From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56092) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alVgJ-0003N7-M4 for qemu-devel@nongnu.org; Thu, 31 Mar 2016 02:02:12 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1alVgG-000439-FX for qemu-devel@nongnu.org; Thu, 31 Mar 2016 02:02:11 -0400 Received: from mailout4.w1.samsung.com ([210.118.77.14]:21028) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1alVgG-000428-8x for qemu-devel@nongnu.org; Thu, 31 Mar 2016 02:02:08 -0400 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout4.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0O4W00JKT3FEUX10@mailout4.w1.samsung.com> for qemu-devel@nongnu.org; Thu, 31 Mar 2016 07:02:02 +0100 (BST) References: <1459350849-31989-1-git-send-email-i.maximets@samsung.com> <20160330195614-mutt-send-email-mst@redhat.com> From: Ilya Maximets Message-id: <56FCBD59.9020203@samsung.com> Date: Thu, 31 Mar 2016 09:02:01 +0300 MIME-version: 1.0 In-reply-to: <20160330195614-mutt-send-email-mst@redhat.com> Content-type: text/plain; charset=windows-1252 Content-transfer-encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/4] Fix QEMU crash on vhost-user socket disconnect. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: Jason Wang , qemu-devel@nongnu.org, Dyasly Sergey On 30.03.2016 20:01, Michael S. Tsirkin wrote: > On Wed, Mar 30, 2016 at 06:14:05PM +0300, Ilya Maximets wrote: >> Currently QEMU always crashes in following scenario (assume that >> vhost-user application is Open vSwitch with 'dpdkvhostuser' port): > > In fact, wouldn't the right thing to do be stopping the VM? I don't think that is reasonable to stop VM on failure of just one of network interfaces. There may be still working vhost-kernel interfaces. Even connection can still be established if vhost-user interface was in bonding with kernel interface. Anyway user should be able to save all his data before QEMU restart. > >> 1. # Check that link in guest is in a normal state. >> [guest]# ip link show eth0 >> 2: eth0: mtu 1500 qdisc <...> >> link/ether 00:16:35:af:aa:4b brd ff:ff:ff:ff:ff:ff >> >> 2. # Kill vhost-user application (using SIGSEGV just to be sure). >> [host]# kill -11 `pgrep ovs-vswitchd` >> >> 3. # Check that guest still thinks that all is good. >> [guest]# ip link show eth0 >> 2: eth0: mtu 1500 qdisc <...> >> link/ether 00:16:35:af:aa:4b brd ff:ff:ff:ff:ff:ff >> >> 4. # Try to unbind virtio-pci driver and observe QEMU crash. >> [guest]# echo -n '0000:00:01.0' > /sys/bus/pci/drivers/virtio-pci/unbind >> qemu: Failed to read msg header. Read 0 instead of 12. Original request 11. >> qemu: Failed to read msg header. Read 0 instead of 12. Original request 11. >> qemu: Failed to read msg header. Read 0 instead of 12. Original request 11. >> >> Child terminated with signal = 0xb (SIGSEGV) >> GDBserver exiting >> >> After the applying of this patch-set: >> >> 4. # Try to unbind virtio-pci driver. Unbind works fine with only few errors. >> [guest]# echo -n '0000:00:01.0' > /sys/bus/pci/drivers/virtio-pci/unbind >> qemu: Failed to read msg header. Read 0 instead of 12. Original request 11. >> qemu: Failed to read msg header. Read 0 instead of 12. Original request 11. >> >> 5. # Bind virtio-pci driver back. >> [guest]# echo -n '0000:00:01.0' > /sys/bus/pci/drivers/virtio-pci/bind >> >> 6. # Check link in guest. No crashes here, link in DOWN state. >> [guest]# ip link show eth0 >> 7: eth0: mtu 1500 qdisc <...> >> link/ether 00:16:35:af:aa:4b brd ff:ff:ff:ff:ff:ff >> >> 7. QEMU may be gracefully restarted to restore communication after restarting >> of vhost-user application. >> >> Ilya Maximets (4): >> vhost-user: fix crash on socket disconnect. >> vhost: prevent double stop of vhost_net device. >> vhost: check for vhost_net device validity. >> net: notify about link status only if it changed. >> >> hw/net/vhost_net.c | 48 ++++++++++++++++++++++++++++++++++++++---- >> hw/net/virtio-net.c | 33 ++++++++++++++++++++++------- >> include/hw/virtio/virtio-net.h | 1 + >> include/net/vhost-user.h | 1 + >> include/net/vhost_net.h | 1 + >> net/filter.c | 1 + >> net/net.c | 7 +++--- >> net/vhost-user.c | 43 +++++++++++++++++++++++++++++-------- >> 8 files changed, 111 insertions(+), 24 deletions(-) >> >> -- >> 2.5.0 > >