diff options
Diffstat (limited to 'virt/kvm/ioapic.c')
| -rw-r--r-- | virt/kvm/ioapic.c | 108 |
1 files changed, 69 insertions, 39 deletions
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c index ce9ed99ad7dc..d4b601547f1f 100644 --- a/virt/kvm/ioapic.c +++ b/virt/kvm/ioapic.c @@ -50,7 +50,7 @@ #else #define ioapic_debug(fmt, arg...) #endif -static int ioapic_deliver(struct kvm_ioapic *vioapic, int irq, +static int ioapic_service(struct kvm_ioapic *vioapic, int irq, bool line_status); static unsigned long ioapic_read_indirect(struct kvm_ioapic *ioapic, @@ -163,23 +163,67 @@ static bool rtc_irq_check_coalesced(struct kvm_ioapic *ioapic) return false; } -static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx, - bool line_status) +static int ioapic_set_irq(struct kvm_ioapic *ioapic, unsigned int irq, + int irq_level, bool line_status) { - union kvm_ioapic_redirect_entry *pent; - int injected = -1; + union kvm_ioapic_redirect_entry entry; + u32 mask = 1 << irq; + u32 old_irr; + int edge, ret; - pent = &ioapic->redirtbl[idx]; + entry = ioapic->redirtbl[irq]; + edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG); - if (!pent->fields.mask) { - injected = ioapic_deliver(ioapic, idx, line_status); - if (injected && pent->fields.trig_mode == IOAPIC_LEVEL_TRIG) - pent->fields.remote_irr = 1; + if (!irq_level) { + ioapic->irr &= ~mask; + ret = 1; + goto out; + } + + /* + * Return 0 for coalesced interrupts; for edge-triggered interrupts, + * this only happens if a previous edge has not been delivered due + * do masking. For level interrupts, the remote_irr field tells + * us if the interrupt is waiting for an EOI. + * + * RTC is special: it is edge-triggered, but userspace likes to know + * if it has been already ack-ed via EOI because coalesced RTC + * interrupts lead to time drift in Windows guests. So we track + * EOI manually for the RTC interrupt. + */ + if (irq == RTC_GSI && line_status && + rtc_irq_check_coalesced(ioapic)) { + ret = 0; + goto out; } - return injected; + old_irr = ioapic->irr; + ioapic->irr |= mask; + if ((edge && old_irr == ioapic->irr) || + (!edge && entry.fields.remote_irr)) { + ret = 0; + goto out; + } + + ret = ioapic_service(ioapic, irq, line_status); + +out: + trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0); + return ret; +} + +static void kvm_ioapic_inject_all(struct kvm_ioapic *ioapic, unsigned long irr) +{ + u32 idx; + + rtc_irq_eoi_tracking_reset(ioapic); + for_each_set_bit(idx, &irr, IOAPIC_NUM_PINS) + ioapic_set_irq(ioapic, idx, 1, true); + + kvm_rtc_eoi_tracking_restore_all(ioapic); } + static void update_handled_vectors(struct kvm_ioapic *ioapic) { DECLARE_BITMAP(handled_vectors, 256); @@ -282,12 +326,15 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val) } } -static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status) +static int ioapic_service(struct kvm_ioapic *ioapic, int irq, bool line_status) { union kvm_ioapic_redirect_entry *entry = &ioapic->redirtbl[irq]; struct kvm_lapic_irq irqe; int ret; + if (entry->fields.mask) + return -1; + ioapic_debug("dest=%x dest_mode=%x delivery_mode=%x " "vector=%x trig_mode=%x\n", entry->fields.dest_id, entry->fields.dest_mode, @@ -302,6 +349,9 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status) irqe.level = 1; irqe.shorthand = 0; + if (irqe.trig_mode == IOAPIC_EDGE_TRIG) + ioapic->irr &= ~(1 << irq); + if (irq == RTC_GSI && line_status) { BUG_ON(ioapic->rtc_status.pending_eoi != 0); ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, @@ -310,45 +360,24 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq, bool line_status) } else ret = kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe, NULL); + if (ret && irqe.trig_mode == IOAPIC_LEVEL_TRIG) + entry->fields.remote_irr = 1; + return ret; } int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id, int level, bool line_status) { - u32 old_irr; - u32 mask = 1 << irq; - union kvm_ioapic_redirect_entry entry; int ret, irq_level; BUG_ON(irq < 0 || irq >= IOAPIC_NUM_PINS); spin_lock(&ioapic->lock); - old_irr = ioapic->irr; irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq], irq_source_id, level); - entry = ioapic->redirtbl[irq]; - irq_level ^= entry.fields.polarity; - if (!irq_level) { - ioapic->irr &= ~mask; - ret = 1; - } else { - int edge = (entry.fields.trig_mode == IOAPIC_EDGE_TRIG); + ret = ioapic_set_irq(ioapic, irq, irq_level, line_status); - if (irq == RTC_GSI && line_status && - rtc_irq_check_coalesced(ioapic)) { - ret = 0; /* coalesced */ - goto out; - } - ioapic->irr |= mask; - if ((edge && old_irr != ioapic->irr) || - (!edge && !entry.fields.remote_irr)) - ret = ioapic_service(ioapic, irq, line_status); - else - ret = 0; /* report coalesced interrupt */ - } -out: - trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0); spin_unlock(&ioapic->lock); return ret; @@ -394,7 +423,7 @@ static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG); ent->fields.remote_irr = 0; - if (!ent->fields.mask && (ioapic->irr & (1 << i))) + if (ioapic->irr & (1 << i)) ioapic_service(ioapic, i, false); } } @@ -595,9 +624,10 @@ int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state) spin_lock(&ioapic->lock); memcpy(ioapic, state, sizeof(struct kvm_ioapic_state)); + ioapic->irr = 0; update_handled_vectors(ioapic); kvm_vcpu_request_scan_ioapic(kvm); - kvm_rtc_eoi_tracking_restore_all(ioapic); + kvm_ioapic_inject_all(ioapic, state->irr); spin_unlock(&ioapic->lock); return 0; } |