From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 103141] Host-triggerable NULL pointer oops Date: Wed, 19 Aug 2015 22:48:55 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE To: kvm@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.136]:59924 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751344AbbHSWtA convert rfc822-to-8bit (ORCPT ); Wed, 19 Aug 2015 18:49:00 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6B2DF20840 for ; Wed, 19 Aug 2015 22:48:59 +0000 (UTC) Received: from bugzilla1.web.kernel.org (bugzilla1.web.kernel.org [172.20.200.51]) by mail.kernel.org (Postfix) with ESMTP id 61FE220822 for ; Wed, 19 Aug 2015 22:48:55 +0000 (UTC) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: https://bugzilla.kernel.org/show_bug.cgi?id=3D103141 Wanpeng Li changed: What |Removed |Added -----------------------------------------------------------------------= ----- CC| |wanpeng.li@hotmail.com --- Comment #1 from Wanpeng Li --- The below commit can fix it. commit 370777daab3f024f1645177039955088e2e9ae73 Author: Radim Kr=C4=8Dm=C3=A1=C5=99 Date: Fri Jul 3 15:49:28 2015 +0200 KVM: VMX: fix vmwrite to invalid VMCS fpu_activate is called outside of vcpu_load(), which means it shoul= d not touch VMCS, but fpu_activate needs to. Avoid the call by moving it= to a point where we know that the guest needs eager FPU and VMCS is load= ed. This will get rid of the following trace vmwrite error: reg 6800 value 0 (err 1) [] dump_stack+0x19/0x1b [] vmwrite_error+0x2c/0x2e [kvm_intel] [] vmcs_writel+0x1f/0x30 [kvm_intel] [] vmx_fpu_activate.part.61+0x45/0xb0 [kvm_inte= l] [] vmx_fpu_activate+0x15/0x20 [kvm_intel] [] kvm_arch_vcpu_create+0x51/0x70 [kvm] [] kvm_vm_ioctl+0x1c1/0x760 [kvm] [] ? handle_mm_fault+0x49a/0xec0 [] do_vfs_ioctl+0x2e5/0x4c0 [] ? file_has_perm+0xae/0xc0 [] SyS_ioctl+0xa1/0xc0 [] system_call_fastpath+0x16/0x1b (Note: we also unconditionally activate FPU in vmx_vcpu_reset(), so= the removed code added nothing.) Fixes: c447e76b4cab ("kvm/fpu: Enable eager restore kvm FPU for MPX= ") Cc: Reported-by: Vlastimil Holer Signed-off-by: Radim Kr=C4=8Dm=C3=A1=C5=99 Signed-off-by: Paolo Bonzini --=20 You are receiving this mail because: You are watching the assignee of the bug.