From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48568) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cSFK8-0007SC-Fl for qemu-devel@nongnu.org; Fri, 13 Jan 2017 22:48:13 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cSFK7-00059V-I9 for qemu-devel@nongnu.org; Fri, 13 Jan 2017 22:48:12 -0500 Received: from mail-pg0-x243.google.com ([2607:f8b0:400e:c05::243]:35847) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cSFK7-00059J-C7 for qemu-devel@nongnu.org; Fri, 13 Jan 2017 22:48:11 -0500 Received: by mail-pg0-x243.google.com with SMTP id 75so125023pgf.3 for ; Fri, 13 Jan 2017 19:48:11 -0800 (PST) Sender: Richard Henderson References: <20170112114612.14520-1-stefanha@redhat.com> From: Richard Henderson Message-ID: Date: Fri, 13 Jan 2017 19:48:08 -0800 MIME-Version: 1.0 In-Reply-To: <20170112114612.14520-1-stefanha@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/2] virtio: revert virtio_queue_set_notification() nesting List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Hajnoczi , qemu-devel@nongnu.org Cc: Doug Goldstein , "Dr . David Alan Gilbert" , "Michael S. Tsirkin" On 01/12/2017 03:46 AM, Stefan Hajnoczi wrote: > The virtio_queue_set_notification() nesting introduced for AioContext polling > raised an assertion with virtio-net (even in non-polling mode). Converting > virtio-net and virtio-crypto to use virtio_queue_set_notification() in a > nesting fashion would be invasive and isn't worth it. > > Patch 1 contains the revert to resolve the bug that Doug noticed. > > Patch 2 is a less efficient but safe alternative. > > Stefan Hajnoczi (2): > Revert "virtio: turn vq->notification into a nested counter" > virtio: disable notifications again after poll succeeded > > hw/virtio/virtio.c | 21 +++++++++------------ > 1 file changed, 9 insertions(+), 12 deletions(-) Tested-by: Richard Henderson This problem affected Alpha as well. I tested the two patches together. r~