Re: libxl - b_info.{acpi,apic} behaves differently than b_info.u.hvm.{acpi,apic}

[Marek Marczykowski-Górecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>]

On Thu, Sep 10, 2020 at 10:51:48AM +0200, Roger Pau Monné wrote:
> On Thu, Sep 10, 2020 at 05:57:23AM +0200, Marek Marczykowski-Górecki wrote:
> > Hi,
> > 
> > After updating from Xen 4.13 to Xen 4.14 I have troubles starting any
> > HVM: just after hvmloader saying "Invoking SeaBIOS" I get "(XEN) MMIO
> > emulation failed (1): d29v0 32bit @ 0008:fffeedf d -> "
> > 
> > I come to a situation where seemingly the same domU started via xl
> > works, while when started via libvirt it crashes. This seems to be
> > related to xl setting b_info.{acpi,apic}, while libvirt setting
> > b_info.u.hvm.{acpi,apic}. Modifying libvirt to use the former fixes the
> > issue.
> 
> Could you print the values of the involved fields at the end of
> libxl__domain_build_info_setdefault in both cases?
> 
> I'm not able to spot what changed between 4.13 and 4.14 that could
> alter the behavior, but knowing the values at that point might make
> it easier.

Sure, will do.
It may be also something else: maybe it acpi/apic settings were broken
before, but did not results in a domU crash this way.
FWIW when looking into /var/lib/xen/*-libxl-json I clearly see
difference between b_info.{acpi,apic} and b_info.u.hvm.{acpi,apic}.

> > So, handling the old option got broken sometime between 4.13 and 4.14.
> > Or perhaps it is some other related side effect.
> 
> Libvirt master tests seem to have been failing for some time (60 days)
> in the build phase [0], maybe you are using a newer version of libvirt
> than what osstest is currently testing? (Xen flights are currently
> stuck at libvirt commit 2c846fa6bcc11929c9fb857a22430fb9945654ad).

I use libvirt 6.6.0, so even older one, and in fact updated it from
6.4.0 together with Xen 4.14. But I don't see relevant change between
those two versions.

BTW The libvirt build may require more attention, they've changed build
system... Now it is built with meson/ninja (haven't figured it out yet).

> Thanks, Roger.
> 
> [0] 
> http://logs.test-lab.xenproject.org/osstest/logs/152881/build-amd64-libvirt/6.ts-libvirt-build.log

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?

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