virtio: introduce macro IRTIO_CONFIG_IRQ_IDX

To support configure interrupt for vhost-vdpa
Introduce VIRTIO_CONFIG_IRQ_IDX -1 as configure interrupt's queue index,
Then we can reuse the functions guest_notifier_mask and guest_notifier_pending.
Add the check of queue index in these drivers, if the driver does not support
configure interrupt, the function will just return

Signed-off-by: Cindy Lu <lulu@redhat.com>
Message-Id: <20211104164827.21911-2-lulu@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/display/vhost-user-gpu.c

@@ -485,6 +485,9 @@ vhost_user_gpu_guest_notifier_pending(VirtIODevice *vdev, int idx)
 {
     VhostUserGPU *g = VHOST_USER_GPU(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_virtqueue_pending(&g->vhost->dev, idx);
 }
 
@@ -493,6 +496,9 @@ vhost_user_gpu_guest_notifier_mask(VirtIODevice *vdev, int idx, bool mask)
 {
     VhostUserGPU *g = VHOST_USER_GPU(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
     vhost_virtqueue_mask(&g->vhost->dev, vdev, idx, mask);
 }
 

hw/net/virtio-net.c

@@ -3168,6 +3168,9 @@ static bool virtio_net_guest_notifier_pending(VirtIODevice *vdev, int idx)
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_net_virtqueue_pending(get_vhost_net(nc->peer), idx);
 }
 
@@ -3177,8 +3180,11 @@ static void virtio_net_guest_notifier_mask(VirtIODevice *vdev, int idx,
     VirtIONet *n = VIRTIO_NET(vdev);
     NetClientState *nc = qemu_get_subqueue(n->nic, vq2q(idx));
     assert(n->vhost_started);
-    vhost_net_virtqueue_mask(get_vhost_net(nc->peer),
-                             vdev, idx, mask);
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
+
+    vhost_net_virtqueue_mask(get_vhost_net(nc->peer), vdev, idx, mask);
 }
 
 static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features)

hw/virtio/vhost-user-fs.c

@@ -161,6 +161,9 @@ static void vuf_guest_notifier_mask(VirtIODevice *vdev, int idx,
 {
     VHostUserFS *fs = VHOST_USER_FS(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
     vhost_virtqueue_mask(&fs->vhost_dev, vdev, idx, mask);
 }
 
@@ -168,6 +171,9 @@ static bool vuf_guest_notifier_pending(VirtIODevice *vdev, int idx)
 {
     VHostUserFS *fs = VHOST_USER_FS(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_virtqueue_pending(&fs->vhost_dev, idx);
 }
 

hw/virtio/vhost-vsock-common.c

@@ -125,6 +125,9 @@ static void vhost_vsock_common_guest_notifier_mask(VirtIODevice *vdev, int idx,
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
     vhost_virtqueue_mask(&vvc->vhost_dev, vdev, idx, mask);
 }
 
@@ -133,6 +136,9 @@ static bool vhost_vsock_common_guest_notifier_pending(VirtIODevice *vdev,
 {
     VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return vhost_virtqueue_pending(&vvc->vhost_dev, idx);
 }
 

hw/virtio/virtio-crypto.c

@@ -948,6 +948,9 @@ static void virtio_crypto_guest_notifier_mask(VirtIODevice *vdev, int idx,
 
     assert(vcrypto->vhost_started);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return;
+    }
     cryptodev_vhost_virtqueue_mask(vdev, queue, idx, mask);
 }
 
@@ -958,6 +961,9 @@ static bool virtio_crypto_guest_notifier_pending(VirtIODevice *vdev, int idx)
 
     assert(vcrypto->vhost_started);
 
+    if (idx == VIRTIO_CONFIG_IRQ_IDX) {
+        return false;
+    }
     return cryptodev_vhost_virtqueue_pending(vdev, queue, idx);
 }
 

include/hw/virtio/virtio.h

@@ -67,6 +67,9 @@ typedef struct VirtQueueElement
 
 #define VIRTIO_NO_VECTOR 0xffff
 
+/* special index value used internally for config irqs */
+#define VIRTIO_CONFIG_IRQ_IDX -1
+
 #define TYPE_VIRTIO_DEVICE "virtio-device"
 OBJECT_DECLARE_TYPE(VirtIODevice, VirtioDeviceClass, VIRTIO_DEVICE)