[dpdk-dev] [PATCH 25/40] net/virtio: add Virtio-user features ops

[Maxime Coquelin <maxime.coquelin@redhat.com>]

This patch introduce new callbacks for getting
and setting Virtio features, and implements them
for the different backend types.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 drivers/net/virtio/virtio_user/vhost.h        |   2 +
 drivers/net/virtio/virtio_user/vhost_kernel.c | 150 +++++++++---------
 .../net/virtio/virtio_user/vhost_kernel_tap.c |  23 +++
 .../net/virtio/virtio_user/vhost_kernel_tap.h |   1 +
 drivers/net/virtio/virtio_user/vhost_user.c   |  63 +++++++-
 drivers/net/virtio/virtio_user/vhost_vdpa.c   |  38 +++--
 .../net/virtio/virtio_user/virtio_user_dev.c  |   5 +-
 drivers/net/virtio/virtio_user_ethdev.c       |   3 +-
 8 files changed, 188 insertions(+), 97 deletions(-)

diff --git a/drivers/net/virtio/virtio_user/vhost.h b/drivers/net/virtio/virtio_user/vhost.h
index 8e819ecfb8..16978e27ed 100644
--- a/drivers/net/virtio/virtio_user/vhost.h
+++ b/drivers/net/virtio/virtio_user/vhost.h
@@ -102,6 +102,8 @@ struct virtio_user_dev;
 struct virtio_user_backend_ops {
 	int (*setup)(struct virtio_user_dev *dev);
 	int (*set_owner)(struct virtio_user_dev *dev);
+	int (*get_features)(struct virtio_user_dev *dev, uint64_t *features);
+	int (*set_features)(struct virtio_user_dev *dev, uint64_t features);
 	int (*send_request)(struct virtio_user_dev *dev,
 			    enum vhost_user_request req,
 			    void *arg);
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel.c b/drivers/net/virtio/virtio_user/vhost_kernel.c
index b79dcad179..f44df8ef1f 100644
--- a/drivers/net/virtio/virtio_user/vhost_kernel.c
+++ b/drivers/net/virtio/virtio_user/vhost_kernel.c
@@ -38,6 +38,28 @@ struct vhost_memory_kernel {
 #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
 #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
 
+/* with below features, vhost kernel does not need to do the checksum and TSO,
+ * these info will be passed to virtio_user through virtio net header.
+ */
+#define VHOST_KERNEL_GUEST_OFFLOADS_MASK	\
+	((1ULL << VIRTIO_NET_F_GUEST_CSUM) |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_TSO4) |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_TSO6) |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_ECN)  |	\
+	 (1ULL << VIRTIO_NET_F_GUEST_UFO))
+
+/* with below features, when flows from virtio_user to vhost kernel
+ * (1) if flows goes up through the kernel networking stack, it does not need
+ * to verify checksum, which can save CPU cycles;
+ * (2) if flows goes through a Linux bridge and outside from an interface
+ * (kernel driver), checksum and TSO will be done by GSO in kernel or even
+ * offloaded into real physical device.
+ */
+#define VHOST_KERNEL_HOST_OFFLOADS_MASK		\
+	((1ULL << VIRTIO_NET_F_HOST_TSO4) |	\
+	 (1ULL << VIRTIO_NET_F_HOST_TSO6) |	\
+	 (1ULL << VIRTIO_NET_F_CSUM))
+
 static uint64_t max_regions = 64;
 
 static void
@@ -77,10 +99,57 @@ vhost_kernel_set_owner(struct virtio_user_dev *dev)
 	return vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_OWNER, NULL);
 }
 
+static int
+vhost_kernel_get_features(struct virtio_user_dev *dev, uint64_t *features)
+{
+	int ret;
+	unsigned int tap_features;
+
+	ret = vhost_kernel_ioctl(dev->vhostfds[0], VHOST_GET_FEATURES, features);
+	if (ret < 0) {
+		PMD_DRV_LOG(ERR, "Failed to get features");
+		return -1;
+	}
+
+	ret = tap_support_features(&tap_features);
+	if (ret < 0) {
+		PMD_DRV_LOG(ERR, "Failed to get TAP features)");
+		return -1;
+	}
+
+	/* with tap as the backend, all these features are supported
+	 * but not claimed by vhost-net, so we add them back when
+	 * reporting to upper layer.
+	 */
+	if (tap_features & IFF_VNET_HDR) {
+		*features |= VHOST_KERNEL_GUEST_OFFLOADS_MASK;
+		*features |= VHOST_KERNEL_HOST_OFFLOADS_MASK;
+	}
+
+	/* vhost_kernel will not declare this feature, but it does
+	 * support multi-queue.
+	 */
+	if (tap_features & IFF_MULTI_QUEUE)
+		*features |= (1ull << VIRTIO_NET_F_MQ);
+
+	return 0;
+}
+
+static int
+vhost_kernel_set_features(struct virtio_user_dev *dev, uint64_t features)
+{
+	/* We don't need memory protection here */
+	features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
+	/* VHOST kernel does not know about below flags */
+	features &= ~VHOST_KERNEL_GUEST_OFFLOADS_MASK;
+	features &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
+	features &= ~(1ULL << VIRTIO_NET_F_MQ);
+
+	return vhost_kernel_ioctl(dev->vhostfds[0], VHOST_SET_FEATURES, &features);
+}
+
 static uint64_t vhost_req_user_to_kernel[] = {
 	[VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
-	[VHOST_USER_SET_FEATURES] = VHOST_SET_FEATURES,
-	[VHOST_USER_GET_FEATURES] = VHOST_GET_FEATURES,
 	[VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
 	[VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
 	[VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
@@ -150,51 +219,6 @@ prepare_vhost_memory_kernel(void)
 	return vm;
 }
 
-/* with below features, vhost kernel does not need to do the checksum and TSO,
- * these info will be passed to virtio_user through virtio net header.
- */
-#define VHOST_KERNEL_GUEST_OFFLOADS_MASK	\
-	((1ULL << VIRTIO_NET_F_GUEST_CSUM) |	\
-	 (1ULL << VIRTIO_NET_F_GUEST_TSO4) |	\
-	 (1ULL << VIRTIO_NET_F_GUEST_TSO6) |	\
-	 (1ULL << VIRTIO_NET_F_GUEST_ECN)  |	\
-	 (1ULL << VIRTIO_NET_F_GUEST_UFO))
-
-/* with below features, when flows from virtio_user to vhost kernel
- * (1) if flows goes up through the kernel networking stack, it does not need
- * to verify checksum, which can save CPU cycles;
- * (2) if flows goes through a Linux bridge and outside from an interface
- * (kernel driver), checksum and TSO will be done by GSO in kernel or even
- * offloaded into real physical device.
- */
-#define VHOST_KERNEL_HOST_OFFLOADS_MASK		\
-	((1ULL << VIRTIO_NET_F_HOST_TSO4) |	\
-	 (1ULL << VIRTIO_NET_F_HOST_TSO6) |	\
-	 (1ULL << VIRTIO_NET_F_CSUM))
-
-static unsigned int
-tap_support_features(void)
-{
-	int tapfd;
-	unsigned int tap_features;
-
-	tapfd = open(PATH_NET_TUN, O_RDWR);
-	if (tapfd < 0) {
-		PMD_DRV_LOG(ERR, "fail to open %s: %s",
-			    PATH_NET_TUN, strerror(errno));
-		return -1;
-	}
-
-	if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) {
-		PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
-		close(tapfd);
-		return -1;
-	}
-
-	close(tapfd);
-	return tap_features;
-}
-
 static int
 vhost_kernel_send_request(struct virtio_user_dev *dev,
 		   enum vhost_user_request req,
@@ -206,7 +230,6 @@ vhost_kernel_send_request(struct virtio_user_dev *dev,
 	struct vhost_memory_kernel *vm = NULL;
 	int vhostfd;
 	unsigned int queue_sel;
-	unsigned int features;
 
 	PMD_DRV_LOG(INFO, "%s", vhost_msg_strings[req]);
 
@@ -219,17 +242,6 @@ vhost_kernel_send_request(struct virtio_user_dev *dev,
 		arg = (void *)vm;
 	}
 
-	if (req_kernel == VHOST_SET_FEATURES) {
-		/* We don't need memory protection here */
-		*(uint64_t *)arg &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
-
-		/* VHOST kernel does not know about below flags */
-		*(uint64_t *)arg &= ~VHOST_KERNEL_GUEST_OFFLOADS_MASK;
-		*(uint64_t *)arg &= ~VHOST_KERNEL_HOST_OFFLOADS_MASK;
-
-		*(uint64_t *)arg &= ~(1ULL << VIRTIO_NET_F_MQ);
-	}
-
 	switch (req_kernel) {
 	case VHOST_SET_VRING_NUM:
 	case VHOST_SET_VRING_ADDR:
@@ -259,24 +271,6 @@ vhost_kernel_send_request(struct virtio_user_dev *dev,
 		ret = ioctl(vhostfd, req_kernel, arg);
 	}
 
-	if (!ret && req_kernel == VHOST_GET_FEATURES) {
-		features = tap_support_features();
-		/* with tap as the backend, all these features are supported
-		 * but not claimed by vhost-net, so we add them back when
-		 * reporting to upper layer.
-		 */
-		if (features & IFF_VNET_HDR) {
-			*((uint64_t *)arg) |= VHOST_KERNEL_GUEST_OFFLOADS_MASK;
-			*((uint64_t *)arg) |= VHOST_KERNEL_HOST_OFFLOADS_MASK;
-		}
-
-		/* vhost_kernel will not declare this feature, but it does
-		 * support multi-queue.
-		 */
-		if (features & IFF_MULTI_QUEUE)
-			*(uint64_t *)arg |= (1ull << VIRTIO_NET_F_MQ);
-	}
-
 	if (vm)
 		free(vm);
 
@@ -407,6 +401,8 @@ vhost_kernel_enable_queue_pair(struct virtio_user_dev *dev,
 struct virtio_user_backend_ops virtio_ops_kernel = {
 	.setup = vhost_kernel_setup,
 	.set_owner = vhost_kernel_set_owner,
+	.get_features = vhost_kernel_get_features,
+	.set_features = vhost_kernel_set_features,
 	.send_request = vhost_kernel_send_request,
 	.enable_qp = vhost_kernel_enable_queue_pair
 };
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
index eade702c5c..99096bdf39 100644
--- a/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
+++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.c
@@ -18,6 +18,29 @@
 #include "../virtio_logs.h"
 #include "../virtio.h"
 
+
+int
+tap_support_features(unsigned int *tap_features)
+{
+	int tapfd;
+
+	tapfd = open(PATH_NET_TUN, O_RDWR);
+	if (tapfd < 0) {
+		PMD_DRV_LOG(ERR, "fail to open %s: %s",
+			    PATH_NET_TUN, strerror(errno));
+		return -1;
+	}
+
+	if (ioctl(tapfd, TUNGETFEATURES, tap_features) == -1) {
+		PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
+		close(tapfd);
+		return -1;
+	}
+
+	close(tapfd);
+	return 0;
+}
+
 int
 vhost_kernel_tap_set_offload(int fd, uint64_t features)
 {
diff --git a/drivers/net/virtio/virtio_user/vhost_kernel_tap.h b/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
index 5c4447b296..ed03fce21e 100644
--- a/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
+++ b/drivers/net/virtio/virtio_user/vhost_kernel_tap.h
@@ -43,5 +43,6 @@ int vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq,
 			 const char *mac, uint64_t features);
 int vhost_kernel_tap_set_offload(int fd, uint64_t features);
 int vhost_kernel_tap_set_queue(int fd, bool attach);
+int tap_support_features(unsigned int *tap_features);
 
 #endif
diff --git a/drivers/net/virtio/virtio_user/vhost_user.c b/drivers/net/virtio/virtio_user/vhost_user.c
index 5ab15318ac..d204fa1eb0 100644
--- a/drivers/net/virtio/virtio_user/vhost_user.c
+++ b/drivers/net/virtio/virtio_user/vhost_user.c
@@ -143,6 +143,62 @@ vhost_user_set_owner(struct virtio_user_dev *dev)
 	return 0;
 }
 
+static int
+vhost_user_get_features(struct virtio_user_dev *dev, uint64_t *features)
+{
+	int ret;
+	struct vhost_user_msg msg = {
+		.request = VHOST_USER_GET_FEATURES,
+		.flags = VHOST_USER_VERSION,
+	};
+
+	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
+	if (ret < 0)
+		goto err;
+
+	ret = vhost_user_read(dev->vhostfd, &msg);
+	if (ret < 0)
+		goto err;
+
+	if (msg.request != VHOST_USER_GET_FEATURES) {
+		PMD_DRV_LOG(ERR, "Unexpected request type (%d)", msg.request);
+		goto err;
+	}
+
+	if (msg.size != sizeof(*features)) {
+		PMD_DRV_LOG(ERR, "Unexpected payload size (%d)", msg.size);
+		goto err;
+	}
+
+	*features = msg.payload.u64;
+
+	return 0;
+err:
+	PMD_DRV_LOG(ERR, "Failed to get backend features");
+
+	return -1;
+}
+
+static int
+vhost_user_set_features(struct virtio_user_dev *dev, uint64_t features)
+{
+	int ret;
+	struct vhost_user_msg msg = {
+		.request = VHOST_USER_SET_FEATURES,
+		.flags = VHOST_USER_VERSION,
+		.size = sizeof(features),
+		.payload.u64 = features,
+	};
+
+	ret = vhost_user_write(dev->vhostfd, &msg, NULL, 0);
+	if (ret < 0) {
+		PMD_DRV_LOG(ERR, "Failed to set features");
+		return -1;
+	}
+
+	return 0;
+}
+
 struct walk_arg {
 	struct vhost_memory *vm;
 	int *fds;
@@ -249,8 +305,6 @@ static struct vhost_user_msg m;
 
 const char * const vhost_msg_strings[] = {
 	[VHOST_USER_RESET_OWNER] = "VHOST_RESET_OWNER",
-	[VHOST_USER_SET_FEATURES] = "VHOST_SET_FEATURES",
-	[VHOST_USER_GET_FEATURES] = "VHOST_GET_FEATURES",
 	[VHOST_USER_SET_VRING_CALL] = "VHOST_SET_VRING_CALL",
 	[VHOST_USER_SET_VRING_NUM] = "VHOST_SET_VRING_NUM",
 	[VHOST_USER_SET_VRING_BASE] = "VHOST_SET_VRING_BASE",
@@ -299,7 +353,6 @@ vhost_user_sock(struct virtio_user_dev *dev,
 				(1ULL << VHOST_USER_PROTOCOL_F_STATUS))))
 			return -ENOTSUP;
 		/* Fallthrough */
-	case VHOST_USER_GET_FEATURES:
 	case VHOST_USER_GET_PROTOCOL_FEATURES:
 		need_reply = 1;
 		break;
@@ -313,7 +366,6 @@ vhost_user_sock(struct virtio_user_dev *dev,
 		if (has_reply_ack)
 			msg.flags |= VHOST_USER_NEED_REPLY_MASK;
 		/* Fallthrough */
-	case VHOST_USER_SET_FEATURES:
 	case VHOST_USER_SET_PROTOCOL_FEATURES:
 	case VHOST_USER_SET_LOG_BASE:
 		msg.payload.u64 = *((__u64 *)arg);
@@ -393,7 +445,6 @@ vhost_user_sock(struct virtio_user_dev *dev,
 		}
 
 		switch (req) {
-		case VHOST_USER_GET_FEATURES:
 		case VHOST_USER_GET_STATUS:
 		case VHOST_USER_GET_PROTOCOL_FEATURES:
 			if (msg.size != sizeof(m.payload.u64)) {
@@ -531,6 +582,8 @@ vhost_user_enable_queue_pair(struct virtio_user_dev *dev,
 struct virtio_user_backend_ops virtio_ops_user = {
 	.setup = vhost_user_setup,
 	.set_owner = vhost_user_set_owner,
+	.get_features = vhost_user_get_features,
+	.set_features = vhost_user_set_features,
 	.send_request = vhost_user_sock,
 	.enable_qp = vhost_user_enable_queue_pair
 };
diff --git a/drivers/net/virtio/virtio_user/vhost_vdpa.c b/drivers/net/virtio/virtio_user/vhost_vdpa.c
index f405b6b86a..c0a9b5b767 100644
--- a/drivers/net/virtio/virtio_user/vhost_vdpa.c
+++ b/drivers/net/virtio/virtio_user/vhost_vdpa.c
@@ -38,8 +38,6 @@
 
 static uint64_t vhost_req_user_to_vdpa[] = {
 	[VHOST_USER_RESET_OWNER] = VHOST_RESET_OWNER,
-	[VHOST_USER_SET_FEATURES] = VHOST_SET_FEATURES,
-	[VHOST_USER_GET_FEATURES] = VHOST_GET_FEATURES,
 	[VHOST_USER_SET_VRING_CALL] = VHOST_SET_VRING_CALL,
 	[VHOST_USER_SET_VRING_NUM] = VHOST_SET_VRING_NUM,
 	[VHOST_USER_SET_VRING_BASE] = VHOST_SET_VRING_BASE,
@@ -101,6 +99,32 @@ vhost_vdpa_set_owner(struct virtio_user_dev *dev)
 	return vhost_vdpa_ioctl(dev->vhostfd, VHOST_SET_OWNER, NULL);
 }
 
+static int
+vhost_vdpa_get_features(struct virtio_user_dev *dev, uint64_t *features)
+{
+	int ret;
+
+	ret = vhost_vdpa_ioctl(dev->vhostfd, VHOST_GET_FEATURES, features);
+	if (ret) {
+		PMD_DRV_LOG(ERR, "Failed to get features");
+		return -1;
+	}
+
+	/* Multiqueue not supported for now */
+	*features &= ~(1ULL << VIRTIO_NET_F_MQ);
+
+	return 0;
+}
+
+static int
+vhost_vdpa_set_features(struct virtio_user_dev *dev, uint64_t features)
+{
+	/* WORKAROUND */
+	features |= 1ULL << VIRTIO_F_IOMMU_PLATFORM;
+
+	return vhost_vdpa_ioctl(dev->vhostfd, VHOST_SET_FEATURES, &features);
+}
+
 static int
 vhost_vdpa_dma_map(struct virtio_user_dev *dev, void *addr,
 				  uint64_t iova, size_t len)
@@ -227,14 +251,6 @@ vhost_vdpa_send_request(struct virtio_user_dev *dev,
 	if (req_vdpa == VHOST_SET_MEM_TABLE)
 		return vhost_vdpa_dma_map_all(dev);
 
-	if (req_vdpa == VHOST_SET_FEATURES) {
-		/* WORKAROUND */
-		*(uint64_t *)arg |= 1ULL << VIRTIO_F_IOMMU_PLATFORM;
-
-		/* Multiqueue not supported for now */
-		*(uint64_t *)arg &= ~(1ULL << VIRTIO_NET_F_MQ);
-	}
-
 	switch (req_vdpa) {
 	case VHOST_SET_VRING_NUM:
 	case VHOST_SET_VRING_ADDR:
@@ -313,6 +329,8 @@ vhost_vdpa_enable_queue_pair(struct virtio_user_dev *dev,
 struct virtio_user_backend_ops virtio_ops_vdpa = {
 	.setup = vhost_vdpa_setup,
 	.set_owner = vhost_vdpa_set_owner,
+	.get_features = vhost_vdpa_get_features,
+	.set_features = vhost_vdpa_set_features,
 	.send_request = vhost_vdpa_send_request,
 	.enable_qp = vhost_vdpa_enable_queue_pair,
 	.dma_map = vhost_vdpa_dma_map,
diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index f8e4581951..0a85d058a8 100644
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -141,7 +141,7 @@ virtio_user_dev_set_features(struct virtio_user_dev *dev)
 	/* Strip VIRTIO_NET_F_CTRL_VQ, as devices do not really need to know */
 	features &= ~(1ull << VIRTIO_NET_F_CTRL_VQ);
 	features &= ~(1ull << VIRTIO_NET_F_STATUS);
-	ret = dev->ops->send_request(dev, VHOST_USER_SET_FEATURES, &features);
+	ret = dev->ops->set_features(dev, features);
 	if (ret < 0)
 		goto error;
 	PMD_DRV_LOG(INFO, "set features: %" PRIx64, features);
@@ -488,8 +488,7 @@ virtio_user_dev_init(struct virtio_user_dev *dev, char *path, int queues,
 			return -1;
 		}
 
-		if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
-					   &dev->device_features) < 0) {
+		if (dev->ops->get_features(dev, &dev->device_features) < 0) {
 			PMD_INIT_LOG(ERR, "get_features failed: %s",
 				     strerror(errno));
 			return -1;
diff --git a/drivers/net/virtio/virtio_user_ethdev.c b/drivers/net/virtio/virtio_user_ethdev.c
index 283f5c7a36..4d2635c8aa 100644
--- a/drivers/net/virtio/virtio_user_ethdev.c
+++ b/drivers/net/virtio/virtio_user_ethdev.c
@@ -85,8 +85,7 @@ virtio_user_server_reconnect(struct virtio_user_dev *dev)
 
 	virtio_set_status(hw, VIRTIO_CONFIG_STATUS_DRIVER);
 
-	if (dev->ops->send_request(dev, VHOST_USER_GET_FEATURES,
-				   &dev->device_features) < 0) {
+	if (dev->ops->get_features(dev, &dev->device_features) < 0) {
 		PMD_INIT_LOG(ERR, "get_features failed: %s",
 			     strerror(errno));
 		return -1;
-- 
2.29.2