From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=48014 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q0ARJ-0005it-Vg for qemu-devel@nongnu.org; Thu, 17 Mar 2011 06:28:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q0AQm-00072b-NB for qemu-devel@nongnu.org; Thu, 17 Mar 2011 06:28:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:21531) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q0AQm-00072J-Ch for qemu-devel@nongnu.org; Thu, 17 Mar 2011 06:27:48 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p2HARkPc011636 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 17 Mar 2011 06:27:47 -0400 Date: Thu, 17 Mar 2011 12:27:20 +0200 From: Alon Levy Subject: Re: [Qemu-devel] [PATCH v3 4/4] hw/qxl-render: drop cursor locks, replace with pipe Message-ID: <20110317102720.GO7413@playa.tlv.redhat.com> References: <1300290769-31155-1-git-send-email-alevy@redhat.com> <1300290769-31155-5-git-send-email-alevy@redhat.com> <4D80E9E9.7000505@redhat.com> <20110317093206.GL7413@playa.tlv.redhat.com> <4D81D8FB.6080009@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D81D8FB.6080009@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jes Sorensen Cc: hdegoede@redhat.com, uril@redhat.com, qemu-devel@nongnu.org, gleb@redhat.com On Thu, Mar 17, 2011 at 10:48:43AM +0100, Jes Sorensen wrote: > On 03/17/11 10:32, Alon Levy wrote: > > On Wed, Mar 16, 2011 at 05:48:41PM +0100, Jes Sorensen wrote: > >> > On 03/16/11 16:52, Alon Levy wrote: > >>> > > +void qxl_server_request_cursor_set(PCIQXLDevice *qxl, QEMUCursor *c, int x, int y) > >>> > > +{ > >>> > > + QXLServerCursorSetRequest req; > >>> > > + int r; > >>> > > + > >>> > > + req.req = QXL_SERVER_CURSOR_SET; > >>> > > + req.data.c = c; > >>> > > + req.data.x = x; > >>> > > + req.data.y = y; > >>> > > + r = write(qxl->ssd.pipe[1], &req, sizeof(req)); > >>> > > + assert(r == sizeof(req)); > >>> > > +} > >> > > >> > There's a number of asserts here, which I am not sure is a good thing. I > >> > don't understand how far down the code this is, and if it is really > >> > fatal if this write fails? > > A failure there means we can't write to a pipe between the server thread > > and the iothread (main thread). That is not supposed to happen - and if > > it does it means some operation by the spice server will never complete. > > > > Same for the asserts below, writes are from spice server thread, reads > > are in iothread. > > But shouldn't this make it try to reconnect? Even if the reconnect > fails, it shouldn't kill the guest IMHO. reconnect? between two threads in the qemu process? why would the write fail to begin with? this is like saying if I'm failing a kvm ioctl I should just retry. > > Cheers, > Jes > > >