From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33815) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eKngp-0000YF-50 for qemu-devel@nongnu.org; Fri, 01 Dec 2017 10:57:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eKnfi-0002Rz-BV for qemu-devel@nongnu.org; Fri, 01 Dec 2017 10:56:52 -0500 Received: from mx1.redhat.com ([209.132.183.28]:41420) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1eKnfi-0002QU-0T for qemu-devel@nongnu.org; Fri, 01 Dec 2017 10:56:14 -0500 Date: Fri, 1 Dec 2017 16:39:28 +0200 From: "Michael S. Tsirkin" Message-ID: <20171201163813-mutt-send-email-mst@kernel.org> References: <20171201055832.8392-1-fangying1@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171201055832.8392-1-fangying1@huawei.com> Subject: Re: [Qemu-devel] [PATCH v4] vhost: Don't abort when vhost-user connection is lost during migration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: fangying Cc: qemu-devel@nongnu.org, quintela@redhat.com, marcandre.lureau@redhat.com On Fri, Dec 01, 2017 at 01:58:32PM +0800, fangying wrote: > QEMU will abort when vhost-user process is restarted during migration > when vhost_log_global_start/stop is called. The reason is clear that > vhost_dev_set_log returns -1 because network connection is lost. > > To handle this situation, let's cancel migration by setting migrate > state to failure and report it to user. In fact I don't see this as the right way to fix it. Backend is dead so why not just proceed with migration? We just need to make sure we re-send migration data on re-connect. > --- > hw/virtio/vhost.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c > index ddc42f0..92725f7 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -26,6 +26,8 @@ > #include "hw/virtio/virtio-bus.h" > #include "hw/virtio/virtio-access.h" > #include "migration/blocker.h" > +#include "migration/migration.h" > +#include "migration/qemu-file.h" > #include "sysemu/dma.h" > > /* enabled until disconnected backend stabilizes */ > @@ -885,7 +887,10 @@ static void vhost_log_global_start(MemoryListener *listener) > > r = vhost_migration_log(listener, true); > if (r < 0) { > - abort(); > + error_report("Failed to start vhost dirty log"); > + if (migrate_get_current()->migration_thread_running) { > + qemu_file_set_error(migrate_get_current()->to_dst_file, -ECHILD); > + } > } > } > > @@ -895,7 +900,10 @@ static void vhost_log_global_stop(MemoryListener *listener) > > r = vhost_migration_log(listener, false); > if (r < 0) { > - abort(); > + error_report("Failed to stop vhost dirty log"); > + if (migrate_get_current()->migration_thread_running) { > + qemu_file_set_error(migrate_get_current()->to_dst_file, -ECHILD); > + } > } > } > > -- > 1.8.3.1 >