From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1N8DzW-0002c0-8X for qemu-devel@nongnu.org; Wed, 11 Nov 2009 09:16:10 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1N8DzS-0002Ze-2Z for qemu-devel@nongnu.org; Wed, 11 Nov 2009 09:16:09 -0500 Received: from [199.232.76.173] (port=48332 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1N8DzP-0002ZH-OV for qemu-devel@nongnu.org; Wed, 11 Nov 2009 09:16:04 -0500 Received: from mx20.gnu.org ([199.232.41.8]:32690) by monty-python.gnu.org with esmtps (TLS-1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1N8DzP-0001Ir-JL for qemu-devel@nongnu.org; Wed, 11 Nov 2009 09:16:03 -0500 Received: from mail.codesourcery.com ([38.113.113.100]) by mx20.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1N8DzO-0002hm-N4 for qemu-devel@nongnu.org; Wed, 11 Nov 2009 09:16:03 -0500 From: Paul Brook Date: Wed, 11 Nov 2009 14:16:00 +0000 References: <20091026131715.GA25271@redhat.com> <200911111345.35249.paul@codesourcery.com> <20091111140819.GA29736@redhat.com> In-Reply-To: <20091111140819.GA29736@redhat.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200911111416.00355.paul@codesourcery.com> Subject: [Qemu-devel] Re: [PATCH] qemu/virtio: make wmb compiler barrier + comments List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Michael S. Tsirkin" Cc: qemu-devel@nongnu.org On Wednesday 11 November 2009, Michael S. Tsirkin wrote: > On Wed, Nov 11, 2009 at 01:45:35PM +0000, Paul Brook wrote: > > If you don't need real barriers, then why does the kvm code have them? > > We need real barriers but AFAIK kvm does not have them :( > IOW: virtio is currently broken with kvm, and my patch did > not fix this. The comment that I added says as much. So your code just makes the bug harder to reproduce? Doesn't sound like a good thing to me. Paul