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@xxxxxxxxxx> --- 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 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html