Gleb Natapov wrote on 2013-04-07: > On Sun, Apr 07, 2013 at 01:05:02PM +0000, Zhang, Yang Z wrote: >> Gleb Natapov wrote on 2013-04-07: >>> On Sun, Apr 07, 2013 at 12:39:32PM +0000, Zhang, Yang Z wrote: >>>> Gleb Natapov wrote on 2013-04-07: >>>>> On Sun, Apr 07, 2013 at 02:30:15AM +0000, Zhang, Yang Z wrote: >>>>>> Gleb Natapov wrote on 2013-04-04: >>>>>>> On Mon, Apr 01, 2013 at 08:40:13AM +0800, Yang Zhang wrote: >>>>>>>> From: Yang Zhang <yang.z.zhang@xxxxxxxxx> >>>>>>>> >>>>>>>> Signed-off-by: Yang Zhang <yang.z.zhang@xxxxxxxxx> >>>>>>>> --- >>>>>>>> arch/x86/kvm/lapic.c | 9 +++++++++ arch/x86/kvm/lapic.h | 2 >>>>>>>> ++ virt/kvm/ioapic.c | 43 >>>>>>>> +++++++++++++++++++++++++++++++++++++++++++ virt/kvm/ioapic.h | >>>>>>>> 1 + 4 files changed, 55 insertions(+), 0 deletions(-) >>>>>>>> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c >>>>>>>> index 96ab160..9c041fa 100644 >>>>>>>> --- a/arch/x86/kvm/lapic.c >>>>>>>> +++ b/arch/x86/kvm/lapic.c >>>>>>>> @@ -94,6 +94,14 @@ static inline int apic_test_vector(int vec, void >>> *bitmap) >>>>>>>> return test_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); >>>>>>>> } >>>>>>>> +bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector) >>>>>>>> +{ >>>>>>>> + struct kvm_lapic *apic = vcpu->arch.apic; >>>>>>>> + >>>>>>>> + return apic_test_vector(vector, apic->regs + APIC_ISR) || >>>>>>>> + apic_test_vector(vector, apic->regs + APIC_IRR); >>>>>>>> +} >>>>>>>> + >>>>>>>> static inline void apic_set_vector(int vec, void *bitmap) >>>>>>>> { >>>>>>>> set_bit(VEC_POS(vec), (bitmap) + REG_POS(vec)); >>>>>>>> @@ -1665,6 +1673,7 @@ void kvm_apic_post_state_restore(struct >>>>> kvm_vcpu >>>>>>> *vcpu, >>>>>>>> apic->highest_isr_cache = -1; >>>>>>>> kvm_x86_ops->hwapic_isr_update(vcpu->kvm, >>>>>>>> apic_find_highest_isr(apic)); kvm_make_request(KVM_REQ_EVENT, >>>>>>>> vcpu); + kvm_rtc_irq_restore(vcpu); } >>>>>>>> >>>>>>>> void __kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) >>>>>>>> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h >>>>>>>> index 967519c..004d2ad 100644 >>>>>>>> --- a/arch/x86/kvm/lapic.h >>>>>>>> +++ b/arch/x86/kvm/lapic.h >>>>>>>> @@ -170,4 +170,6 @@ static inline bool kvm_apic_has_events(struct >>>>>>> kvm_vcpu *vcpu) >>>>>>>> return vcpu->arch.apic->pending_events; >>>>>>>> } >>>>>>>> +bool kvm_apic_pending_eoi(struct kvm_vcpu *vcpu, int vector); >>>>>>>> + >>>>>>>> #endif >>>>>>>> diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c >>>>>>>> index 8664812..0b12b17 100644 >>>>>>>> --- a/virt/kvm/ioapic.c >>>>>>>> +++ b/virt/kvm/ioapic.c >>>>>>>> @@ -90,6 +90,47 @@ static unsigned long ioapic_read_indirect(struct >>>>>>> kvm_ioapic *ioapic, >>>>>>>> return result; >>>>>>>> } >>>>>>>> +static void rtc_irq_reset(struct kvm_ioapic *ioapic) >>>>>>>> +{ >>>>>>>> + ioapic->rtc_status.pending_eoi = 0; >>>>>>>> + bitmap_zero(ioapic->rtc_status.dest_map, KVM_MAX_VCPUS); >>>>>>>> +} >>>>>>>> + >>>>>>>> +static void rtc_irq_restore(struct kvm_ioapic *ioapic) >>>>>>>> +{ >>>>>>>> + struct kvm_vcpu *vcpu; >>>>>>>> + int vector, i, pending_eoi = 0; >>>>>>>> + >>>>>>>> + if (RTC_GSI >= IOAPIC_NUM_PINS) >>>>>>>> + return; >>>>>>>> + >>>>>>>> + vector = ioapic->redirtbl[RTC_GSI].fields.vector; >>>>>>>> + kvm_for_each_vcpu(i, vcpu, ioapic->kvm) { >>>>>>>> + if (kvm_apic_pending_eoi(vcpu, vector)) { >>>>>>>> + pending_eoi++; >>>>>>>> + __set_bit(vcpu->vcpu_id, > ioapic->rtc_status.dest_map); >>>>>>> You should cleat dest_map at the beginning to get rid of stale bits. >>>>>> I thought kvm_set_ioapic is called only after save/restore or migration. > And >>> the >>>>> ioapic should be reset successfully before call it. So the dest_map is empty >>>>> before call rtc_irq_restore(). >>>>>> But it is possible kvm_set_ioapic is called beside save/restore or >>>>>> migration. Right? >>>>>> >>>>> First of all userspace should not care when it calls kvm_set_ioapic() >>>>> the kernel need to do the right thing. Second, believe it or not, >>>>> kvm_ioapic_reset() is not called during system reset. Instead userspace >>>>> reset it by calling kvm_set_ioapic() with ioapic state after reset. >>>> Ok. I see. As the logic you suggested, it will clear dest_map if no >>>> pending eoi in vcpu, so we don't need to do it again. >>>> >>> You again rely on userspace doing thing in certain manner. What is >>> set_lapic() is never called? Kernel internal state have to be correct >>> after each ioctl call. >> Sorry. I cannot figure out what's the problem if don't clear dest_map? >> Can you elaborate it? >> > What is not obvious about it? If there is a bit in dest_map that should > be cleared after rtc_irq_restore() it will not. Why it will not? If new_val is false, and the old_val is true. __clear_bit() will clear the dest_map. Am I wrong? new_val = kvm_apic_pending_eoi(vcpu, vector); old_val = test_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map); if (new_val == old_val) return; if (new_val) { __set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map); ioapic->rtc_status.pending_eoi++; } else { __clear_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map); ioapic->rtc_status.pending_eoi--; } Best regards, Yang -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html