From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
The complete work handler runs with assigned_dev_lock acquired and
interrupts disabled, so there is nothing to gain pushing this work out
of the actually IRQ handler. Fold them together.
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---
include/linux/kvm_host.h | 1 -
virt/kvm/assigned-dev.c | 71 +++++++++++++++-------------------------------
2 files changed, 23 insertions(+), 49 deletions(-)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 462b982..df5497f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -465,7 +465,6 @@ struct kvm_guest_msix_entry {
struct kvm_assigned_dev_kernel {
struct kvm_irq_ack_notifier ack_notifier;
- struct work_struct interrupt_work;
struct list_head list;
int assigned_dev_id;
int host_segnr;
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 7c98928..5c1b56a 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -55,18 +55,24 @@ static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
return index;
}
-static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
+static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
{
- struct kvm_assigned_dev_kernel *assigned_dev;
- int i;
-
- assigned_dev = container_of(work, struct kvm_assigned_dev_kernel,
- interrupt_work);
+ struct kvm_assigned_dev_kernel *assigned_dev =
+ (struct kvm_assigned_dev_kernel *) dev_id;
+ unsigned long flags;
- spin_lock_irq(&assigned_dev->assigned_dev_lock);
+ spin_lock_irqsave(&assigned_dev->assigned_dev_lock, flags);
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
struct kvm_guest_msix_entry *guest_entries =
assigned_dev->guest_msix_entries;
+ int index = find_index_from_host_irq(assigned_dev, irq);
+ int i;
+
+ if (index < 0)
+ goto out;
+
+ guest_entries[index].flags |= KVM_ASSIGNED_MSIX_PENDING;
+
for (i = 0; i < assigned_dev->entries_nr; i++) {
if (!(guest_entries[i].flags &
KVM_ASSIGNED_MSIX_PENDING))
@@ -76,33 +82,15 @@ static void kvm_assigned_dev_interrupt_work_handler(struct work_struct *work)
assigned_dev->irq_source_id,
guest_entries[i].vector, 1);
}
- } else
+ } else {
kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
assigned_dev->guest_irq, 1);
- spin_unlock_irq(&assigned_dev->assigned_dev_lock);
-}
-
-static irqreturn_t kvm_assigned_dev_intr(int irq, void *dev_id)
-{
- unsigned long flags;
- struct kvm_assigned_dev_kernel *assigned_dev =
- (struct kvm_assigned_dev_kernel *) dev_id;
-
- spin_lock_irqsave(&assigned_dev->assigned_dev_lock, flags);
- if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
- int index = find_index_from_host_irq(assigned_dev, irq);
- if (index < 0)
- goto out;
- assigned_dev->guest_msix_entries[index].flags |=
- KVM_ASSIGNED_MSIX_PENDING;
- }
-
- schedule_work(&assigned_dev->interrupt_work);
-
- if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) {
- disable_irq_nosync(irq);
- assigned_dev->host_irq_disabled = true;
+ if (assigned_dev->irq_requested_type &
+ KVM_DEV_IRQ_GUEST_INTX) {
+ disable_irq_nosync(irq);
+ assigned_dev->host_irq_disabled = true;
+ }
}
out:
@@ -147,33 +135,23 @@ static void deassign_guest_irq(struct kvm *kvm,
assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK);
}
-/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
static void deassign_host_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev)
{
/*
- * In kvm_free_device_irq, cancel_work_sync return true if:
- * 1. work is scheduled, and then cancelled.
- * 2. work callback is executed.
- *
- * The first one ensured that the irq is disabled and no more events
- * would happen. But for the second one, the irq may be enabled (e.g.
- * for MSI). So we disable irq here to prevent further events.
+ * We disable irq here to prevent further events.
*
* Notice this maybe result in nested disable if the interrupt type is
* INTx, but it's OK for we are going to free it.
*
* If this function is a part of VM destroy, please ensure that till
* now, the kvm state is still legal for probably we also have to wait
- * interrupt_work done.
+ * on a currently running IRQ handler.
*/
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
int i;
for (i = 0; i < assigned_dev->entries_nr; i++)
- disable_irq_nosync(assigned_dev->
- host_msix_entries[i].vector);
-
- cancel_work_sync(&assigned_dev->interrupt_work);
+ disable_irq(assigned_dev->host_msix_entries[i].vector);
for (i = 0; i < assigned_dev->entries_nr; i++)
free_irq(assigned_dev->host_msix_entries[i].vector,
@@ -185,8 +163,7 @@ static void deassign_host_irq(struct kvm *kvm,
pci_disable_msix(assigned_dev->dev);
} else {
/* Deal with MSI and INTx */
- disable_irq_nosync(assigned_dev->host_irq);
- cancel_work_sync(&assigned_dev->interrupt_work);
+ disable_irq(assigned_dev->host_irq);
free_irq(assigned_dev->host_irq, (void *)assigned_dev);
@@ -558,8 +535,6 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
match->irq_source_id = -1;
match->kvm = kvm;
match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
- INIT_WORK(&match->interrupt_work,
- kvm_assigned_dev_interrupt_work_handler);
list_add(&match->list, &kvm->arch.assigned_dev_head);
--
1.7.1
--
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