rte_virtio: create call/kick fds on queue setup

This makes us open only as many descriptors as we need.

Change-Id: I2dbce218efdd37f015a0d4b250be9539373c6028
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/379336
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Reviewed-by: Pawel Wodkowski <pawelx.wodkowski@intel.com>

lib/bdev/virtio/rte_virtio/virtio_user.c

@@ -37,6 +37,7 @@
 #include <fcntl.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/eventfd.h>
 
 #include <linux/virtio_scsi.h>
 
@@ -157,6 +158,33 @@ virtio_user_setup_queue(struct virtio_dev *vdev, struct virtqueue *vq)
 	struct virtio_user_dev *dev = virtio_dev_get_user_dev(vdev);
 	uint16_t queue_idx = vq->vq_queue_index;
 	uint64_t desc_addr, avail_addr, used_addr;
+	int callfd;
+	int kickfd;
+
+	if (dev->callfds[queue_idx] != -1 || dev->kickfds[queue_idx] != -1) {
+		PMD_DRV_LOG(ERR, "queue %u already exists", queue_sel);
+		return -1;
+	}
+
+	/* May use invalid flag, but some backend uses kickfd and
+	 * callfd as criteria to judge if dev is alive. so finally we
+	 * use real event_fd.
+	 */
+	callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
+	if (callfd < 0) {
+		PMD_DRV_LOG(ERR, "callfd error, %s", strerror(errno));
+		return -1;
+	}
+
+	kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
+	if (kickfd < 0) {
+		PMD_DRV_LOG(ERR, "kickfd error, %s", strerror(errno));
+		close(callfd);
+		return -1;
+	}
+
+	dev->callfds[queue_idx] = callfd;
+	dev->kickfds[queue_idx] = kickfd;
 
 	desc_addr = (uintptr_t)vq->vq_ring_virt_mem;
 	avail_addr = desc_addr + vq->vq_nentries * sizeof(struct vring_desc);
@@ -188,6 +216,8 @@ virtio_user_del_queue(struct virtio_dev *vdev, struct virtqueue *vq)
 
 	close(dev->callfds[vq->vq_queue_index]);
 	close(dev->kickfds[vq->vq_queue_index]);
+	dev->callfds[vq->vq_queue_index] = -1;
+	dev->kickfds[vq->vq_queue_index] = -1;
 }
 
 static void

lib/bdev/virtio/rte_virtio/virtio_user/virtio_user_dev.c

@@ -166,65 +166,25 @@ is_vhost_user_by_type(const char *path)
 	return S_ISSOCK(sb.st_mode);
 }
 
-static int
-virtio_user_dev_init_notify(struct virtio_user_dev *dev)
-{
-	uint32_t i, j;
-	int callfd;
-	int kickfd;
-
-	for (i = 0; i < VIRTIO_MAX_VIRTQUEUES; ++i) {
-		if (i >= dev->vdev.max_queues) {
-			dev->kickfds[i] = -1;
-			dev->callfds[i] = -1;
-			continue;
-		}
-
-		/* May use invalid flag, but some backend uses kickfd and
-		 * callfd as criteria to judge if dev is alive. so finally we
-		 * use real event_fd.
-		 */
-		callfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
-		if (callfd < 0) {
-			PMD_DRV_LOG(ERR, "callfd error, %s", strerror(errno));
-			break;
-		}
-		kickfd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
-		if (kickfd < 0) {
-			PMD_DRV_LOG(ERR, "kickfd error, %s", strerror(errno));
-			break;
-		}
-		dev->callfds[i] = callfd;
-		dev->kickfds[i] = kickfd;
-	}
-
-	if (i < VIRTIO_MAX_VIRTQUEUES) {
-		for (j = 0; j <= i; ++j) {
-			close(dev->callfds[j]);
-			close(dev->kickfds[j]);
-		}
-
-		return -1;
-	}
-
-	return 0;
-}
-
 static int
 virtio_user_dev_setup(struct virtio_user_dev *dev)
 {
+	uint16_t i;
+
 	dev->vhostfd = -1;
 	dev->vhostfds = NULL;
 	dev->tapfds = NULL;
 
+	for (i = 0; i < VIRTIO_MAX_VIRTQUEUES; ++i) {
+		dev->callfds[i] = -1;
+		dev->kickfds[i] = -1;
+	}
+
 	dev->ops = &ops_user;
 
 	if (dev->ops->setup(dev) < 0)
 		return -1;
 
-	if (virtio_user_dev_init_notify(dev) < 0)
-		return -1;
-
 	return 0;
 }
 
@@ -287,11 +247,6 @@ virtio_user_dev_uninit(struct virtio_user_dev *dev)
 
 	virtio_user_stop_device(dev);
 
-	for (i = 0; i < dev->vdev.max_queues; ++i) {
-		close(dev->callfds[i]);
-		close(dev->kickfds[i]);
-	}
-
 	close(dev->vhostfd);
 
 	if (dev->vhostfds) {