Re: [PATCH] domctl: fix IRQ permission granting/revocation

[Ian Campbell <Ian.Campbell@eu.citrix.com>]

On Wed, 2014-12-10 at 10:00 +0000, Jan Beulich wrote:
> >>> On 10.12.14 at 10:53, <Ian.Campbell@eu.citrix.com> wrote:
> > On Wed, 2014-12-10 at 08:07 +0000, 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.
> > 
> > Specifically you need to do the translation using the mapping of the
> > domain doing the granting, not the domain being granted too, correct?
> > 
> > It takes a little bit of thought to figure out which domain to check
> > here, it would be worth a sentence or two explaining why this is the
> > right one.
> 
> Would
> 
> "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."
> 
> make this more clear without being purely redundant with the code?

Yes, thanks.

Ian.