From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757504AbXHEHQP (ORCPT ); Sun, 5 Aug 2007 03:16:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753516AbXHEHQD (ORCPT ); Sun, 5 Aug 2007 03:16:03 -0400 Received: from il.qumranet.com ([82.166.9.18]:48255 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753024AbXHEHQC (ORCPT ); Sun, 5 Aug 2007 03:16:02 -0400 From: Avi Kivity To: Linus Torvalds Cc: kvm-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, Alistair John Strachan , Avi Kivity Subject: [PATCH RESEND] KVM: x86 emulator: fix debug reg mov instructions Date: Sun, 5 Aug 2007 10:16:11 +0300 Message-Id: <11862981712121-git-send-email-avi@qumranet.com> X-Mailer: git-send-email 1.5.2.4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org More fallout from the writeback fixes: debug register transfer instructions do their own writeback and thus need to disable the general writeback mechanism. This fixes oopses and some guest failures on AMD machines (the Intel variant decodes the instruction in hardware and thus does not need emulation). Cc: Alistair John Strachan Signed-off-by: Avi Kivity diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c index 1f979cb..4b8a0cc 100644 --- a/drivers/kvm/x86_emulate.c +++ b/drivers/kvm/x86_emulate.c @@ -1217,11 +1217,13 @@ twobyte_insn: } break; case 0x21: /* mov from dr to reg */ + no_wb = 1; if (modrm_mod != 3) goto cannot_emulate; rc = emulator_get_dr(ctxt, modrm_reg, &_regs[modrm_rm]); break; case 0x23: /* mov from reg to dr */ + no_wb = 1; if (modrm_mod != 3) goto cannot_emulate; rc = emulator_set_dr(ctxt, modrm_reg, _regs[modrm_rm]);