From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53756) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VC3O9-0008K2-5v for qemu-devel@nongnu.org; Wed, 21 Aug 2013 04:03:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1VC3O1-0000tE-3e for qemu-devel@nongnu.org; Wed, 21 Aug 2013 04:03:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28646) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1VC3O0-0000t2-St for qemu-devel@nongnu.org; Wed, 21 Aug 2013 04:03:25 -0400 Message-ID: <1377072197.1888.35.camel@localhost.localdomain> From: Marcel Apfelbaum Date: Wed, 21 Aug 2013 11:03:17 +0300 In-Reply-To: <520B2B8D.8070401@redhat.com> References: <1376233843-19410-1-git-send-email-marcel.a@redhat.com> <520B2B8D.8070401@redhat.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH for-1.6 V2 0/2] pvpanic: Separate pvpanic from machine type List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Ronen Hod Cc: aliguori@us.ibm.com, gleb@redhat.com, mst@redhat.com, hutao@cn.fujitsu.com, qemu-devel@nongnu.org, kraxel@redhat.com, pbonzini@redhat.com, afaerber@suse.de, vrozenfe@redhat.com On Wed, 2013-08-14 at 10:02 +0300, Ronen Hod wrote: > How about adding a flag that tells QEMU whether to pause or reboot the = guest > after the panic? > We cannot assume that we always have a management layer that takes care > of this. > One example is Microsoft's WHQL that deliberately generates a BSOD, and= then > examines the dump files. After this patch the pvpanic is not part of the global devices anymore so= just don't enable it if you want to reboot on BSOD. In my opinion "reboot after panic" equals "run without pvpanic device" Marcel >=20 > Ronen. >=20 > On 08/11/2013 06:10 PM, Marcel Apfelbaum wrote: > > Creating the pvpanic device as part of the machine type has the > > potential to trigger guest OS, guest firmware and driver bugs. > > The potential of such was originally viewed as minimal. > > However, since releasing 1.5 with pvpanic as part > > of the builtin machine type, several issues were observed > > in the field: > > - Some Windows versions triggered 'New Hardware Wizard' and > > an unidentified device appeared in Device Manager. > > - Issue reported off list: on Linux >=3D 3.10 > > the pvpanic driver breaks the reset on crash option: > > VM stops instead of being reset. > > > > pvpanic device also changes monitor command behaviour in some cases, > > such silent incompatible changes aren't expected by management tools: > > - Monitor command requires 'cont' before 'system_reset' > > in order to restart the VM after kernel panic/BSOD > > > > Note that libvirt is the main user and libvirt people indicated their > > preference to creating device with -device pvpanic rather than a > > built-in one that can't be removed. > > > > These issues were raised at last KVM call. The agreement reached > > there was that we were a bit too rash to make the device > > a builtin, and that for 1.6 we should drop the pvpanic device from th= e > > default machine type, instead teach management tools to add it by > > default using -device pvpanic. > > It's not clear whether changing 1.5 behaviour at this point > > is a sane thing, so this patchset doesn't touch 1.5 machine type. > > > > This patch series reworks the patchset from Hu Tao > > (don't create pvpanic device by default) > > addressing comments and modifying behaviour according > > to what was discussed on the call. > > Please review and consider for 1.6. > > > > A related discussion can be followed at > > http://lists.nongnu.org/archive/html/qemu-devel/2013-08/msg00036.html. > > > > This is a continuation of patches sent by Hu Tao: > > http://lists.nongnu.org/archive/html/qemu-devel/2013-08/msg00124.html > > http://lists.nongnu.org/archive/html/qemu-devel/2013-08/msg00125.html > > > > Changes from v1 (by Hu Tao): > > - Keep pvpanic device enabled by default for 1.5 > > for backport compatibility > > - Addressed Andreas F=C3=A4rber review (removed bus type) > > - Small changes to be posible to enable pvpanic > > both from command line and from machine_init > > - Added pvpanic to MISC category > > > > Marcel Apfelbaum (2): > > hw/misc: don't create pvpanic device by default > > hw/misc: make pvpanic known to user > > > > hw/i386/pc_piix.c | 9 ++++----- > > hw/i386/pc_q35.c | 7 ++++--- > > hw/misc/pvpanic.c | 25 ++++++++++--------------- > > 3 files changed, 18 insertions(+), 23 deletions(-) > > >=20