qemu/qemu-virtio-pci-irqfd-suppo...

71 lines
2.5 KiB
Diff

Use irqfd when supported by kernel.
This uses msix mask notifiers: when vector is masked, we poll it from
userspace. When it is unmasked, we poll it from kernel.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/virtio-pci.c | 31 +++++++++++++++++++++++++++++--
1 files changed, 29 insertions(+), 2 deletions(-)
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index c454093..e8e0d82 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -404,6 +404,27 @@ static void virtio_pci_guest_notifier_read(void *opaque)
}
}
+static int virtio_pci_mask_notifier(PCIDevice *dev, unsigned vector,
+ void *opaque, int masked)
+{
+ VirtQueue *vq = opaque;
+ EventNotifier *notifier = virtio_queue_guest_notifier(vq);
+ int r = kvm_set_irqfd(dev->msix_irq_entries[vector].gsi,
+ event_notifier_get_fd(notifier),
+ !masked);
+ if (r < 0) {
+ return (r == -ENOSYS) ? 0 : r;
+ }
+ if (masked) {
+ qemu_set_fd_handler(event_notifier_get_fd(notifier),
+ virtio_pci_guest_notifier_read, NULL, vq);
+ } else {
+ qemu_set_fd_handler(event_notifier_get_fd(notifier),
+ NULL, NULL, vq);
+ }
+ return 0;
+}
+
static int virtio_pci_guest_notifier(void *opaque, int n, bool assign)
{
VirtIOPCIProxy *proxy = opaque;
@@ -412,11 +433,15 @@ static int virtio_pci_guest_notifier(void *opaque, int n, bool assign)
if (assign) {
int r = event_notifier_init(notifier, 0);
- if (r < 0)
- return r;
+ if (r < 0)
+ return r;
qemu_set_fd_handler(event_notifier_get_fd(notifier),
virtio_pci_guest_notifier_read, NULL, vq);
+ msix_set_mask_notifier(&proxy->pci_dev,
+ virtio_queue_vector(proxy->vdev, n), vq);
} else {
+ msix_set_mask_notifier(&proxy->pci_dev,
+ virtio_queue_vector(proxy->vdev, n), NULL);
qemu_set_fd_handler(event_notifier_get_fd(notifier),
NULL, NULL, vq);
event_notifier_cleanup(notifier);
@@ -501,6 +526,8 @@ static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,
proxy->pci_dev.config_write = virtio_write_config;
+ proxy->pci_dev.msix_mask_notifier = virtio_pci_mask_notifier;
+
size = VIRTIO_PCI_REGION_SIZE(&proxy->pci_dev) + vdev->config_len;
if (size & (size-1))
size = 1 << qemu_fls(size);
--
1.6.6.144.g5c3af