@@ -150,6 +150,7 @@ void sev_prep_identity_maps(unsigned long top_level_pgt);
enum es_result vc_decode_insn(struct es_em_ctxt *ctxt);
bool insn_has_rep_prefix(struct insn *insn);
void sev_insn_decode_init(void);
+bool early_setup_ghcb(void);
#else
static inline void sev_enable(struct boot_params *bp)
{
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include "misc.h"
+#include "sev.h"
#include <linux/kernel.h>
#include <linux/string.h>
@@ -8,6 +9,9 @@
#include <asm/pgtable_types.h>
#include <asm/ptrace.h>
#include <asm/sev.h>
+#include <asm/trapnr.h>
+#include <asm/trap_pf.h>
+#include <asm/fpu/xcr.h>
#define __BOOT_COMPRESSED
@@ -49,3 +53,82 @@ enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
}
extern void sev_insn_decode_init(void) __alias(inat_init_tables);
+
+/*
+ * 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 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;
+}
+
+static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
+{
+ return ES_OK;
+}
+
+static bool fault_in_kernel_space(unsigned long address)
+{
+ return false;
+}
+
+#define sev_printk(fmt, ...)
+
+#include "../../coco/sev/vc-shared.c"
+
+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_ghcb())
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+
+ vc_ghcb_invalidate(boot_ghcb);
+ result = vc_init_em_ctxt(&ctxt, regs, exit_code);
+ if (result != ES_OK)
+ goto finish;
+
+ result = vc_check_opcode_bytes(&ctxt, 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)
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+}
@@ -24,63 +24,11 @@
#include <asm/cpuid.h>
#include "error.h"
-#include "../msr.h"
+#include "sev.h"
static struct ghcb boot_ghcb_page __aligned(PAGE_SIZE);
struct ghcb *boot_ghcb;
-/*
- * 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)
-{
- struct msr m;
-
- boot_rdmsr(MSR_AMD64_SEV_ES_GHCB, &m);
-
- return m.q;
-}
-
-static inline void sev_es_wr_ghcb_msr(u64 val)
-{
- struct msr m;
-
- m.q = val;
- boot_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m);
-}
-
-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;
-}
-
-static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
-{
- return ES_OK;
-}
-
-static bool fault_in_kernel_space(unsigned long address)
-{
- return false;
-}
-
#undef __init
#define __init
@@ -182,7 +130,7 @@ void snp_set_page_shared(unsigned long paddr)
__page_state_change(paddr, SNP_PAGE_STATE_SHARED);
}
-static bool early_setup_ghcb(void)
+bool early_setup_ghcb(void)
{
if (set_page_decrypted((unsigned long)&boot_ghcb_page))
return false;
@@ -266,46 +214,6 @@ bool sev_es_check_ghcb_fault(unsigned long address)
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_ghcb())
- sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
-
- vc_ghcb_invalidate(boot_ghcb);
- result = vc_init_em_ctxt(&ctxt, regs, exit_code);
- if (result != ES_OK)
- goto finish;
-
- result = vc_check_opcode_bytes(&ctxt, 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)
- sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
-}
-
/*
* SNP_FEATURES_IMPL_REQ is the mask of SNP features that will need
* guest side implementation for proper functioning of the guest. If any
@@ -10,10 +10,29 @@
#ifdef CONFIG_AMD_MEM_ENCRYPT
+#include "../msr.h"
+
void snp_accept_memory(phys_addr_t start, phys_addr_t end);
u64 sev_get_status(void);
bool early_is_sevsnp_guest(void);
+static inline u64 sev_es_rd_ghcb_msr(void)
+{
+ struct msr m;
+
+ boot_rdmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+
+ return m.q;
+}
+
+static inline void sev_es_wr_ghcb_msr(u64 val)
+{
+ struct msr m;
+
+ m.q = val;
+ boot_wrmsr(MSR_AMD64_SEV_ES_GHCB, &m);
+}
+
#else
static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { }
@@ -14,13 +14,9 @@
#ifndef __BOOT_COMPRESSED
#define error(v) pr_err(v)
#define has_cpuflag(f) boot_cpu_has(f)
-#define sev_printk(fmt, ...) printk(fmt, ##__VA_ARGS__)
-#define sev_printk_rtl(fmt, ...) printk_ratelimited(fmt, ##__VA_ARGS__)
#else
#undef WARN
#define WARN(condition, format...) (!!(condition))
-#define sev_printk(fmt, ...)
-#define sev_printk_rtl(fmt, ...)
#undef vc_forward_exception
#define vc_forward_exception(c) panic("SNP: Hypervisor requested exception\n")
#endif
@@ -36,16 +32,6 @@
struct svsm_ca *boot_svsm_caa __ro_after_init;
u64 boot_svsm_caa_pa __ro_after_init;
-/* I/O parameters for CPUID-related helpers */
-struct cpuid_leaf {
- u32 fn;
- u32 subfn;
- u32 eax;
- u32 ebx;
- u32 ecx;
- u32 edx;
-};
-
/*
* Since feature negotiation related variables are set early in the boot
* process they must reside in the .data section so as not to be zeroed
@@ -151,33 +137,6 @@ bool sev_es_negotiate_protocol(void)
return true;
}
-static bool vc_decoding_needed(unsigned long exit_code)
-{
- /* Exceptions don't require to decode the instruction */
- return !(exit_code >= SVM_EXIT_EXCP_BASE &&
- exit_code <= SVM_EXIT_LAST_EXCP);
-}
-
-static enum es_result vc_init_em_ctxt(struct es_em_ctxt *ctxt,
- struct pt_regs *regs,
- unsigned long exit_code)
-{
- enum es_result ret = ES_OK;
-
- memset(ctxt, 0, sizeof(*ctxt));
- ctxt->regs = regs;
-
- if (vc_decoding_needed(exit_code))
- ret = vc_decode_insn(ctxt);
-
- return ret;
-}
-
-static void vc_finish_insn(struct es_em_ctxt *ctxt)
-{
- ctxt->regs->ip += ctxt->insn.length;
-}
-
static enum es_result verify_exception_info(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
{
u32 ret;
@@ -627,7 +586,7 @@ snp_cpuid_postprocess(struct ghcb *ghcb, struct es_em_ctxt *ctxt,
* Returns -EOPNOTSUPP if feature not enabled. Any other non-zero return value
* should be treated as fatal by caller.
*/
-static int __head
+int __head
snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf)
{
const struct snp_cpuid_table *cpuid_table = snp_cpuid_get_table();
@@ -737,391 +696,6 @@ fail:
sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
}
-static enum es_result vc_insn_string_check(struct es_em_ctxt *ctxt,
- unsigned long address,
- bool write)
-{
- if (user_mode(ctxt->regs) && fault_in_kernel_space(address)) {
- ctxt->fi.vector = X86_TRAP_PF;
- ctxt->fi.error_code = X86_PF_USER;
- ctxt->fi.cr2 = address;
- if (write)
- ctxt->fi.error_code |= X86_PF_WRITE;
-
- return ES_EXCEPTION;
- }
-
- return ES_OK;
-}
-
-static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
- void *src, char *buf,
- unsigned int data_size,
- unsigned int count,
- bool backwards)
-{
- int i, b = backwards ? -1 : 1;
- unsigned long address = (unsigned long)src;
- enum es_result ret;
-
- ret = vc_insn_string_check(ctxt, address, false);
- if (ret != ES_OK)
- return ret;
-
- for (i = 0; i < count; i++) {
- void *s = src + (i * data_size * b);
- char *d = buf + (i * data_size);
-
- ret = vc_read_mem(ctxt, s, d, data_size);
- if (ret != ES_OK)
- break;
- }
-
- return ret;
-}
-
-static enum es_result vc_insn_string_write(struct es_em_ctxt *ctxt,
- void *dst, char *buf,
- unsigned int data_size,
- unsigned int count,
- bool backwards)
-{
- int i, s = backwards ? -1 : 1;
- unsigned long address = (unsigned long)dst;
- enum es_result ret;
-
- ret = vc_insn_string_check(ctxt, address, true);
- if (ret != ES_OK)
- return ret;
-
- for (i = 0; i < count; i++) {
- void *d = dst + (i * data_size * s);
- char *b = buf + (i * data_size);
-
- ret = vc_write_mem(ctxt, d, b, data_size);
- if (ret != ES_OK)
- break;
- }
-
- return ret;
-}
-
-#define IOIO_TYPE_STR BIT(2)
-#define IOIO_TYPE_IN 1
-#define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR)
-#define IOIO_TYPE_OUT 0
-#define IOIO_TYPE_OUTS (IOIO_TYPE_OUT | IOIO_TYPE_STR)
-
-#define IOIO_REP BIT(3)
-
-#define IOIO_ADDR_64 BIT(9)
-#define IOIO_ADDR_32 BIT(8)
-#define IOIO_ADDR_16 BIT(7)
-
-#define IOIO_DATA_32 BIT(6)
-#define IOIO_DATA_16 BIT(5)
-#define IOIO_DATA_8 BIT(4)
-
-#define IOIO_SEG_ES (0 << 10)
-#define IOIO_SEG_DS (3 << 10)
-
-static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo)
-{
- struct insn *insn = &ctxt->insn;
- size_t size;
- u64 port;
-
- *exitinfo = 0;
-
- switch (insn->opcode.bytes[0]) {
- /* INS opcodes */
- case 0x6c:
- case 0x6d:
- *exitinfo |= IOIO_TYPE_INS;
- *exitinfo |= IOIO_SEG_ES;
- port = ctxt->regs->dx & 0xffff;
- break;
-
- /* OUTS opcodes */
- case 0x6e:
- case 0x6f:
- *exitinfo |= IOIO_TYPE_OUTS;
- *exitinfo |= IOIO_SEG_DS;
- port = ctxt->regs->dx & 0xffff;
- break;
-
- /* IN immediate opcodes */
- case 0xe4:
- case 0xe5:
- *exitinfo |= IOIO_TYPE_IN;
- port = (u8)insn->immediate.value & 0xffff;
- break;
-
- /* OUT immediate opcodes */
- case 0xe6:
- case 0xe7:
- *exitinfo |= IOIO_TYPE_OUT;
- port = (u8)insn->immediate.value & 0xffff;
- break;
-
- /* IN register opcodes */
- case 0xec:
- case 0xed:
- *exitinfo |= IOIO_TYPE_IN;
- port = ctxt->regs->dx & 0xffff;
- break;
-
- /* OUT register opcodes */
- case 0xee:
- case 0xef:
- *exitinfo |= IOIO_TYPE_OUT;
- port = ctxt->regs->dx & 0xffff;
- break;
-
- default:
- return ES_DECODE_FAILED;
- }
-
- *exitinfo |= port << 16;
-
- switch (insn->opcode.bytes[0]) {
- case 0x6c:
- case 0x6e:
- case 0xe4:
- case 0xe6:
- case 0xec:
- case 0xee:
- /* Single byte opcodes */
- *exitinfo |= IOIO_DATA_8;
- size = 1;
- break;
- default:
- /* Length determined by instruction parsing */
- *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16
- : IOIO_DATA_32;
- size = (insn->opnd_bytes == 2) ? 2 : 4;
- }
-
- switch (insn->addr_bytes) {
- case 2:
- *exitinfo |= IOIO_ADDR_16;
- break;
- case 4:
- *exitinfo |= IOIO_ADDR_32;
- break;
- case 8:
- *exitinfo |= IOIO_ADDR_64;
- break;
- }
-
- if (insn_has_rep_prefix(insn))
- *exitinfo |= IOIO_REP;
-
- return vc_ioio_check(ctxt, (u16)port, size);
-}
-
-static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
-{
- struct pt_regs *regs = ctxt->regs;
- u64 exit_info_1, exit_info_2;
- enum es_result ret;
-
- ret = vc_ioio_exitinfo(ctxt, &exit_info_1);
- if (ret != ES_OK)
- return ret;
-
- if (exit_info_1 & IOIO_TYPE_STR) {
-
- /* (REP) INS/OUTS */
-
- bool df = ((regs->flags & X86_EFLAGS_DF) == X86_EFLAGS_DF);
- unsigned int io_bytes, exit_bytes;
- unsigned int ghcb_count, op_count;
- unsigned long es_base;
- u64 sw_scratch;
-
- /*
- * For the string variants with rep prefix the amount of in/out
- * operations per #VC exception is limited so that the kernel
- * has a chance to take interrupts and re-schedule while the
- * instruction is emulated.
- */
- io_bytes = (exit_info_1 >> 4) & 0x7;
- ghcb_count = sizeof(ghcb->shared_buffer) / io_bytes;
-
- op_count = (exit_info_1 & IOIO_REP) ? regs->cx : 1;
- exit_info_2 = min(op_count, ghcb_count);
- exit_bytes = exit_info_2 * io_bytes;
-
- es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
-
- /* Read bytes of OUTS into the shared buffer */
- if (!(exit_info_1 & IOIO_TYPE_IN)) {
- ret = vc_insn_string_read(ctxt,
- (void *)(es_base + regs->si),
- ghcb->shared_buffer, io_bytes,
- exit_info_2, df);
- if (ret)
- return ret;
- }
-
- /*
- * Issue an VMGEXIT to the HV to consume the bytes from the
- * shared buffer or to have it write them into the shared buffer
- * depending on the instruction: OUTS or INS.
- */
- sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
- ghcb_set_sw_scratch(ghcb, sw_scratch);
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
- exit_info_1, exit_info_2);
- if (ret != ES_OK)
- return ret;
-
- /* Read bytes from shared buffer into the guest's destination. */
- if (exit_info_1 & IOIO_TYPE_IN) {
- ret = vc_insn_string_write(ctxt,
- (void *)(es_base + regs->di),
- ghcb->shared_buffer, io_bytes,
- exit_info_2, df);
- if (ret)
- return ret;
-
- if (df)
- regs->di -= exit_bytes;
- else
- regs->di += exit_bytes;
- } else {
- if (df)
- regs->si -= exit_bytes;
- else
- regs->si += exit_bytes;
- }
-
- if (exit_info_1 & IOIO_REP)
- regs->cx -= exit_info_2;
-
- ret = regs->cx ? ES_RETRY : ES_OK;
-
- } else {
-
- /* IN/OUT into/from rAX */
-
- int bits = (exit_info_1 & 0x70) >> 1;
- u64 rax = 0;
-
- if (!(exit_info_1 & IOIO_TYPE_IN))
- rax = lower_bits(regs->ax, bits);
-
- ghcb_set_rax(ghcb, rax);
-
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
- if (ret != ES_OK)
- return ret;
-
- if (exit_info_1 & IOIO_TYPE_IN) {
- if (!ghcb_rax_is_valid(ghcb))
- return ES_VMM_ERROR;
- regs->ax = lower_bits(ghcb->save.rax, bits);
- }
- }
-
- return ret;
-}
-
-static int vc_handle_cpuid_snp(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
-{
- struct pt_regs *regs = ctxt->regs;
- struct cpuid_leaf leaf;
- int ret;
-
- leaf.fn = regs->ax;
- leaf.subfn = regs->cx;
- ret = snp_cpuid(ghcb, ctxt, &leaf);
- if (!ret) {
- regs->ax = leaf.eax;
- regs->bx = leaf.ebx;
- regs->cx = leaf.ecx;
- regs->dx = leaf.edx;
- }
-
- return ret;
-}
-
-static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
- struct es_em_ctxt *ctxt)
-{
- struct pt_regs *regs = ctxt->regs;
- u32 cr4 = native_read_cr4();
- enum es_result ret;
- int snp_cpuid_ret;
-
- snp_cpuid_ret = vc_handle_cpuid_snp(ghcb, ctxt);
- if (!snp_cpuid_ret)
- return ES_OK;
- if (snp_cpuid_ret != -EOPNOTSUPP)
- return ES_VMM_ERROR;
-
- ghcb_set_rax(ghcb, regs->ax);
- ghcb_set_rcx(ghcb, regs->cx);
-
- if (cr4 & X86_CR4_OSXSAVE)
- /* Safe to read xcr0 */
- ghcb_set_xcr0(ghcb, xgetbv(XCR_XFEATURE_ENABLED_MASK));
- else
- /* xgetbv will cause #GP - use reset value for xcr0 */
- ghcb_set_xcr0(ghcb, 1);
-
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
- if (ret != ES_OK)
- return ret;
-
- if (!(ghcb_rax_is_valid(ghcb) &&
- ghcb_rbx_is_valid(ghcb) &&
- ghcb_rcx_is_valid(ghcb) &&
- ghcb_rdx_is_valid(ghcb)))
- return ES_VMM_ERROR;
-
- regs->ax = ghcb->save.rax;
- regs->bx = ghcb->save.rbx;
- regs->cx = ghcb->save.rcx;
- regs->dx = ghcb->save.rdx;
-
- return ES_OK;
-}
-
-static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
- struct es_em_ctxt *ctxt,
- unsigned long exit_code)
-{
- bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
- enum es_result ret;
-
- /*
- * The hypervisor should not be intercepting RDTSC/RDTSCP when Secure
- * TSC is enabled. A #VC exception will be generated if the RDTSC/RDTSCP
- * instructions are being intercepted. If this should occur and Secure
- * TSC is enabled, guest execution should be terminated as the guest
- * cannot rely on the TSC value provided by the hypervisor.
- */
- if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
- return ES_VMM_ERROR;
-
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
- if (ret != ES_OK)
- return ret;
-
- if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) &&
- (!rdtscp || ghcb_rcx_is_valid(ghcb))))
- return ES_VMM_ERROR;
-
- ctxt->regs->ax = ghcb->save.rax;
- ctxt->regs->dx = ghcb->save.rdx;
- if (rdtscp)
- ctxt->regs->cx = ghcb->save.rcx;
-
- return ES_OK;
-}
-
struct cc_setup_data {
struct setup_data header;
u32 cc_blob_address;
@@ -1238,97 +812,6 @@ static void __head pvalidate_4k_page(unsigned long vaddr, unsigned long paddr,
}
}
-static enum es_result vc_check_opcode_bytes(struct es_em_ctxt *ctxt,
- unsigned long exit_code)
-{
- unsigned int opcode = (unsigned int)ctxt->insn.opcode.value;
- u8 modrm = ctxt->insn.modrm.value;
-
- switch (exit_code) {
-
- case SVM_EXIT_IOIO:
- case SVM_EXIT_NPF:
- /* handled separately */
- return ES_OK;
-
- case SVM_EXIT_CPUID:
- if (opcode == 0xa20f)
- return ES_OK;
- break;
-
- case SVM_EXIT_INVD:
- if (opcode == 0x080f)
- return ES_OK;
- break;
-
- case SVM_EXIT_MONITOR:
- /* MONITOR and MONITORX instructions generate the same error code */
- if (opcode == 0x010f && (modrm == 0xc8 || modrm == 0xfa))
- return ES_OK;
- break;
-
- case SVM_EXIT_MWAIT:
- /* MWAIT and MWAITX instructions generate the same error code */
- if (opcode == 0x010f && (modrm == 0xc9 || modrm == 0xfb))
- return ES_OK;
- break;
-
- case SVM_EXIT_MSR:
- /* RDMSR */
- if (opcode == 0x320f ||
- /* WRMSR */
- opcode == 0x300f)
- return ES_OK;
- break;
-
- case SVM_EXIT_RDPMC:
- if (opcode == 0x330f)
- return ES_OK;
- break;
-
- case SVM_EXIT_RDTSC:
- if (opcode == 0x310f)
- return ES_OK;
- break;
-
- case SVM_EXIT_RDTSCP:
- if (opcode == 0x010f && modrm == 0xf9)
- return ES_OK;
- break;
-
- case SVM_EXIT_READ_DR7:
- if (opcode == 0x210f &&
- X86_MODRM_REG(ctxt->insn.modrm.value) == 7)
- return ES_OK;
- break;
-
- case SVM_EXIT_VMMCALL:
- if (opcode == 0x010f && modrm == 0xd9)
- return ES_OK;
-
- break;
-
- case SVM_EXIT_WRITE_DR7:
- if (opcode == 0x230f &&
- X86_MODRM_REG(ctxt->insn.modrm.value) == 7)
- return ES_OK;
- break;
-
- case SVM_EXIT_WBINVD:
- if (opcode == 0x90f)
- return ES_OK;
- break;
-
- default:
- break;
- }
-
- sev_printk(KERN_ERR "Wrong/unhandled opcode bytes: 0x%x, exit_code: 0x%lx, rIP: 0x%lx\n",
- opcode, exit_code, ctxt->regs->ip);
-
- return ES_UNSUPPORTED;
-}
-
/*
* Maintain the GPA of the SVSM Calling Area (CA) in order to utilize the SVSM
* services needed when not running in VMPL0.
@@ -9,7 +9,6 @@
#define pr_fmt(fmt) "SEV: " fmt
-#include <linux/sched/debug.h> /* For show_regs() */
#include <linux/percpu-defs.h>
#include <linux/cc_platform.h>
#include <linux/printk.h>
@@ -112,315 +111,6 @@ noinstr struct ghcb *__sev_get_ghcb(struct ghcb_state *state)
return ghcb;
}
-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 insn_bytes;
-
- insn_bytes = insn_fetch_from_user_inatomic(ctxt->regs, buffer);
- if (insn_bytes == 0) {
- /* Nothing could be copied */
- 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;
- } else if (insn_bytes == -EINVAL) {
- /* Effective RIP could not be calculated */
- ctxt->fi.vector = X86_TRAP_GP;
- ctxt->fi.error_code = 0;
- ctxt->fi.cr2 = 0;
- return ES_EXCEPTION;
- }
-
- if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes))
- 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;
-
- /*
- * This function uses __put_user() independent of whether kernel or user
- * memory is accessed. This works fine because __put_user() does no
- * sanity checks of the pointer being accessed. All that it does is
- * to report when the access failed.
- *
- * Also, this function runs in atomic context, so __put_user() is not
- * allowed to sleep. The page-fault handler detects that it is running
- * in atomic context and will not try to take mmap_sem and handle the
- * fault, so additional pagefault_enable()/disable() calls are not
- * needed.
- *
- * The access can't be done via copy_to_user() here because
- * vc_write_mem() must not use string instructions to access unsafe
- * memory. The reason is that MOVS is emulated by the #VC handler by
- * splitting the move up into a read and a write and taking a nested #VC
- * exception on whatever of them is the MMIO access. Using string
- * instructions here would cause infinite nesting.
- */
- switch (size) {
- case 1: {
- u8 d1;
- u8 __user *target = (u8 __user *)dst;
-
- memcpy(&d1, buf, 1);
- if (__put_user(d1, target))
- goto fault;
- break;
- }
- case 2: {
- u16 d2;
- u16 __user *target = (u16 __user *)dst;
-
- memcpy(&d2, buf, 2);
- if (__put_user(d2, target))
- goto fault;
- break;
- }
- case 4: {
- u32 d4;
- u32 __user *target = (u32 __user *)dst;
-
- memcpy(&d4, buf, 4);
- if (__put_user(d4, target))
- goto fault;
- break;
- }
- case 8: {
- u64 d8;
- u64 __user *target = (u64 __user *)dst;
-
- 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;
-
- /*
- * This function uses __get_user() independent of whether kernel or user
- * memory is accessed. This works fine because __get_user() does no
- * sanity checks of the pointer being accessed. All that it does is
- * to report when the access failed.
- *
- * Also, this function runs in atomic context, so __get_user() is not
- * allowed to sleep. The page-fault handler detects that it is running
- * in atomic context and will not try to take mmap_sem and handle the
- * fault, so additional pagefault_enable()/disable() calls are not
- * needed.
- *
- * The access can't be done via copy_from_user() here because
- * vc_read_mem() must not use string instructions to access unsafe
- * memory. The reason is that MOVS is emulated by the #VC handler by
- * splitting the move up into a read and a write and taking a nested #VC
- * exception on whatever of them is the MMIO access. Using string
- * instructions here would cause infinite nesting.
- */
- switch (size) {
- case 1: {
- u8 d1;
- u8 __user *s = (u8 __user *)src;
-
- if (__get_user(d1, s))
- goto fault;
- memcpy(buf, &d1, 1);
- break;
- }
- case 2: {
- u16 d2;
- u16 __user *s = (u16 __user *)src;
-
- if (__get_user(d2, s))
- goto fault;
- memcpy(buf, &d2, 2);
- break;
- }
- case 4: {
- u32 d4;
- u32 __user *s = (u32 __user *)src;
-
- if (__get_user(d4, s))
- goto fault;
- memcpy(buf, &d4, 4);
- break;
- }
- case 8: {
- u64 d8;
- u64 __user *s = (u64 __user *)src;
- 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;
-}
-
-static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
-{
- BUG_ON(size > 4);
-
- if (user_mode(ctxt->regs)) {
- struct thread_struct *t = ¤t->thread;
- struct io_bitmap *iobm = t->io_bitmap;
- size_t idx;
-
- if (!iobm)
- goto fault;
-
- for (idx = port; idx < port + size; ++idx) {
- if (test_bit(idx, iobm->bitmap))
- goto fault;
- }
- }
-
- return ES_OK;
-
-fault:
- ctxt->fi.vector = X86_TRAP_GP;
- ctxt->fi.error_code = 0;
-
- return ES_EXCEPTION;
-}
-
-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_PF:
- write_cr2(ctxt->fi.cr2);
- exc_page_fault(ctxt->regs, error_code);
- 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();
- }
-}
-
/* Include code shared with pre-decompression boot stage */
#include "sev-shared.c"
@@ -563,718 +253,6 @@ void __head early_snp_set_memory_shared(unsigned long vaddr, unsigned long paddr
early_set_pages_state(vaddr, paddr, npages, SNP_PAGE_STATE_SHARED);
}
-/* Writes to the SVSM CAA MSR are ignored */
-static enum es_result __vc_handle_msr_caa(struct pt_regs *regs, bool write)
-{
- if (write)
- return ES_OK;
-
- regs->ax = lower_32_bits(this_cpu_read(svsm_caa_pa));
- regs->dx = upper_32_bits(this_cpu_read(svsm_caa_pa));
-
- return ES_OK;
-}
-
-/*
- * TSC related accesses should not exit to the hypervisor when a guest is
- * executing with Secure TSC enabled, so special handling is required for
- * accesses of MSR_IA32_TSC and MSR_AMD64_GUEST_TSC_FREQ.
- */
-static enum es_result __vc_handle_secure_tsc_msrs(struct pt_regs *regs, bool write)
-{
- u64 tsc;
-
- /*
- * GUEST_TSC_FREQ should not be intercepted when Secure TSC is enabled.
- * Terminate the SNP guest when the interception is enabled.
- */
- if (regs->cx == MSR_AMD64_GUEST_TSC_FREQ)
- return ES_VMM_ERROR;
-
- /*
- * Writes: Writing to MSR_IA32_TSC can cause subsequent reads of the TSC
- * to return undefined values, so ignore all writes.
- *
- * Reads: Reads of MSR_IA32_TSC should return the current TSC value, use
- * the value returned by rdtsc_ordered().
- */
- if (write) {
- WARN_ONCE(1, "TSC MSR writes are verboten!\n");
- return ES_OK;
- }
-
- tsc = rdtsc_ordered();
- regs->ax = lower_32_bits(tsc);
- regs->dx = upper_32_bits(tsc);
-
- return ES_OK;
-}
-
-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;
- bool write;
-
- /* Is it a WRMSR? */
- write = ctxt->insn.opcode.bytes[1] == 0x30;
-
- switch (regs->cx) {
- case MSR_SVSM_CAA:
- return __vc_handle_msr_caa(regs, write);
- case MSR_IA32_TSC:
- case MSR_AMD64_GUEST_TSC_FREQ:
- if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
- return __vc_handle_secure_tsc_msrs(regs, write);
- break;
- default:
- break;
- }
-
- ghcb_set_rcx(ghcb, regs->cx);
- if (write) {
- ghcb_set_rax(ghcb, regs->ax);
- ghcb_set_rdx(ghcb, regs->dx);
- }
-
- ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, write, 0);
-
- if ((ret == ES_OK) && !write) {
- regs->ax = ghcb->save.rax;
- regs->dx = ghcb->save.rdx;
- }
-
- return ret;
-}
-
-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_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);
-}
-
-/*
- * 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;
- enum insn_mmio_type mmio;
- unsigned int bytes = 0;
- enum es_result ret;
- u8 sign_byte;
- long *reg_data;
-
- mmio = insn_decode_mmio(insn, &bytes);
- if (mmio == INSN_MMIO_DECODE_FAILED)
- return ES_DECODE_FAILED;
-
- if (mmio != INSN_MMIO_WRITE_IMM && mmio != INSN_MMIO_MOVS) {
- reg_data = insn_get_modrm_reg_ptr(insn, ctxt->regs);
- if (!reg_data)
- return ES_DECODE_FAILED;
- }
-
- if (user_mode(ctxt->regs))
- return ES_UNSUPPORTED;
-
- switch (mmio) {
- case INSN_MMIO_WRITE:
- memcpy(ghcb->shared_buffer, reg_data, bytes);
- ret = vc_do_mmio(ghcb, ctxt, bytes, false);
- break;
- case INSN_MMIO_WRITE_IMM:
- memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);
- ret = vc_do_mmio(ghcb, ctxt, bytes, false);
- break;
- case INSN_MMIO_READ:
- ret = vc_do_mmio(ghcb, ctxt, bytes, true);
- if (ret)
- break;
-
- /* Zero-extend for 32-bit operation */
- if (bytes == 4)
- *reg_data = 0;
-
- memcpy(reg_data, ghcb->shared_buffer, bytes);
- break;
- case INSN_MMIO_READ_ZERO_EXTEND:
- ret = vc_do_mmio(ghcb, ctxt, bytes, true);
- if (ret)
- break;
-
- /* Zero extend based on operand size */
- memset(reg_data, 0, insn->opnd_bytes);
- memcpy(reg_data, ghcb->shared_buffer, bytes);
- break;
- case INSN_MMIO_READ_SIGN_EXTEND:
- ret = vc_do_mmio(ghcb, ctxt, bytes, true);
- if (ret)
- break;
-
- 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;
- }
-
- /* Sign extend based on operand size */
- memset(reg_data, sign_byte, insn->opnd_bytes);
- memcpy(reg_data, ghcb->shared_buffer, bytes);
- break;
- case INSN_MMIO_MOVS:
- ret = vc_handle_mmio_movs(ctxt, bytes);
- break;
- default:
- ret = ES_UNSUPPORTED;
- break;
- }
-
- 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 (sev_status & MSR_AMD64_SNP_DEBUG_SWAP)
- return ES_VMM_ERROR;
-
- 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 (sev_status & MSR_AMD64_SNP_DEBUG_SWAP)
- return ES_VMM_ERROR;
-
- 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 enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
- struct ghcb *ghcb,
- unsigned long exit_code)
-{
- enum es_result result = vc_check_opcode_bytes(ctxt, exit_code);
-
- if (result != ES_OK)
- return 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 bool is_vc2_stack(unsigned long sp)
-{
- return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
-}
-
-static __always_inline bool vc_from_invalid_context(struct pt_regs *regs)
-{
- unsigned long sp, prev_sp;
-
- sp = (unsigned long)regs;
- prev_sp = regs->sp;
-
- /*
- * If the code was already executing on the VC2 stack when the #VC
- * happened, let it proceed to the normal handling routine. This way the
- * code executing on the VC2 stack can cause #VC exceptions to get handled.
- */
- return is_vc2_stack(sp) && !is_vc2_stack(prev_sp);
-}
-
-static bool vc_raw_handle_exception(struct pt_regs *regs, unsigned long error_code)
-{
- struct ghcb_state state;
- struct es_em_ctxt ctxt;
- enum es_result result;
- struct ghcb *ghcb;
- bool ret = true;
-
- ghcb = __sev_get_ghcb(&state);
-
- 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_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 #VC exception (IP: 0x%lx)\n",
- error_code, regs->ip);
- ret = false;
- break;
- case ES_VMM_ERROR:
- pr_err_ratelimited("Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
- error_code, regs->ip);
- ret = false;
- break;
- case ES_DECODE_FAILED:
- pr_err_ratelimited("Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
- error_code, regs->ip);
- ret = false;
- break;
- 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();
- }
-
- return ret;
-}
-
-static __always_inline bool vc_is_db(unsigned long error_code)
-{
- return error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB;
-}
-
-/*
- * Runtime #VC exception handler when raised from kernel mode. Runs in NMI mode
- * and will panic when an error happens.
- */
-DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
-{
- irqentry_state_t irq_state;
-
- /*
- * 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.
- *
- * But keep this here in case the noinstr annotations are violated due
- * to bug elsewhere.
- */
- if (unlikely(vc_from_invalid_context(regs))) {
- instrumentation_begin();
- panic("Can't handle #VC exception from unsupported context\n");
- instrumentation_end();
- }
-
- /*
- * Handle #DB before calling into !noinstr code to avoid recursive #DB.
- */
- if (vc_is_db(error_code)) {
- exc_debug(regs);
- return;
- }
-
- irq_state = irqentry_nmi_enter(regs);
-
- instrumentation_begin();
-
- if (!vc_raw_handle_exception(regs, error_code)) {
- /* Show some debug info */
- show_regs(regs);
-
- /* Ask hypervisor to sev_es_terminate */
- sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
-
- /* If that fails and we get here - just panic */
- panic("Returned from Terminate-Request to Hypervisor\n");
- }
-
- instrumentation_end();
- irqentry_nmi_exit(regs, irq_state);
-}
-
-/*
- * Runtime #VC exception handler when raised from user mode. Runs in IRQ mode
- * and will kill the current task with SIGBUS when an error happens.
- */
-DEFINE_IDTENTRY_VC_USER(exc_vmm_communication)
-{
- /*
- * Handle #DB before calling into !noinstr code to avoid recursive #DB.
- */
- if (vc_is_db(error_code)) {
- noist_exc_debug(regs);
- return;
- }
-
- irqentry_enter_from_user_mode(regs);
- instrumentation_begin();
-
- if (!vc_raw_handle_exception(regs, error_code)) {
- /*
- * 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);
- }
-
- instrumentation_end();
- irqentry_exit_to_user_mode(regs);
-}
-
-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;
-
- 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);
-
- sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
-}
-
/*
* Initial set up of SNP relies on information provided by the
* Confidential Computing blob, which can be passed to the kernel
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
-obj-y += core.o sev-nmi.o
+obj-y += core.o sev-nmi.o vc-handle.o
# Clang 14 and older may fail to respect __no_sanitize_undefined when inlining
UBSAN_SANITIZE_sev-nmi.o := n
new file mode 100644
@@ -0,0 +1,1061 @@
+// 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: " fmt
+
+#include <linux/sched/debug.h> /* For show_regs() */
+#include <linux/cc_platform.h>
+#include <linux/printk.h>
+#include <linux/mm_types.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <linux/psp-sev.h>
+#include <uapi/linux/sev-guest.h>
+
+#include <asm/init.h>
+#include <asm/stacktrace.h>
+#include <asm/sev.h>
+#include <asm/sev-internal.h>
+#include <asm/insn-eval.h>
+#include <asm/fpu/xcr.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+#include <asm/traps.h>
+#include <asm/svm.h>
+#include <asm/smp.h>
+#include <asm/cpu.h>
+#include <asm/apic.h>
+#include <asm/cpuid.h>
+
+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;
+}
+
+static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)
+{
+ BUG_ON(size > 4);
+
+ if (user_mode(ctxt->regs)) {
+ struct thread_struct *t = ¤t->thread;
+ struct io_bitmap *iobm = t->io_bitmap;
+ size_t idx;
+
+ if (!iobm)
+ goto fault;
+
+ for (idx = port; idx < port + size; ++idx) {
+ if (test_bit(idx, iobm->bitmap))
+ goto fault;
+ }
+ }
+
+ return ES_OK;
+
+fault:
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+
+ return ES_EXCEPTION;
+}
+
+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_PF:
+ write_cr2(ctxt->fi.cr2);
+ exc_page_fault(ctxt->regs, error_code);
+ 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 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 insn_bytes;
+
+ insn_bytes = insn_fetch_from_user_inatomic(ctxt->regs, buffer);
+ if (insn_bytes == 0) {
+ /* Nothing could be copied */
+ 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;
+ } else if (insn_bytes == -EINVAL) {
+ /* Effective RIP could not be calculated */
+ ctxt->fi.vector = X86_TRAP_GP;
+ ctxt->fi.error_code = 0;
+ ctxt->fi.cr2 = 0;
+ return ES_EXCEPTION;
+ }
+
+ if (!insn_decode_from_regs(&ctxt->insn, ctxt->regs, buffer, insn_bytes))
+ 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;
+
+ /*
+ * This function uses __put_user() independent of whether kernel or user
+ * memory is accessed. This works fine because __put_user() does no
+ * sanity checks of the pointer being accessed. All that it does is
+ * to report when the access failed.
+ *
+ * Also, this function runs in atomic context, so __put_user() is not
+ * allowed to sleep. The page-fault handler detects that it is running
+ * in atomic context and will not try to take mmap_sem and handle the
+ * fault, so additional pagefault_enable()/disable() calls are not
+ * needed.
+ *
+ * The access can't be done via copy_to_user() here because
+ * vc_write_mem() must not use string instructions to access unsafe
+ * memory. The reason is that MOVS is emulated by the #VC handler by
+ * splitting the move up into a read and a write and taking a nested #VC
+ * exception on whatever of them is the MMIO access. Using string
+ * instructions here would cause infinite nesting.
+ */
+ switch (size) {
+ case 1: {
+ u8 d1;
+ u8 __user *target = (u8 __user *)dst;
+
+ memcpy(&d1, buf, 1);
+ if (__put_user(d1, target))
+ goto fault;
+ break;
+ }
+ case 2: {
+ u16 d2;
+ u16 __user *target = (u16 __user *)dst;
+
+ memcpy(&d2, buf, 2);
+ if (__put_user(d2, target))
+ goto fault;
+ break;
+ }
+ case 4: {
+ u32 d4;
+ u32 __user *target = (u32 __user *)dst;
+
+ memcpy(&d4, buf, 4);
+ if (__put_user(d4, target))
+ goto fault;
+ break;
+ }
+ case 8: {
+ u64 d8;
+ u64 __user *target = (u64 __user *)dst;
+
+ 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;
+
+ /*
+ * This function uses __get_user() independent of whether kernel or user
+ * memory is accessed. This works fine because __get_user() does no
+ * sanity checks of the pointer being accessed. All that it does is
+ * to report when the access failed.
+ *
+ * Also, this function runs in atomic context, so __get_user() is not
+ * allowed to sleep. The page-fault handler detects that it is running
+ * in atomic context and will not try to take mmap_sem and handle the
+ * fault, so additional pagefault_enable()/disable() calls are not
+ * needed.
+ *
+ * The access can't be done via copy_from_user() here because
+ * vc_read_mem() must not use string instructions to access unsafe
+ * memory. The reason is that MOVS is emulated by the #VC handler by
+ * splitting the move up into a read and a write and taking a nested #VC
+ * exception on whatever of them is the MMIO access. Using string
+ * instructions here would cause infinite nesting.
+ */
+ switch (size) {
+ case 1: {
+ u8 d1;
+ u8 __user *s = (u8 __user *)src;
+
+ if (__get_user(d1, s))
+ goto fault;
+ memcpy(buf, &d1, 1);
+ break;
+ }
+ case 2: {
+ u16 d2;
+ u16 __user *s = (u16 __user *)src;
+
+ if (__get_user(d2, s))
+ goto fault;
+ memcpy(buf, &d2, 2);
+ break;
+ }
+ case 4: {
+ u32 d4;
+ u32 __user *s = (u32 __user *)src;
+
+ if (__get_user(d4, s))
+ goto fault;
+ memcpy(buf, &d4, 4);
+ break;
+ }
+ case 8: {
+ u64 d8;
+ u64 __user *s = (u64 __user *)src;
+ 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;
+}
+
+#define sev_printk(fmt, ...) printk(fmt, ##__VA_ARGS__)
+
+#include "vc-shared.c"
+
+/* Writes to the SVSM CAA MSR are ignored */
+static enum es_result __vc_handle_msr_caa(struct pt_regs *regs, bool write)
+{
+ if (write)
+ return ES_OK;
+
+ regs->ax = lower_32_bits(this_cpu_read(svsm_caa_pa));
+ regs->dx = upper_32_bits(this_cpu_read(svsm_caa_pa));
+
+ return ES_OK;
+}
+
+/*
+ * TSC related accesses should not exit to the hypervisor when a guest is
+ * executing with Secure TSC enabled, so special handling is required for
+ * accesses of MSR_IA32_TSC and MSR_AMD64_GUEST_TSC_FREQ.
+ */
+static enum es_result __vc_handle_secure_tsc_msrs(struct pt_regs *regs, bool write)
+{
+ u64 tsc;
+
+ /*
+ * GUEST_TSC_FREQ should not be intercepted when Secure TSC is enabled.
+ * Terminate the SNP guest when the interception is enabled.
+ */
+ if (regs->cx == MSR_AMD64_GUEST_TSC_FREQ)
+ return ES_VMM_ERROR;
+
+ /*
+ * Writes: Writing to MSR_IA32_TSC can cause subsequent reads of the TSC
+ * to return undefined values, so ignore all writes.
+ *
+ * Reads: Reads of MSR_IA32_TSC should return the current TSC value, use
+ * the value returned by rdtsc_ordered().
+ */
+ if (write) {
+ WARN_ONCE(1, "TSC MSR writes are verboten!\n");
+ return ES_OK;
+ }
+
+ tsc = rdtsc_ordered();
+ regs->ax = lower_32_bits(tsc);
+ regs->dx = upper_32_bits(tsc);
+
+ return ES_OK;
+}
+
+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;
+ bool write;
+
+ /* Is it a WRMSR? */
+ write = ctxt->insn.opcode.bytes[1] == 0x30;
+
+ switch (regs->cx) {
+ case MSR_SVSM_CAA:
+ return __vc_handle_msr_caa(regs, write);
+ case MSR_IA32_TSC:
+ case MSR_AMD64_GUEST_TSC_FREQ:
+ if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
+ return __vc_handle_secure_tsc_msrs(regs, write);
+ break;
+ default:
+ break;
+ }
+
+ ghcb_set_rcx(ghcb, regs->cx);
+ if (write) {
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rdx(ghcb, regs->dx);
+ }
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_MSR, write, 0);
+
+ if ((ret == ES_OK) && !write) {
+ regs->ax = ghcb->save.rax;
+ regs->dx = ghcb->save.rdx;
+ }
+
+ return ret;
+}
+
+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_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);
+}
+
+/*
+ * 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;
+ enum insn_mmio_type mmio;
+ unsigned int bytes = 0;
+ enum es_result ret;
+ u8 sign_byte;
+ long *reg_data;
+
+ mmio = insn_decode_mmio(insn, &bytes);
+ if (mmio == INSN_MMIO_DECODE_FAILED)
+ return ES_DECODE_FAILED;
+
+ if (mmio != INSN_MMIO_WRITE_IMM && mmio != INSN_MMIO_MOVS) {
+ reg_data = insn_get_modrm_reg_ptr(insn, ctxt->regs);
+ if (!reg_data)
+ return ES_DECODE_FAILED;
+ }
+
+ if (user_mode(ctxt->regs))
+ return ES_UNSUPPORTED;
+
+ switch (mmio) {
+ case INSN_MMIO_WRITE:
+ memcpy(ghcb->shared_buffer, reg_data, bytes);
+ ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+ break;
+ case INSN_MMIO_WRITE_IMM:
+ memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);
+ ret = vc_do_mmio(ghcb, ctxt, bytes, false);
+ break;
+ case INSN_MMIO_READ:
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ /* Zero-extend for 32-bit operation */
+ if (bytes == 4)
+ *reg_data = 0;
+
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+ case INSN_MMIO_READ_ZERO_EXTEND:
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ /* Zero extend based on operand size */
+ memset(reg_data, 0, insn->opnd_bytes);
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+ case INSN_MMIO_READ_SIGN_EXTEND:
+ ret = vc_do_mmio(ghcb, ctxt, bytes, true);
+ if (ret)
+ break;
+
+ 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;
+ }
+
+ /* Sign extend based on operand size */
+ memset(reg_data, sign_byte, insn->opnd_bytes);
+ memcpy(reg_data, ghcb->shared_buffer, bytes);
+ break;
+ case INSN_MMIO_MOVS:
+ ret = vc_handle_mmio_movs(ctxt, bytes);
+ break;
+ default:
+ ret = ES_UNSUPPORTED;
+ break;
+ }
+
+ 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 (sev_status & MSR_AMD64_SNP_DEBUG_SWAP)
+ return ES_VMM_ERROR;
+
+ 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 (sev_status & MSR_AMD64_SNP_DEBUG_SWAP)
+ return ES_VMM_ERROR;
+
+ 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 enum es_result vc_handle_exitcode(struct es_em_ctxt *ctxt,
+ struct ghcb *ghcb,
+ unsigned long exit_code)
+{
+ enum es_result result = vc_check_opcode_bytes(ctxt, exit_code);
+
+ if (result != ES_OK)
+ return 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 bool is_vc2_stack(unsigned long sp)
+{
+ return (sp >= __this_cpu_ist_bottom_va(VC2) && sp < __this_cpu_ist_top_va(VC2));
+}
+
+static __always_inline bool vc_from_invalid_context(struct pt_regs *regs)
+{
+ unsigned long sp, prev_sp;
+
+ sp = (unsigned long)regs;
+ prev_sp = regs->sp;
+
+ /*
+ * If the code was already executing on the VC2 stack when the #VC
+ * happened, let it proceed to the normal handling routine. This way the
+ * code executing on the VC2 stack can cause #VC exceptions to get handled.
+ */
+ return is_vc2_stack(sp) && !is_vc2_stack(prev_sp);
+}
+
+static bool vc_raw_handle_exception(struct pt_regs *regs, unsigned long error_code)
+{
+ struct ghcb_state state;
+ struct es_em_ctxt ctxt;
+ enum es_result result;
+ struct ghcb *ghcb;
+ bool ret = true;
+
+ ghcb = __sev_get_ghcb(&state);
+
+ 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_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 #VC exception (IP: 0x%lx)\n",
+ error_code, regs->ip);
+ ret = false;
+ break;
+ case ES_VMM_ERROR:
+ pr_err_ratelimited("Failure in communication with VMM (exit-code 0x%02lx IP: 0x%lx)\n",
+ error_code, regs->ip);
+ ret = false;
+ break;
+ case ES_DECODE_FAILED:
+ pr_err_ratelimited("Failed to decode instruction (exit-code 0x%02lx IP: 0x%lx)\n",
+ error_code, regs->ip);
+ ret = false;
+ break;
+ 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();
+ }
+
+ return ret;
+}
+
+static __always_inline bool vc_is_db(unsigned long error_code)
+{
+ return error_code == SVM_EXIT_EXCP_BASE + X86_TRAP_DB;
+}
+
+/*
+ * Runtime #VC exception handler when raised from kernel mode. Runs in NMI mode
+ * and will panic when an error happens.
+ */
+DEFINE_IDTENTRY_VC_KERNEL(exc_vmm_communication)
+{
+ irqentry_state_t irq_state;
+
+ /*
+ * 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.
+ *
+ * But keep this here in case the noinstr annotations are violated due
+ * to bug elsewhere.
+ */
+ if (unlikely(vc_from_invalid_context(regs))) {
+ instrumentation_begin();
+ panic("Can't handle #VC exception from unsupported context\n");
+ instrumentation_end();
+ }
+
+ /*
+ * Handle #DB before calling into !noinstr code to avoid recursive #DB.
+ */
+ if (vc_is_db(error_code)) {
+ exc_debug(regs);
+ return;
+ }
+
+ irq_state = irqentry_nmi_enter(regs);
+
+ instrumentation_begin();
+
+ if (!vc_raw_handle_exception(regs, error_code)) {
+ /* Show some debug info */
+ show_regs(regs);
+
+ /* Ask hypervisor to sev_es_terminate */
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+
+ /* If that fails and we get here - just panic */
+ panic("Returned from Terminate-Request to Hypervisor\n");
+ }
+
+ instrumentation_end();
+ irqentry_nmi_exit(regs, irq_state);
+}
+
+/*
+ * Runtime #VC exception handler when raised from user mode. Runs in IRQ mode
+ * and will kill the current task with SIGBUS when an error happens.
+ */
+DEFINE_IDTENTRY_VC_USER(exc_vmm_communication)
+{
+ /*
+ * Handle #DB before calling into !noinstr code to avoid recursive #DB.
+ */
+ if (vc_is_db(error_code)) {
+ noist_exc_debug(regs);
+ return;
+ }
+
+ irqentry_enter_from_user_mode(regs);
+ instrumentation_begin();
+
+ if (!vc_raw_handle_exception(regs, error_code)) {
+ /*
+ * 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);
+ }
+
+ instrumentation_end();
+ irqentry_exit_to_user_mode(regs);
+}
+
+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;
+
+ 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);
+
+ sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);
+}
+
new file mode 100644
@@ -0,0 +1,504 @@
+// SPDX-License-Identifier: GPL-2.0
+
+static enum es_result vc_check_opcode_bytes(struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
+{
+ unsigned int opcode = (unsigned int)ctxt->insn.opcode.value;
+ u8 modrm = ctxt->insn.modrm.value;
+
+ switch (exit_code) {
+
+ case SVM_EXIT_IOIO:
+ case SVM_EXIT_NPF:
+ /* handled separately */
+ return ES_OK;
+
+ case SVM_EXIT_CPUID:
+ if (opcode == 0xa20f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_INVD:
+ if (opcode == 0x080f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_MONITOR:
+ /* MONITOR and MONITORX instructions generate the same error code */
+ if (opcode == 0x010f && (modrm == 0xc8 || modrm == 0xfa))
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_MWAIT:
+ /* MWAIT and MWAITX instructions generate the same error code */
+ if (opcode == 0x010f && (modrm == 0xc9 || modrm == 0xfb))
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_MSR:
+ /* RDMSR */
+ if (opcode == 0x320f ||
+ /* WRMSR */
+ opcode == 0x300f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_RDPMC:
+ if (opcode == 0x330f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_RDTSC:
+ if (opcode == 0x310f)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_RDTSCP:
+ if (opcode == 0x010f && modrm == 0xf9)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_READ_DR7:
+ if (opcode == 0x210f &&
+ X86_MODRM_REG(ctxt->insn.modrm.value) == 7)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_VMMCALL:
+ if (opcode == 0x010f && modrm == 0xd9)
+ return ES_OK;
+
+ break;
+
+ case SVM_EXIT_WRITE_DR7:
+ if (opcode == 0x230f &&
+ X86_MODRM_REG(ctxt->insn.modrm.value) == 7)
+ return ES_OK;
+ break;
+
+ case SVM_EXIT_WBINVD:
+ if (opcode == 0x90f)
+ return ES_OK;
+ break;
+
+ default:
+ break;
+ }
+
+ sev_printk(KERN_ERR "Wrong/unhandled opcode bytes: 0x%x, exit_code: 0x%lx, rIP: 0x%lx\n",
+ opcode, exit_code, ctxt->regs->ip);
+
+ return ES_UNSUPPORTED;
+}
+
+static bool vc_decoding_needed(unsigned long exit_code)
+{
+ /* Exceptions don't require to decode the instruction */
+ return !(exit_code >= SVM_EXIT_EXCP_BASE &&
+ exit_code <= SVM_EXIT_LAST_EXCP);
+}
+
+static enum es_result vc_init_em_ctxt(struct es_em_ctxt *ctxt,
+ struct pt_regs *regs,
+ unsigned long exit_code)
+{
+ enum es_result ret = ES_OK;
+
+ memset(ctxt, 0, sizeof(*ctxt));
+ ctxt->regs = regs;
+
+ if (vc_decoding_needed(exit_code))
+ ret = vc_decode_insn(ctxt);
+
+ return ret;
+}
+
+static void vc_finish_insn(struct es_em_ctxt *ctxt)
+{
+ ctxt->regs->ip += ctxt->insn.length;
+}
+
+static enum es_result vc_insn_string_check(struct es_em_ctxt *ctxt,
+ unsigned long address,
+ bool write)
+{
+ if (user_mode(ctxt->regs) && fault_in_kernel_space(address)) {
+ ctxt->fi.vector = X86_TRAP_PF;
+ ctxt->fi.error_code = X86_PF_USER;
+ ctxt->fi.cr2 = address;
+ if (write)
+ ctxt->fi.error_code |= X86_PF_WRITE;
+
+ return ES_EXCEPTION;
+ }
+
+ return ES_OK;
+}
+
+static enum es_result vc_insn_string_read(struct es_em_ctxt *ctxt,
+ void *src, char *buf,
+ unsigned int data_size,
+ unsigned int count,
+ bool backwards)
+{
+ int i, b = backwards ? -1 : 1;
+ unsigned long address = (unsigned long)src;
+ enum es_result ret;
+
+ ret = vc_insn_string_check(ctxt, address, false);
+ if (ret != ES_OK)
+ return ret;
+
+ for (i = 0; i < count; i++) {
+ void *s = src + (i * data_size * b);
+ char *d = buf + (i * data_size);
+
+ ret = vc_read_mem(ctxt, s, d, data_size);
+ if (ret != ES_OK)
+ break;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_insn_string_write(struct es_em_ctxt *ctxt,
+ void *dst, char *buf,
+ unsigned int data_size,
+ unsigned int count,
+ bool backwards)
+{
+ int i, s = backwards ? -1 : 1;
+ unsigned long address = (unsigned long)dst;
+ enum es_result ret;
+
+ ret = vc_insn_string_check(ctxt, address, true);
+ if (ret != ES_OK)
+ return ret;
+
+ for (i = 0; i < count; i++) {
+ void *d = dst + (i * data_size * s);
+ char *b = buf + (i * data_size);
+
+ ret = vc_write_mem(ctxt, d, b, data_size);
+ if (ret != ES_OK)
+ break;
+ }
+
+ return ret;
+}
+
+#define IOIO_TYPE_STR BIT(2)
+#define IOIO_TYPE_IN 1
+#define IOIO_TYPE_INS (IOIO_TYPE_IN | IOIO_TYPE_STR)
+#define IOIO_TYPE_OUT 0
+#define IOIO_TYPE_OUTS (IOIO_TYPE_OUT | IOIO_TYPE_STR)
+
+#define IOIO_REP BIT(3)
+
+#define IOIO_ADDR_64 BIT(9)
+#define IOIO_ADDR_32 BIT(8)
+#define IOIO_ADDR_16 BIT(7)
+
+#define IOIO_DATA_32 BIT(6)
+#define IOIO_DATA_16 BIT(5)
+#define IOIO_DATA_8 BIT(4)
+
+#define IOIO_SEG_ES (0 << 10)
+#define IOIO_SEG_DS (3 << 10)
+
+static enum es_result vc_ioio_exitinfo(struct es_em_ctxt *ctxt, u64 *exitinfo)
+{
+ struct insn *insn = &ctxt->insn;
+ size_t size;
+ u64 port;
+
+ *exitinfo = 0;
+
+ switch (insn->opcode.bytes[0]) {
+ /* INS opcodes */
+ case 0x6c:
+ case 0x6d:
+ *exitinfo |= IOIO_TYPE_INS;
+ *exitinfo |= IOIO_SEG_ES;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ /* OUTS opcodes */
+ case 0x6e:
+ case 0x6f:
+ *exitinfo |= IOIO_TYPE_OUTS;
+ *exitinfo |= IOIO_SEG_DS;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ /* IN immediate opcodes */
+ case 0xe4:
+ case 0xe5:
+ *exitinfo |= IOIO_TYPE_IN;
+ port = (u8)insn->immediate.value & 0xffff;
+ break;
+
+ /* OUT immediate opcodes */
+ case 0xe6:
+ case 0xe7:
+ *exitinfo |= IOIO_TYPE_OUT;
+ port = (u8)insn->immediate.value & 0xffff;
+ break;
+
+ /* IN register opcodes */
+ case 0xec:
+ case 0xed:
+ *exitinfo |= IOIO_TYPE_IN;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ /* OUT register opcodes */
+ case 0xee:
+ case 0xef:
+ *exitinfo |= IOIO_TYPE_OUT;
+ port = ctxt->regs->dx & 0xffff;
+ break;
+
+ default:
+ return ES_DECODE_FAILED;
+ }
+
+ *exitinfo |= port << 16;
+
+ switch (insn->opcode.bytes[0]) {
+ case 0x6c:
+ case 0x6e:
+ case 0xe4:
+ case 0xe6:
+ case 0xec:
+ case 0xee:
+ /* Single byte opcodes */
+ *exitinfo |= IOIO_DATA_8;
+ size = 1;
+ break;
+ default:
+ /* Length determined by instruction parsing */
+ *exitinfo |= (insn->opnd_bytes == 2) ? IOIO_DATA_16
+ : IOIO_DATA_32;
+ size = (insn->opnd_bytes == 2) ? 2 : 4;
+ }
+
+ switch (insn->addr_bytes) {
+ case 2:
+ *exitinfo |= IOIO_ADDR_16;
+ break;
+ case 4:
+ *exitinfo |= IOIO_ADDR_32;
+ break;
+ case 8:
+ *exitinfo |= IOIO_ADDR_64;
+ break;
+ }
+
+ if (insn_has_rep_prefix(insn))
+ *exitinfo |= IOIO_REP;
+
+ return vc_ioio_check(ctxt, (u16)port, size);
+}
+
+static enum es_result vc_handle_ioio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u64 exit_info_1, exit_info_2;
+ enum es_result ret;
+
+ ret = vc_ioio_exitinfo(ctxt, &exit_info_1);
+ if (ret != ES_OK)
+ return ret;
+
+ if (exit_info_1 & IOIO_TYPE_STR) {
+
+ /* (REP) INS/OUTS */
+
+ bool df = ((regs->flags & X86_EFLAGS_DF) == X86_EFLAGS_DF);
+ unsigned int io_bytes, exit_bytes;
+ unsigned int ghcb_count, op_count;
+ unsigned long es_base;
+ u64 sw_scratch;
+
+ /*
+ * For the string variants with rep prefix the amount of in/out
+ * operations per #VC exception is limited so that the kernel
+ * has a chance to take interrupts and re-schedule while the
+ * instruction is emulated.
+ */
+ io_bytes = (exit_info_1 >> 4) & 0x7;
+ ghcb_count = sizeof(ghcb->shared_buffer) / io_bytes;
+
+ op_count = (exit_info_1 & IOIO_REP) ? regs->cx : 1;
+ exit_info_2 = min(op_count, ghcb_count);
+ exit_bytes = exit_info_2 * io_bytes;
+
+ es_base = insn_get_seg_base(ctxt->regs, INAT_SEG_REG_ES);
+
+ /* Read bytes of OUTS into the shared buffer */
+ if (!(exit_info_1 & IOIO_TYPE_IN)) {
+ ret = vc_insn_string_read(ctxt,
+ (void *)(es_base + regs->si),
+ ghcb->shared_buffer, io_bytes,
+ exit_info_2, df);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Issue an VMGEXIT to the HV to consume the bytes from the
+ * shared buffer or to have it write them into the shared buffer
+ * depending on the instruction: OUTS or INS.
+ */
+ sw_scratch = __pa(ghcb) + offsetof(struct ghcb, shared_buffer);
+ ghcb_set_sw_scratch(ghcb, sw_scratch);
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO,
+ exit_info_1, exit_info_2);
+ if (ret != ES_OK)
+ return ret;
+
+ /* Read bytes from shared buffer into the guest's destination. */
+ if (exit_info_1 & IOIO_TYPE_IN) {
+ ret = vc_insn_string_write(ctxt,
+ (void *)(es_base + regs->di),
+ ghcb->shared_buffer, io_bytes,
+ exit_info_2, df);
+ if (ret)
+ return ret;
+
+ if (df)
+ regs->di -= exit_bytes;
+ else
+ regs->di += exit_bytes;
+ } else {
+ if (df)
+ regs->si -= exit_bytes;
+ else
+ regs->si += exit_bytes;
+ }
+
+ if (exit_info_1 & IOIO_REP)
+ regs->cx -= exit_info_2;
+
+ ret = regs->cx ? ES_RETRY : ES_OK;
+
+ } else {
+
+ /* IN/OUT into/from rAX */
+
+ int bits = (exit_info_1 & 0x70) >> 1;
+ u64 rax = 0;
+
+ if (!(exit_info_1 & IOIO_TYPE_IN))
+ rax = lower_bits(regs->ax, bits);
+
+ ghcb_set_rax(ghcb, rax);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_IOIO, exit_info_1, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (exit_info_1 & IOIO_TYPE_IN) {
+ if (!ghcb_rax_is_valid(ghcb))
+ return ES_VMM_ERROR;
+ regs->ax = lower_bits(ghcb->save.rax, bits);
+ }
+ }
+
+ return ret;
+}
+
+static int vc_handle_cpuid_snp(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ struct cpuid_leaf leaf;
+ int ret;
+
+ leaf.fn = regs->ax;
+ leaf.subfn = regs->cx;
+ ret = snp_cpuid(ghcb, ctxt, &leaf);
+ if (!ret) {
+ regs->ax = leaf.eax;
+ regs->bx = leaf.ebx;
+ regs->cx = leaf.ecx;
+ regs->dx = leaf.edx;
+ }
+
+ return ret;
+}
+
+static enum es_result vc_handle_cpuid(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt)
+{
+ struct pt_regs *regs = ctxt->regs;
+ u32 cr4 = native_read_cr4();
+ enum es_result ret;
+ int snp_cpuid_ret;
+
+ snp_cpuid_ret = vc_handle_cpuid_snp(ghcb, ctxt);
+ if (!snp_cpuid_ret)
+ return ES_OK;
+ if (snp_cpuid_ret != -EOPNOTSUPP)
+ return ES_VMM_ERROR;
+
+ ghcb_set_rax(ghcb, regs->ax);
+ ghcb_set_rcx(ghcb, regs->cx);
+
+ if (cr4 & X86_CR4_OSXSAVE)
+ /* Safe to read xcr0 */
+ ghcb_set_xcr0(ghcb, xgetbv(XCR_XFEATURE_ENABLED_MASK));
+ else
+ /* xgetbv will cause #GP - use reset value for xcr0 */
+ ghcb_set_xcr0(ghcb, 1);
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, SVM_EXIT_CPUID, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) &&
+ ghcb_rbx_is_valid(ghcb) &&
+ ghcb_rcx_is_valid(ghcb) &&
+ ghcb_rdx_is_valid(ghcb)))
+ return ES_VMM_ERROR;
+
+ regs->ax = ghcb->save.rax;
+ regs->bx = ghcb->save.rbx;
+ regs->cx = ghcb->save.rcx;
+ regs->dx = ghcb->save.rdx;
+
+ return ES_OK;
+}
+
+static enum es_result vc_handle_rdtsc(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ unsigned long exit_code)
+{
+ bool rdtscp = (exit_code == SVM_EXIT_RDTSCP);
+ enum es_result ret;
+
+ /*
+ * The hypervisor should not be intercepting RDTSC/RDTSCP when Secure
+ * TSC is enabled. A #VC exception will be generated if the RDTSC/RDTSCP
+ * instructions are being intercepted. If this should occur and Secure
+ * TSC is enabled, guest execution should be terminated as the guest
+ * cannot rely on the TSC value provided by the hypervisor.
+ */
+ if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
+ return ES_VMM_ERROR;
+
+ ret = sev_es_ghcb_hv_call(ghcb, ctxt, exit_code, 0, 0);
+ if (ret != ES_OK)
+ return ret;
+
+ if (!(ghcb_rax_is_valid(ghcb) && ghcb_rdx_is_valid(ghcb) &&
+ (!rdtscp || ghcb_rcx_is_valid(ghcb))))
+ return ES_VMM_ERROR;
+
+ ctxt->regs->ax = ghcb->save.rax;
+ ctxt->regs->dx = ghcb->save.rdx;
+ if (rdtscp)
+ ctxt->regs->cx = ghcb->save.rcx;
+
+ return ES_OK;
+}
@@ -3,7 +3,6 @@
#define DR7_RESET_VALUE 0x400
extern struct ghcb boot_ghcb_page;
-extern struct ghcb *boot_ghcb;
extern u64 sev_hv_features;
extern u64 sev_secrets_pa;
@@ -59,8 +58,6 @@ DECLARE_PER_CPU(struct sev_es_save_area *, sev_vmsa);
void early_set_pages_state(unsigned long vaddr, unsigned long paddr,
unsigned long npages, enum psc_op op);
-void __noreturn sev_es_terminate(unsigned int set, unsigned int reason);
-
DECLARE_PER_CPU(struct svsm_ca *, svsm_caa);
DECLARE_PER_CPU(u64, svsm_caa_pa);
@@ -100,11 +97,6 @@ static __always_inline void sev_es_wr_ghcb_msr(u64 val)
native_wrmsr(MSR_AMD64_SEV_ES_GHCB, low, high);
}
-enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
- struct es_em_ctxt *ctxt,
- u64 exit_code, u64 exit_info_1,
- u64 exit_info_2);
-
void snp_register_ghcb_early(unsigned long paddr);
bool sev_es_negotiate_protocol(void);
bool sev_es_check_cpu_features(void);
@@ -521,6 +521,28 @@ static __always_inline void vc_ghcb_invalidate(struct ghcb *ghcb)
__builtin_memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
}
+void vc_forward_exception(struct es_em_ctxt *ctxt);
+
+/* I/O parameters for CPUID-related helpers */
+struct cpuid_leaf {
+ u32 fn;
+ u32 subfn;
+ u32 eax;
+ u32 ebx;
+ u32 ecx;
+ u32 edx;
+};
+
+int snp_cpuid(struct ghcb *ghcb, struct es_em_ctxt *ctxt, struct cpuid_leaf *leaf);
+
+void __noreturn sev_es_terminate(unsigned int set, unsigned int reason);
+enum es_result sev_es_ghcb_hv_call(struct ghcb *ghcb,
+ struct es_em_ctxt *ctxt,
+ u64 exit_code, u64 exit_info_1,
+ u64 exit_info_2);
+
+extern struct ghcb *boot_ghcb;
+
#else /* !CONFIG_AMD_MEM_ENCRYPT */
#define snp_vmpl 0