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authorMichael S. Tsirkin <mst@redhat.com>2012-10-17 18:06:06 +0200
committerGleb Natapov <gleb@redhat.com>2012-12-05 15:10:53 +0200
commit78c634402a1825f1f5bef13077f0985f3b8a3212 (patch)
tree1dac3b54821c39c1b893f0a2db4806dacc917bdc /virt
parent01f218803757c9ec1152ac2fd39d03c27c452634 (diff)
downloadvexpress-lsk-78c634402a1825f1f5bef13077f0985f3b8a3212.tar.gz
kvm: deliver msi interrupts from irq handler
We can deliver certain interrupts, notably MSI, from atomic context. Use kvm_set_irq_inatomic, to implement an irq handler for msi. This reduces the pressure on scheduler in case where host and guest irq share a host cpu. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/assigned-dev.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 23a41a9f8db..3642239252b 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -105,6 +105,15 @@ static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
}
#ifdef __KVM_HAVE_MSI
+static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
+{
+ struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
+ int ret = kvm_set_irq_inatomic(assigned_dev->kvm,
+ assigned_dev->irq_source_id,
+ assigned_dev->guest_irq, 1);
+ return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
+}
+
static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
{
struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
@@ -117,6 +126,23 @@ static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
#endif
#ifdef __KVM_HAVE_MSIX
+static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
+{
+ struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
+ int index = find_index_from_host_irq(assigned_dev, irq);
+ u32 vector;
+ int ret = 0;
+
+ if (index >= 0) {
+ vector = assigned_dev->guest_msix_entries[index].vector;
+ ret = kvm_set_irq_inatomic(assigned_dev->kvm,
+ assigned_dev->irq_source_id,
+ vector, 1);
+ }
+
+ return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
+}
+
static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
{
struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
@@ -334,11 +360,6 @@ static int assigned_device_enable_host_intx(struct kvm *kvm,
}
#ifdef __KVM_HAVE_MSI
-static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
-{
- return IRQ_WAKE_THREAD;
-}
-
static int assigned_device_enable_host_msi(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev)
{
@@ -363,11 +384,6 @@ static int assigned_device_enable_host_msi(struct kvm *kvm,
#endif
#ifdef __KVM_HAVE_MSIX
-static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
-{
- return IRQ_WAKE_THREAD;
-}
-
static int assigned_device_enable_host_msix(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev)
{