> Subject: [Qemu-devel] [PATCH] kvm: ioapic: conditionally delay irq delivery > duringeoi broadcast > > Currently, we call ioapic_service() immediately when we find the irq is still > active during eoi broadcast. But for real hardware, there's some dealy between > the EOI writing and irq delivery (system bus latency?). So we need to emulate > this behavior. Otherwise, for a guest who haven't register a proper irq > handler > , it would stay in the interrupt routine as this irq would be re-injected > immediately after guest enables interrupt. This would lead guest can't move > forward and may miss the possibility to get proper irq handler registered (one > example is windows guest resuming from hibernation). > > As there's no way to differ the unhandled irq from new raised ones, this patch > solve this problems by scheduling a delayed work when the count of irq > injected > during eoi broadcast exceeds a threshold value. After this patch, the guest > can > move a little forward when there's no suitable irq handler in case it may > register one very soon and for guest who has a bad irq detection routine ( > such > as note_interrupt() in linux ), this bad irq would be recognized soon as in > the > past. > > Cc: Michael S. Tsirkin <m...@redhat.com> > Signed-off-by: Jason Wang <jasow...@redhat.com> > Signed-off-by: Zhang Haoyu <zhan...@sangfor.com> > --- > include/trace/events/kvm.h | 20 +++++++++++++++++++ > virt/kvm/ioapic.c | 50 > ++++++++++++++++++++++++++++++++++++++++++++-- > virt/kvm/ioapic.h | 6 ++++++ > 3 files changed, 74 insertions(+), 2 deletions(-) > If this is a new version, please add a v2/v3 suffix and describe the changes at those different versions .
You can get more information from: http://wiki.qemu.org/Contribute/SubmitAPatch Best regards, -Gonglei
