Currently the emulator does not recognize vex-prefix instructions. However, it
may incorrectly decode lgdt/lidt instructions and try to execute them. This
patch returns unhandlable error on their emulation.
Signed-off-by: Nadav Amit <namit@xxxxxxxxxxxxxxxxx>
---
arch/x86/kvm/emulate.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e4e833d..8ec4a3e 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -4314,6 +4314,13 @@ done_prefixes:
if (ctxt->d & ModRM)
ctxt->modrm = insn_fetch(u8, ctxt);
+ /* vex-prefix instructions are not implemented */
+ if (ctxt->opcode_len == 1 && (ctxt->b == 0xc5 || ctxt->b == 0xc4) &&
+ (mode == X86EMUL_MODE_PROT64 ||
+ (mode >= X86EMUL_MODE_PROT16 && (ctxt->modrm & 0x80)))) {
+ ctxt->d = NotImpl;
+ }
+
while (ctxt->d & GroupMask) {
switch (ctxt->d & GroupMask) {
case Group:
--
1.9.1
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