On 2013-06-24 14:19, Gleb Natapov wrote:
> This reverts most of the f1ed0450a5fac7067590317cbf027f566b6ccbca. After
> the commit kvm_apic_set_irq() no longer returns accurate information
> about interrupt injection status if injection is done into disabled
> APIC. RTC interrupt coalescing tracking relies on the information to be
> accurate and cannot recover if it is not.
>
> Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
> diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
> index 9d75193..9f4bea8 100644
> --- a/arch/x86/kvm/lapic.c
> +++ b/arch/x86/kvm/lapic.c
> @@ -405,17 +405,17 @@ int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu)
> return highest_irr;
> }
>
> -static void __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> - int vector, int level, int trig_mode,
> - unsigned long *dest_map);
> +static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> + int vector, int level, int trig_mode,
> + unsigned long *dest_map);
I still think __apic_accept_irq should unconditionally inject, and the
test for acpi_enabled belongs into kvm_apic_set_irq. Why should
__apic_accept_irq accept non-APIC_DM_FIXED messages if the APIC is off?
See below for another reason to refactor this part of the interface.
>
> -void kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
> - unsigned long *dest_map)
> +int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
> + unsigned long *dest_map)
> {
> struct kvm_lapic *apic = vcpu->arch.apic;
>
> - __apic_accept_irq(apic, irq->delivery_mode, irq->vector,
> - irq->level, irq->trig_mode, dest_map);
> + return __apic_accept_irq(apic, irq->delivery_mode, irq->vector,
> + irq->level, irq->trig_mode, dest_map);
> }
>
> static int pv_eoi_put_user(struct kvm_vcpu *vcpu, u8 val)
> @@ -608,8 +608,7 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
> *r = -1;
>
> if (irq->shorthand == APIC_DEST_SELF) {
> - kvm_apic_set_irq(src->vcpu, irq, dest_map);
> - *r = 1;
> + *r = kvm_apic_set_irq(src->vcpu, irq, dest_map);
> return true;
> }
>
> @@ -654,8 +653,7 @@ bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
> continue;
> if (*r < 0)
> *r = 0;
> - kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map);
> - *r += 1;
> + *r += kvm_apic_set_irq(dst[i]->vcpu, irq, dest_map);
> }
>
> ret = true;
> @@ -664,11 +662,15 @@ out:
> return ret;
> }
>
> -/* Set an IRQ pending in the lapic. */
> -static void __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> - int vector, int level, int trig_mode,
> - unsigned long *dest_map)
> +/*
> + * Add a pending IRQ into lapic.
> + * Return 1 if successfully added and 0 if discarded.
> + */
> +static int __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> + int vector, int level, int trig_mode,
> + unsigned long *dest_map)
> {
> + int result = 0;
> struct kvm_vcpu *vcpu = apic->vcpu;
>
> switch (delivery_mode) {
> @@ -682,10 +684,13 @@ static void __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> if (dest_map)
> __set_bit(vcpu->vcpu_id, dest_map);
>
> - if (kvm_x86_ops->deliver_posted_interrupt)
> + if (kvm_x86_ops->deliver_posted_interrupt) {
> + result = 1;
> kvm_x86_ops->deliver_posted_interrupt(vcpu, vector);
> - else {
> - if (apic_test_and_set_irr(vector, apic)) {
> + } else {
> + result = !apic_test_and_set_irr(vector, apic);
This part of the revert makes no sense. If deliver_posted_interrupt is
on, we don't have this feedback anymore, thus we decided to remove it, no?
Jan
> +
> + if (!result) {
> if (trig_mode)
> apic_debug("level trig mode repeatedly "
> "for vector %d", vector);
> @@ -697,7 +702,7 @@ static void __apic_accept_irq(struct kvm_lapic *apic, int delivery_mode,
> }
> out:
> trace_kvm_apic_accept_irq(vcpu->vcpu_id, delivery_mode,
> - trig_mode, vector, false);
> + trig_mode, vector, !result);
> break;
>
> case APIC_DM_REMRD:
> @@ -709,12 +714,14 @@ out:
> break;
>
> case APIC_DM_NMI:
> + result = 1;
> kvm_inject_nmi(vcpu);
> kvm_vcpu_kick(vcpu);
> break;
>
> case APIC_DM_INIT:
> if (!trig_mode || level) {
> + result = 1;
> /* assumes that there are only KVM_APIC_INIT/SIPI */
> apic->pending_events = (1UL << KVM_APIC_INIT);
> /* make sure pending_events is visible before sending
> @@ -731,6 +738,7 @@ out:
> case APIC_DM_STARTUP:
> apic_debug("SIPI to vcpu %d vector 0x%02x\n",
> vcpu->vcpu_id, vector);
> + result = 1;
> apic->sipi_vector = vector;
> /* make sure sipi_vector is visible for the receiver */
> smp_wmb();
> @@ -752,6 +760,7 @@ out:
> delivery_mode);
> break;
> }
> + return result;
> }
>
> int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2)
> @@ -1461,7 +1470,7 @@ int apic_has_pending_timer(struct kvm_vcpu *vcpu)
> return 0;
> }
>
> -void kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type)
> +int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type)
> {
> u32 reg = kvm_apic_get_reg(apic, lvt_type);
> int vector, mode, trig_mode;
> @@ -1470,8 +1479,10 @@ void kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type)
> vector = reg & APIC_VECTOR_MASK;
> mode = reg & APIC_MODE_MASK;
> trig_mode = reg & APIC_LVT_LEVEL_TRIGGER;
> - __apic_accept_irq(apic, mode, vector, 1, trig_mode, NULL);
> + return __apic_accept_irq(apic, mode, vector, 1, trig_mode,
> + NULL);
> }
> + return 0;
> }
>
> void kvm_apic_nmi_wd_deliver(struct kvm_vcpu *vcpu)
> diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
> index 61a73a0..c730ac9 100644
> --- a/arch/x86/kvm/lapic.h
> +++ b/arch/x86/kvm/lapic.h
> @@ -57,9 +57,9 @@ void kvm_apic_update_tmr(struct kvm_vcpu *vcpu, u32 *tmr);
> void kvm_apic_update_irr(struct kvm_vcpu *vcpu, u32 *pir);
> int kvm_apic_match_physical_addr(struct kvm_lapic *apic, u16 dest);
> int kvm_apic_match_logical_addr(struct kvm_lapic *apic, u8 mda);
> -void kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
> - unsigned long *dest_map);
> -void kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type);
> +int kvm_apic_set_irq(struct kvm_vcpu *vcpu, struct kvm_lapic_irq *irq,
> + unsigned long *dest_map);
> +int kvm_apic_local_deliver(struct kvm_lapic *apic, int lvt_type);
>
> bool kvm_irq_delivery_to_apic_fast(struct kvm *kvm, struct kvm_lapic *src,
> struct kvm_lapic_irq *irq, int *r, unsigned long *dest_map);
> diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
> index ef1817b..e2e6b44 100644
> --- a/virt/kvm/irq_comm.c
> +++ b/virt/kvm/irq_comm.c
> @@ -91,8 +91,7 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
> if (!kvm_is_dm_lowest_prio(irq)) {
> if (r < 0)
> r = 0;
> - kvm_apic_set_irq(vcpu, irq, dest_map);
> - r++;
> + r += kvm_apic_set_irq(vcpu, irq, dest_map);
> } else if (kvm_lapic_enabled(vcpu)) {
> if (!lowest)
> lowest = vcpu;
> @@ -101,10 +100,8 @@ int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
> }
> }
>
> - if (lowest) {
> - kvm_apic_set_irq(lowest, irq, dest_map);
> - r = 1;
> - }
> + if (lowest)
> + r = kvm_apic_set_irq(lowest, irq, dest_map);
>
> return r;
> }
> --
> Gleb.
>
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