[Qemu-devel] [PATCH-RFC 05/13] syborg_virtio: add irqfd/eventfd support

["Michael S. Tsirkin" <mst@redhat.com>]

No idea if it's right .. and syborg does not support vectors so we won't
get performance gains out of it either - so quite likely it's best to
just keep this patch out of qemu.  But just to show what's possible.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/syborg_virtio.c |   25 +++++++++++++++++++++++++
 1 files changed, 25 insertions(+), 0 deletions(-)

diff --git a/hw/syborg_virtio.c b/hw/syborg_virtio.c
index 65239a0..ef6364f 100644
--- a/hw/syborg_virtio.c
+++ b/hw/syborg_virtio.c
@@ -249,9 +249,34 @@ static unsigned syborg_virtio_get_features(void *opaque)
     return proxy->host_features;
 }
 
+static void syborg_virtio_irqfd_read(void *opaque)
+{
+    VirtQueue *vq = opaque;
+    virtio_irq(vq->vdev, vq);
+}
+
+static int syborg_virtio_irqfd(void * opaque, int n, int fd, bool assign)
+{
+    SyborgVirtIOProxy *proxy = opaque;
+    VirtQueue *vq = &proxy->vdev->vq[n];
+
+    qemu_set_fd_handler(fd, assign ? syborg_virtio_irqfd_read : NULL, NULL, vq);
+    return 0;
+}
+
+static int syborg_virtio_queuefd(void * opaque, int n, int fd, bool assign)
+{
+    SyborgVirtIOProxy *proxy = opaque;
+    return kvm_set_ioeventfd(proxy->busdev.mmio[0].addr +
+                             SYBORG_VIRTIO_QUEUE_NOTIFY << 2,
+                             n, fd, assign);
+}
+
 static VirtIOBindings syborg_virtio_bindings = {
     .notify = syborg_virtio_update_irq,
     .get_features = syborg_virtio_get_features,
+    .set_irqfd = syborg_virtio_irqfd,
+    .set_queuefd = syborg_virtio_queuefd,
 };
 
 static int syborg_virtio_init(SyborgVirtIOProxy *proxy, VirtIODevice *vdev)
-- 
1.6.6.rc1.43.gf55cc