Re: [BUG] Consistent LBR/TSX vmentry failure (0x80000022) calling domain_crash() in vmx.c:3324

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 20/05/2020 15:59, Elliot Killick wrote:
> On 2020-05-20 12:31, Andrew Cooper wrote:
>> On 20/05/2020 12:46, Elliot Killick wrote:
>>> processor   : 0
>>> vendor_id   : GenuineIntel
>>> cpu family  : 6
>>> model               : 60
>>> model name  : Intel(R) Core(TM) i5-4590 CPU @ 3.30GHz
>>> stepping    : 3
>>> microcode   : 0x27
>>> cpu MHz             : 3299.926
>>> cache size  : 6144 KB
>>> physical id : 0
>> Ok, so the errata is one of HSM182/HSD172.
>>
>> Xen has workaround for all of these.  However, I also see:
>>
>>> (XEN) ----[ Xen-4.8.5-15.fc25  x86_64  debug=n   Not tainted ]----
>> which is an obsolete version of Xen these days.  It looks like these
>> issues were first fixed in Xen 4.9, but you should upgrade to something
>> rather newer.
>>
>> ~Andrew
>>
> Ah, so this is originally a CPU bug which Xen has had to patch over.

Yes.  It was an unintended consequence of Intel being forced to disable
TSX in most of their Haswell/Broadwell CPUs.

> As for the Xen version, that's controlled by the "distribution" of Xen I
> run which is Qubes. To remedy this I could run the testing stream of
> Qubes which currently provides the latest version of Xen (4.13) but that
> could bring its own set of problems.

Ah, in which case Qubes will probably consider backporting the fixes. 
Open a bug with them, and I can probably point out a minimum set of
backports to make it work.

~Andrew