Re: [PATCH 2/3] xen/domain: Introduce domain_teardown()

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

On 21/12/2020 18:36, Julien Grall wrote:
>> @@ -553,6 +606,9 @@ struct domain *domain_create(domid_t domid,
>>       if ( init_status & INIT_watchdog )
>>           watchdog_domain_destroy(d);
>>   +    /* Must not hit a continuation in this context. */
>> +    ASSERT(domain_teardown(d) == 0);
> The ASSERT() will become a NOP in production build, so
> domain_teardown_down() will not be called.

Urgh - its not really a nop, but it's evaluation isn't symmetric between
debug and release builds.  I'll need an extra local variable.

>
> However, I think it would be better if we pass an extra argument to
> indicated wheter the code is allowed to preempt. This would make the
> preemption check more obvious in evtchn_destroy() compare to the
> current d->is_dying != DOMDYING_dead.

We can have a predicate if you'd prefer, but plumbing an extra parameter
is wasteful, and can only cause confusion if it is out of sync with
d->is_dying.

~Andrew