On 21.03.2025 10:50, Mykola Kvach wrote:
> On Thu, Mar 13, 2025 at 5:34 PM Jan Beulich <jbeul...@suse.com> wrote:
>> On 05.03.2025 10:11, Mykola Kvach wrote:
>>> +void watchdog_domain_resume(struct domain *d)
>>> +{
>>> + unsigned int i;
>>> +
>>> + spin_lock(&d->watchdog_lock);
>>> +
>>> + for ( i = 0; i < NR_DOMAIN_WATCHDOG_TIMERS; i++ )
>>> + {
>>> + if ( test_bit(i, &d->watchdog_inuse_map) )
>>> + {
>>> + set_timer(&d->watchdog_timer[i].timer,
>>> + NOW() + SECONDS(d->watchdog_timer[i].timeout));
>>
>> The timeout may have almost expired before suspending; restoring to the
>> full original period feels wrong. At the very least, if that's indeed
>> intended behavior, imo this needs spelling out explicitly.
>
> It takes some time to wake up the domain, but the watchdog timeout is
> reset by a userspace daemon. As a result, we can easily encounter a
> watchdog trigger during the resume process.
Which may mean the restoring is done too early, or needs doing in two
phases.
> It looks like we should
> stop the watchdog timer from the guest, and in that case, we can drop
> all changes related to the watchdog in this patch series.
Except that then you require a guest to be aware of host suspend. Which
may not be desirable.
Jan
