Re: [Xen-devel] [PATCH v2] domctl: fix IRQ permission granting/revocation

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 12.12.14 at 11:49, <andrew.cooper3@xxxxxxxxxx> wrote:
> On 12/12/14 10:24, Jan Beulich wrote:
>> Commit 545607eb3c ("x86: fix various issues with handling guest IRQs")
>> wasn't really consistent in one respect: The granting of access to an
>> IRQ shouldn't assume the pIRQ->IRQ translation to be the same in both
>> domains. In fact it is wrong to assume that a translation is already/
>> still in place at the time access is being granted/revoked.
>>
>> What is wanted is to translate the incoming pIRQ to an IRQ for
>> the invoking domain (as the pIRQ is the only notion the invoking
>> domain has of the IRQ), and grant the subject domain access to
>> the resulting IRQ.
>>
>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
> 
> Should domain_pirq_to_irq() be using 0 as its default invalid value,
> rather than -1?  irq 0 is a real irq and could plausibly be wanted to be
> passed through to a guest.

Not on x86. If another architecture would ever need this, I think
we'd need to audit all current users of domain_pirq_to_irq() before
doing such a change.

Jan


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