[PATCH v5 16/18] kvm: ioapic: Refactor kvm_ioapic_update_eoi()

Suravee Suthikulpanit
2019-11-14T20:16:23Z

Refactor code for handling IOAPIC EOI for subsequent patch.
There is no functional change.

Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
---
arch/x86/kvm/ioapic.c | 110 +++++++++++++++++++++++++-------------------------
1 file changed, 56 insertions(+), 54 deletions(-)

diff --git a/arch/x86/kvm/ioapic.c b/arch/x86/kvm/ioapic.c
index d859ae8..c57b7bb 100644
--- a/arch/x86/kvm/ioapic.c
+++ b/arch/x86/kvm/ioapic.c
@@ -151,10 +151,16 @@ static void kvm_rtc_eoi_tracking_restore_all(struct kvm_ioapic *ioapic)
__rtc_irq_eoi_tracking_restore_one(vcpu);
}

-static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu)
+static void rtc_irq_eoi(struct kvm_ioapic *ioapic, struct kvm_vcpu *vcpu,
+ int vector)
{
- if (test_and_clear_bit(vcpu->vcpu_id,
- ioapic->rtc_status.dest_map.map)) {
+ struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
+
+ /* RTC special handling */
+ if (test_bit(vcpu->vcpu_id, dest_map->map) &&
+ (vector == dest_map->vectors[vcpu->vcpu_id]) &&
+ (test_and_clear_bit(vcpu->vcpu_id,
+ ioapic->rtc_status.dest_map.map))) {
--ioapic->rtc_status.pending_eoi;
rtc_status_pending_eoi_check_valid(ioapic);
}
@@ -415,72 +421,68 @@ static void kvm_ioapic_eoi_inject_work(struct work_struct *work)
}

#define IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT 10000
-
-static void __kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu,
- struct kvm_ioapic *ioapic, int vector, int trigger_mode)
+static void kvm_ioapic_update_eoi_one(struct kvm_vcpu *vcpu,
+ struct kvm_ioapic *ioapic,
+ int trigger_mode,
+ int pin)
{
- struct dest_map *dest_map = &ioapic->rtc_status.dest_map;
struct kvm_lapic *apic = vcpu->arch.apic;
- int i;
-
- /* RTC special handling */
- if (test_bit(vcpu->vcpu_id, dest_map->map) &&
- vector == dest_map->vectors[vcpu->vcpu_id])
- rtc_irq_eoi(ioapic, vcpu);
-
- for (i = 0; i < IOAPIC_NUM_PINS; i++) {
- union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
-
- if (ent->fields.vector != vector)
- continue;
+ union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[pin];

- /*
- * We are dropping lock while calling ack notifiers because ack
- * notifier callbacks for assigned devices call into IOAPIC
- * recursively. Since remote_irr is cleared only after call
- * to notifiers if the same vector will be delivered while lock
- * is dropped it will be put into irr and will be delivered
- * after ack notifier returns.
- */
- spin_unlock(&ioapic->lock);
- kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
- spin_lock(&ioapic->lock);
+ /*
+ * We are dropping lock while calling ack notifiers because ack
+ * notifier callbacks for assigned devices call into IOAPIC
+ * recursively. Since remote_irr is cleared only after call
+ * to notifiers if the same vector will be delivered while lock
+ * is dropped it will be put into irr and will be delivered
+ * after ack notifier returns.
+ */
+ spin_unlock(&ioapic->lock);
+ kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
+ spin_lock(&ioapic->lock);

- if (trigger_mode != IOAPIC_LEVEL_TRIG ||
- kvm_lapic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)
- continue;
+ if (trigger_mode != IOAPIC_LEVEL_TRIG ||
+ kvm_lapic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)
+ return;

- ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
- ent->fields.remote_irr = 0;
- if (!ent->fields.mask && (ioapic->irr & (1 << i))) {
- ++ioapic->irq_eoi[i];
- if (ioapic->irq_eoi[i] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
- /*
- * Real hardware does not deliver the interrupt
- * immediately during eoi broadcast, and this
- * lets a buggy guest make slow progress
- * even if it does not correctly handle a
- * level-triggered interrupt. Emulate this
- * behavior if we detect an interrupt storm.
- */
- schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
- ioapic->irq_eoi[i] = 0;
- trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
- } else {
- ioapic_service(ioapic, i, false);
- }
+ ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
+ ent->fields.remote_irr = 0;
+ if (!ent->fields.mask && (ioapic->irr & (1 << pin))) {
+ ++ioapic->irq_eoi[pin];
+ if (ioapic->irq_eoi[pin] == IOAPIC_SUCCESSIVE_IRQ_MAX_COUNT) {
+ /*
+ * Real hardware does not deliver the interrupt
+ * immediately during eoi broadcast, and this
+ * lets a buggy guest make slow progress
+ * even if it does not correctly handle a
+ * level-triggered interrupt. Emulate this
+ * behavior if we detect an interrupt storm.
+ */
+ schedule_delayed_work(&ioapic->eoi_inject, HZ / 100);
+ ioapic->irq_eoi[pin] = 0;
+ trace_kvm_ioapic_delayed_eoi_inj(ent->bits);
} else {
- ioapic->irq_eoi[i] = 0;
+ ioapic_service(ioapic, pin, false);
}
+ } else {
+ ioapic->irq_eoi[pin] = 0;
}
}

void kvm_ioapic_update_eoi(struct kvm_vcpu *vcpu, int vector, int trigger_mode)
{
+ int i;
struct kvm_ioapic *ioapic = vcpu->kvm->arch.vioapic;

spin_lock(&ioapic->lock);
- __kvm_ioapic_update_eoi(vcpu, ioapic, vector, trigger_mode);
+ rtc_irq_eoi(ioapic, vcpu, vector);
+ for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+ union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
+
+ if (ent->fields.vector != vector)
+ continue;
+ kvm_ioapic_update_eoi_one(vcpu, ioapic, trigger_mode, i);
+ }
spin_unlock(&ioapic->lock);
}

--
1.8.3.1