From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vadim Rozenfeld Subject: Re: Binary Windows guest drivers are released Date: Fri, 25 Sep 2009 12:01:32 +0300 Message-ID: <4ABC86EC.6000505@redhat.com> References: <00be01ca3d18$d5820d60$80862820$@com> <3b1f68ef0909241338n2a88b332u585697a3452acdee@mail.gmail.com> <90eb1dc70909241359i41ba8d9rdcb8364289d740db@mail.gmail.com> <4ABBDF77.2060106@redhat.com> <4ABC6896.5040805@redhat.com> <3b1f68ef0909250053v21634eb6o7bdbf856213ea716@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: dlaor@redhat.com, Javier Guerra , Yan Vugenfirer , kvm@vger.kernel.org To: Kenni Lund Return-path: Received: from mx1.redhat.com ([209.132.183.28]:3095 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752106AbZIYJBg (ORCPT ); Fri, 25 Sep 2009 05:01:36 -0400 In-Reply-To: <3b1f68ef0909250053v21634eb6o7bdbf856213ea716@mail.gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: On 09/25/2009 10:53 AM, Kenni Lund wrote: > 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 wrote: >>>> >>>>> I've done some benchmarking with the drivers on Windows XP SP3 32bit, >>>>> 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 driver >>>>> still >>>>> need optimization? >>>>> >>>> very interesting! >>>> >>>> it seems that IDE wins on all the performance numbers, but VirtIO >>>> always has lower CPU utilization. i guess this is guest CPU %, right? >>>> 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 important >>>> 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 code >> almost for fun. >> Not like our mainline code, which is STORPORT oriented, it is a SCSIPORT >> (!!!!) 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 stack. >> > Ok, in that case, wouldn't it be better simply not to build the XP driver and > instead put a note somewhere (in the wiki?), saying that it doesn't make > sense to use VirtIO on XP due to these reasons? > I have no idea what was the reason for building and announcing XP 32bit driver. I mean, technically it is possible. You can also expect less CPU consumption by switching to SCSIPORT virtio driver. But please don't expect any significant performance burst. > >> Developing monolithic disk driver, which will sit right on top of virtio-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 old, > I suppose no efforts will be put into developing such driver, or? > I don't know, but why not? It shouldn't be too complicated. > Best Regards, > Kenni > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >