Re: [Xen-devel] [PATCH] xen: do not unmask disabled IRQ on eoi.

["Jan Beulich" <JBeulich@xxxxxxxxxx>]

>>> On 18.10.10 at 22:04, Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx> 
>>> wrote:
> Actually it has just occurred to me that we can safely have clear_evtchn in
> do_upcall and at the same time not mask the evtchn because we are
> protected against executing multiple upcalls at the same time anyway by
> xed_nesting_count.

I wouldn't suggest doing so - while this protects against recursion
for the actual handlers, you may still get do_upcall() invoked way too
many times, up to allowing a guest to continuously trigger an event
making do_upcall() get continuously invoked (as long as event
delivery isn't disabled altogether) - the very situation Ian's patch
you're suggesting to revert tried to address.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel