libvhost-user: support host notifier (d84599f5) · Commits · SUMMER2020 / students / proj-2021291

contrib/libvhost-user/libvhost-user.c

+73 −8

Original line number	Diff line number	Diff line
		@@ -314,11 +314,6 @@ vu_message_write(VuDev dev, int conn_fd, VhostUserMsg vmsg)
		msg.msg_controllen = 0;
		}

		/* Set the version in the flags when sending the reply */
		vmsg->flags &= ~VHOST_USER_VERSION_MASK;
		vmsg->flags \|= VHOST_USER_VERSION;
		vmsg->flags \|= VHOST_USER_REPLY_MASK;

		do {
		rc = sendmsg(conn_fd, &msg, 0);
		} while (rc < 0 && (errno == EINTR \|\| errno == EAGAIN));
		@@ -341,6 +336,39 @@ vu_message_write(VuDev dev, int conn_fd, VhostUserMsg vmsg)
		return true;
		}

		static bool
		vu_send_reply(VuDev dev, int conn_fd, VhostUserMsg vmsg)
		{
		/* Set the version in the flags when sending the reply */
		vmsg->flags &= ~VHOST_USER_VERSION_MASK;
		vmsg->flags \|= VHOST_USER_VERSION;
		vmsg->flags \|= VHOST_USER_REPLY_MASK;

		return vu_message_write(dev, conn_fd, vmsg);
		}

		static bool
		vu_process_message_reply(VuDev dev, const VhostUserMsg vmsg)
		{
		VhostUserMsg msg_reply;

		if ((vmsg->flags & VHOST_USER_NEED_REPLY_MASK) == 0) {
		return true;
		}

		if (!vu_message_read(dev, dev->slave_fd, &msg_reply)) {
		return false;
		}

		if (msg_reply.request != vmsg->request) {
		DPRINT("Received unexpected msg type. Expected %d received %d",
		vmsg->request, msg_reply.request);
		return false;
		}

		return msg_reply.payload.u64 == 0;
		}

		/* Kick the log_call_fd if required. */
		static void
		vu_log_kick(VuDev *dev)
		@@ -536,7 +564,7 @@ vu_set_mem_table_exec_postcopy(VuDev dev, VhostUserMsg vmsg)

		/* Send the message back to qemu with the addresses filled in */
		vmsg->fd_num = 0;
		if (!vu_message_write(dev, dev->sock, vmsg)) {
		if (!vu_send_reply(dev, dev->sock, vmsg)) {
		vu_panic(dev, "failed to respond to set-mem-table for postcopy");
		return false;
		}
		@@ -916,6 +944,41 @@ void vu_set_queue_handler(VuDev dev, VuVirtq vq,
		}
		}

		bool vu_set_queue_host_notifier(VuDev dev, VuVirtq vq, int fd,
		int size, int offset)
		{
		int qidx = vq - dev->vq;
		int fd_num = 0;
		VhostUserMsg vmsg = {
		.request = VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG,
		.flags = VHOST_USER_VERSION \| VHOST_USER_NEED_REPLY_MASK,
		.size = sizeof(vmsg.payload.area),
		.payload.area = {
		.u64 = qidx & VHOST_USER_VRING_IDX_MASK,
		.size = size,
		.offset = offset,
		},
		};

		if (fd == -1) {
		vmsg.payload.area.u64 \|= VHOST_USER_VRING_NOFD_MASK;
		} else {
		vmsg.fds[fd_num++] = fd;
		}

		vmsg.fd_num = fd_num;

		if ((dev->protocol_features & VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD) == 0) {
		return false;
		}

		if (!vu_message_write(dev, dev->slave_fd, &vmsg)) {
		return false;
		}

		return vu_process_message_reply(dev, &vmsg);
		}

		static bool
		vu_set_vring_call_exec(VuDev dev, VhostUserMsg vmsg)
		{
		@@ -968,7 +1031,9 @@ static bool
		vu_get_protocol_features_exec(VuDev dev, VhostUserMsg vmsg)
		{
		uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_LOG_SHMFD \|
		1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ;
		1ULL << VHOST_USER_PROTOCOL_F_SLAVE_REQ \|
		1ULL << VHOST_USER_PROTOCOL_F_HOST_NOTIFIER \|
		1ULL << VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD;

		if (have_userfault()) {
		features \|= 1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT;
		@@ -1252,7 +1317,7 @@ vu_dispatch(VuDev *dev)
		goto end;
		}

		if (!vu_message_write(dev, dev->sock, &vmsg)) {
		if (!vu_send_reply(dev, dev->sock, &vmsg)) {
		goto end;
		}

contrib/libvhost-user/libvhost-user.h

+32 −0

Original line number	Diff line number	Diff line
		@@ -51,6 +51,8 @@ enum VhostUserProtocolFeature {
		VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
		VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
		VHOST_USER_PROTOCOL_F_CONFIG = 9,
		VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
		VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,

		VHOST_USER_PROTOCOL_F_MAX
		};
		@@ -92,6 +94,14 @@ typedef enum VhostUserRequest {
		VHOST_USER_MAX
		} VhostUserRequest;

		typedef enum VhostUserSlaveRequest {
		VHOST_USER_SLAVE_NONE = 0,
		VHOST_USER_SLAVE_IOTLB_MSG = 1,
		VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
		VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
		VHOST_USER_SLAVE_MAX
		} VhostUserSlaveRequest;

		typedef struct VhostUserMemoryRegion {
		uint64_t guest_phys_addr;
		uint64_t memory_size;
		@@ -122,6 +132,12 @@ static VhostUserConfig c __attribute__ ((unused));
		+ sizeof(c.size) \
		+ sizeof(c.flags))

		typedef struct VhostUserVringArea {
		uint64_t u64;
		uint64_t size;
		uint64_t offset;
		} VhostUserVringArea;

		#if defined(_WIN32)
		# define VU_PACKED __attribute__((gcc_struct, packed))
		#else
		@@ -133,6 +149,7 @@ typedef struct VhostUserMsg {

		#define VHOST_USER_VERSION_MASK (0x3)
		#define VHOST_USER_REPLY_MASK (0x1 << 2)
		#define VHOST_USER_NEED_REPLY_MASK (0x1 << 3)
		uint32_t flags;
		uint32_t size; /* the following payload size */

		@@ -145,6 +162,7 @@ typedef struct VhostUserMsg {
		VhostUserMemory memory;
		VhostUserLog log;
		VhostUserConfig config;
		VhostUserVringArea area;
		} payload;

		int fds[VHOST_MEMORY_MAX_NREGIONS];
		@@ -368,6 +386,20 @@ VuVirtq vu_get_queue(VuDev dev, int qidx);
		void vu_set_queue_handler(VuDev dev, VuVirtq vq,
		vu_queue_handler_cb handler);

		/**
		* vu_set_queue_host_notifier:
		* @dev: a VuDev context
		* @vq: a VuVirtq queue
		* @fd: a file descriptor
		* @size: host page size
		* @offset: notifier offset in @fd file
		*
		* Set queue's host notifier. This function may be called several
		* times for the same queue. If called with -1 @fd, the notifier
		* is removed.
		*/
		bool vu_set_queue_host_notifier(VuDev dev, VuVirtq vq, int fd,
		int size, int offset);

		/**
		* vu_queue_set_notification: