>> 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 > Okay, thanks.
>Best regards, >-Gonglei
