Re: [PATCH v10 0/4] x86/pvh: fix unbootable VMs again (PVH + KASAN)
From: Mauricio Faria de Oliveira
Date: Wed Sep 23 2026 - 08:47:50 EST
On 2026-09-22 22:12, Borislav Petkov wrote:
> On Tue, Sep 22, 2026 at 07:13:35PM -0300, Mauricio Faria de Oliveira wrote:
>> I think that is fine, yes. Even though it's a boot failure, actually
>> hitting it depends on all of: CONFIG_KASAN, CONFIG_PVH, booting from the
>> PVH entry point, _plus_ a compiler version that triggers it.
>>
>> Nonetheless, this may be picked up for stable due to the Fixes: tags,
>> but I can provide backports as needed.
>
> Right, just consider all the bandwidth of the folks involved downstream:
> stable team and all distros backporting stuff every day. This sounds like an
> exotic thing so let's be conservative here pls.
Absolutely. I worked for a long time with distro kernels and
backporting. I just mentioned that it is possible for this to be picked
up, and that if it is, then I can help with it if needed; not pushing.
:)
>> BTW, I just realized that the title of patch 4/4 is missing memset().
>> Would you mind adding it, please? Or I can send v11.
>> -x86/cpuid: fix unbootable VMs by really inlining memcmp() in
>> cpuid_base_hypervisor() and xen_prepare_pvh()
>> +x86/cpuid: fix unbootable VMs by really inlining memcmp() and memset()
>> in cpuid_base_hypervisor() and xen_prepare_pvh()
>
> Sure, np.
Thanks!
>
> Thx.
--
Mauricio