Re: kern/58118: NetBSD/i386 Xen PV guest panic "fpudna from userland"

[Brad Spencer <brad%anduin.eldar.org@localhost>]

Manuel Bouyer <bouyer%antioche.eu.org@localhost> writes:

> On Fri, Apr 05, 2024 at 05:30:01PM +0000, brad%anduin.eldar.org@localhost wrote:
>> >Number:         58118
>> >Category:       kern
>> >Synopsis:       NetBSD/i386 Xen PV guest panic "fpudna from userland"
>
> FWIW I've seen this from time to time running anita tests:
> http://largo.lip6.fr/~bouyer/NetBSD-tests/xen/
>
> I'm seeing FPU issues for PVH and HVM guests too, and for both i386 and amd64.
>
> This happens since the lazy FPU context switching has been removed.
>
> I tried to track it down but failed. The issue may be in Xen itself.
>
> I just upgraded the test box to Xen 4.18, maybe this will help ...


I also noticed this on the DOM0:

(XEN) d354v0 Triple fault - invoking HVM shutdown action 1
(XEN) *** Dumping Dom354 vcpu#0 state: ***
(XEN) ----[ Xen-4.15.3nb0  x86_64  debug=n  Not tainted ]----
(XEN) CPU:    6
(XEN) RIP:    0008:[<ffffffff80235384>]
(XEN) RFLAGS: 0000000000010046   CONTEXT: hvm guest (d354v0)
(XEN) rax: 0000000000000000   rbx: 0000000000000000   rcx: 0000000000000000
(XEN) rdx: ffffd36a5495a780   rsi: 0000000000000002   rdi: ffff9a0000002000
(XEN) rbp: ffff9a0240900e50   rsp: ffff9a0240900e50   r8:  0000000020000020
(XEN) r9:  0070e9311f5676db   r10: 000000001dcd6500   r11: 0000000000000000
(XEN) r12: 0000000000000000   r13: 0000000000000000   r14: ffff9a0240900fb0
(XEN) r15: ffffffff81887ae0   cr0: 000000008005003b   cr4: 00000000003606b0
(XEN) cr3: 0000000113b07000   cr2: 00007f7fffa88fe8
(XEN) fsb: 00007402ee324850   gsb: ffffffff8183bd40   gss: 0000000000000000
(XEN) ds: 0023   es: 0023   fs: 0000   gs: 0000   ss: 0010   cs: 0008


I can't say with 100% confidence that domain 354 was the NetBSD/i386
that panic'ed, but it is possible.  I have made node of the domain id
number and will see if it survives the cron job run.  The build it was
doing completed without a panic...  but I could probably start it all
over again and see if I can force the issue to happen.



-- 
Brad Spencer - brad%anduin.eldar.org@localhost - KC8VKS - http://anduin.eldar.org