On 07.04.2025 20:16, Jason Andryuk wrote:
> On 2025-04-04 03:38, Jan Beulich wrote:
>> On 03.04.2025 23:46, Jason Andryuk wrote:
>>> From: "Daniel P. Smith" <dpsm...@apertussolutions.com>
>>>
>>> Add and use a new internal create domain flag to specify the hardware
>>> domain. This removes the hardcoding of domid 0 as the hardware domain.
>>>
>>> This allows more flexibility with domain creation.
>>>
>>> Signed-off-by: Daniel P. Smith <dpsm...@apertussolutions.com>
>>> Signed-off-by: Jason Andryuk <jason.andr...@amd.com>
>>> Reviewed-by: Jan Beulich <jbeul...@suse.com>
>>> ---
>>> v3:
>>> Or-in CDF_hardware for late hwdom case
>>
>> Except that ...
>>
>>> --- a/xen/common/domain.c
>>> +++ b/xen/common/domain.c
>>> @@ -820,13 +820,18 @@ struct domain *domain_create(domid_t domid,
>>> d->is_privileged = flags & CDF_privileged;
>>>
>>> /* Sort out our idea of is_hardware_domain(). */
>>> - if ( domid == 0 || domid == hardware_domid )
>>> + if ( (flags & CDF_hardware) || domid == hardware_domid )
>>> {
>>> if ( hardware_domid < 0 || hardware_domid >= DOMID_FIRST_RESERVED
>>> )
>>> panic("The value of hardware_dom must be a valid domain
>>> ID\n");
>>>
>>> + /* late_hwdom is only allowed for dom0. */
>>> + if ( hardware_domain && hardware_domain->domain_id )
>>> + return ERR_PTR(-EINVAL);
>>> +
>>> old_hwdom = hardware_domain;
>>> hardware_domain = d;
>>> + flags |= CDF_hardware;
>>> }
>>
>> ... this isn't quite enough. You're only modifying what will go out of scope
>> when returning from the function. What's at least equally important to OR
>> into
>> is d->cdf.
>
> Yes, thanks for catching that.
>
> I'll move d->cdf assignment to after here instead of or-ing in a second
> time.
Not sure that'll be good to do - intermediate code (in particular passing
d to other functions) may need to have that set already. And even if not
now, then maybe going forward.
> With that, it seems like it should also be removed from old_hwdom?
>
> old_hwdom->cdf &= ~CDF_hardware
Oh, indeed. Thanks in turn for catching this further aspect.
Jan
