52,6 +53,30 @@ static bool is_string_insn(struct insn *insn)
 	}
 }
 
+/**
+ * insn_has_rep_prefix() - Determine if instruction has a REP prefix
+ * @insn:	Instruction containing the prefix to inspect
+ *
+ * Returns:
+ *
+ * true if the instruction has a REP prefix, false if not.
+ */
+bool insn_has_rep_prefix(struct insn *insn)
+{
+	int i;
+
+	insn_get_prefixes(insn);
+
+	for (i = 0; i < insn->prefixes.nbytes; i++) {
+		insn_byte_t p = insn->prefixes.bytes[i];
+
+		if (p == 0xf2 || p == 0xf3)
+			return true;
+	}
+
+	return false;
+}
+
 /**
  * get_seg_reg_override_idx() - obtain segment register override index
  * @insn:	Valid instruction with segment override prefixes
@@ -439,6 +464,13 @@ static int get_reg_offset(struct insn *insn, struct pt_regs *regs,
 			regno += 8;
 		break;
 
+	case REG_TYPE_REG:
+		regno = X86_MODRM_REG(insn->modrm.value);
+
+		if (X86_REX_R(insn->rex_prefix.value))
+			regno += 8;
+		break;
+
 	case REG_TYPE_INDEX:
 		regno = X86_SIB_INDEX(insn->sib.value);
 		if (X86_REX_X(insn->rex_prefix.value))
@@ -807,6 +839,21 @@ int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs)
 	return get_reg_offset(insn, regs, REG_TYPE_RM);
 }
 
+/**
+ * insn_get_modrm_reg_off() - Obtain register in reg part of the ModRM byte
+ * @insn:	Instruction containing the ModRM byte
+ * @regs:	Register values as seen when entering kernel mode
+ *
+ * Returns:
+ *
+ * The register indicated by the reg part of the ModRM byte. The
+ * register is obtained as an offset from the base of pt_regs.
+ */
+int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs)
+{
+	return get_reg_offset(insn, regs, REG_TYPE_REG);
+}
+
 /**
  * get_seg_base_limit() - obtain base address and limit of a segment
  * @insn:	Instruction. Must be valid.
@@ -1367,3 +1414,86 @@ void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs)
 		return (void __user *)-1L;
 	}
 }
+
+/**
+ * insn_fetch_from_user() - Copy instruction bytes from user-space memory
+ * @regs:	Structure with register values as seen when entering kernel mode
+ * @buf:	Array to store the fetched instruction
+ *
+ * Gets the linear address of the instruction and copies the instruction bytes
+ * to the buf.
+ *
+ * Returns:
+ *
+ * Number of instruction bytes copied.
+ *
+ * 0 if nothing was copied.
+ */
+int insn_fetch_from_user(struct pt_regs *regs, unsigned char buf[MAX_INSN_SIZE])
+{
+	unsigned long seg_base = 0;
+	int not_copied;
+
+	/*
+	 * 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 0;
+	}
+
+
+	not_copied = copy_from_user(buf, (void __user *)(seg_base + regs->ip),
+				    MAX_INSN_SIZE);
+
+	return MAX_INSN_SIZE - not_copied;
+}
+
+/**
+ * insn_decode() - Decode an instruction
+ * @insn:	Structure to store decoded instruction
+ * @regs:	Structure with register values as seen when entering kernel mode
+ * @buf:	Buffer containing the instruction bytes
+ * @buf_size:   Number of instruction bytes available in buf
+ *
+ * Decodes the instruction provided in buf and stores the decoding results in
+ * insn. Also determines the correct address and operand sizes.
+ *
+ * Returns:
+ *
+ * True if instruction was decoded, False otherwise.
+ */
+bool insn_decode(struct insn *insn, struct pt_regs *regs,
+		 unsigned char buf[MAX_INSN_SIZE], int buf_size)
+{
+	int seg_defs;
+
+	insn_init(insn, buf, buf_size, 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 (buf_size < insn->length)
+		return false;
+
+	return true;
+}

arch/x86/mm/cpu_entry_area.c

@@ -21,7 +21,8 @@ DEFINE_PER_CPU(struct cea_exception_stacks*, cea_exception_stacks);
 DECLARE_PER_CPU_PAGE_ALIGNED(struct doublefault_stack, doublefault_stack);
 #endif
 
-struct cpu_entry_area *get_cpu_entry_area(int cpu)
+/* Is called from entry code, so must be noinstr */
+noinstr struct cpu_entry_area *get_cpu_entry_area(int cpu)
 {
 	unsigned long va = CPU_ENTRY_AREA_PER_CPU + cpu * CPU_ENTRY_AREA_SIZE;
 	BUILD_BUG_ON(sizeof(struct cpu_entry_area) % PAGE_SIZE != 0);

arch/x86/mm/extable.c

@@ -5,6 +5,7 @@
 #include <xen/xen.h>
 
 #include <asm/fpu/internal.h>
+#include <asm/sev-es.h>
 #include <asm/traps.h>
 #include <asm/kdebug.h>
 

arch/x86/mm/mem_encrypt.c

@@ -38,6 +38,7 @@
  * section is later cleared.
  */
 u64 sme_me_mask __section(.data) = 0;
+u64 sev_status __section(.data) = 0;
 EXPORT_SYMBOL(sme_me_mask);
 DEFINE_STATIC_KEY_FALSE(sev_enable_key);
 EXPORT_SYMBOL_GPL(sev_enable_key);
@@ -347,7 +348,13 @@ bool sme_active(void)
 
 bool sev_active(void)
 {
-	return sme_me_mask && sev_enabled;
+	return sev_status & MSR_AMD64_SEV_ENABLED;
+}
+
+/* Needs to be called from non-instrumentable code */
+bool noinstr sev_es_active(void)
+{
+	return sev_status & MSR_AMD64_SEV_ES_ENABLED;
 }
 
 /* Override for DMA direct allocation check - ARCH_HAS_FORCE_DMA_UNENCRYPTED */
@@ -400,6 +407,31 @@ void __init mem_encrypt_free_decrypted_mem(void)
 	free_init_pages("unused decrypted", vaddr, vaddr_end);
 }
 
+static void print_mem_encrypt_feature_info(void)
+{
+	pr_info("AMD Memory Encryption Features active:");
+
+	/* Secure Memory Encryption */
+	if (sme_active()) {
+		/*
+		 * SME is mutually exclusive with any of the SEV
+		 * features below.
+		 */
+		pr_cont(" SME\n");
+		return;
+	}
+
+	/* Secure Encrypted Virtualization */
+	if (sev_active())
+		pr_cont(" SEV");
+
+	/* Encrypted Register State */
+	if (sev_es_active())
+		pr_cont(" SEV-ES");
+
+	pr_cont("\n");
+}
+
 /* Architecture __weak replacement functions */
 void __init mem_encrypt_init(void)
 {
@@ -415,8 +447,6 @@ void __init mem_encrypt_init(void)
 	if (sev_active())
 		static_branch_enable(&sev_enable_key);
 
-	pr_info("AMD %s active\n",
-		sev_active() ? "Secure Encrypted Virtualization (SEV)"
-			     : "Secure Memory Encryption (SME)");
+	print_mem_encrypt_feature_info();
 }
 

arch/x86/mm/mem_encrypt_identity.c

@@ -540,6 +540,9 @@ void __init sme_enable(struct boot_params *bp)
 		if (!(msr & MSR_AMD64_SEV_ENABLED))
 			return;
 
+		/* Save SEV_STATUS to avoid reading MSR again */
+		sev_status = msr;
+
 		/* SEV state cannot be controlled by a command line option */
 		sme_me_mask = me_mask;
 		sev_enabled = true;

arch/x86/platform/efi/efi_64.c

@@ -47,6 +47,7 @@
 #include <asm/realmode.h>
 #include <asm/time.h>
 #include <asm/pgalloc.h>
+#include <asm/sev-es.h>
 
 /*
  * We allocate runtime services regions top-down, starting from -4G, i.e.
@@ -229,6 +230,15 @@ int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
 		return 1;
 	}
 
+	/*
+	 * When SEV-ES is active, the GHCB as set by the kernel will be used
+	 * by firmware. Create a 1:1 unencrypted mapping for each GHCB.
+	 */
+	if (sev_es_efi_map_ghcbs(pgd)) {
+		pr_err("Failed to create 1:1 mapping for the GHCBs!\n");
+		return 1;
+	}
+
 	/*
 	 * When making calls to the firmware everything needs to be 1:1
 	 * mapped and addressable with 32-bit pointers. Map the kernel