This patch adds support to start/stop/flush slave channel functionality. Signed-off-by: Vivek Goyal <vgo...@redhat.com> --- subprojects/libvhost-user/libvhost-user.c | 103 ++++++++++++++++++++-- subprojects/libvhost-user/libvhost-user.h | 8 +- 2 files changed, 105 insertions(+), 6 deletions(-)
diff --git a/subprojects/libvhost-user/libvhost-user.c b/subprojects/libvhost-user/libvhost-user.c index 7a56c56dc8..b4c795c63e 100644 --- a/subprojects/libvhost-user/libvhost-user.c +++ b/subprojects/libvhost-user/libvhost-user.c @@ -140,6 +140,8 @@ vu_request_to_string(unsigned int req) REQ(VHOST_USER_GET_MAX_MEM_SLOTS), REQ(VHOST_USER_ADD_MEM_REG), REQ(VHOST_USER_REM_MEM_REG), + REQ(VHOST_USER_START_SLAVE_CHANNEL), + REQ(VHOST_USER_STOP_SLAVE_CHANNEL), REQ(VHOST_USER_MAX), }; #undef REQ @@ -437,11 +439,11 @@ out: return result; } -/* Returns true on success, false otherwise */ +/* slave mutex should be held. Will be unlocked upon return */ static bool -vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, uint64_t *payload) +vu_message_slave_send_receive_locked(VuDev *dev, VhostUserMsg *vmsg, + uint64_t *payload) { - pthread_mutex_lock(&dev->slave_mutex); if (!vu_message_write(dev, dev->slave_fd, vmsg)) { pthread_mutex_unlock(&dev->slave_mutex); return false; @@ -456,6 +458,46 @@ vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, uint64_t *payload) return vu_process_message_reply(dev, vmsg, payload); } +/* Returns true on success, false otherwise */ +static bool +vu_message_slave_send_receive(VuDev *dev, VhostUserMsg *vmsg, + uint64_t *payload) +{ + pthread_mutex_lock(&dev->slave_mutex); + if (!dev->slave_channel_open) { + pthread_mutex_unlock(&dev->slave_mutex); + return false; + } + return vu_message_slave_send_receive_locked(dev, vmsg, payload); +} + +static bool +vu_finish_stop_slave(VuDev *dev) +{ + bool res; + uint64_t payload = 0; + VhostUserMsg vmsg = { + .request = VHOST_USER_SLAVE_STOP_CHANNEL_COMPLETE, + .flags = VHOST_USER_VERSION | VHOST_USER_NEED_REPLY_MASK, + .size = sizeof(vmsg.payload.u64), + .payload.u64 = 0, + }; + + /* + * Once we get slave_mutex, this should make sure no other caller is + * currently in the process of sending or receiving message on slave_fd. + * And setting slave_channel_open to false now will make sure any new + * callers will not send message and instead get error back. So it + * is now safe to send stop finished message to master. + */ + pthread_mutex_lock(&dev->slave_mutex); + dev->slave_channel_open = false; + /* This also drops slave_mutex */ + res = vu_message_slave_send_receive_locked(dev, &vmsg, &payload); + res = res && (payload == 0); + return res; +} + /* Kick the log_call_fd if required. */ static void vu_log_kick(VuDev *dev) @@ -1529,6 +1571,35 @@ vu_set_slave_req_fd(VuDev *dev, VhostUserMsg *vmsg) return false; } +static bool +vu_slave_channel_start(VuDev *dev, VhostUserMsg *vmsg) +{ + pthread_mutex_lock(&dev->slave_mutex); + dev->slave_channel_open = true; + pthread_mutex_unlock(&dev->slave_mutex); + /* Caller (vu_dispatch()) will send a reply */ + return false; +} + +static bool +vu_slave_channel_stop(VuDev *dev, VhostUserMsg *vmsg, bool *reply_sent, + bool *reply_status) +{ + vmsg_set_reply_u64(vmsg, 0); + *reply_sent = true; + *reply_status = false; + if (!vu_send_reply(dev, dev->sock, vmsg)) { + return false; + } + + if (!vu_finish_stop_slave(dev)) { + return false; + } + + *reply_status = true; + return false; +} + static bool vu_get_config(VuDev *dev, VhostUserMsg *vmsg) { @@ -1823,7 +1894,8 @@ static bool vu_handle_get_max_memslots(VuDev *dev, VhostUserMsg *vmsg) } static bool -vu_process_message(VuDev *dev, VhostUserMsg *vmsg) +vu_process_message(VuDev *dev, VhostUserMsg *vmsg, bool *reply_sent, + bool *reply_status) { int do_reply = 0; @@ -1843,6 +1915,14 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg) DPRINT("\n"); } + if (reply_sent) { + *reply_sent = false; + } + + if (reply_status) { + *reply_status = false; + } + if (dev->iface->process_msg && dev->iface->process_msg(dev, vmsg, &do_reply)) { return do_reply; @@ -1912,6 +1992,10 @@ vu_process_message(VuDev *dev, VhostUserMsg *vmsg) return vu_add_mem_reg(dev, vmsg); case VHOST_USER_REM_MEM_REG: return vu_rem_mem_reg(dev, vmsg); + case VHOST_USER_START_SLAVE_CHANNEL: + return vu_slave_channel_start(dev, vmsg); + case VHOST_USER_STOP_SLAVE_CHANNEL: + return vu_slave_channel_stop(dev, vmsg, reply_sent, reply_status); default: vmsg_close_fds(vmsg); vu_panic(dev, "Unhandled request: %d", vmsg->request); @@ -1926,6 +2010,7 @@ vu_dispatch(VuDev *dev) VhostUserMsg vmsg = { 0, }; int reply_requested; bool need_reply, success = false; + bool reply_sent = false, reply_status = false; if (!dev->read_msg(dev, dev->sock, &vmsg)) { goto end; @@ -1933,7 +2018,14 @@ vu_dispatch(VuDev *dev) need_reply = vmsg.flags & VHOST_USER_NEED_REPLY_MASK; - reply_requested = vu_process_message(dev, &vmsg); + reply_requested = vu_process_message(dev, &vmsg, &reply_sent, + &reply_status); + /* reply has already been sent, if needed */ + if (reply_sent) { + success = reply_status; + goto end; + } + if (!reply_requested && need_reply) { vmsg_set_reply_u64(&vmsg, 0); reply_requested = 1; @@ -2051,6 +2143,7 @@ vu_init(VuDev *dev, dev->log_call_fd = -1; pthread_mutex_init(&dev->slave_mutex, NULL); dev->slave_fd = -1; + dev->slave_channel_open = false; dev->max_queues = max_queues; dev->vq = malloc(max_queues * sizeof(dev->vq[0])); diff --git a/subprojects/libvhost-user/libvhost-user.h b/subprojects/libvhost-user/libvhost-user.h index ee75d4931f..1d0ef54f69 100644 --- a/subprojects/libvhost-user/libvhost-user.h +++ b/subprojects/libvhost-user/libvhost-user.h @@ -64,6 +64,7 @@ enum VhostUserProtocolFeature { VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12, VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS = 14, VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15, + VHOST_USER_PROTOCOL_F_SLAVE_CH_START_STOP = 16, VHOST_USER_PROTOCOL_F_MAX }; @@ -109,6 +110,8 @@ typedef enum VhostUserRequest { VHOST_USER_GET_MAX_MEM_SLOTS = 36, VHOST_USER_ADD_MEM_REG = 37, VHOST_USER_REM_MEM_REG = 38, + VHOST_USER_START_SLAVE_CHANNEL = 39, + VHOST_USER_STOP_SLAVE_CHANNEL = 40, VHOST_USER_MAX } VhostUserRequest; @@ -123,6 +126,7 @@ typedef enum VhostUserSlaveRequest { VHOST_USER_SLAVE_FS_UNMAP = 7, VHOST_USER_SLAVE_FS_SYNC = 8, VHOST_USER_SLAVE_FS_IO = 9, + VHOST_USER_SLAVE_STOP_CHANNEL_COMPLETE = 10, VHOST_USER_SLAVE_MAX } VhostUserSlaveRequest; @@ -405,9 +409,11 @@ struct VuDev { VuVirtq *vq; VuDevInflightInfo inflight_info; int log_call_fd; - /* Must be held while using slave_fd */ + /* Must be held while using slave_fd, slave_channel_open */ pthread_mutex_t slave_mutex; int slave_fd; + /* If not set, do not send more requests on slave fd. */ + bool slave_channel_open; uint64_t log_size; uint8_t *log_table; uint64_t features; -- 2.25.4