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authorNadav Amit <namit@cs.technion.ac.il>2014-06-02 18:34:03 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2014-06-18 17:46:15 +0200
commit7fe864dc942c041cc4f56e287c4025d54a8e6c1e (patch)
tree59a787182aaa8544aa03fb56bbbc9d183c40c93f /arch
parent7171511eaec5bf23fb06078f59784a3a0626b38f (diff)
downloadlinux-7fe864dc942c041cc4f56e287c4025d54a8e6c1e.tar.gz
KVM: x86: Mark VEX-prefix instructions emulation as unimplemented
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@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/emulate.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e4e833d3d7d7..8ec4a3ebf403 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: