Re: [PATCH][RFC] Support S3 for MSI interrupt in latest kernel dom0

[Keir Fraser <keir.fraser@eu.citrix.com>]

On 17/12/2008 15:31, "Jan Beulich" <jbeulich@novell.com> wrote:

>>>> Keir Fraser <keir.fraser@eu.citrix.com> 17.12.08 16:22 >>>
>> Well, maybe it's okay then. I don't think Yunhong's patch was a good
>> argument for it -- looking again it appears to have plenty of not really
>> related chunks contained in it.
> 
> I don't think it's really okay as-is: As he indicated, there may be side
> effects of the changes during other than resume from S3 (in particular
> the IRQ_GUEST check around the newly added call to ->startup()), and
> I was hoping you might have a suggestion on how to better distinguish
> that particular case. In the worst case, Xen has to set another flag in
> each MSI irq_desc when it resumes from S3, and do the startup as well
> as the clearing of the flag when map_domain_pirq runs first for that
> particular vector.

Then do it as a new hypercall? How much complexity does that add on the
guest side?

 -- Keir