Re: [Xen-devel] Ping: [PATCH] VMX: sync CPU state upon vCPU destruction

[George Dunlap <george.dunlap@xxxxxxxxxx>]

On 11/21/2017 01:22 PM, Jan Beulich wrote:
>>>> On 09.11.17 at 15:49, <JBeulich@xxxxxxxx> wrote:
>> See the code comment being added for why we need this.
>>
>> Reported-by: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> I realize we aren't settled yet on where to put the sync call. The
> discussion appears to have stalled, though. Just to recap,
> alternatives to the placement below are
> - at the top of complete_domain_destroy(), being the specific
>   RCU callback exhibiting the problem (others are unlikely to
>   touch guest state)
> - in rcu_do_batch(), paralleling the similar call from
>   do_tasklet_work()

I read through the discussion yesterday without digging into the code.
At the moment, I'd say that specific code needing to touch potentially
non-sync'd state should be marked to sync it, rather than syncing it all
the time.  But I don't have a strong opinion (particularly as I haven't
dug into the code).

 -George

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel