[dpdk-dev] [PATCH 1/4] vhost: handle VHOST_USER_SET_LOG_BASE request

[Yuanhan Liu]

VHOST_USER_SET_LOG_BASE request is used to tell the backend (dpdk
vhost-user) where we should log dirty pages, and how big the log
buffer is.

This request introduces a new payload:

	typedef struct VhostUserLog {
		uint64_t mmap_size;
		uint64_t mmap_offset;
	} VhostUserLog;

Also, a fd is delivered from QEMU by ancillary data.

With those info given, an area of memory is mmaped, assigned
to dev->log_base, for logging dirty pages.

Signed-off-by: Yuanhan Liu <yuanhan.liu at linux.intel.com>
---
 lib/librte_vhost/rte_virtio_net.h             |  2 ++
 lib/librte_vhost/vhost_user/vhost-net-user.c  |  7 ++++-
 lib/librte_vhost/vhost_user/vhost-net-user.h  |  6 ++++
 lib/librte_vhost/vhost_user/virtio-net-user.c | 44 +++++++++++++++++++++++++++
 lib/librte_vhost/vhost_user/virtio-net-user.h |  1 +
 5 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/lib/librte_vhost/rte_virtio_net.h b/lib/librte_vhost/rte_virtio_net.h
index 5687452..416dac2 100644
--- a/lib/librte_vhost/rte_virtio_net.h
+++ b/lib/librte_vhost/rte_virtio_net.h
@@ -127,6 +127,8 @@ struct virtio_net {
 #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 */
+	uint64_t		log_size;	/**< Size of log area */
+	uint8_t			*log_base;	/**< Where dirty pages are logged */
 	void			*priv;		/**< private context */
 	struct vhost_virtqueue	*virtqueue[VHOST_MAX_QUEUE_PAIRS * 2];	/**< Contains all virtqueue information. */
 } __rte_cache_aligned;
diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c
index 2dc0547..76bcac2 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.c
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
@@ -388,7 +388,12 @@ vserver_message_handler(int connfd, void *dat, int *remove)
 		break;
 
 	case VHOST_USER_SET_LOG_BASE:
-		RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
+		user_set_log_base(ctx, &msg);
+
+		/* it needs a reply */
+		msg.size = sizeof(msg.payload.u64);
+		send_vhost_message(connfd, &msg);
+		break;
 	case VHOST_USER_SET_LOG_FD:
 		close(msg.fds[0]);
 		RTE_LOG(INFO, VHOST_CONFIG, "not implemented.\n");
diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.h b/lib/librte_vhost/vhost_user/vhost-net-user.h
index 38637cc..6d252a3 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.h
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.h
@@ -83,6 +83,11 @@ typedef struct VhostUserMemory {
 	VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
 } VhostUserMemory;
 
+typedef struct VhostUserLog {
+	uint64_t mmap_size;
+	uint64_t mmap_offset;
+} VhostUserLog;
+
 typedef struct VhostUserMsg {
 	VhostUserRequest request;
 
@@ -97,6 +102,7 @@ typedef struct VhostUserMsg {
 		struct vhost_vring_state state;
 		struct vhost_vring_addr addr;
 		VhostUserMemory memory;
+		VhostUserLog    log;
 	} payload;
 	int fds[VHOST_MEMORY_MAX_NREGIONS];
 } __attribute((packed)) VhostUserMsg;
diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.c b/lib/librte_vhost/vhost_user/virtio-net-user.c
index 2934d1c..1d705fd 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.c
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.c
@@ -365,3 +365,47 @@ user_set_protocol_features(struct vhost_device_ctx ctx,
 
 	dev->protocol_features = protocol_features;
 }
+
+int
+user_set_log_base(struct vhost_device_ctx ctx,
+		 struct VhostUserMsg *msg)
+{
+	struct virtio_net *dev;
+	int fd = msg->fds[0];
+	uint64_t size, off;
+	void *addr;
+
+	dev = get_device(ctx);
+	if (!dev)
+		return -1;
+
+	if (fd < 0) {
+		RTE_LOG(ERR, VHOST_CONFIG, "invalid log fd: %d\n", fd);
+		return -1;
+	}
+
+	if (msg->size != sizeof(VhostUserLog)) {
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"invalid log base msg size: %"PRId32" != %d\n",
+			msg->size, (int)sizeof(VhostUserLog));
+		return -1;
+	}
+
+	size = msg->payload.log.mmap_size;
+	off  = msg->payload.log.mmap_offset;
+	RTE_LOG(INFO, VHOST_CONFIG,
+		"log mmap size: %"PRId64", offset: %"PRId64"\n",
+		size, off);
+
+	addr = mmap(0, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, off);
+	if (addr == MAP_FAILED) {
+		RTE_LOG(ERR, VHOST_CONFIG, "mmap log base failed!\n");
+		return -1;
+	}
+
+	/* TODO: unmap on stop */
+	dev->log_base = addr;
+	dev->log_size = size;
+
+	return 0;
+}
diff --git a/lib/librte_vhost/vhost_user/virtio-net-user.h b/lib/librte_vhost/vhost_user/virtio-net-user.h
index b82108d..013cf38 100644
--- a/lib/librte_vhost/vhost_user/virtio-net-user.h
+++ b/lib/librte_vhost/vhost_user/virtio-net-user.h
@@ -49,6 +49,7 @@ void user_set_vring_kick(struct vhost_device_ctx, struct VhostUserMsg *);
 
 void user_set_protocol_features(struct vhost_device_ctx ctx,
 				uint64_t protocol_features);
+int user_set_log_base(struct vhost_device_ctx ctx, struct VhostUserMsg *);
 
 int user_get_vring_base(struct vhost_device_ctx, struct vhost_vring_state *);
 
-- 
1.9.0