2019. április 6., szombat 12:34:31 UTC időpontban awokd a következőt írta:
> dm1.libe...@gmail.com wrote on 4/6/19 7:14 AM:
> 
> > This issue is due to a xen patch ("Fix resume, when using microcode 
> > upgrade"), that has been included when releases changed from xen-4.8.3-4 to 
> > xen-4.8.3-5. This patch checks the availability of previous CPU features 
> > (..Spectre) during resume, and results in a xen panic on G505s - IMHO due 
> > to the static nature how the most recent (0x600111f) AMD microcodes need to 
> > be compiled in Corebooted systems.
> > It is no use to revert the whole patch, because it'll break the other xen 
> > patches introduced since. But you can:
> > 
> > diff -ur a/xen/arch/x86/acpi/power.c b/xen/arch/x86/acpi/power.c
> > --- a/xen/arch/x86/acpi/power.c 2019-03-31
> > +++ b/xen/arch/x86/acpi/power.c 2019-03-31
> > @@ -256,9 +256,9 @@
> >   
> >       microcode_resume_cpu(0);
> >   
> > -    if ( !recheck_cpu_features(0) )
> > +/*    if ( !recheck_cpu_features(0) )
> >           panic("Missing previously available feature(s).");
> > -
> > +*/
> >       /* Re-enabled default NMI/#MC use of MSR_SPEC_CTRL. */
> >       ci->spec_ctrl_flags |= (default_spec_ctrl_flags & SCF_ist_wrmsr);
> >       spec_ctrl_exit_idle(ci);
> > 
> > have this workaround, which solves the issue until someone provides a 
> > working solution on CB'd systems with AMD Fam15h. (..and also assesses the 
> > possible security impacts...)
> > Of course you'll need to recompile git:qubes-vmm-xen, but that is 
> > straightforward.
> > There could be some strange kernel messages in dom0 after resume, and you 
> > might have issues in sys-net devices waking up, but this mostly works fine 
> > (with kernel 4.14.103 --> kernels 4.19-xx still have issues with the radeon 
> > module)
> > 
> 
> Thank you, I will definitely try it out and report back here! Any idea 
> if someone has submitted upstream to Xen? Seems like it would be an 
> issue with any Corebooted AMD AGESA system since they all handle 
> microcode the same way.

I haven't seen this, and also could be wrong about the root cause...

What I found is that kernels without Xen are not affected (resume OK), however 
stock kernels with xen (Fedora, Ubuntu...) even up-to the latest stable 
Xen-4.11.x have this issue.

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