Re: XSAVE/XRSTOR crash resurgence in 4.3

[Ben Guthro <ben.guthro@gmail.com>]

On Jul 8, 2013, at 10:41 AM, Jan Beulich <JBeulich@suse.com> wrote:

>>>> On 08.07.13 at 16:31, Ben Guthro <ben@guthro.net> wrote:
>> On Mon, Jul 8, 2013 at 10:24 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>>> On 08.07.13 at 16:13, Ben Guthro <ben@guthro.net> wrote:
>>>> On Fri, Jul 5, 2013 at 8:58 AM, Ben Guthro <ben.guthro@gmail.com> wrote:
>>>>> On Jul 5, 2013, at 8:15 AM, Jan Beulich <JBeulich@suse.com> wrote:
>>>>>
>>>>>>>>> On 05.07.13 at 14:10, Ben Guthro <ben.guthro@gmail.com> wrote:
>>>>>>> Since I am not in the office today, nor near a machine that I can
>>>>>>> access this, I asked someone else to apply and check in this patch, in
>>>>>>> the hope that we could get some useful debug info from the weekend
>>>>>>> test run.
>>>>>>>
>>>>>>> However, when he went to test booting a VM with this patch, the host
>>>>>>> machine rebooted - presumably a Xen crash.
>>>>>>
>>>>>> Oops - it's just printing stuff, so I can't immediately see how that
>>>>>> would happen. But perhaps a trivial oversight of mine...
>>>>
>>>> Here's the crash with this patch
>>>> I'm continuing to look at it, but if something jumps out at you,
>>>> please let me know.
>>>
>>> Quite obvious: hvm_guest_x86_mode() has this assertion. Yet
>>> the original, supposedly working patch had a use of this too iirc.
>>
>> It did...which is worrying.
>>
>> One difference here, is that 4.2 is running in debug=n mode, where 4.3
>> is debug=y
>>
>> iirc, asserts are disabled on debug=n builds.
>
> Oh, right. And in the context here the assertion triggering is
> apparently wrong anyway. For the purpose of debugging the
> issue at hand, I think it is safe to comment it out.

Ok, I'll do that, thanks

>
> But then again I thought you had assertions always enabled in
> XenServer.

This is in XenClient

It is perhaps something to consider doing

>
> Jan
>