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Subject[PATCH 23/40] KVM: Fix vmload and friends misinterpreted as lidt
Date
The AMD SVM instruction family all overload the 0f 01 /3 opcode, further
multiplexing on the three r/m bits. But the code decided that anything that
isn't a vmmcall must be an lidt (which shares the 0f 01 /3 opcode, for the
case that mod = 3).

Fix by aborting emulation if this isn't a vmmcall.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/x86_emulate.c | 15 ++++++++++-----
1 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c
index d174db7..54fb098 100644
--- a/arch/x86/kvm/x86_emulate.c
+++ b/arch/x86/kvm/x86_emulate.c
@@ -1908,11 +1908,16 @@ twobyte_insn:
c->dst.type = OP_NONE;
break;
case 3: /* lidt/vmmcall */
- if (c->modrm_mod == 3 && c->modrm_rm == 1) {
- rc = kvm_fix_hypercall(ctxt->vcpu);
- if (rc)
- goto done;
- kvm_emulate_hypercall(ctxt->vcpu);
+ if (c->modrm_mod == 3) {
+ switch (c->modrm_rm) {
+ case 1:
+ rc = kvm_fix_hypercall(ctxt->vcpu);
+ if (rc)
+ goto done;
+ break;
+ default:
+ goto cannot_emulate;
+ }
} else {
rc = read_descriptor(ctxt, ops, c->src.ptr,
&size, &address,
--
1.6.0.6


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