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authorAlex Williamson <alex.williamson@redhat.com>2012-07-09 10:53:22 -0600
committerAvi Kivity <avi@redhat.com>2012-07-11 13:01:48 +0300
commita76beb14123a69ca080f5a5425e28b786d62318d (patch)
treefb2023fbc90fb082221d06487e6e7bdb6dfa6bbb /virt
parent055c9fa8874fa7261eec7a268366565db84af474 (diff)
downloadlinux-a76beb14123a69ca080f5a5425e28b786d62318d.tar.gz
KVM: Fix device assignment threaded irq handler
The kernel no longer allows us to pass NULL for the hard handler without also specifying IRQF_ONESHOT. IRQF_ONESHOT imposes latency in the exit path that we don't need for MSI interrupts. Long term we'd like to inject these interrupts from the hard handler when possible. In the short term, we can create dummy hard handlers that return us to the previous behavior. Credit to Michael for original patch. Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=43328 Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/assigned-dev.c15
1 files changed, 13 insertions, 2 deletions
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index b1e091ae2f3..23a41a9f8db 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -334,6 +334,11 @@ 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)
{
@@ -346,7 +351,7 @@ static int assigned_device_enable_host_msi(struct kvm *kvm,
}
dev->host_irq = dev->dev->irq;
- if (request_threaded_irq(dev->host_irq, NULL,
+ if (request_threaded_irq(dev->host_irq, kvm_assigned_dev_msi,
kvm_assigned_dev_thread_msi, 0,
dev->irq_name, dev)) {
pci_disable_msi(dev->dev);
@@ -358,6 +363,11 @@ 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)
{
@@ -374,7 +384,8 @@ static int assigned_device_enable_host_msix(struct kvm *kvm,
for (i = 0; i < dev->entries_nr; i++) {
r = request_threaded_irq(dev->host_msix_entries[i].vector,
- NULL, kvm_assigned_dev_thread_msix,
+ kvm_assigned_dev_msix,
+ kvm_assigned_dev_thread_msix,
0, dev->irq_name, dev);
if (r)
goto err;