Gleb Natapov wrote on 2013-04-04:
> On Mon, Apr 01, 2013 at 08:40:13AM +0800, Yang Zhang wrote:
>> From: Yang Zhang <[email protected]>
>>
>> Signed-off-by: Yang Zhang <[email protected]>
>> ---
>> 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?
>
>> + }
>> + }
>> + ioapic->rtc_status.pending_eoi = pending_eoi;
>> +}
>> +
>> +void kvm_rtc_irq_restore(struct kvm_vcpu *vcpu)
>> +{
>> + struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;
>> + int vector;
>> +
>> + if (!ioapic)
>> + return;
>> +
> Can this be called if ioapic == NULL?
Yes. IIRC, unit test will test lapic function without ioapic.
> Should check for if (RTC_GSI >= IOAPIC_NUM_PINS) here too.
Not necessary. kvm_rtc_irq_restore is called from "arch/x86/" and we have the
defination:
#ifdef CONFIG_X86
#define RTC_GSI 8
The check will be false always. As the logic you suggested below, this check is
necessary for _all() not _one();
>
>> + spin_lock(&ioapic->lock);
>> + vector = ioapic->redirtbl[RTC_GSI].fields.vector;
>> + if (kvm_apic_pending_eoi(vcpu, vector)) {
>> + __set_bit(vcpu->vcpu_id, ioapic->rtc_status.dest_map);
>> + ioapic->rtc_status.pending_eoi++;
> The bit may have been set already. The logic should be:
Right.
>
>
> new_val = kvm_apic_pending_eoi(vcpu, vector)
> old_val = set_bit(vcpu_id, dest_map)
>
> if (new_val == old_val)
> return;
>
> if (new_val) {
> __set_bit(vcpu_id, dest_map);
> pending_eoi++;
> } else {
> __clear_bit(vcpu_id, dest_map);
> pending_eoi--;
> }
>
> The naming of above two functions are not good either. Call
> them something like kvm_rtc_eoi_tracking_restore_all() and
> kvm_rtc_eoi_tracking_restore_one(). And _all should call _one() for
> each vcpu. Make __rtc_irq_eoi_tracking_restore_one() that does not
> take ioapic lock and call it from kvm_rtc_eoi_tracking_restore_one()
> surrounded by locks.
Ok. Just confirm whether I am understanding correct:
kvm_rtc_eoi_tracking_restore_all():
{
for_each_vcpu:
kvm_rtc_eoi_tracking_restore_one():
}
kvm_rtc_eoi_tracking_restore_one():
{
lock();
__rtc_irq_eoi_tracking_restore_one():
unlock();
}
kvm_set_ioapic()
{
kvm_rtc_eoi_tracking_restore_all();
}
kvm_apic_post_state_restore()
{
kvm_rtc_eoi_tracking_restore_one();
}
>
> --
> Gleb.
> --
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Best regards,
Yang
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