>>> On 24.08.10 at 23:35, Jeremy Fitzhardinge <jeremy@goop.org> wrote:
While this description would seem plausible at the first glance, it
doesn't match up with unmask_evtchn() already taking care of
exactly this case. Or are you implicitly saying that this code is
broken in some way (if so, how, and shouldn't it then be that
code that needs fixing, or removing if you want to stay with the
edge handling)?
I do however agree that using handle_level_irq() is problematic
(see http://lists.xensource.com/archives/html/xen-devel/2010-04/msg01178.html),
but as said there I think using the fasteoi logic is preferable. No
matter whether using edge or level, the ->end() method will
never be called (whereas fasteoi calls ->eoi(), which would
just need to be vectored to the same function as ->end()).
Without end_pirq() ever called, you can't let Xen know of
bad PIRQs (so that it can disable them instead of continuing
to call the [now shortcut] handler in the owning domain).
This doesn't seem right for the general VIRQ case: global ones
should not be disallowed migration between CPUs. Since in your
model the requestor has to pass IRQF_PERCPU anyway,
shouldn't you make the selection of the handler dependent
upon this flag?
Jan
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