Re: [Xen-devel] [win-pv-devel] Question about windows domU long boot time in xen and help for update libxl virtio patch (for a test)

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Fri, May 08, 2015 at 05:47:25PM +0100, Paul Durrant wrote:
> > -----Original Message-----
> > From: Fabio Fantoni [mailto:fabio.fantoni@xxxxxxx]
> > Sent: 08 May 2015 16:11
> > To: Paul Durrant; xen-devel; win-pv-devel@xxxxxxxxxxxxxxxxxxxx
> > Cc: Anthony Perard; Wei Liu; Ian Campbell; Stefano Stabellini
> > Subject: Re: [win-pv-devel] Question about windows domU long boot time in
> > xen and help for update libxl virtio patch (for a test)
> > 
> > Il 08/05/2015 16:59, Paul Durrant ha scritto:
> > >> -----Original Message-----
> > >> From: win-pv-devel-bounces@xxxxxxxxxxxxxxxxxxxx [mailto:win-pv-devel-
> > >> bounces@xxxxxxxxxxxxxxxxxxxx] On Behalf Of Fabio Fantoni
> > >> Sent: 08 May 2015 15:54
> > >> To: xen-devel; win-pv-devel@xxxxxxxxxxxxxxxxxxxx
> > >> Cc: Anthony Perard; Wei Liu; Ian Campbell; Stefano Stabellini
> > >> Subject: [win-pv-devel] Question about windows domU long boot time in
> > >> xen and help for update libxl virtio patch (for a test)
> > >>
> > >> In latest years hvm domUs support and performance was increased but
> > >> windows boot time is still too long.
> > >> I tried out all sort of combinations (without pv, with old gplpv and new
> > >> winpv, with vnc, spice or without both, with different vgas and many
> > >> other options) with same result: strange long boot time (before arrive
> > >> to user login).
> > >> On kvm (trying with same qemu/seabios versions, qdisk with raw ecc...)
> > >> instead for example the boot time is faster and similar to the phisical
> > >> pc one with same vcpu ram ecc as assigned.
> > >> Is there something that need to be improved/fixed in windows pv drivers
> > >> or xen?
> > >>
> > > Which version of QEMU are you using. I tend to use upstream, but I see a
> > *very* long pause between the end of firmware logging and sampling the
> > viridian cpuid leaves (which is generally the next thing to cause some 
> > logging)
> > so my suspicion is that the int13 handling in seabios is probably the 
> > culprit.
> > That's only a hunch, but using rombios and qemu trad is quite a lot faster.
> > 
> > Thanks for reply.
> > With qemu-trad if I remember good was faster on initial boot but have
> > lower general performance, I don't use anymore qemu-trad on dom0 with
> > xen >= 4.3
> > About qemu upstream I started use it on 1.2 if I remember good and after
> > I always tested all versions up to 2.2 and seabios I keeped updated
> > rebuilding from debian sid package (now 1.8.1)
> > 
> 
> I'm using the seabios image from the Xen build. Turns out that it's built 
> with CONFIG_ATA_DMA off (because that's not set when you run make defconfig). 
> Turning that on manually in the config and rebuilding makes things a *lot* 
> faster :-)
> 

Maybe we should turn that on in our build?


Wei.

>   Paul
> 
> > >
> > > Once the kernel starts to boot I see no significant delays. PV drivers 
> > > are not
> > wonderfully fast to start up as the xenstore state dance does take a while. 
> > It
> > is somewhat unavoidable though.
> > >
> > >    Paul
> > >
> > >> I tried to narrow down my search trying with virtio disk on xen but I
> > >> was unable to have libxl patch working.
> > >> I taken very old Wei Liu patch from here:
> > >> http://downloads.xen.org/Wiki/VirtioOnXen/libxl-virtio-support.patch
> > >>
> > >> And I tried to adapt it but there is something that I not understand and
> > >> causing the build fails:
> > >> libxl.c:2339:32: error: LIBXL__DEVICE_KIND_VIRTIO undeclared (first use
> > >> in this function)
> > >>
> > >> Here the path I updated and tried failing, I did only disks part (nic
> > >> need only model change in xl.cfg FWIK):
> > >>
> > https://github.com/Fantu/Xen/commit/783c1739df3a87689ab8c152632b2493
> > >> 34d92f0a
> > >>
> > >> Can someone help me to complete/fix it please?
> > >>
> > >>
> > >> Thanks for any reply and sorry for my bad english.
> > >>
> > >>
> > >> _______________________________________________
> > >> win-pv-devel mailing list
> > >> win-pv-devel@xxxxxxxxxxxxxxxxxxxx
> > >> http://lists.xenproject.org/cgi-bin/mailman/listinfo/win-pv-devel

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