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)

[Paul Durrant <Paul.Durrant@xxxxxxxxxx>]

> -----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 :-)

  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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