Re: [PATCH v9 7/7] KVM: Use eoi to track RTC interrupt delivery status

[Gleb Natapov <gleb@redhat.com>]

On Thu, Apr 11, 2013 at 07:54:01AM +0000, Zhang, Yang Z wrote:
> Gleb Natapov wrote on 2013-04-11:
> > On Wed, Apr 10, 2013 at 09:22:20PM +0800, Yang Zhang wrote:
> >> From: Yang Zhang <yang.z.zhang@Intel.com>
> >> 
> >> Current interrupt coalescing logci which only used by RTC has conflict
> >> with Posted Interrupt.
> >> This patch introduces a new mechinism to use eoi to track interrupt:
> >> When delivering an interrupt to vcpu, the pending_eoi set to number of
> >> vcpu that received the interrupt. And decrease it when each vcpu writing
> >> eoi. No subsequent RTC interrupt can deliver to vcpu until all vcpus
> >> write eoi.
> >> 
> >> Signed-off-by: Yang Zhang <yang.z.zhang@Intel.com>
> >> ---
> >>  virt/kvm/ioapic.c |   39 ++++++++++++++++++++++++++++++++++++++-
> >>  1 files changed, 38 insertions(+), 1 deletions(-)
> >> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
> >> index a49fcd5..aeac154 100644
> >> --- a/virt/kvm/ioapic.c
> >> +++ b/virt/kvm/ioapic.c
> >> @@ -147,6 +147,26 @@ static void kvm_rtc_eoi_tracking_restore_all(struct
> > kvm_ioapic *ioapic)
> >>  	    __rtc_irq_eoi_tracking_restore_one(vcpu);
> >>  }
> >> +static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
> >> +{
> >> +	if (test_and_clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map))
> >> +		--ioapic->rtc_status.pending_eoi;
> >> +
> >> +	WARN_ON(ioapic->rtc_status.pending_eoi < 0);
> >> +}
> >> +
> >> +static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic, int irq,
> >> +				bool line_status)
> >> +{
> >> +	if (irq != RTC_GSI || !line_status)
> >> +		return false;
> > Please move the check from rtc_irq_check_coalesced() to
> > kvm_ioapic_set_irq() like this: if (irq == RTC_GSI && line_status &&
> > rtc_irq_check_coalesced(ioapic, irq, line_status)) ....
> > 
> > I was going to fix it myself while applying, but since there will be
> > new posted interrupt series anyway you can as well fix this one too.
> You mean fix it and send out it with posted interrupt series? Or just rebase the posted interrupt series on the top of this fix, but needn't to send out it?
> 
Send both series. RTC one with this change.

--
			Gleb.