From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kenni Lund Subject: Re: Binary Windows guest drivers are released Date: Fri, 25 Sep 2009 09:53:31 +0200 Message-ID: <3b1f68ef0909250053v21634eb6o7bdbf856213ea716@mail.gmail.com> References: <00be01ca3d18$d5820d60$80862820$@com> <3b1f68ef0909241338n2a88b332u585697a3452acdee@mail.gmail.com> <90eb1dc70909241359i41ba8d9rdcb8364289d740db@mail.gmail.com> <4ABBDF77.2060106@redhat.com> <4ABC6896.5040805@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: dlaor@redhat.com, Javier Guerra , Yan Vugenfirer , kvm@vger.kernel.org To: Vadim Rozenfeld Return-path: Received: from asmtp.unoeuro.com ([195.41.131.37]:39725 "HELO asmtp.unoeuro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752172AbZIYHxa convert rfc822-to-8bit (ORCPT ); Fri, 25 Sep 2009 03:53:30 -0400 Received: from localhost (localhost [127.0.0.1]) by asmtp.unoeuro.com (Postfix) with ESMTP id 2BA4B36DF37 for ; Fri, 25 Sep 2009 09:53:32 +0200 (CEST) Received: from asmtp.unoeuro.com ([127.0.0.1]) by localhost (asmtp.unoeuro.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id EC2Trvjy8BUc for ; Fri, 25 Sep 2009 09:53:32 +0200 (CEST) Received: from mail-fx0-f218.google.com (mail-fx0-f218.google.com [209.85.220.218]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) by asmtp.unoeuro.com (Postfix) with ESMTP id E3DCA36DECC for ; Fri, 25 Sep 2009 09:53:31 +0200 (CEST) Received: by fxm18 with SMTP id 18so2006404fxm.17 for ; Fri, 25 Sep 2009 00:53:31 -0700 (PDT) In-Reply-To: <4ABC6896.5040805@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 2009/9/25 Vadim Rozenfeld : > On 09/25/2009 12:07 AM, Dor Laor wrote: >> >> On 09/24/2009 11:59 PM, Javier Guerra wrote: >>> >>> On Thu, Sep 24, 2009 at 3:38 PM, Kenni Lund =A0wrote= : >>>> >>>> I've done some benchmarking with the drivers on Windows XP SP3 32b= it, >>>> but it seems like using the VirtIO drivers are slower than the IDE >>>> drivers in >>>> (almost) all cases. Perhaps I've missed something or does the driv= er >>>> still >>>> need optimization? >>> >>> very interesting! >>> >>> it seems that IDE wins on all the performance numbers, but VirtIO >>> always has lower CPU utilization. =A0i guess this is guest CPU %, r= ight? >>> it would also be interesting to compare the CPU usage from the host >>> point of view, since a lower 'off-guest' CPU usage is very importan= t >>> for scaling to many guests doing I/O. >>> >> These drivers are mainly tweaked for win2k3 and win2k8. We once had = queue >> depth settings in the driver, not sure we still have it, Vadim, can = you add >> more info? >> Dor > > Windows XP 32-bit virtio block driver was created from our mainline c= ode > almost for fun. > Not like our mainline code, which is STORPORT oriented, it is a SCSIP= ORT > (!!!!) mini-port driver. > SCSIPORT has never been known as I/O optimized storage stack. > SCSIPORT architecture is almost dead officially. > Windows XP 32-bit has no support for STORPORT or virtual storage stac= k. Ok, in that case, wouldn't it be better simply not to build the XP driv= er and instead put a note somewhere (in the wiki?), saying that it doesn't mak= e sense to use VirtIO on XP due to these reasons? > Developing monolithic disk driver, which will sit right on top of vir= tio-blk > PCI device, looks like the one way > to have some kind of high throughput storage for Windows XP 32-bit. Ok, since these drivers are targeted Windows Server and XP is getting o= ld, I suppose no efforts will be put into developing such driver, or? Best Regards, Kenni