From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48092) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFPpB-0004ul-AP for qemu-devel@nongnu.org; Wed, 15 Jul 2015 12:46:26 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZFPp7-0003em-3H for qemu-devel@nongnu.org; Wed, 15 Jul 2015 12:46:25 -0400 Received: from mail-la0-x229.google.com ([2a00:1450:4010:c03::229]:33508) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZFPp6-0003e6-IH for qemu-devel@nongnu.org; Wed, 15 Jul 2015 12:46:21 -0400 Received: by laem6 with SMTP id m6so28295497lae.0 for ; Wed, 15 Jul 2015 09:46:19 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150715190709-mutt-send-email-mst@redhat.com> References: <1436348808-223033-1-git-send-email-imammedo@redhat.com> <20150708125901-mutt-send-email-mst@redhat.com> <20150708174602.4126f466@igors-macbook-pro.local> <20150715171828.4ab9dff8@nial.brq.redhat.com> <20150715190709-mutt-send-email-mst@redhat.com> From: Andrey Korolyov Date: Wed, 15 Jul 2015 19:46:00 +0300 Message-ID: Content-Type: text/plain; charset=UTF-8 Subject: Re: [Qemu-devel] [RFC v3 0/8] Fix QEMU crash during memory hotplug with vhost=on List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Igor Mammedov , Peter Krempa , "qemu-devel@nongnu.org" , Paolo Bonzini On Wed, Jul 15, 2015 at 7:08 PM, Michael S. Tsirkin wrote: > On Wed, Jul 15, 2015 at 06:26:03PM +0300, Andrey Korolyov wrote: >> On Wed, Jul 15, 2015 at 6:18 PM, Igor Mammedov wrote: >> > On Thu, 9 Jul 2015 20:04:35 +0300 >> > Andrey Korolyov wrote: >> > >> >> On Wed, Jul 8, 2015 at 6:46 PM, Igor Mammedov wrote: >> >> > On Wed, 8 Jul 2015 13:01:05 +0300 >> >> > "Michael S. Tsirkin" wrote: >> >> > >> >> > [...] >> >> >> - this fixes qemu on current kernels, so it's a bugfix >> >> >> >> >> >> - this changes the semantics of memory hot unplug slightly >> >> >> so I think it's important to merge in 2.4 before we >> >> >> release qemu with memory hot unplug, this way we >> >> >> won't have to maintain old semantics forever >> >> > concerning semantic change, I've just chatted with Peter >> >> > who implemented libvirt side of the memory hotplug stack. >> >> > And it's not a problem for libvirt since it always does >> >> > unplug dimm -> remove backend sequence. >> >> > >> >> > >> >> >> >> >> >> Just for the record - top of the series somehow fixed mysterious guest >> >> memory corruption issue described in >> >> https://lists.gnu.org/archive/html/qemu-devel/2015-06/msg03117.html >> >> which existed right from a moment of a memory hotplug introduction, I >> >> checked series for its disappearance only with vhost for now. Thanks >> >> Igor! >> > just to be sure which patch exactly fixed issue for you? >> > >> >> Had not bisected this yet, 2.3 is fairly distant from mine production >> yet... will post a result today or tomorrow. Until then, I`ll be >> absolutely out of clues of what was behind mentioned corruption. > > Igor merely asked which of his 8 patches fixed it. I mentioned exactly the same thing - right now I`m bisecting over his series from abovementioned branch to find out what commit fixes the issue, it should take about a hour for completion of the test series. The expression is about nature of the bug, as it should be ultimately weird or well-hidded, given conditions of its exposure.