From c534bfb76524145e32a5066ca73b6836ce744c38 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 30 May 2013 16:35:55 +0200 Subject: KVM: fix sil/dil/bpl/spl in the mod/rm fields commit 8acb42070ec4c87a9baab5c7bac626030d5bef28 upstream. The x86-64 extended low-byte registers were fetched correctly from reg, but not from mod/rm. This fixes another bug in the boot of RHEL5.9 64-bit, but it is still not enough. Signed-off-by: Paolo Bonzini Signed-off-by: Gleb Natapov Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/emulate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index 25792086fb8..698eecee918 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -1239,9 +1239,12 @@ static int decode_modrm(struct x86_emulate_ctxt *ctxt, ctxt->modrm_seg = VCPU_SREG_DS; if (ctxt->modrm_mod == 3) { + int highbyte_regs = ctxt->rex_prefix == 0; + op->type = OP_REG; op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes; - op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, ctxt->d & ByteOp); + op->addr.reg = decode_register(ctxt, ctxt->modrm_rm, + highbyte_regs && (ctxt->d & ByteOp)); if (ctxt->d & Sse) { op->type = OP_XMM; op->bytes = 16; -- cgit v1.2.3