Certain xapic MMIO reads and writes get compiled into movabs instruction which uses rax as the register containing data and 8-byte address encoded as part of the instruction. Add support to decode these instructions.
Signed-off-by: Neeraj Upadhyay Neeraj.Upadhyay@amd.com --- .../testing/selftests/kvm/lib/x86/insn-eval.c | 8 +++++ tools/testing/selftests/kvm/lib/x86/sev.c | 35 ++++++++++++++----- 2 files changed, 34 insertions(+), 9 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86/insn-eval.c b/tools/testing/selftests/kvm/lib/x86/insn-eval.c index efa4d3fde504..60c8c7cf5658 100644 --- a/tools/testing/selftests/kvm/lib/x86/insn-eval.c +++ b/tools/testing/selftests/kvm/lib/x86/insn-eval.c @@ -1712,6 +1712,14 @@ enum insn_mmio_type insn_decode_mmio(struct insn *insn, int *bytes) break; } break; + case 0xa1: + type = INSN_MMIO_READ_MOV_ABS; + *bytes = insn->opnd_bytes; + break; + case 0xa3: + type = INSN_MMIO_WRITE_MOV_ABS; + *bytes = insn->opnd_bytes; + break; }
return type; diff --git a/tools/testing/selftests/kvm/lib/x86/sev.c b/tools/testing/selftests/kvm/lib/x86/sev.c index 16d6b21649d1..24aaa75ec450 100644 --- a/tools/testing/selftests/kvm/lib/x86/sev.c +++ b/tools/testing/selftests/kvm/lib/x86/sev.c @@ -517,9 +517,11 @@ void sev_es_pv_mmio_rw(uint32_t *reg_gpa, uint32_t *data, bool write) }
static void do_mmio(struct ghcb_entry *entry, struct ex_regs *regs, - struct insn *insn, unsigned int bytes, bool read) + struct insn *insn, unsigned int bytes, bool read, + void *ref) { - void *ref = insn_get_addr_ref(insn, regs); + if (!ref) + ref = insn_get_addr_ref(insn, regs);
register_ghcb_page(entry->gpa); __sev_es_hv_mmio_rw(entry, ref, bytes, !read); @@ -648,11 +650,12 @@ static void sev_es_vc_mmio_handler(struct ex_regs *regs) char buffer[MAX_INSN_SIZE]; struct ghcb_entry *entry; enum insn_mmio_type mmio; - unsigned long *reg_data; + unsigned long *reg_data = NULL; unsigned int bytes; struct ghcb *ghcb; uint8_t sign_byte; struct insn insn; + void *abs_ref; int ret;
memcpy(buffer, (uint8_t *)regs->rip, MAX_INSN_SIZE); @@ -664,7 +667,9 @@ static void sev_es_vc_mmio_handler(struct ex_regs *regs) mmio = insn_decode_mmio(&insn, (int *)&bytes); __GUEST_ASSERT(!(mmio == INSN_MMIO_DECODE_FAILED), " MMIO decode failed\n");
- if (mmio != INSN_MMIO_WRITE_IMM && mmio != INSN_MMIO_MOVS) { + if (mmio == INSN_MMIO_WRITE_MOV_ABS || mmio == INSN_MMIO_READ_MOV_ABS) { + reg_data = ®s->rax; + } else if (mmio != INSN_MMIO_WRITE_IMM && mmio != INSN_MMIO_MOVS) { reg_data = insn_get_modrm_reg_ptr(&insn, regs); __GUEST_ASSERT(reg_data, "insn_get_modrm_reg_ptr failed\n"); } @@ -675,25 +680,37 @@ static void sev_es_vc_mmio_handler(struct ex_regs *regs) switch (mmio) { case INSN_MMIO_WRITE: memcpy(ghcb->shared_buffer, reg_data, bytes); - do_mmio(entry, regs, &insn, bytes, false); + do_mmio(entry, regs, &insn, bytes, false, NULL); break; case INSN_MMIO_WRITE_IMM: memcpy(ghcb->shared_buffer, insn.immediate1.bytes, bytes); - do_mmio(entry, regs, &insn, bytes, false); + do_mmio(entry, regs, &insn, bytes, false, NULL); + break; + case INSN_MMIO_WRITE_MOV_ABS: + abs_ref = (void *)*(uint64_t *)((uint8_t *)regs->rip + 1); + memcpy(ghcb->shared_buffer, reg_data, bytes); + do_mmio(entry, regs, &insn, bytes, false, abs_ref); break; case INSN_MMIO_READ: - do_mmio(entry, regs, &insn, bytes, true); + do_mmio(entry, regs, &insn, bytes, true, NULL); + if (bytes == 4) + *reg_data = 0; + memcpy(reg_data, ghcb->shared_buffer, bytes); + break; + case INSN_MMIO_READ_MOV_ABS: + abs_ref = (void *)*(uint64_t *)((char *)regs->rip + 1); + do_mmio(entry, regs, &insn, bytes, true, abs_ref); if (bytes == 4) *reg_data = 0; memcpy(reg_data, ghcb->shared_buffer, bytes); break; case INSN_MMIO_READ_ZERO_EXTEND: - do_mmio(entry, regs, &insn, bytes, true); + do_mmio(entry, regs, &insn, bytes, true, NULL); memset(reg_data, 0, insn.opnd_bytes); memcpy(reg_data, ghcb->shared_buffer, bytes); break; case INSN_MMIO_READ_SIGN_EXTEND: - do_mmio(entry, regs, &insn, bytes, true); + do_mmio(entry, regs, &insn, bytes, true, NULL); if (bytes == 1) { uint8_t *val = (uint8_t *)ghcb->shared_buffer;