From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: XP machine freeze Date: Sun, 19 Apr 2015 19:16:30 +0200 Message-ID: <5533E2EE.6000906@redhat.com> References: <009701d05ffb$5e37a740$1aa6f5c0$@astim.si> <550EE047.3030605@fnarfbargle.com> <5519BBF4.7080600@redhat.com> <552B40F7.5080107@fnarfbargle.com> <552BB8D5.7060200@redhat.com> <552BBA87.50109@fnarfbargle.com> <552BCC60.1000103@redhat.com> <5533C95E.5030707@fnarfbargle.com> <45D7B761-5F3B-4A1B-8057-6C77693A308B@gmail.com> <5533DCE0.4080606@fnarfbargle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Cc: Saso Slavicic , kvm list , =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= To: Brad Campbell , Nadav Amit Return-path: Received: from mail-wg0-f46.google.com ([74.125.82.46]:34380 "EHLO mail-wg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752180AbbDSRQg (ORCPT ); Sun, 19 Apr 2015 13:16:36 -0400 Received: by wgso17 with SMTP id o17so157388308wgs.1 for ; Sun, 19 Apr 2015 10:16:34 -0700 (PDT) In-Reply-To: <5533DCE0.4080606@fnarfbargle.com> Sender: kvm-owner@vger.kernel.org List-ID: On 19/04/2015 18:50, Brad Campbell wrote: > And I can confidently state that over the years I've seen this happen a > number of times, but in each case I was using qemu with an SDL console > as a user-interactive VM, and a moving the mouse would restore network > connectivity. It was obviously seriously exacerbated by something that > went into 3.16. Yes, it was---it's straight in the commit message for commit f210f7572bed: > commit 56cc2406d68c ("KVM: nVMX: fix "acknowledge interrupt on exit" > when APICv is in use") changed the behavior of apic_clear_irr [...] > Nonetheless, it appears the race might even occur prior to this commit: Note that there is another regression between 3.17 and 3.19 (visible as migration failures with XFS in the guest), so I'd keep 3.17.x for a while in production. The hard disk holding my test system's root filesystem died on Friday so it may take a few days before I actually prepare the fix for stable@ and also apply the other pending patches. Nevertheless, no data was lost (/home is safe) so it's just a matter of finding some time to reinstall the OSes. Paolo