Re: [dpdk-dev] [PATCH v8 3/8] vhost: vring queue setup for multiple queue support

[Yuanhan Liu <yuanhan.liu@linux.intel.com>]

On Mon, Oct 26, 2015 at 02:24:08PM +0900, Tetsuya Mukawa wrote:
> On 2015/10/22 21:35, Yuanhan Liu wrote:
...
> > @@ -292,13 +300,13 @@ user_get_vring_base(struct vhost_device_ctx ctx,
> >  	 * sent and only sent in vhost_vring_stop.
> >  	 * TODO: cleanup the vring, it isn't usable since here.
> >  	 */
> > -	if ((dev->virtqueue[VIRTIO_RXQ]->kickfd) >= 0) {
> > -		close(dev->virtqueue[VIRTIO_RXQ]->kickfd);
> > -		dev->virtqueue[VIRTIO_RXQ]->kickfd = -1;
> > +	if ((dev->virtqueue[state->index]->kickfd + VIRTIO_RXQ) >= 0) {
> > +		close(dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd);
> > +		dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd = -1;
> >  	}
> 
> Hi Yuanhan,
> 
> Please let me make sure whether below is correct.
>     if ((dev->virtqueue[state->index]->kickfd + VIRTIO_RXQ) >= 0) {
> 
> > -	if ((dev->virtqueue[VIRTIO_TXQ]->kickfd) >= 0) {
> > -		close(dev->virtqueue[VIRTIO_TXQ]->kickfd);
> > -		dev->virtqueue[VIRTIO_TXQ]->kickfd = -1;
> > +	if ((dev->virtqueue[state->index]->kickfd + VIRTIO_TXQ) >= 0) {
> > +		close(dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd);
> > +		dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd = -1;
> 
> Also, same question here.

Oops, silly typos... Thanks for catching it out!

Here is an update patch (Thomas, please let me know if you prefer me
to send the whole patchset for you to apply):

-- >8 --
>From 2b7d8155b6c9f37bffcbb220e87f7634f329acee Mon Sep 17 00:00:00 2001
From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Date: Fri, 18 Sep 2015 16:01:10 +0800
Subject: [PATCH] vhost: vring queue setup for multiple queue support

All queue pairs, including the default (the first) queue pair,
are allocated dynamically, when a vring_call message is received
first time for a specific queue pair.

This is a refactor work for enabling vhost-user multiple queue;
it should not break anything as it does no functional changes:
we don't support mq set, so there is only one mq at max.

This patch is based on Changchun's patch.

Signed-off-by: Ouyang Changchun <changchun.ouyang@intel.com>
Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Acked-by: Flavio Leitner <fbl@sysclose.org>

---

v9: - fix silly error "dev->virtqueue[state->index]->kickfd + VIRTIO_RXQ"

v8: - move virtuque field to the end of `virtio_net' struct.

    - Add a FIXME at set_vring_call() for doing vring queue pair
      allocation.
---
 lib/librte_vhost/rte_virtio_net.h             |   3 +-
 lib/librte_vhost/vhost_user/virtio-net-user.c |  46 ++++----
 lib/librte_vhost/virtio-net.c                 | 156 ++++++++++++++++----------
 3 files changed, 123 insertions(+), 82 deletions(-)

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index e3a21e5..9a32a95 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -96,7 +96,6 @@ struct vhost_virtqueue {
  * Device structure contains all configuration information relating to the device.
  */
 struct virtio_net {
-	struct vhost_virtqueue	*virtqueue[VIRTIO_QNUM];	/**< Contains all virtqueue information. */
 	struct virtio_memory	*mem;		/**< QEMU memory and memory region information. */
 	uint64_t		features;	/**< Negotiated feature set. */
 	uint64_t		protocol_features;	/**< Negotiated protocol feature set. */
@@ -104,7 +103,9 @@ struct virtio_net {
 	uint32_t		flags;		/**< Device flags. Only used to check if device is running on data core. */
 #define IF_NAME_SZ (PATH_MAX > IFNAMSIZ ? PATH_MAX : IFNAMSIZ)
 	char			ifname[IF_NAME_SZ];	/**< Name of the tap device or socket path. */
+	uint32_t		virt_qp_nb;	/**< number of queue pair we have allocated */
 	void			*priv;		/**< private context */
+	struct vhost_virtqueue	*virtqueue[VIRTIO_NET_CTRL_MQ_VQ_PAIRS_MAX];	/**< Contains all virtqueue information. */
 } __rte_cache_aligned;
 
 /**
diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index 6da729d..7fc3805 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -206,25 +206,33 @@ err_mmap:
 }
 
 static int
+vq_is_ready(struct vhost_virtqueue *vq)
+{
+	return vq && vq->desc   &&
+	       vq->kickfd != -1 &&
+	       vq->callfd != -1;
+}
+
+static int
 virtio_is_ready(struct virtio_net *dev)
 {
 	struct vhost_virtqueue *rvq, *tvq;
+	uint32_t i;
 
-	/* mq support in future.*/
-	rvq = dev->virtqueue[VIRTIO_RXQ];
-	tvq = dev->virtqueue[VIRTIO_TXQ];
-	if (rvq && tvq && rvq->desc && tvq->desc &&
-		(rvq->kickfd != -1) &&
-		(rvq->callfd != -1) &&
-		(tvq->kickfd != -1) &&
-		(tvq->callfd != -1)) {
-		RTE_LOG(INFO, VHOST_CONFIG,
-			"virtio is now ready for processing.\n");
-		return 1;
+	for (i = 0; i < dev->virt_qp_nb; i++) {
+		rvq = dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_RXQ];
+		tvq = dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_TXQ];
+
+		if (!vq_is_ready(rvq) || !vq_is_ready(tvq)) {
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"virtio is not ready for processing.\n");
+			return 0;
+		}
 	}
+
 	RTE_LOG(INFO, VHOST_CONFIG,
-		"virtio isn't ready for processing.\n");
-	return 0;
+		"virtio is now ready for processing.\n");
+	return 1;
 }
 
 void
@@ -292,13 +300,13 @@ user_get_vring_base(struct vhost_device_ctx ctx,
 	 * sent and only sent in vhost_vring_stop.
 	 * TODO: cleanup the vring, it isn't usable since here.
 	 */
-	if ((dev->virtqueue[VIRTIO_RXQ]->kickfd) >= 0) {
-		close(dev->virtqueue[VIRTIO_RXQ]->kickfd);
-		dev->virtqueue[VIRTIO_RXQ]->kickfd = -1;
+	if (dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd >= 0) {
+		close(dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd);
+		dev->virtqueue[state->index + VIRTIO_RXQ]->kickfd = -1;
 	}
-	if ((dev->virtqueue[VIRTIO_TXQ]->kickfd) >= 0) {
-		close(dev->virtqueue[VIRTIO_TXQ]->kickfd);
-		dev->virtqueue[VIRTIO_TXQ]->kickfd = -1;
+	if (dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd >= 0) {
+		close(dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd);
+		dev->virtqueue[state->index + VIRTIO_TXQ]->kickfd = -1;
 	}
 
 	return 0;
diff --git a/lib/librte_vhost/virtio-net.c b/lib/librte_vhost/virtio-net.c
index 830f22a..772f835 100644
--- a/lib/librte_vhost/virtio-net.c
+++ b/lib/librte_vhost/virtio-net.c
@@ -36,6 +36,7 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <assert.h>
 #include <sys/mman.h>
 #include <unistd.h>
 #ifdef RTE_LIBRTE_VHOST_NUMA
@@ -178,6 +179,15 @@ add_config_ll_entry(struct virtio_net_config_ll *new_ll_dev)
 
 }
 
+static void
+cleanup_vq(struct vhost_virtqueue *vq)
+{
+	if (vq->callfd >= 0)
+		close(vq->callfd);
+	if (vq->kickfd >= 0)
+		close(vq->kickfd);
+}
+
 /*
  * Unmap any memory, close any file descriptors and
  * free any memory owned by a device.
@@ -185,6 +195,8 @@ add_config_ll_entry(struct virtio_net_config_ll *new_ll_dev)
 static void
 cleanup_device(struct virtio_net *dev)
 {
+	uint32_t i;
+
 	/* Unmap QEMU memory file if mapped. */
 	if (dev->mem) {
 		munmap((void *)(uintptr_t)dev->mem->mapped_address,
@@ -192,15 +204,10 @@ cleanup_device(struct virtio_net *dev)
 		free(dev->mem);
 	}
 
-	/* Close any event notifiers opened by device. */
-	if (dev->virtqueue[VIRTIO_RXQ]->callfd >= 0)
-		close(dev->virtqueue[VIRTIO_RXQ]->callfd);
-	if (dev->virtqueue[VIRTIO_RXQ]->kickfd >= 0)
-		close(dev->virtqueue[VIRTIO_RXQ]->kickfd);
-	if (dev->virtqueue[VIRTIO_TXQ]->callfd >= 0)
-		close(dev->virtqueue[VIRTIO_TXQ]->callfd);
-	if (dev->virtqueue[VIRTIO_TXQ]->kickfd >= 0)
-		close(dev->virtqueue[VIRTIO_TXQ]->kickfd);
+	for (i = 0; i < dev->virt_qp_nb; i++) {
+		cleanup_vq(dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_RXQ]);
+		cleanup_vq(dev->virtqueue[i * VIRTIO_QNUM + VIRTIO_TXQ]);
+	}
 }
 
 /*
@@ -209,9 +216,11 @@ cleanup_device(struct virtio_net *dev)
 static void
 free_device(struct virtio_net_config_ll *ll_dev)
 {
-	/* Free any malloc'd memory */
-	rte_free(ll_dev->dev.virtqueue[VIRTIO_RXQ]);
-	rte_free(ll_dev->dev.virtqueue[VIRTIO_TXQ]);
+	uint32_t i;
+
+	for (i = 0; i < ll_dev->dev.virt_qp_nb; i++)
+		rte_free(ll_dev->dev.virtqueue[i * VIRTIO_QNUM]);
+
 	rte_free(ll_dev);
 }
 
@@ -244,34 +253,68 @@ rm_config_ll_entry(struct virtio_net_config_ll *ll_dev,
 	}
 }
 
+static void
+init_vring_queue(struct vhost_virtqueue *vq)
+{
+	memset(vq, 0, sizeof(struct vhost_virtqueue));
+
+	vq->kickfd = -1;
+	vq->callfd = -1;
+
+	/* Backends are set to -1 indicating an inactive device. */
+	vq->backend = -1;
+}
+
+static void
+init_vring_queue_pair(struct virtio_net *dev, uint32_t qp_idx)
+{
+	init_vring_queue(dev->virtqueue[qp_idx * VIRTIO_QNUM + VIRTIO_RXQ]);
+	init_vring_queue(dev->virtqueue[qp_idx * VIRTIO_QNUM + VIRTIO_TXQ]);
+}
+
+static int
+alloc_vring_queue_pair(struct virtio_net *dev, uint32_t qp_idx)
+{
+	struct vhost_virtqueue *virtqueue = NULL;
+	uint32_t virt_rx_q_idx = qp_idx * VIRTIO_QNUM + VIRTIO_RXQ;
+	uint32_t virt_tx_q_idx = qp_idx * VIRTIO_QNUM + VIRTIO_TXQ;
+
+	virtqueue = rte_malloc(NULL,
+			       sizeof(struct vhost_virtqueue) * VIRTIO_QNUM, 0);
+	if (virtqueue == NULL) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Failed to allocate memory for virt qp:%d.\n", qp_idx);
+		return -1;
+	}
+
+	dev->virtqueue[virt_rx_q_idx] = virtqueue;
+	dev->virtqueue[virt_tx_q_idx] = virtqueue + VIRTIO_TXQ;
+
+	init_vring_queue_pair(dev, qp_idx);
+
+	dev->virt_qp_nb += 1;
+
+	return 0;
+}
+
 /*
  *  Initialise all variables in device structure.
  */
 static void
 init_device(struct virtio_net *dev)
 {
-	uint64_t vq_offset;
+	int vq_offset;
+	uint32_t i;
 
 	/*
 	 * Virtqueues have already been malloced so
 	 * we don't want to set them to NULL.
 	 */
-	vq_offset = offsetof(struct virtio_net, mem);
-
-	/* Set everything to 0. */
-	memset((void *)(uintptr_t)((uint64_t)(uintptr_t)dev + vq_offset), 0,
-		(sizeof(struct virtio_net) - (size_t)vq_offset));
-	memset(dev->virtqueue[VIRTIO_RXQ], 0, sizeof(struct vhost_virtqueue));
-	memset(dev->virtqueue[VIRTIO_TXQ], 0, sizeof(struct vhost_virtqueue));
-
-	dev->virtqueue[VIRTIO_RXQ]->kickfd = -1;
-	dev->virtqueue[VIRTIO_RXQ]->callfd = -1;
-	dev->virtqueue[VIRTIO_TXQ]->kickfd = -1;
-	dev->virtqueue[VIRTIO_TXQ]->callfd = -1;
+	vq_offset = offsetof(struct virtio_net, virtqueue);
+	memset(dev, 0, vq_offset);
 
-	/* Backends are set to -1 indicating an inactive device. */
-	dev->virtqueue[VIRTIO_RXQ]->backend = VIRTIO_DEV_STOPPED;
-	dev->virtqueue[VIRTIO_TXQ]->backend = VIRTIO_DEV_STOPPED;
+	for (i = 0; i < dev->virt_qp_nb; i++)
+		init_vring_queue_pair(dev, i);
 }
 
 /*
@@ -283,7 +326,6 @@ static int
 new_device(struct vhost_device_ctx ctx)
 {
 	struct virtio_net_config_ll *new_ll_dev;
-	struct vhost_virtqueue *virtqueue_rx, *virtqueue_tx;
 
 	/* Setup device and virtqueues. */
 	new_ll_dev = rte_malloc(NULL, sizeof(struct virtio_net_config_ll), 0);
@@ -294,28 +336,6 @@ new_device(struct vhost_device_ctx ctx)
 		return -1;
 	}
 
-	virtqueue_rx = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0);
-	if (virtqueue_rx == NULL) {
-		rte_free(new_ll_dev);
-		RTE_LOG(ERR, VHOST_CONFIG,
-			"(%"PRIu64") Failed to allocate memory for rxq.\n",
-			ctx.fh);
-		return -1;
-	}
-
-	virtqueue_tx = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0);
-	if (virtqueue_tx == NULL) {
-		rte_free(virtqueue_rx);
-		rte_free(new_ll_dev);
-		RTE_LOG(ERR, VHOST_CONFIG,
-			"(%"PRIu64") Failed to allocate memory for txq.\n",
-			ctx.fh);
-		return -1;
-	}
-
-	new_ll_dev->dev.virtqueue[VIRTIO_RXQ] = virtqueue_rx;
-	new_ll_dev->dev.virtqueue[VIRTIO_TXQ] = virtqueue_tx;
-
 	/* Initialise device and virtqueues. */
 	init_device(&new_ll_dev->dev);
 
@@ -441,6 +461,8 @@ static int
 set_features(struct vhost_device_ctx ctx, uint64_t *pu)
 {
 	struct virtio_net *dev;
+	uint16_t vhost_hlen;
+	uint16_t i;
 
 	dev = get_device(ctx);
 	if (dev == NULL)
@@ -448,27 +470,26 @@ set_features(struct vhost_device_ctx ctx, uint64_t *pu)
 	if (*pu & ~VHOST_FEATURES)
 		return -1;
 
-	/* Store the negotiated feature list for the device. */
 	dev->features = *pu;
-
-	/* Set the vhost_hlen depending on if VIRTIO_NET_F_MRG_RXBUF is set. */
 	if (dev->features & (1 << VIRTIO_NET_F_MRG_RXBUF)) {
 		LOG_DEBUG(VHOST_CONFIG,
 			"(%"PRIu64") Mergeable RX buffers enabled\n",
 			dev->device_fh);
-		dev->virtqueue[VIRTIO_RXQ]->vhost_hlen =
-			sizeof(struct virtio_net_hdr_mrg_rxbuf);
-		dev->virtqueue[VIRTIO_TXQ]->vhost_hlen =
-			sizeof(struct virtio_net_hdr_mrg_rxbuf);
+		vhost_hlen = sizeof(struct virtio_net_hdr_mrg_rxbuf);
 	} else {
 		LOG_DEBUG(VHOST_CONFIG,
 			"(%"PRIu64") Mergeable RX buffers disabled\n",
 			dev->device_fh);
-		dev->virtqueue[VIRTIO_RXQ]->vhost_hlen =
-			sizeof(struct virtio_net_hdr);
-		dev->virtqueue[VIRTIO_TXQ]->vhost_hlen =
-			sizeof(struct virtio_net_hdr);
+		vhost_hlen = sizeof(struct virtio_net_hdr);
+	}
+
+	for (i = 0; i < dev->virt_qp_nb; i++) {
+		uint16_t base_idx = i * VIRTIO_QNUM;
+
+		dev->virtqueue[base_idx + VIRTIO_RXQ]->vhost_hlen = vhost_hlen;
+		dev->virtqueue[base_idx + VIRTIO_TXQ]->vhost_hlen = vhost_hlen;
 	}
+
 	return 0;
 }
 
@@ -684,13 +705,24 @@ set_vring_call(struct vhost_device_ctx ctx, struct vhost_vring_file *file)
 {
 	struct virtio_net *dev;
 	struct vhost_virtqueue *vq;
+	uint32_t cur_qp_idx = file->index / VIRTIO_QNUM;
 
 	dev = get_device(ctx);
 	if (dev == NULL)
 		return -1;
 
+	/*
+	 * FIXME: VHOST_SET_VRING_CALL is the first per-vring message
+	 * we get, so we do vring queue pair allocation here.
+	 */
+	if (cur_qp_idx + 1 > dev->virt_qp_nb) {
+		if (alloc_vring_queue_pair(dev, cur_qp_idx) < 0)
+			return -1;
+	}
+
 	/* file->index refers to the queue index. The txq is 1, rxq is 0. */
 	vq = dev->virtqueue[file->index];
+	assert(vq != NULL);
 
 	if (vq->callfd >= 0)
 		close(vq->callfd);
-- 
1.9.0