From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 2/3] virtio-pci: Use ioeventfd for virtqueue notify Date: Thu, 11 Nov 2010 19:12:40 +0200 Message-ID: <20101111171240.GA30171@redhat.com> References: <1289483242-6069-1-git-send-email-stefanha@linux.vnet.ibm.com> <1289483242-6069-3-git-send-email-stefanha@linux.vnet.ibm.com> <4CDC20F1.1030305@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stefan Hajnoczi , qemu-devel@nongnu.org, kvm@vger.kernel.org, gleb@redhat.com To: Avi Kivity Return-path: Received: from mx1.redhat.com ([209.132.183.28]:39618 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754365Ab0KKRNH (ORCPT ); Thu, 11 Nov 2010 12:13:07 -0500 Content-Disposition: inline In-Reply-To: <4CDC20F1.1030305@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Nov 11, 2010 at 06:59:29PM +0200, Avi Kivity wrote: > On 11/11/2010 03:47 PM, Stefan Hajnoczi wrote: > >Some virtio devices are known to have guest drivers which expect a notify to be > >processed synchronously and spin waiting for completion. Only enable ioeventfd > >for virtio-blk and virtio-net for now. > > Which drivers are these? > > I only know of the virtio-gl driver, which isn't upstream. I think that PXE virtio drivers do polling. But I think this change does not break these drivers. It'll probably make them a bit slower. Right, Gleb? -- MST