[PATCH v2 06/26] KVM: x86 emulator: fix LIDT/LGDT in long mode

Avi Kivity
2012-06-27T15:19:49Z

The operand size for these instructions is 8 bytes in long mode, even without
a REX prefix. Set it explicitly.

Triggered while booting Linux with emulate_invalid_guest_state=1.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/emulate.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index fe4340f..24c8425 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -2997,6 +2997,8 @@ static int em_lgdt(struct x86_emulate_ctxt *ctxt)
struct desc_ptr desc_ptr;
int rc;

+ if (ctxt->mode == X86EMUL_MODE_PROT64)
+ ctxt->op_bytes = 8;
rc = read_descriptor(ctxt, ctxt->src.addr.mem,
&desc_ptr.size, &desc_ptr.address,
ctxt->op_bytes);
@@ -3024,6 +3026,8 @@ static int em_lidt(struct x86_emulate_ctxt *ctxt)
struct desc_ptr desc_ptr;
int rc;

+ if (ctxt->mode == X86EMUL_MODE_PROT64)
+ ctxt->op_bytes = 8;
rc = read_descriptor(ctxt, ctxt->src.addr.mem,
&desc_ptr.size, &desc_ptr.address,
ctxt->op_bytes);
--
1.7.11