Re: [Bug 206215] New: QEMU guest crash due to random 'general protection fault' since kernel 5.2.5 on i7-3517UE

Derek Yerger
2020-01-16T01:11:06Z

On 1/15/20 4:52 PM, Sean Christopherson wrote:
> +cc Derek, who is hitting the same thing.
>
> On Wed, Jan 15, 2020 at 09:18:56PM +0000, bugzilla-daemon@bugzilla.kernel.org wrote:
>> https://bugzilla.kernel.org/show_bug.cgi?id=206215
> *snip*
> that's a big smoking gun pointing at commit ca7e6b286333 ("KVM: X86: Fix
> fpu state crash in kvm guest"), which is commit e751732486eb upstream.
>
> 1. Can you verify reverting ca7e6b286333 (or e751732486eb in upstream)
> solves the issue?
>
> 2. Assuming the answer is yes, on a buggy kernel, can you run with the
> attached patch to try get debug info?
I did these out of order since I had 5.3.11 built with the patch, ready to go
for weeks now, waiting for an opportunity to test.

Win10 guest immediately BSOD'ed with:

WARNING: CPU: 2 PID: 9296 at include/linux/thread_info.h:55
kernel_fpu_begin+0x6b/0xc0

Then stashed the patch, reverted ca7e6b286333, compile, reboot.

Guest is running stable now on 5.3.11. Did test my CAD under the guest, did not
experience the crashes that had me stuck at 5.1.