Merge 50f09a3dd587 ("Merge tag 'char-misc-5.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc") into char-misc-next

We want the char/misc driver fixes in here as well

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1461 insertions, 0 deletions

diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c
new file mode 100644
index 000000000000..9578c82832aa
--- /dev/null
+++ b/arch/x86/kernel/sev.c
@@ -0,0 +1,1461 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AMD Memory Encryption Support
+ *
+ * Copyright (C) 2019 SUSE
+ *
+ * Author: Joerg Roedel <jroedel@suse.de>
+ */
+
+#define pr_fmt(fmt)	"SEV-ES: " fmt
+
+#include <linux/sched/debug.h>	/* For show_regs() */
+#include <linux/percpu-defs.h>
+#include <linux/mem_encrypt.h>
+#include <linux/lockdep.h>
+#include <linux/printk.h>
+#include <linux/mm_types.h>
+#include <linux/set_memory.h>
+#include <linux/memblock.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+
+#include <asm/cpu_entry_area.h>
+#include <asm/stacktrace.h>
+#include <asm/sev.h>
+#include <asm/insn-eval.h>
+#include <asm/fpu/internal.h>
+#include <asm/processor.h>
+#include <asm/realmode.h>
+#include <asm/traps.h>
+#include <asm/svm.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+
+#define DR7_RESET_VALUE        0x400
+
+/* For early boot hypervisor communication in SEV-ES enabled guests */
+static struct ghcb boot_ghcb_page __bss_decrypted __aligned(PAGE_SIZE);
+
+/*
+ * Needs to be in the .data section because we need it NULL before bss is
+ * cleared
+ */
+static struct ghcb __initdata *boot_ghcb;
+
+/* #VC handler runtime per-CPU data */
+struct sev_es_runtime_data {
+	struct ghcb ghcb_page;
+
+	/* Physical storage for the per-CPU IST stack of the #VC handler */
+	char ist_stack[EXCEPTION_STKSZ] __aligned(PAGE_SIZE);
+
+	/*
+	 * Physical storage for the per-CPU fall-back stack of the #VC handler.
+	 * The fall-back stack is used when it is not safe to switch back to the
+	 * interrupted stack in the #VC entry code.
+	 */
+	char fallback_stack[EXCEPTION_STKSZ] __aligned(PAGE_SIZE);
+
+	/*
+	 * Reserve one page per CPU as backup storage for the unencrypted GHCB.
+	 * It is needed when an NMI happens while the #VC handler uses the real
+	 * GHCB, and the NMI handler itself is causing another #VC exception. In
+	 * that case the GHCB content of the first handler needs to be backed up
+	 * and restored.
+	 */
+	struct ghcb backup_ghcb;
+
+	/*
+	 * Mark the per-cpu GHCBs as in-use to detect nested #VC exceptions.
+	 * There is no need for it to be atomic, because nothing is written to
+	 * the GHCB between the read and the write of ghcb_active. So it is safe
+	 * to use it when a nested #VC exception happens before the write.
+	 *
+	 * This is necessary for example in the #VC->NMI->#VC case when the NMI
+	 * happens while the first #VC handler uses the GHCB. When the NMI code
+	 * raises a second #VC handler it might overwrite the contents of the
+	 * GHCB written by the first handler. To avoid this the content of the
+	 * GHCB is saved and restored when the GHCB is detected to be in use
+	 * already.
+	 */
+	bool ghcb_active;
+	bool backup_ghcb_active;
+
+	/*
+	 * Cached DR7 value - write it on DR7 writes and return it on reads.
+	 * That value will never make it to the real hardware DR7 as debugging
+	 * is currently unsupported in SEV-ES guests.
+	 */
+	unsigned long dr7;
+};
+
+struct ghcb_state {
+	struct ghcb *ghcb;
+};
+
+static DEFINE_PER_CPU(struct sev_es_runtime_data*, runtime_data);
+DEFINE_STATIC_KEY_FALSE(sev_es_enable_key);
+
+/* Needed in vc_early_forward_exception */
+void do_early_exception(struct pt_regs *regs, int trapnr);
+
+static void __init setup_vc_stacks(int cpu)
+{
+	struct sev_es_runtime_data *data;
+	struct cpu_entry_area *cea;
+	unsigned long vaddr;
+	phys_addr_t pa;
+
+	data = per_cpu(runtime_data, cpu);
+	cea  = get_cpu_entry_area(cpu);
+
+	/* Map #VC IST stack */
+	vaddr = CEA_ESTACK_BOT(&cea->estacks, VC);
+	pa    = __pa(data->ist_stack);
+	cea_set_pte((void *)vaddr, pa, PAGE_KERNEL);
+
+	/* Map VC fall-back stack */
+	vaddr = CEA_ESTACK_BOT(&cea->estacks, VC2);
+	pa    = __pa(data->fallback_stack);
+	cea_set_pte((void *)vaddr, pa, PAGE_KERNEL);
+}
+
+static __always_inline bool on_vc_stack(struct pt_regs *regs)
+{
+	unsigned long sp = regs->sp;
+
+	/* User-mode RSP is not trusted */
+	if (user_mode(regs))
+		return false;
+
+	/* SYSCALL gap still has user-mode RSP */
+	if (ip_within_syscall_gap(regs))
+		return false;
+
+	return ((sp >= __this_cpu_ist_bottom_va(VC)) && (sp < __this_cpu_ist_top_va(VC)));
+}
+
+/*
+ * This function handles the case when an NMI is raised in the #VC
+ * exception handler entry code, before the #VC handler has switched off
+ * its IST stack. In this case, the IST entry for #VC must be adjusted,
+ * so that any nested #VC exception will not overwrite the stack
+ * contents of the interrupted #VC handler.
+ *
+ * The IST entry is adjusted unconditionally so that it can be also be
+ * unconditionally adjusted back in __sev_es_ist_exit(). Otherwise a
+ * nested sev_es_ist_exit() call may adjust back the IST entry too
+ * early.
+ *
+ * The __sev_es_ist_enter() and __sev_es_ist_exit() functions always run
+ * on the NMI IST stack, as they are only called from NMI handling code
+ * right now.
+ */
+void noinstr __sev_es_ist_enter(struct pt_regs *regs)
+{
+	unsigned long old_ist, new_ist;
+
+	/* Read old IST entry */
+	new_ist = old_ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
+
+	/*
+	 * If NMI happened while on the #VC IST stack, set the new IST
+	 * value below regs->sp, so that the interrupted stack frame is
+	 * not overwritten by subsequent #VC exceptions.
+	 */
+	if (on_vc_stack(regs))
+		new_ist = regs->sp;
+
+	/*
+	 * Reserve additional 8 bytes and store old IST value so this
+	 * adjustment can be unrolled in __sev_es_ist_exit().
+	 */
+	new_ist -= sizeof(old_ist);
+	*(unsigned long *)new_ist = old_ist;
+
+	/* Set new IST entry */
+	this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], new_ist);
+}
+
+void noinstr __sev_es_ist_exit(void)
+{
+	unsigned long ist;
+
+	/* Read IST entry */
+	ist = __this_cpu_read(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC]);
+
+	if (WARN_ON(ist == __this_cpu_ist_top_va(VC)))
+		return;
+
+	/* Read back old IST entry and write it to the TSS */
+	this_cpu_write(cpu_tss_rw.x86_tss.ist[IST_INDEX_VC], *(unsigned long *)ist);
+}
+
+static __always_inline struct ghcb *sev_es_get_ghcb(struct ghcb_state *state)
+{
+	struct sev_es_runtime_data *data;
+	struct ghcb *ghcb;
+
+	data = this_cpu_read(runtime_data);
+	ghcb = &data->ghcb_page;
+
+	if (unlikely(data->ghcb_active)) {
+		/* GHCB is already in use - save its contents */
+
+		if (unlikely(data->backup_ghcb_active))
+			return NULL;
+
+		/* Mark backup_ghcb active before writing to it */
+		data->backup_ghcb_active = true;
+
+		state->ghcb = &data->backup_ghcb;
+
+		/* Backup GHCB content */
+		*state->ghcb = *ghcb;
+	} else {
+		state->ghcb = NULL;
+		data->ghcb_active = true;
+	}
+
+	return ghcb;
+}
+
+static __always_inline void sev_es_put_ghcb(struct ghcb_state *state)
+{
+	struct sev_es_runtime_data *data;
+	struct ghcb *ghcb;
+
+	data = this_cpu_read(runtime_data);
+	ghcb = &data->ghcb_page;
+
+	if (state->ghcb) {
+		/* Restore GHCB from Backup */
+		*ghcb = *state->ghcb;
+		data->backup_ghcb_active = false;
+		state->ghcb = NULL;
+	} else {
+		data->ghcb_active = false;
+	}
+}
+
+/* Needed in vc_early_forward_exception */
+void do_early_exception(struct pt_regs *regs, int trapnr);
+
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+	return __rdmsr(MSR_AMD64_SEV_ES_GHCB);
+}
+
+static __always_inline void sev_es_wr_ghcb_msr(u64 val)
+{
+	u32 low, high;
+
+	low  = (u32)(val);
+	high = (u32)(val >> 32);
+
+	native_wrmsr(MSR_AMD64_SEV_ES_GHCB, low, high);
+}
+
+static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
+				unsigned char *buffer)
+{
+	return copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
+}
+
+static enum es_result __vc_decode_user_insn(struct es_em_ctxt *ctxt)
+{
+	char buffer[MAX_INSN_SIZE];
+	int res;
+
+	res = insn_fetch_from_user_inatomic(ctxt->regs, buffer);
+	if (!res) {
+		ctxt->fi.vector     = X86_TRAP_PF;
+		ctxt->fi.error_code = X86_PF_INSTR | X86_PF_USER;
+		ctxt->fi.cr2        = ctxt->regs->ip;
+		return ES_EXCEPTION;
+	}
+
+	if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, res))
+		return ES_DECODE_FAILED;
+
+	if (ctxt->insn.immediate.got)
+		return ES_OK;
+	else
+		return ES_DECODE_FAILED;
+}
+
+static enum es_result __vc_decode_kern_insn(struct es_em_ctxt *ctxt)
+{
+	char buffer[MAX_INSN_SIZE];
+	int res, ret;
+
+	res = vc_fetch_insn_kernel(ctxt, buffer);
+	if (res) {
+		ctxt->fi.vector     = X86_TRAP_PF;
+		ctxt->fi.error_code = X86_PF_INSTR;
+		ctxt->fi.cr2        = ctxt->regs->ip;
+		return ES_EXCEPTION;
+	}
+
+	ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64);
+	if (ret < 0)
+		return ES_DECODE_FAILED;
+	else
+		return ES_OK;
+}
+
+static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
+{
+	if (user_mode(ctxt->regs))
+		return __vc_decode_user_insn(ctxt);
+	else
+		return __vc_decode_kern_insn(ctxt);
+}
+
+static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
+				   char *dst, char *buf, size_t size)
+{
+	unsigned long error_code = X86_PF_PROT | X86_PF_WRITE;
+	char __user *target = (char __user *)dst;
+	u64 d8;
+	u32 d4;
+	u16 d2;
+	u8  d1;
+
+	/* If instruction ran in kernel mode and the I/O buffer is in kernel space */
+	if (!user_mode(ctxt->regs) && !access_ok(target, size)) {
+		memcpy(dst, buf, size);
+		return ES_OK;
+	}
+
+	switch (size) {
+	case 1:
+		memcpy(&d1, buf, 1);
+		if (put_user(d1, target))
+			goto fault;
+		break;
+	case 2:
+		memcpy(&d2, buf, 2);
+		if (put_user(d2, target))
+			goto fault;
+		break;
+	case 4:
+		memcpy(&d4, buf, 4);
+		if (put_user(d4, target))
+			goto fault;
+		break;
+	case 8:
+		memcpy(&d8, buf, 8);
+		if (put_user(d8, target))
+			goto fault;
+		break;
+	default:
+		WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
+		return ES_UNSUPPORTED;
+	}
+
+	return ES_OK;
+
+fault:
+	if (user_mode(ctxt->regs))
+		error_code |= X86_PF_USER;
+
+	ctxt->fi.vector = X86_TRAP_PF;
+	ctxt->fi.error_code = error_code;
+	ctxt->fi.cr2 = (unsigned long)dst;
+
+	return ES_EXCEPTION;
+}
+
+static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
+				  char *src, char *buf, size_t size)
+{
+	unsigned long error_code = X86_PF_PROT;
+	char __user *s = (char __user *)src;
+	u64 d8;
+	u32 d4;
+	u16 d2;
+	u8  d1;
+
+	/* If instruction ran in kernel mode and the I/O buffer is in kernel space */
+	if (!user_mode(ctxt->regs) && !access_ok(s, size)) {
+		memcpy(buf, src, size);
+		return ES_OK;
+	}
+
+	switch (size) {
+	case 1:
+		if (get_user(d1, s))
+			goto fault;
+		memcpy(buf, &d1, 1);
+		break;
+	case 2:
+		if (get_user(d2, s))
+			goto fault;
+		memcpy(buf, &d2, 2);
+		break;
+	case 4:
+		if (get_user(d4, s))
+			goto fault;
+		memcpy(buf, &d4, 4);
+		break;
+	case 8:
+		if (get_user(d8, s))
+			goto fault;
+		memcpy(buf, &d8, 8);
+		break;
+	default:
+		WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
+		return ES_UNSUPPORTED;
+	}
+
+	return ES_OK;
+
+fault:
+	if (user_mode(ctxt->regs))
+		error_code |= X86_PF_USER;
+
+	ctxt->fi.vector = X86_TRAP_PF;
+	ctxt->fi.error_code = error_code;
+	ctxt->fi.cr2 = (unsigned long)src;
+
+	return ES_EXCEPTION;
+}
+
+static enum es_result vc_slow_virt_to_phys(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
+					   unsigned long vaddr, phys_addr_t *paddr)
+{
+	unsigned long va = (unsigned long)vaddr;
+	unsigned int level;
+	phys_addr_t pa;
+	pgd_t *pgd;
+	pte_t *pte;
+
+	pgd = __va(read_cr3_pa());
+	pgd = &pgd[pgd_index(va)];
+	pte = lookup_address_in_pgd(pgd, va, &level);
+	if (!pte) {
+		ctxt->fi.vector     = X86_TRAP_PF;
+		ctxt->fi.cr2        = vaddr;
+		ctxt->fi.error_code = 0;
+
+		if (user_mode(ctxt->regs))
+			ctxt->fi.error_code |= X86_PF_USER;
+
+		return ES_EXCEPTION;
+	}
+
+	if (WARN_ON_ONCE(pte_val(*pte) & _PAGE_ENC))
+		/* Emulated MMIO to/from encrypted memory not supported */
+		return ES_UNSUPPORTED;
+
+	pa = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
+	pa |= va & ~page_level_mask(level);
+
+	*paddr = pa;
+
+	return ES_OK;
+}
+
+/* Include code shared with pre-decompression boot stage */
+#include "sev-shared.c"
+
+void noinstr __sev_es_nmi_complete(void)
+{
+	struct ghcb_state state;
+	struct ghcb *ghcb;
+
+	ghcb = sev_es_get_ghcb(&state);
+
+	vc_ghcb_invalidate(ghcb);
+	ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_NMI_COMPLETE);
+	ghcb_set_sw_exit_info_1(ghcb, 0);
+	ghcb_set_sw_exit_info_2(ghcb, 0);
+
+	sev_es_wr_ghcb_msr(__pa_nodebug(ghcb));
+	VMGEXIT();
+
+	sev_es_put_ghcb(&state);
+}
+
+static u64 get_jump_table_addr(void)
+{
+	struct ghcb_state state;
+	unsigned long flags;
+	struct ghcb *ghcb;
+	u64 ret = 0;
+
+	local_irq_save(flags);
+
+	ghcb = sev_es_get_ghcb(&state);
+
+	vc_ghcb_invalidate(ghcb);
+	ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_JUMP_TABLE);
+	ghcb_set_sw_exit_info_1(ghcb, SVM_VMGEXIT_GET_AP_JUMP_TABLE);
+	ghcb_set_sw_exit_info_2(ghcb, 0);
+
+	sev_es_wr_ghcb_msr(__pa(ghcb));
+	VMGEXIT();
+
+	if (ghcb_sw_exit_info_1_is_valid(ghcb) &&
+	    ghcb_sw_exit_info_2_is_valid(ghcb))
+		ret = ghcb->save.sw_exit_info_2;
+
+	sev_es_put_ghcb(&state);
+
+	local_irq_restore(flags);
+
+	return ret;
+}
+
+int sev_es_setup_ap_jump_table(struct real_mode_header *rmh)
+{
+	u16 startup_cs, startup_ip;
+	phys_addr_t jump_table_pa;
+	u64 jump_table_addr;
+	u16 __iomem *jump_table;
+
+	jump_table_addr = get_jump_table_addr();
+
+	/* On UP guests there is no jump table so this is not a failure */
+	if (!jump_table_addr)
+		return 0;
+
+	/* Check if AP Jump Table is page-aligned */
+	if (jump_table_addr & ~PAGE_MASK)
+		return -EINVAL;
+
+	jump_table_pa = jump_table_addr & PAGE_MASK;
+
+	startup_cs = (u16)(rmh->trampoline_start >> 4);
+	startup_ip = (u16)(rmh->sev_es_trampoline_start -
+			   rmh->trampoline_start);
+
+	jump_table = ioremap_encrypted(jump_table_pa, PAGE_SIZE);
+	if (!jump_table)
+		return -EIO;
+
+	writew(startup_ip, &jump_table[0]);
+	writew(startup_cs, &jump_table[1]);
+
+	iounmap(jump_table);
+
+	return 0;
+}
+
+/*
+ * This is needed by the OVMF UEFI firmware which will use whatever it finds in
+ * the GHCB MSR as its GHCB to talk to the hypervisor. So make sure the per-cpu
+ * runtime GHCBs used by the kernel are also mapped in the EFI page-table.
+ */
+int __init sev_es_efi_map_ghcbs(pgd_t *pgd)
+{
+	struct sev_es_runtime_data *data;
+	unsigned long address, pflags;
+	int cpu;
+	u64 pfn;
+
+	if (!sev_es_active())
+		return 0;
+
+	pflags = _PAGE_NX | _PAGE_RW;
+
+	for_each_possible_cpu(cpu) {
+		data = per_cpu(runtime_data, cpu);
+
+		address = __pa(&data->ghcb_page);
+		pfn = address >> PAGE_SHIFT;
+
+		if (kernel_map_pages_in_pgd(pgd, pfn, address, 1, pflags))
+			return 1;
+	}
+
+	return 0;
+}
+
+static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+	struct pt_regs *regs = ctxt->regs;
+	enum es_result ret;
+	u64 exit_info_1;
+
+	/* Is it a WRMSR? */
+	exit_info_1 = (ctxt->insn.opcode.bytes[1] == 0x30) ? 1 : 0;
+
+	ghcb_set_rcx(ghcb, regs->cx);
+	if (exit_info_1) {
+		ghcb_set_rax(ghcb, regs->ax);
+		ghcb_set_rdx(ghcb, regs->dx);
+	}
+
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, exit_info_1, 0);
+
+	if ((ret == ES_OK) && (!exit_info_1)) {
+		regs->ax = ghcb->save.rax;
+		regs->dx = ghcb->save.rdx;
+	}
+
+	return ret;
+}
+
+/*
+ * This function runs on the first #VC exception after the kernel
+ * switched to virtual addresses.
+ */
+static bool __init sev_es_setup_ghcb(void)
+{
+	/* First make sure the hypervisor talks a supported protocol. */
+	if (!sev_es_negotiate_protocol())
+		return false;
+
+	/*
+	 * Clear the boot_ghcb. The first exception comes in before the bss
+	 * section is cleared.
+	 */
+	memset(&boot_ghcb_page, 0, PAGE_SIZE);
+
+	/* Alright - Make the boot-ghcb public */
+	boot_ghcb = &boot_ghcb_page;
+
+	return true;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void sev_es_ap_hlt_loop(void)
+{
+	struct ghcb_state state;
+	struct ghcb *ghcb;
+
+	ghcb = sev_es_get_ghcb(&state);
+
+	while (true) {
+		vc_ghcb_invalidate(ghcb);
+		ghcb_set_sw_exit_code(ghcb, SVM_VMGEXIT_AP_HLT_LOOP);
+		ghcb_set_sw_exit_info_1(ghcb, 0);
+		ghcb_set_sw_exit_info_2(ghcb, 0);
+
+		sev_es_wr_ghcb_msr(__pa(ghcb));
+		VMGEXIT();
+
+		/* Wakeup signal? */
+		if (ghcb_sw_exit_info_2_is_valid(ghcb) &&
+		    ghcb->save.sw_exit_info_2)
+			break;
+	}
+
+	sev_es_put_ghcb(&state);
+}
+
+/*
+ * Play_dead handler when running under SEV-ES. This is needed because
+ * the hypervisor can't deliver an SIPI request to restart the AP.
+ * Instead the kernel has to issue a VMGEXIT to halt the VCPU until the
+ * hypervisor wakes it up again.
+ */
+static void sev_es_play_dead(void)
+{
+	play_dead_common();
+
+	/* IRQs now disabled */
+
+	sev_es_ap_hlt_loop();
+
+	/*
+	 * If we get here, the VCPU was woken up again. Jump to CPU
+	 * startup code to get it back online.
+	 */
+	start_cpu0();
+}
+#else  /* CONFIG_HOTPLUG_CPU */
+#define sev_es_play_dead	native_play_dead
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#ifdef CONFIG_SMP
+static void __init sev_es_setup_play_dead(void)
+{
+	smp_ops.play_dead = sev_es_play_dead;
+}
+#else
+static inline void sev_es_setup_play_dead(void) { }
+#endif
+
+static void __init alloc_runtime_data(int cpu)
+{
+	struct sev_es_runtime_data *data;
+
+	data = memblock_alloc(sizeof(*data), PAGE_SIZE);
+	if (!data)
+		panic("Can't allocate SEV-ES runtime data");
+
+	per_cpu(runtime_data, cpu) = data;
+}
+
+static void __init init_ghcb(int cpu)
+{
+	struct sev_es_runtime_data *data;
+	int err;
+
+	data = per_cpu(runtime_data, cpu);
+
+	err = early_set_memory_decrypted((unsigned long)&data->ghcb_page,
+					 sizeof(data->ghcb_page));
+	if (err)
+		panic("Can't map GHCBs unencrypted");
+
+	memset(&data->ghcb_page, 0, sizeof(data->ghcb_page));
+
+	data->ghcb_active = false;
+	data->backup_ghcb_active = false;
+}
+
+void __init sev_es_init_vc_handling(void)
+{
+	int cpu;
+
+	BUILD_BUG_ON(offsetof(struct sev_es_runtime_data, ghcb_page) % PAGE_SIZE);
+
+	if (!sev_es_active())
+		return;
+
+	if (!sev_es_check_cpu_features())
+		panic("SEV-ES CPU Features missing");
+
+	/* Enable SEV-ES special handling */
+	static_branch_enable(&sev_es_enable_key);
+
+	/* Initialize per-cpu GHCB pages */
+	for_each_possible_cpu(cpu) {
+		alloc_runtime_data(cpu);
+		init_ghcb(cpu);
+		setup_vc_stacks(cpu);
+	}
+
+	sev_es_setup_play_dead();
+
+	/* Secondary CPUs use the runtime #VC handler */
+	initial_vc_handler = (unsigned long)safe_stack_exc_vmm_communication;
+}
+
+static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt)
+{
+	int trapnr = ctxt->fi.vector;
+
+	if (trapnr == X86_TRAP_PF)
+		native_write_cr2(ctxt->fi.cr2);
+
+	ctxt->regs->orig_ax = ctxt->fi.error_code;
+	do_early_exception(ctxt->regs, trapnr);
+}
+
+static long *vc_insn_get_reg(struct es_em_ctxt *ctxt)
+{
+	long *reg_array;
+	int offset;
+
+	reg_array = (long *)ctxt->regs;
+	offset    = insn_get_modrm_reg_off(&ctxt->insn, ctxt->regs);
+
+	if (offset < 0)
+		return NULL;
+
+	offset /= sizeof(long);
+
+	return reg_array + offset;
+}
+
+static long *vc_insn_get_rm(struct es_em_ctxt *ctxt)
+{
+	long *reg_array;
+	int offset;
+
+	reg_array = (long *)ctxt->regs;
+	offset    = insn_get_modrm_rm_off(&ctxt->insn, ctxt->regs);
+
+	if (offset < 0)
+		return NULL;
+
+	offset /= sizeof(long);
+
+	return reg_array + offset;
+}
+static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
+				 unsigned int bytes, bool read)
+{
+	u64 exit_code, exit_info_1, exit_info_2;
+	unsigned long ghcb_pa = __pa(ghcb);
+	enum es_result res;
+	phys_addr_t paddr;
+	void __user *ref;
+
+	ref = insn_get_addr_ref(&ctxt->insn, ctxt->regs);
+	if (ref == (void __user *)-1L)
+		return ES_UNSUPPORTED;
+
+	exit_code = read ? SVM_VMGEXIT_MMIO_READ : SVM_VMGEXIT_MMIO_WRITE;
+
+	res = vc_slow_virt_to_phys(ghcb, ctxt, (unsigned long)ref, &paddr);
+	if (res != ES_OK) {
+		if (res == ES_EXCEPTION && !read)
+			ctxt->fi.error_code |= X86_PF_WRITE;
+
+		return res;
+	}
+
+	exit_info_1 = paddr;
+	/* Can never be greater than 8 */
+	exit_info_2 = bytes;
+
+	ghcb_set_sw_scratch(ghcb, ghcb_pa + offsetof(struct ghcb, shared_buffer));
+
+	return sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, exit_info_1, exit_info_2);
+}
+
+static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
+						 struct es_em_ctxt *ctxt)
+{
+	struct insn *insn = &ctxt->insn;
+	unsigned int bytes = 0;
+	enum es_result ret;
+	int sign_byte;
+	long *reg_data;
+
+	switch (insn->opcode.bytes[1]) {
+		/* MMIO Read w/ zero-extension */
+	case 0xb6:
+		bytes = 1;
+		fallthrough;
+	case 0xb7:
+		if (!bytes)
+			bytes = 2;
+
+		ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+		if (ret)
+			break;
+
+		/* Zero extend based on operand size */
+		reg_data = vc_insn_get_reg(ctxt);
+		if (!reg_data)
+			return ES_DECODE_FAILED;
+
+		memset(reg_data, 0, insn->opnd_bytes);
+
+		memcpy(reg_data, ghcb->shared_buffer, bytes);
+		break;
+
+		/* MMIO Read w/ sign-extension */
+	case 0xbe:
+		bytes = 1;
+		fallthrough;
+	case 0xbf:
+		if (!bytes)
+			bytes = 2;
+
+		ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+		if (ret)
+			break;
+
+		/* Sign extend based on operand size */
+		reg_data = vc_insn_get_reg(ctxt);
+		if (!reg_data)
+			return ES_DECODE_FAILED;
+
+		if (bytes == 1) {
+			u8 *val = (u8 *)ghcb->shared_buffer;
+
+			sign_byte = (*val & 0x80) ? 0xff : 0x00;
+		} else {
+			u16 *val = (u16 *)ghcb->shared_buffer;
+
+			sign_byte = (*val & 0x8000) ? 0xff : 0x00;
+		}
+		memset(reg_data, sign_byte, insn->opnd_bytes);
+
+		memcpy(reg_data, ghcb->shared_buffer, bytes);
+		break;
+
+	default:
+		ret = ES_UNSUPPORTED;
+	}
+
+	return ret;
+}
+
+/*
+ * The MOVS instruction has two memory operands, which raises the
+ * problem that it is not known whether the access to the source or the
+ * destination caused the #VC exception (and hence whether an MMIO read
+ * or write operation needs to be emulated).
+ *
+ * Instead of playing games with walking page-tables and trying to guess
+ * whether the source or destination is an MMIO range, split the move
+ * into two operations, a read and a write with only one memory operand.
+ * This will cause a nested #VC exception on the MMIO address which can
+ * then be handled.
+ *
+ * This implementation has the benefit that it also supports MOVS where
+ * source _and_ destination are MMIO regions.
+ *
+ * It will slow MOVS on MMIO down a lot, but in SEV-ES guests it is a
+ * rare operation. If it turns out to be a performance problem the split
+ * operations can be moved to memcpy_fromio() and memcpy_toio().
+ */
+static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt,
+					  unsigned int bytes)
+{
+	unsigned long ds_base, es_base;
+	unsigned char *src, *dst;
+	unsigned char buffer[8];
+	enum es_result ret;
+	bool rep;
+	int off;
+
+	ds_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_DS);
+	es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
+
+	if (ds_base == -1L || es_base == -1L) {
+		ctxt->fi.vector = X86_TRAP_GP;
+		ctxt->fi.error_code = 0;
+		return ES_EXCEPTION;
+	}
+
+	src = ds_base + (unsigned char *)ctxt->regs->si;
+	dst = es_base + (unsigned char *)ctxt->regs->di;
+
+	ret = vc_read_mem(ctxt, src, buffer, bytes);
+	if (ret != ES_OK)
+		return ret;
+
+	ret = vc_write_mem(ctxt, dst, buffer, bytes);
+	if (ret != ES_OK)
+		return ret;
+
+	if (ctxt->regs->flags & X86_EFLAGS_DF)
+		off = -bytes;
+	else
+		off =  bytes;
+
+	ctxt->regs->si += off;
+	ctxt->regs->di += off;
+
+	rep = insn_has_rep_prefix(&ctxt->insn);
+	if (rep)
+		ctxt->regs->cx -= 1;
+
+	if (!rep || ctxt->regs->cx == 0)
+		return ES_OK;
+	else
+		return ES_RETRY;
+}
+
+static enum es_result vc_handle_mmio(struct ghcb *ghcb,
+				     struct es_em_ctxt *ctxt)
+{
+	struct insn *insn = &ctxt->insn;
+	unsigned int bytes = 0;
+	enum es_result ret;
+	long *reg_data;
+
+	switch (insn->opcode.bytes[0]) {
+	/* MMIO Write */
+	case 0x88:
+		bytes = 1;
+		fallthrough;
+	case 0x89:
+		if (!bytes)
+			bytes = insn->opnd_bytes;
+
+		reg_data = vc_insn_get_reg(ctxt);
+		if (!reg_data)
+			return ES_DECODE_FAILED;
+
+		memcpy(ghcb->shared_buffer, reg_data, bytes);
+
+		ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+		break;
+
+	case 0xc6:
+		bytes = 1;
+		fallthrough;
+	case 0xc7:
+		if (!bytes)
+			bytes = insn->opnd_bytes;
+
+		memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);
+
+		ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+		break;
+
+		/* MMIO Read */
+	case 0x8a:
+		bytes = 1;
+		fallthrough;
+	case 0x8b:
+		if (!bytes)
+			bytes = insn->opnd_bytes;
+
+		ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+		if (ret)
+			break;
+
+		reg_data = vc_insn_get_reg(ctxt);
+		if (!reg_data)
+			return ES_DECODE_FAILED;
+
+		/* Zero-extend for 32-bit operation */
+		if (bytes == 4)
+			*reg_data = 0;
+
+		memcpy(reg_data, ghcb->shared_buffer, bytes);
+		break;
+
+		/* MOVS instruction */
+	case 0xa4:
+		bytes = 1;
+		fallthrough;
+	case 0xa5:
+		if (!bytes)
+			bytes = insn->opnd_bytes;
+
+		ret = vc_handle_mmio_movs(ctxt, bytes);
+		break;
+		/* Two-Byte Opcodes */
+	case 0x0f:
+		ret = vc_handle_mmio_twobyte_ops(ghcb, ctxt);
+		break;
+	default:
+		ret = ES_UNSUPPORTED;
+	}
+
+	return ret;
+}
+
+static enum es_result vc_handle_dr7_write(struct ghcb *ghcb,
+					  struct es_em_ctxt *ctxt)
+{
+	struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+	long val, *reg = vc_insn_get_rm(ctxt);
+	enum es_result ret;
+
+	if (!reg)
+		return ES_DECODE_FAILED;
+
+	val = *reg;
+
+	/* Upper 32 bits must be written as zeroes */
+	if (val >> 32) {
+		ctxt->fi.vector = X86_TRAP_GP;
+		ctxt->fi.error_code = 0;
+		return ES_EXCEPTION;
+	}
+
+	/* Clear out other reserved bits and set bit 10 */
+	val = (val & 0xffff23ffL) | BIT(10);
+
+	/* Early non-zero writes to DR7 are not supported */
+	if (!data && (val & ~DR7_RESET_VALUE))
+		return ES_UNSUPPORTED;
+
+	/* Using a value of 0 for ExitInfo1 means RAX holds the value */
+	ghcb_set_rax(ghcb, val);
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WRITE_DR7, 0, 0);
+	if (ret != ES_OK)
+		return ret;
+
+	if (data)
+		data->dr7 = val;
+
+	return ES_OK;
+}
+
+static enum es_result vc_handle_dr7_read(struct ghcb *ghcb,
+					 struct es_em_ctxt *ctxt)
+{
+	struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+	long *reg = vc_insn_get_rm(ctxt);
+
+	if (!reg)
+		return ES_DECODE_FAILED;
+
+	if (data)
+		*reg = data->dr7;
+	else
+		*reg = DR7_RESET_VALUE;
+
+	return ES_OK;
+}
+
+static enum es_result vc_handle_wbinvd(struct ghcb *ghcb,
+				       struct es_em_ctxt *ctxt)
+{
+	return sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_WBINVD, 0, 0);
+}
+
+static enum es_result vc_handle_rdpmc(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+	enum es_result ret;
+
+	ghcb_set_rcx(ghcb, ctxt->regs->cx);
+
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_RDPMC, 0, 0);
+	if (ret != ES_OK)
+		return ret;
+
+	if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb)))
+		return ES_VMM_ERROR;
+
+	ctxt->regs->ax = ghcb->save.rax;
+	ctxt->regs->dx = ghcb->save.rdx;
+
+	return ES_OK;
+}
+
+static enum es_result vc_handle_monitor(struct ghcb *ghcb,
+					struct es_em_ctxt *ctxt)
+{
+	/*
+	 * Treat it as a NOP and do not leak a physical address to the
+	 * hypervisor.
+	 */
+	return ES_OK;
+}
+
+static enum es_result vc_handle_mwait(struct ghcb *ghcb,
+				      struct es_em_ctxt *ctxt)
+{
+	/* Treat the same as MONITOR/MONITORX */
+	return ES_OK;
+}
+
+static enum es_result vc_handle_vmmcall(struct ghcb *ghcb,
+					struct es_em_ctxt *ctxt)
+{
+	enum es_result ret;
+
+	ghcb_set_rax(ghcb, ctxt->regs->ax);
+	ghcb_set_cpl(ghcb, user_mode(ctxt->regs) ? 3 : 0);
+
+	if (x86_platform.hyper.sev_es_hcall_prepare)
+		x86_platform.hyper.sev_es_hcall_prepare(ghcb, ctxt->regs);
+
+	ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_VMMCALL, 0, 0);
+	if (ret != ES_OK)
+		return ret;
+
+	if (!ghcb_rax_is_valid(ghcb))
+		return ES_VMM_ERROR;
+
+	ctxt->regs->ax = ghcb->save.rax;
+
+	/*
+	 * Call sev_es_hcall_finish() after regs->ax is already set.
+	 * This allows the hypervisor handler to overwrite it again if
+	 * necessary.
+	 */
+	if (x86_platform.hyper.sev_es_hcall_finish &&
+	    !x86_platform.hyper.sev_es_hcall_finish(ghcb, ctxt->regs))
+		return ES_VMM_ERROR;
+
+	return ES_OK;
+}
+
+static enum es_result vc_handle_trap_ac(struct ghcb *ghcb,
+					struct es_em_ctxt *ctxt)
+{
+	/*
+	 * Calling ecx_alignment_check() directly does not work, because it
+	 * enables IRQs and the GHCB is active. Forward the exception and call
+	 * it later from vc_forward_exception().
+	 */
+	ctxt->fi.vector = X86_TRAP_AC;
+	ctxt->fi.error_code = 0;
+	return ES_EXCEPTION;
+}
+
+static __always_inline void vc_handle_trap_db(struct pt_regs *regs)
+{
+	if (user_mode(regs))
+		noist_exc_debug(regs);
+	else
+		exc_debug(regs);
+}
+
+static enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
+					 struct ghcb *ghcb,
+					 unsigned long exit_code)
+{
+	enum es_result result;
+
+	switch (exit_code) {
+	case SVM_EXIT_READ_DR7:
+		result = vc_handle_dr7_read(ghcb, ctxt);
+		break;
+	case SVM_EXIT_WRITE_DR7:
+		result = vc_handle_dr7_write(ghcb, ctxt);
+		break;
+	case SVM_EXIT_EXCP_BASE + X86_TRAP_AC:
+		result = vc_handle_trap_ac(ghcb, ctxt);
+		break;
+	case SVM_EXIT_RDTSC:
+	case SVM_EXIT_RDTSCP:
+		result = vc_handle_rdtsc(ghcb, ctxt, exit_code);
+		break;
+	case SVM_EXIT_RDPMC:
+		result = vc_handle_rdpmc(ghcb, ctxt);
+		break;
+	case SVM_EXIT_INVD:
+		pr_err_ratelimited("#VC exception for INVD??? Seriously???\n");
+		result = ES_UNSUPPORTED;
+		break;
+	case SVM_EXIT_CPUID:
+		result = vc_handle_cpuid(ghcb, ctxt);
+		break;
+	case SVM_EXIT_IOIO:
+		result = vc_handle_ioio(ghcb, ctxt);
+		break;
+	case SVM_EXIT_MSR:
+		result = vc_handle_msr(ghcb, ctxt);
+		break;
+	case SVM_EXIT_VMMCALL:
+		result = vc_handle_vmmcall(ghcb, ctxt);
+		break;
+	case SVM_EXIT_WBINVD:
+		result = vc_handle_wbinvd(ghcb, ctxt);
+		break;
+	case SVM_EXIT_MONITOR:
+		result = vc_handle_monitor(ghcb, ctxt);
+		break;
+	case SVM_EXIT_MWAIT:
+		result = vc_handle_mwait(ghcb, ctxt);
+		break;
+	case SVM_EXIT_NPF:
+		result = vc_handle_mmio(ghcb, ctxt);
+		break;
+	default:
+		/*
+		 * Unexpected #VC exception
+		 */
+		result = ES_UNSUPPORTED;
+	}
+
+	return result;
+}
+
+static __always_inline void vc_forward_exception(struct es_em_ctxt *ctxt)
+{
+	long error_code = ctxt->fi.error_code;
+	int trapnr = ctxt->fi.vector;
+
+	ctxt->regs->orig_ax = ctxt->fi.error_code;
+
+	switch (trapnr) {
+	case X86_TRAP_GP:
+		exc_general_protection(ctxt->regs, error_code);
+		break;
+	case X86_TRAP_UD:
+		exc_invalid_op(ctxt->regs);
+		break;
+	case X86_TRAP_AC:
+		exc_alignment_check(ctxt->regs, error_code);
+		break;
+	default:
+		pr_emerg("Unsupported exception in #VC instruction emulation - can't continue\n");
+		BUG();
+	}
+}
+
+static __always_inline bool on_vc_fallback_stack(struct pt_regs *regs)
+{
+	unsigned long sp = (unsigned long)regs;
+
+	return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
+}
+
+/*
+ * Main #VC exception handler. It is called when the entry code was able to
+ * switch off the IST to a safe kernel stack.
+ *
+ * With the current implementation it is always possible to switch to a safe
+ * stack because #VC exceptions only happen at known places, like intercepted
+ * instructions or accesses to MMIO areas/IO ports. They can also happen with
+ * code instrumentation when the hypervisor intercepts #DB, but the critical
+ * paths are forbidden to be instrumented, so #DB exceptions currently also
+ * only happen in safe places.
+ */
+DEFINE_IDTENTRY_VC_SAFE_STACK(exc_vmm_communication)
+{
+	struct sev_es_runtime_data *data = this_cpu_read(runtime_data);
+	irqentry_state_t irq_state;
+	struct ghcb_state state;
+	struct es_em_ctxt ctxt;
+	enum es_result result;
+	struct ghcb *ghcb;
+
+	/*
+	 * Handle #DB before calling into !noinstr code to avoid recursive #DB.
+	 */
+	if (error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB) {
+		vc_handle_trap_db(regs);
+		return;
+	}
+
+	irq_state = irqentry_nmi_enter(regs);
+	lockdep_assert_irqs_disabled();
+	instrumentation_begin();
+
+	/*
+	 * This is invoked through an interrupt gate, so IRQs are disabled. The
+	 * code below might walk page-tables for user or kernel addresses, so
+	 * keep the IRQs disabled to protect us against concurrent TLB flushes.
+	 */
+
+	ghcb = sev_es_get_ghcb(&state);
+	if (!ghcb) {
+		/*
+		 * Mark GHCBs inactive so that panic() is able to print the
+		 * message.
+		 */
+		data->ghcb_active        = false;
+		data->backup_ghcb_active = false;
+
+		panic("Unable to handle #VC exception! GHCB and Backup GHCB are already in use");
+	}
+
+	vc_ghcb_invalidate(ghcb);
+	result = vc_init_em_ctxt(&ctxt, regs, error_code);
+
+	if (result == ES_OK)
+		result = vc_handle_exitcode(&ctxt, ghcb, error_code);
+
+	sev_es_put_ghcb(&state);
+
+	/* Done - now check the result */
+	switch (result) {
+	case ES_OK:
+		vc_finish_insn(&ctxt);
+		break;
+	case ES_UNSUPPORTED:
+		pr_err_ratelimited("Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
+				   error_code, regs->ip);
+		goto fail;
+	case ES_VMM_ERROR:
+		pr_err_ratelimited("Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+				   error_code, regs->ip);
+		goto fail;
+	case ES_DECODE_FAILED:
+		pr_err_ratelimited("Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+				   error_code, regs->ip);
+		goto fail;
+	case ES_EXCEPTION:
+		vc_forward_exception(&ctxt);
+		break;
+	case ES_RETRY:
+		/* Nothing to do */
+		break;
+	default:
+		pr_emerg("Unknown result in %s():%d\n", __func__, result);
+		/*
+		 * Emulating the instruction which caused the #VC exception
+		 * failed - can't continue so print debug information
+		 */
+		BUG();
+	}
+
+out:
+	instrumentation_end();
+	irqentry_nmi_exit(regs, irq_state);
+
+	return;
+
+fail:
+	if (user_mode(regs)) {
+		/*
+		 * Do not kill the machine if user-space triggered the
+		 * exception. Send SIGBUS instead and let user-space deal with
+		 * it.
+		 */
+		force_sig_fault(SIGBUS, BUS_OBJERR, (void __user *)0);
+	} else {
+		pr_emerg("PANIC: Unhandled #VC exception in kernel space (result=%d)\n",
+			 result);
+
+		/* Show some debug info */
+		show_regs(regs);
+
+		/* Ask hypervisor to sev_es_terminate */
+		sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+
+		/* If that fails and we get here - just panic */
+		panic("Returned from Terminate-Request to Hypervisor\n");
+	}
+
+	goto out;
+}
+
+/* This handler runs on the #VC fall-back stack. It can cause further #VC exceptions */
+DEFINE_IDTENTRY_VC_IST(exc_vmm_communication)
+{
+	instrumentation_begin();
+	panic("Can't handle #VC exception from unsupported context\n");
+	instrumentation_end();
+}
+
+DEFINE_IDTENTRY_VC(exc_vmm_communication)
+{
+	if (likely(!on_vc_fallback_stack(regs)))
+		safe_stack_exc_vmm_communication(regs, error_code);
+	else
+		ist_exc_vmm_communication(regs, error_code);
+}
+
+bool __init handle_vc_boot_ghcb(struct pt_regs *regs)
+{
+	unsigned long exit_code = regs->orig_ax;
+	struct es_em_ctxt ctxt;
+	enum es_result result;
+
+	/* Do initial setup or terminate the guest */
+	if (unlikely(boot_ghcb == NULL && !sev_es_setup_ghcb()))
+		sev_es_terminate(GHCB_SEV_ES_REASON_GENERAL_REQUEST);
+
+	vc_ghcb_invalidate(boot_ghcb);
+
+	result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+	if (result == ES_OK)
+		result = vc_handle_exitcode(&ctxt, boot_ghcb, exit_code);
+
+	/* Done - now check the result */
+	switch (result) {
+	case ES_OK:
+		vc_finish_insn(&ctxt);
+		break;
+	case ES_UNSUPPORTED:
+		early_printk("PANIC: Unsupported exit-code 0x%02lx in early #VC exception (IP: 0x%lx)\n",
+				exit_code, regs->ip);
+		goto fail;
+	case ES_VMM_ERROR:
+		early_printk("PANIC: Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+				exit_code, regs->ip);
+		goto fail;
+	case ES_DECODE_FAILED:
+		early_printk("PANIC: Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+				exit_code, regs->ip);
+		goto fail;
+	case ES_EXCEPTION:
+		vc_early_forward_exception(&ctxt);
+		break;
+	case ES_RETRY:
+		/* Nothing to do */
+		break;
+	default:
+		BUG();
+	}
+
+	return true;
+
+fail:
+	show_regs(regs);
+
+	while (true)
+		halt();
+}