Gleb Natapov wrote on 2013-03-19:
> On Fri, Mar 15, 2013 at 09:31:11PM +0800, Yang Zhang wrote:
>> From: Yang Zhang <yang.z.zhang@xxxxxxxxx>
>>
>> If posted interrupt is avaliable, then uses it to inject virtual
>> interrupt to guest.
>>
>> Signed-off-by: Yang Zhang <yang.z.zhang@xxxxxxxxx>
>> ---
>> arch/x86/kvm/irq.c | 3 ++-
>> arch/x86/kvm/lapic.c | 16 +++++++++++++---
>> arch/x86/kvm/lapic.h | 1 +
>> arch/x86/kvm/vmx.c | 11 +++++++++++
>> arch/x86/kvm/x86.c | 4 ++++
>> 5 files changed, 31 insertions(+), 4 deletions(-)
>> diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
>> index 484bc87..5179988 100644
>> --- a/arch/x86/kvm/irq.c
>> +++ b/arch/x86/kvm/irq.c
>> @@ -81,7 +81,8 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *v)
>> if (kvm_cpu_has_extint(v))
>> return 1;
>> - return kvm_apic_has_interrupt(v) != -1; /* LAPIC */
>> + return (kvm_apic_has_interrupt(v) != -1) ||
>> + kvm_hwapic_has_interrupt(v);
> That's incorrect. kvm_cpu_has_interrupt() should return true only it
> there is IRR suitable to be injected, not just any IRR.
> kvm_apic_has_interrupt() should call kvm_apic_update_irr().
You are right.
>> }
>> EXPORT_SYMBOL_GPL(kvm_cpu_has_interrupt);
>> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
>> index b3ea50e..46c7310 100644
>> --- a/arch/x86/kvm/lapic.c
>> +++ b/arch/x86/kvm/lapic.c
>> @@ -713,7 +713,10 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int
> delivery_mode,
>> } else
>> apic_clear_vector(vector, apic->regs + APIC_TMR);
>> - result = !apic_test_and_set_irr(vector, apic);
>> + result = 1;
>> + if (!kvm_x86_ops->deliver_posted_interrupt(vcpu, vector))
>> + result = !apic_test_and_set_irr(vector, apic);
>> +
>> trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
>> trig_mode, vector, !result);
>> if (!result) {
>> @@ -723,8 +726,10 @@ static int __apic_accept_irq(struct kvm_lapic *apic, int
> delivery_mode,
>> break;
>> }
>> - kvm_make_request(KVM_REQ_EVENT, vcpu);
>> - kvm_vcpu_kick(vcpu);
>> + if (!kvm_x86_ops->vm_has_apicv(vcpu->kvm)) {
>> + kvm_make_request(KVM_REQ_EVENT, vcpu);
>> + kvm_vcpu_kick(vcpu);
>> + }
>> break;
> apicv code and non apicv code are completely different. What's the point
> checking for apicv twice here?
> Just do:
>
> if (kvm_x86_ops->deliver_posted_interrupt)
> kvm_x86_ops->deliver_posted_interrupt(vcpu, vector)
> else {
> result = !apic_test_and_set_irr(vector, apic);
> kvm_make_request(KVM_REQ_EVENT, vcpu);
> kvm_vcpu_kick(vcpu);
> }
>
> And set kvm_x86_ops->deliver_posted_interrupt only if apicv is enabled.
>
> Also rearrange patches so that APIC_TMR handling goes before posted
> interrupt series.
Sure.
>>
>> case APIC_DM_REMRD: @@ -1604,6 +1609,11 @@ int
>> kvm_apic_has_interrupt(struct kvm_vcpu *vcpu) return highest_irr; }
>> +bool kvm_hwapic_has_interrupt(struct kvm_vcpu *vcpu)
>> +{
>> + return kvm_x86_ops->hwapic_has_interrupt(vcpu);
>> +}
>> +
>> int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu)
>> {
>> u32 lvt0 = kvm_apic_get_reg(vcpu->arch.apic, APIC_LVT0);
>> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
>> index e5327be..c6abc63 100644
>> --- a/arch/x86/kvm/lapic.h
>> +++ b/arch/x86/kvm/lapic.h
>> @@ -37,6 +37,7 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu);
>> void kvm_free_lapic(struct kvm_vcpu *vcpu);
>>
>> int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu); +bool
>> kvm_hwapic_has_interrupt(struct kvm_vcpu *vcpu); int
>> kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu); int
>> kvm_get_apic_interrupt(struct kvm_vcpu *vcpu); void
>> kvm_lapic_reset(struct kvm_vcpu *vcpu);
>> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
>> index 0b5a8ae..48a2239 100644
>> --- a/arch/x86/kvm/vmx.c
>> +++ b/arch/x86/kvm/vmx.c
>> @@ -3932,6 +3932,17 @@ static void vmx_posted_intr_clear_on(struct
> kvm_vcpu *vcpu)
>> clear_bit(POSTED_INTR_ON, (unsigned long *)&vmx->pi_desc.u.control);
>> }
>> +/*
>> + * Send interrupt to vcpu via posted interrupt way.
>> + * Return false if posted interrupt is not supported and the caller will
>> + * roll back to old way(via set vIRR).
>> + * Return true if posted interrupt is avalialbe, the interrupt is set
>> + * in pir(posted interrupt requests):
>> + * 1. If target vcpu is running(non-root mode), send posted interrupt
>> + * notification to vcpu and hardware will sync pir to vIRR atomically.
>> + * 2. If target vcpu isn't running(root mode), kick it to pick up the
>> + * interrupt from pir in next vmentry.
>> + */
> The comment should go into previous patch. Also I prefer to not check
> for posted interrupt inside the callback, but set it to NULL instead.
> This way we avoid calling a callback on a hot path needlessly.
It's make sense. So just follow the logic you mentioned above?
>> static bool vmx_deliver_posted_interrupt(struct kvm_vcpu *vcpu, int vector)
>> {
>> struct vcpu_vmx *vmx = to_vmx(vcpu);
>> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
>> index 0baa90d..0981100 100644
>> --- a/arch/x86/kvm/x86.c
>> +++ b/arch/x86/kvm/x86.c
>> @@ -2679,6 +2679,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
>> static int kvm_vcpu_ioctl_get_lapic(struct kvm_vcpu *vcpu,
>> struct kvm_lapic_state *s) { + kvm_x86_ops->sync_pir_to_irr(vcpu);
>> memcpy(s->regs, vcpu->arch.apic->regs, sizeof *s);
>>
>> return 0; @@ -5699,6 +5700,7 @@ static int vcpu_enter_guest(struct
>> kvm_vcpu *vcpu) }
>>
>> if (kvm_check_request(KVM_REQ_EVENT, vcpu) || req_int_win) {
>> + kvm_x86_ops->sync_pir_to_irr(vcpu); inject_pending_event(vcpu);
>>
>> /* enable NMI/IRQ window open exits if needed */
>> @@ -5741,6 +5743,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
>>
>> local_irq_disable();
>> + kvm_x86_ops->posted_intr_clear_on(vcpu);
>> +
> Why is this separate from pir_to_irr syncing?
This is the result of discussion with Marcelo.
It is more reasonable to put it here to avoid unnecessary posted interrupt between:
vcpu->mode = IN_GUEST_MODE;
<--interrupt may arrived here and this is unnecessary.
local_irq_disable();
>> if (vcpu->mode == EXITING_GUEST_MODE || vcpu->requests
>> || need_resched() || signal_pending(current)) {
>> vcpu->mode = OUTSIDE_GUEST_MODE;
>> --
>> 1.7.1
>
> --
> Gleb.
Best regards,
Yang
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