Re: [PATCH 2/5] Don't call svm_complete_interrupts for nested guests

[Gleb Natapov <gleb@redhat.com>]

On Wed, Sep 23, 2009 at 01:05:57AM -0700, Alexander Graf wrote:
> 
> Am 22.09.2009 um 18:26 schrieb Joerg Roedel <joro@8bytes.org>:
> 
> >On Fri, Sep 18, 2009 at 03:00:29PM +0200, Alexander Graf wrote:
> >>SVM has some cleanup code, that tries to reinject interrupts and
> >>exceptions
> >>when the guest didn't manage to deal with them yet. It basically
> >>transfers
> >>them to KVM internal state.
> >>
> >>Unfortunately, the internal state is reserved for the L1 guest
> >>state, so we
> >>shouldn't try to go through that logic when running a nested guest.
> >>
> >>When doing something the host KVM can handle, let's just
> >>reinject the event
> >>into the L2 guest, because we didn't touch its state anyways.
> >
> >I don't really understandt what problem this patch addresses.
> >There are
> >situations where we have events to reinject into the l2 guest
> >directly.
> >But the generic reinjection code works fine for it.
> >The only problematic thing with it is that it implicitly relies on
> >exit_int_info not to be changed in the exit cycle (which would be
> >worth
> >a comment).
> 
> It simply tries to be too clever. Reevaluating exceptions won't work
> for example.
> 
Can you elaborate? What do you mean by "too clever" and why reevaluating
exceptions won't work?

--
			Gleb.