From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=40765 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OgMnu-0007Z4-9l for qemu-devel@nongnu.org; Tue, 03 Aug 2010 15:05:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OgMnp-0002wy-4M for qemu-devel@nongnu.org; Tue, 03 Aug 2010 15:05:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51502) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OgMno-0002wq-Rh for qemu-devel@nongnu.org; Tue, 03 Aug 2010 15:05:29 -0400 Date: Tue, 3 Aug 2010 22:05:25 +0300 From: Gleb Natapov Subject: Re: [Qemu-devel] Anyone seeing huge slowdown launching qemu with Linux 2.6.35? Message-ID: <20100803190525.GB16570@redhat.com> References: <20100803162857.GX13789@amd.home.annexia.org> <4C584781.9040609@redhat.com> <4C5847CD.9080107@codemonkey.ws> <4C5848C7.3090806@redhat.com> <4C584982.5000108@codemonkey.ws> <4C584B66.5070404@redhat.com> <4C5854F1.3000905@codemonkey.ws> <4C5858B2.9090801@redhat.com> <4C585F5B.5070502@codemonkey.ws> <4C58635B.7020407@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4C58635B.7020407@redhat.com> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Avi Kivity Cc: kvm@vger.kernel.org, "Richard W.M. Jones" , qemu-devel@nongnu.org On Tue, Aug 03, 2010 at 09:43:39PM +0300, Avi Kivity wrote: > > > >If Richard is willing to do the work to make -kernel perform > >faster in such a way that it fits into the overall mission of what > >we're building, then I see no reason to reject it. The criteria > >for evaluating a patch should only depend on how it affects other > >areas of qemu and whether it impacts overall usability. > > That's true, but extending fwcfg doesn't fit into the overall > picture well. We have well defined interfaces for pushing data into > a guest: virtio-serial (dma upload), virtio-blk (adds demand > paging), and virtio-p9fs (no image needed). Adapting libguestfs to > use one of these is a better move than adding yet another interface. > +1. I already proposed that. Nobody objects against fast fast communication channel between guest and host. In fact we have one: virtio-serial. Of course it is much easier to hack dma semantic into fw_cfg interface than add virtio-serial to seabios, but it doesn't make it right. Does virtio-serial has to be exposed as PCI to a guest or can we expose it as ISA device too in case someone want to use -kernel option but do not see additional PCI device in a guest? -- Gleb.