/*- * Copyright (c) 2016 Microsoft Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice unmodified, this list of conditions, and the following * disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "hv_snapshot.h" #include "vmbus_if.h" #define VSS_MAJOR 5 #define VSS_MINOR 0 #define VSS_MSGVER VMBUS_IC_VERSION(VSS_MAJOR, VSS_MINOR) #define VSS_FWVER_MAJOR 3 #define VSS_FWVER VMBUS_IC_VERSION(VSS_FWVER_MAJOR, 0) #define TIMEOUT_LIMIT (15) // seconds enum hv_vss_op { VSS_OP_CREATE = 0, VSS_OP_DELETE, VSS_OP_HOT_BACKUP, VSS_OP_GET_DM_INFO, VSS_OP_BU_COMPLETE, /* * Following operations are only supported with IC version >= 5.0 */ VSS_OP_FREEZE, /* Freeze the file systems in the VM */ VSS_OP_THAW, /* Unfreeze the file systems */ VSS_OP_AUTO_RECOVER, VSS_OP_COUNT /* Number of operations, must be last */ }; /* * Header for all VSS messages. */ struct hv_vss_hdr { struct vmbus_icmsg_hdr ic_hdr; uint8_t operation; uint8_t reserved[7]; } __packed; /* * Flag values for the hv_vss_check_feature. Here supports only * one value. */ #define VSS_HBU_NO_AUTO_RECOVERY 0x00000005 struct hv_vss_check_feature { uint32_t flags; } __packed; struct hv_vss_check_dm_info { uint32_t flags; } __packed; struct hv_vss_msg { union { struct hv_vss_hdr vss_hdr; } hdr; union { struct hv_vss_check_feature vss_cf; struct hv_vss_check_dm_info dm_info; } body; } __packed; struct hv_vss_req { struct hv_vss_opt_msg opt_msg; /* used to communicate with daemon */ struct hv_vss_msg msg; /* used to communicate with host */ } __packed; /* hv_vss debug control */ static int hv_vss_log = 0; #define hv_vss_log_error(...) do { \ if (hv_vss_log > 0) \ log(LOG_ERR, "hv_vss: " __VA_ARGS__); \ } while (0) #define hv_vss_log_info(...) do { \ if (hv_vss_log > 1) \ log(LOG_INFO, "hv_vss: " __VA_ARGS__); \ } while (0) static const struct vmbus_ic_desc vmbus_vss_descs[] = { { .ic_guid = { .hv_guid = { 0x29, 0x2e, 0xfa, 0x35, 0x23, 0xea, 0x36, 0x42, 0x96, 0xae, 0x3a, 0x6e, 0xba, 0xcb, 0xa4, 0x40} }, .ic_desc = "Hyper-V VSS" }, VMBUS_IC_DESC_END }; static const char * vss_opt_name[] = {"None", "VSSCheck", "Freeze", "Thaw"}; /* character device prototypes */ static d_open_t hv_vss_dev_open; static d_close_t hv_vss_dev_close; static d_poll_t hv_vss_dev_daemon_poll; static d_ioctl_t hv_vss_dev_daemon_ioctl; static d_open_t hv_appvss_dev_open; static d_close_t hv_appvss_dev_close; static d_poll_t hv_appvss_dev_poll; static d_ioctl_t hv_appvss_dev_ioctl; /* hv_vss character device structure */ static struct cdevsw hv_vss_cdevsw = { .d_version = D_VERSION, .d_open = hv_vss_dev_open, .d_close = hv_vss_dev_close, .d_poll = hv_vss_dev_daemon_poll, .d_ioctl = hv_vss_dev_daemon_ioctl, .d_name = FS_VSS_DEV_NAME, }; static struct cdevsw hv_appvss_cdevsw = { .d_version = D_VERSION, .d_open = hv_appvss_dev_open, .d_close = hv_appvss_dev_close, .d_poll = hv_appvss_dev_poll, .d_ioctl = hv_appvss_dev_ioctl, .d_name = APP_VSS_DEV_NAME, }; struct hv_vss_sc; /* * Global state to track cdev */ struct hv_vss_dev_sc { /* * msg was transferred from host to notify queue, and * ack queue. Finally, it was recyled to free list. */ STAILQ_HEAD(, hv_vss_req_internal) to_notify_queue; STAILQ_HEAD(, hv_vss_req_internal) to_ack_queue; struct hv_vss_sc *sc; struct proc *proc_task; struct selinfo hv_vss_selinfo; }; /* * Global state to track and synchronize the transaction requests from the host. * The VSS allows user to register their function to do freeze/thaw for application. * VSS kernel will notify both vss daemon and user application if it is registered. * The implementation state transition is illustrated by: * https://clovertrail.github.io/assets/vssdot.png */ typedef struct hv_vss_sc { struct vmbus_ic_softc util_sc; device_t dev; struct task task; /* * mutex is used to protect access of list/queue, * callout in request is also used this mutex. */ struct mtx pending_mutex; /* * req_free_list contains all free items */ LIST_HEAD(, hv_vss_req_internal) req_free_list; /* Indicates if daemon registered with driver */ boolean_t register_done; boolean_t app_register_done; /* cdev for file system freeze/thaw */ struct cdev *hv_vss_dev; /* cdev for application freeze/thaw */ struct cdev *hv_appvss_dev; /* sc for app */ struct hv_vss_dev_sc app_sc; /* sc for deamon */ struct hv_vss_dev_sc daemon_sc; } hv_vss_sc; typedef struct hv_vss_req_internal { LIST_ENTRY(hv_vss_req_internal) link; STAILQ_ENTRY(hv_vss_req_internal) slink; struct hv_vss_req vss_req; /* Rcv buffer for communicating with the host*/ uint8_t *rcv_buf; /* Length of host message */ uint32_t host_msg_len; /* Host message id */ uint64_t host_msg_id; hv_vss_sc *sc; struct callout callout; } hv_vss_req_internal; #define SEARCH_REMOVE_REQ_LOCKED(reqp, queue, link, tmp, id) \ do { \ STAILQ_FOREACH_SAFE(reqp, queue, link, tmp) { \ if (reqp->vss_req.opt_msg.msgid == id) { \ STAILQ_REMOVE(queue, \ reqp, hv_vss_req_internal, link); \ break; \ } \ } \ } while (0) static bool hv_vss_is_daemon_killed_after_launch(hv_vss_sc *sc) { return (!sc->register_done && sc->daemon_sc.proc_task); } /* * Callback routine that gets called whenever there is a message from host */ static void hv_vss_callback(struct vmbus_channel *chan __unused, void *context) { hv_vss_sc *sc = (hv_vss_sc*)context; if (hv_vss_is_daemon_killed_after_launch(sc)) hv_vss_log_info("%s: daemon was killed!\n", __func__); if (sc->register_done || sc->daemon_sc.proc_task) { hv_vss_log_info("%s: Queuing work item\n", __func__); if (hv_vss_is_daemon_killed_after_launch(sc)) hv_vss_log_info("%s: daemon was killed!\n", __func__); taskqueue_enqueue(taskqueue_thread, &sc->task); } else { hv_vss_log_info("%s: daemon has never been registered\n", __func__); } hv_vss_log_info("%s: received msg from host\n", __func__); } /* * Send the response back to the host. */ static void hv_vss_respond_host(uint8_t *rcv_buf, struct vmbus_channel *ch, uint32_t recvlen, uint64_t requestid, uint32_t error) { struct vmbus_icmsg_hdr *hv_icmsg_hdrp; hv_icmsg_hdrp = (struct vmbus_icmsg_hdr *)rcv_buf; hv_icmsg_hdrp->ic_status = error; hv_icmsg_hdrp->ic_flags = HV_ICMSGHDRFLAG_TRANSACTION | HV_ICMSGHDRFLAG_RESPONSE; error = vmbus_chan_send(ch, VMBUS_CHANPKT_TYPE_INBAND, 0, rcv_buf, recvlen, requestid); if (error) hv_vss_log_info("%s: hv_vss_respond_host: sendpacket error:%d\n", __func__, error); } static void hv_vss_notify_host_result_locked(struct hv_vss_req_internal *reqp, uint32_t status) { struct hv_vss_msg* msg = (struct hv_vss_msg *)reqp->rcv_buf; hv_vss_sc *sc = reqp->sc; if (reqp->vss_req.opt_msg.opt == HV_VSS_CHECK) { msg->body.vss_cf.flags = VSS_HBU_NO_AUTO_RECOVERY; } hv_vss_log_info("%s, %s response %s to host\n", __func__, vss_opt_name[reqp->vss_req.opt_msg.opt], status == HV_S_OK ? "Success" : "Fail"); hv_vss_respond_host(reqp->rcv_buf, vmbus_get_channel(reqp->sc->dev), reqp->host_msg_len, reqp->host_msg_id, status); /* recycle the request */ LIST_INSERT_HEAD(&sc->req_free_list, reqp, link); } static void hv_vss_notify_host_result(struct hv_vss_req_internal *reqp, uint32_t status) { mtx_lock(&reqp->sc->pending_mutex); hv_vss_notify_host_result_locked(reqp, status); mtx_unlock(&reqp->sc->pending_mutex); } static void hv_vss_cp_vssreq_to_user(struct hv_vss_req_internal *reqp, struct hv_vss_opt_msg *userdata) { struct hv_vss_req *hv_vss_dev_buf; hv_vss_dev_buf = &reqp->vss_req; hv_vss_dev_buf->opt_msg.opt = HV_VSS_NONE; switch (reqp->vss_req.msg.hdr.vss_hdr.operation) { case VSS_OP_FREEZE: hv_vss_dev_buf->opt_msg.opt = HV_VSS_FREEZE; break; case VSS_OP_THAW: hv_vss_dev_buf->opt_msg.opt = HV_VSS_THAW; break; case VSS_OP_HOT_BACKUP: hv_vss_dev_buf->opt_msg.opt = HV_VSS_CHECK; break; } *userdata = hv_vss_dev_buf->opt_msg; hv_vss_log_info("%s, read data from user for " "%s (%ju) \n", __func__, vss_opt_name[userdata->opt], (uintmax_t)userdata->msgid); } /** * Remove the request id from app notifiy or ack queue, * and recyle the request by inserting it to free list. * * When app was notified but not yet sending ack, the request * should locate in either notify queue or ack queue. */ static struct hv_vss_req_internal* hv_vss_drain_req_queue_locked(hv_vss_sc *sc, uint64_t req_id) { struct hv_vss_req_internal *reqp, *tmp; SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->daemon_sc.to_notify_queue, slink, tmp, req_id); if (reqp == NULL) SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->daemon_sc.to_ack_queue, slink, tmp, req_id); if (reqp == NULL) SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->app_sc.to_notify_queue, slink, tmp, req_id); if (reqp == NULL) SEARCH_REMOVE_REQ_LOCKED(reqp, &sc->app_sc.to_ack_queue, slink, tmp, req_id); return (reqp); } /** * Actions for daemon who has been notified. */ static void hv_vss_notified(struct hv_vss_dev_sc *dev_sc, struct hv_vss_opt_msg *userdata) { struct hv_vss_req_internal *reqp; mtx_lock(&dev_sc->sc->pending_mutex); if (!STAILQ_EMPTY(&dev_sc->to_notify_queue)) { reqp = STAILQ_FIRST(&dev_sc->to_notify_queue); hv_vss_cp_vssreq_to_user(reqp, userdata); STAILQ_REMOVE_HEAD(&dev_sc->to_notify_queue, slink); /* insert the msg to queue for write */ STAILQ_INSERT_TAIL(&dev_sc->to_ack_queue, reqp, slink); userdata->status = VSS_SUCCESS; } else { /* Timeout occur, thus request was removed from queue. */ hv_vss_log_info("%s: notify queue is empty!\n", __func__); userdata->status = VSS_FAIL; } mtx_unlock(&dev_sc->sc->pending_mutex); } static void hv_vss_notify(struct hv_vss_dev_sc *dev_sc, struct hv_vss_req_internal *reqp) { uint32_t opt = reqp->vss_req.opt_msg.opt; mtx_lock(&dev_sc->sc->pending_mutex); STAILQ_INSERT_TAIL(&dev_sc->to_notify_queue, reqp, slink); hv_vss_log_info("%s: issuing query %s (%ju) to %s\n", __func__, vss_opt_name[opt], (uintmax_t)reqp->vss_req.opt_msg.msgid, &dev_sc->sc->app_sc == dev_sc ? "app" : "daemon"); mtx_unlock(&dev_sc->sc->pending_mutex); selwakeup(&dev_sc->hv_vss_selinfo); } /** * Actions for daemon who has acknowledged. */ static void hv_vss_daemon_acked(struct hv_vss_dev_sc *dev_sc, struct hv_vss_opt_msg *userdata) { struct hv_vss_req_internal *reqp, *tmp; uint64_t req_id; int opt; uint32_t status; opt = userdata->opt; req_id = userdata->msgid; status = userdata->status; /* make sure the reserved fields are all zeros. */ memset(&userdata->reserved, 0, sizeof(struct hv_vss_opt_msg) - __offsetof(struct hv_vss_opt_msg, reserved)); mtx_lock(&dev_sc->sc->pending_mutex); SEARCH_REMOVE_REQ_LOCKED(reqp, &dev_sc->to_ack_queue, slink, tmp, req_id); mtx_unlock(&dev_sc->sc->pending_mutex); if (reqp == NULL) { hv_vss_log_info("%s Timeout: fail to find daemon ack request\n", __func__); userdata->status = VSS_FAIL; return; } KASSERT(opt == reqp->vss_req.opt_msg.opt, ("Mismatched VSS operation!")); hv_vss_log_info("%s, get response %d from daemon for %s (%ju) \n", __func__, status, vss_opt_name[opt], (uintmax_t)req_id); switch (opt) { case HV_VSS_CHECK: case HV_VSS_FREEZE: callout_drain(&reqp->callout); hv_vss_notify_host_result(reqp, status == VSS_SUCCESS ? HV_S_OK : HV_E_FAIL); break; case HV_VSS_THAW: if (dev_sc->sc->app_register_done) { if (status == VSS_SUCCESS) { hv_vss_notify(&dev_sc->sc->app_sc, reqp); } else { /* handle error */ callout_drain(&reqp->callout); hv_vss_notify_host_result(reqp, HV_E_FAIL); } } else { callout_drain(&reqp->callout); hv_vss_notify_host_result(reqp, status == VSS_SUCCESS ? HV_S_OK : HV_E_FAIL); } break; } } /** * Actions for app who has acknowledged. */ static void hv_vss_app_acked(struct hv_vss_dev_sc *dev_sc, struct hv_vss_opt_msg *userdata) { struct hv_vss_req_internal *reqp, *tmp; uint64_t req_id; int opt; uint8_t status; opt = userdata->opt; req_id = userdata->msgid; status = userdata->status; /* make sure the reserved fields are all zeros. */ memset(&userdata->reserved, 0, sizeof(struct hv_vss_opt_msg) - __offsetof(struct hv_vss_opt_msg, reserved)); mtx_lock(&dev_sc->sc->pending_mutex); SEARCH_REMOVE_REQ_LOCKED(reqp, &dev_sc->to_ack_queue, slink, tmp, req_id); mtx_unlock(&dev_sc->sc->pending_mutex); if (reqp == NULL) { hv_vss_log_info("%s Timeout: fail to find app ack request\n", __func__); userdata->status = VSS_FAIL; return; } KASSERT(opt == reqp->vss_req.opt_msg.opt, ("Mismatched VSS operation!")); hv_vss_log_info("%s, get response %d from app for %s (%ju) \n", __func__, status, vss_opt_name[opt], (uintmax_t)req_id); if (dev_sc->sc->register_done) { switch (opt) { case HV_VSS_CHECK: case HV_VSS_FREEZE: if (status == VSS_SUCCESS) { hv_vss_notify(&dev_sc->sc->daemon_sc, reqp); } else { /* handle error */ callout_drain(&reqp->callout); hv_vss_notify_host_result(reqp, HV_E_FAIL); } break; case HV_VSS_THAW: callout_drain(&reqp->callout); hv_vss_notify_host_result(reqp, status == VSS_SUCCESS ? HV_S_OK : HV_E_FAIL); break; } } else { hv_vss_log_info("%s, Fatal: vss daemon was killed\n", __func__); } } static int hv_vss_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td) { struct proc *td_proc; td_proc = td->td_proc; struct hv_vss_dev_sc *dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; hv_vss_log_info("%s: %s opens device \"%s\" successfully.\n", __func__, td_proc->p_comm, FS_VSS_DEV_NAME); if (dev_sc->sc->register_done) return (EBUSY); dev_sc->sc->register_done = true; hv_vss_callback(vmbus_get_channel(dev_sc->sc->dev), dev_sc->sc); dev_sc->proc_task = curproc; return (0); } static int hv_vss_dev_close(struct cdev *dev, int fflag __unused, int devtype __unused, struct thread *td) { struct proc *td_proc; td_proc = td->td_proc; struct hv_vss_dev_sc *dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; hv_vss_log_info("%s: %s closes device \"%s\"\n", __func__, td_proc->p_comm, FS_VSS_DEV_NAME); dev_sc->sc->register_done = false; return (0); } static int hv_vss_dev_daemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) { struct proc *td_proc; struct hv_vss_dev_sc *sc; td_proc = td->td_proc; sc = (struct hv_vss_dev_sc*)dev->si_drv1; hv_vss_log_info("%s: %s invoked vss ioctl\n", __func__, td_proc->p_comm); struct hv_vss_opt_msg* userdata = (struct hv_vss_opt_msg*)data; switch(cmd) { case IOCHVVSSREAD: hv_vss_notified(sc, userdata); break; case IOCHVVSSWRITE: hv_vss_daemon_acked(sc, userdata); break; } return (0); } /* * hv_vss_daemon poll invokes this function to check if data is available * for daemon to read. */ static int hv_vss_dev_daemon_poll(struct cdev *dev, int events, struct thread *td) { int revent = 0; struct hv_vss_dev_sc *dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; mtx_lock(&dev_sc->sc->pending_mutex); /** * if there is data ready, inform daemon's poll */ if (!STAILQ_EMPTY(&dev_sc->to_notify_queue)) revent = POLLIN; if (revent == 0) selrecord(td, &dev_sc->hv_vss_selinfo); hv_vss_log_info("%s return 0x%x\n", __func__, revent); mtx_unlock(&dev_sc->sc->pending_mutex); return (revent); } static int hv_appvss_dev_open(struct cdev *dev, int oflags, int devtype, struct thread *td) { struct proc *td_proc; td_proc = td->td_proc; struct hv_vss_dev_sc *dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; hv_vss_log_info("%s: %s opens device \"%s\" successfully.\n", __func__, td_proc->p_comm, APP_VSS_DEV_NAME); if (dev_sc->sc->app_register_done) return (EBUSY); dev_sc->sc->app_register_done = true; dev_sc->proc_task = curproc; return (0); } static int hv_appvss_dev_close(struct cdev *dev, int fflag __unused, int devtype __unused, struct thread *td) { struct proc *td_proc; td_proc = td->td_proc; struct hv_vss_dev_sc *dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; hv_vss_log_info("%s: %s closes device \"%s\".\n", __func__, td_proc->p_comm, APP_VSS_DEV_NAME); dev_sc->sc->app_register_done = false; return (0); } static int hv_appvss_dev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td) { struct proc *td_proc; struct hv_vss_dev_sc *dev_sc; td_proc = td->td_proc; dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; hv_vss_log_info("%s: %s invoked vss ioctl\n", __func__, td_proc->p_comm); struct hv_vss_opt_msg* userdata = (struct hv_vss_opt_msg*)data; switch(cmd) { case IOCHVVSSREAD: hv_vss_notified(dev_sc, userdata); break; case IOCHVVSSWRITE: hv_vss_app_acked(dev_sc, userdata); break; } return (0); } /* * hv_vss_daemon poll invokes this function to check if data is available * for daemon to read. */ static int hv_appvss_dev_poll(struct cdev *dev, int events, struct thread *td) { int revent = 0; struct hv_vss_dev_sc *dev_sc = (struct hv_vss_dev_sc*)dev->si_drv1; mtx_lock(&dev_sc->sc->pending_mutex); /** * if there is data ready, inform daemon's poll */ if (!STAILQ_EMPTY(&dev_sc->to_notify_queue)) revent = POLLIN; if (revent == 0) selrecord(td, &dev_sc->hv_vss_selinfo); hv_vss_log_info("%s return 0x%x\n", __func__, revent); mtx_unlock(&dev_sc->sc->pending_mutex); return (revent); } static void hv_vss_timeout(void *arg) { hv_vss_req_internal *reqp = arg; hv_vss_req_internal *request __diagused; hv_vss_sc* sc = reqp->sc; uint64_t req_id = reqp->vss_req.opt_msg.msgid; /* This thread is locked */ KASSERT(mtx_owned(&sc->pending_mutex), ("mutex lock is not owned!")); request = hv_vss_drain_req_queue_locked(sc, req_id); KASSERT(request != NULL, ("timeout but fail to find request")); hv_vss_notify_host_result_locked(reqp, HV_E_FAIL); } /* * This routine is called whenever a message is received from the host */ static void hv_vss_init_req(hv_vss_req_internal *reqp, uint32_t recvlen, uint64_t requestid, uint8_t *vss_buf, hv_vss_sc *sc) { struct timespec vm_ts; struct hv_vss_msg* msg = (struct hv_vss_msg *)vss_buf; memset(reqp, 0, __offsetof(hv_vss_req_internal, callout)); reqp->host_msg_len = recvlen; reqp->host_msg_id = requestid; reqp->rcv_buf = vss_buf; reqp->sc = sc; memcpy(&reqp->vss_req.msg, (struct hv_vss_msg *)vss_buf, sizeof(struct hv_vss_msg)); /* set the opt for users */ switch (msg->hdr.vss_hdr.operation) { case VSS_OP_FREEZE: reqp->vss_req.opt_msg.opt = HV_VSS_FREEZE; break; case VSS_OP_THAW: reqp->vss_req.opt_msg.opt = HV_VSS_THAW; break; case VSS_OP_HOT_BACKUP: reqp->vss_req.opt_msg.opt = HV_VSS_CHECK; break; } /* Use a timestamp as msg request ID */ nanotime(&vm_ts); reqp->vss_req.opt_msg.msgid = (vm_ts.tv_sec * NANOSEC) + vm_ts.tv_nsec; } static hv_vss_req_internal* hv_vss_get_new_req_locked(hv_vss_sc *sc) { hv_vss_req_internal *reqp; if (!STAILQ_EMPTY(&sc->daemon_sc.to_notify_queue) || !STAILQ_EMPTY(&sc->daemon_sc.to_ack_queue) || !STAILQ_EMPTY(&sc->app_sc.to_notify_queue) || !STAILQ_EMPTY(&sc->app_sc.to_ack_queue)) { /* * There is request coming from host before * finishing previous requests */ hv_vss_log_info("%s: Warning: there is new request " "coming before finishing previous requests\n", __func__); return (NULL); } if (LIST_EMPTY(&sc->req_free_list)) { /* TODO Error: no buffer */ hv_vss_log_info("Error: No buffer\n"); return (NULL); } reqp = LIST_FIRST(&sc->req_free_list); LIST_REMOVE(reqp, link); return (reqp); } static void hv_vss_start_notify(hv_vss_req_internal *reqp, uint32_t opt) { hv_vss_sc *sc = reqp->sc; /* * Freeze/Check notification sequence: kernel -> app -> daemon(fs) * Thaw notification sequence: kernel -> daemon(fs) -> app * * We should wake up the daemon, in case it's doing poll(). * The response should be received after 5s, otherwise, trigger timeout. */ switch (opt) { case VSS_OP_FREEZE: case VSS_OP_HOT_BACKUP: if (sc->app_register_done) hv_vss_notify(&sc->app_sc, reqp); else hv_vss_notify(&sc->daemon_sc, reqp); callout_reset(&reqp->callout, TIMEOUT_LIMIT * hz, hv_vss_timeout, reqp); break; case VSS_OP_THAW: hv_vss_notify(&sc->daemon_sc, reqp); callout_reset(&reqp->callout, TIMEOUT_LIMIT * hz, hv_vss_timeout, reqp); break; } } /* * Function to read the vss request buffer from host * and interact with daemon */ static void hv_vss_process_request(void *context, int pending __unused) { uint8_t *vss_buf; struct vmbus_channel *channel; uint32_t recvlen = 0; uint64_t requestid; struct vmbus_icmsg_hdr *icmsghdrp; int ret = 0; hv_vss_sc *sc; hv_vss_req_internal *reqp; hv_vss_log_info("%s: entering hv_vss_process_request\n", __func__); sc = (hv_vss_sc*)context; vss_buf = sc->util_sc.ic_buf; channel = vmbus_get_channel(sc->dev); recvlen = sc->util_sc.ic_buflen; ret = vmbus_chan_recv(channel, vss_buf, &recvlen, &requestid); KASSERT(ret != ENOBUFS, ("hvvss recvbuf is not large enough")); /* XXX check recvlen to make sure that it contains enough data */ while ((ret == 0) && (recvlen > 0)) { icmsghdrp = (struct vmbus_icmsg_hdr *)vss_buf; if (icmsghdrp->ic_type == HV_ICMSGTYPE_NEGOTIATE) { ret = vmbus_ic_negomsg(&sc->util_sc, vss_buf, &recvlen, VSS_FWVER, VSS_MSGVER); hv_vss_respond_host(vss_buf, vmbus_get_channel(sc->dev), recvlen, requestid, ret); hv_vss_log_info("%s: version negotiated\n", __func__); } else if (!hv_vss_is_daemon_killed_after_launch(sc)) { struct hv_vss_msg* msg = (struct hv_vss_msg *)vss_buf; switch(msg->hdr.vss_hdr.operation) { case VSS_OP_FREEZE: case VSS_OP_THAW: case VSS_OP_HOT_BACKUP: mtx_lock(&sc->pending_mutex); reqp = hv_vss_get_new_req_locked(sc); mtx_unlock(&sc->pending_mutex); if (reqp == NULL) { /* ignore this request from host */ break; } hv_vss_init_req(reqp, recvlen, requestid, vss_buf, sc); hv_vss_log_info("%s: receive %s (%ju) from host\n", __func__, vss_opt_name[reqp->vss_req.opt_msg.opt], (uintmax_t)reqp->vss_req.opt_msg.msgid); hv_vss_start_notify(reqp, msg->hdr.vss_hdr.operation); break; case VSS_OP_GET_DM_INFO: hv_vss_log_info("%s: receive GET_DM_INFO from host\n", __func__); msg->body.dm_info.flags = 0; hv_vss_respond_host(vss_buf, vmbus_get_channel(sc->dev), recvlen, requestid, HV_S_OK); break; default: device_printf(sc->dev, "Unknown opt from host: %d\n", msg->hdr.vss_hdr.operation); break; } } else { /* daemon was killed for some reason after it was launched */ struct hv_vss_msg* msg = (struct hv_vss_msg *)vss_buf; switch(msg->hdr.vss_hdr.operation) { case VSS_OP_FREEZE: hv_vss_log_info("%s: response fail for FREEZE\n", __func__); break; case VSS_OP_THAW: hv_vss_log_info("%s: response fail for THAW\n", __func__); break; case VSS_OP_HOT_BACKUP: hv_vss_log_info("%s: response fail for HOT_BACKUP\n", __func__); msg->body.vss_cf.flags = VSS_HBU_NO_AUTO_RECOVERY; break; case VSS_OP_GET_DM_INFO: hv_vss_log_info("%s: response fail for GET_DM_INFO\n", __func__); msg->body.dm_info.flags = 0; break; default: device_printf(sc->dev, "Unknown opt from host: %d\n", msg->hdr.vss_hdr.operation); break; } hv_vss_respond_host(vss_buf, vmbus_get_channel(sc->dev), recvlen, requestid, HV_E_FAIL); } /* * Try reading next buffer */ recvlen = sc->util_sc.ic_buflen; ret = vmbus_chan_recv(channel, vss_buf, &recvlen, &requestid); KASSERT(ret != ENOBUFS, ("hvvss recvbuf is not large enough")); /* XXX check recvlen to make sure that it contains enough data */ hv_vss_log_info("%s: read: context %p, ret =%d, recvlen=%d\n", __func__, context, ret, recvlen); } } static int hv_vss_probe(device_t dev) { return (vmbus_ic_probe(dev, vmbus_vss_descs)); } static int hv_vss_init_send_receive_queue(device_t dev) { hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev); int i; const int max_list = 4; /* It is big enough for the list */ struct hv_vss_req_internal* reqp; LIST_INIT(&sc->req_free_list); STAILQ_INIT(&sc->daemon_sc.to_notify_queue); STAILQ_INIT(&sc->daemon_sc.to_ack_queue); STAILQ_INIT(&sc->app_sc.to_notify_queue); STAILQ_INIT(&sc->app_sc.to_ack_queue); for (i = 0; i < max_list; i++) { reqp = malloc(sizeof(struct hv_vss_req_internal), M_DEVBUF, M_WAITOK|M_ZERO); LIST_INSERT_HEAD(&sc->req_free_list, reqp, link); callout_init_mtx(&reqp->callout, &sc->pending_mutex, 0); } return (0); } static int hv_vss_destroy_send_receive_queue(device_t dev) { hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev); hv_vss_req_internal* reqp; while (!LIST_EMPTY(&sc->req_free_list)) { reqp = LIST_FIRST(&sc->req_free_list); LIST_REMOVE(reqp, link); free(reqp, M_DEVBUF); } while (!STAILQ_EMPTY(&sc->daemon_sc.to_notify_queue)) { reqp = STAILQ_FIRST(&sc->daemon_sc.to_notify_queue); STAILQ_REMOVE_HEAD(&sc->daemon_sc.to_notify_queue, slink); free(reqp, M_DEVBUF); } while (!STAILQ_EMPTY(&sc->daemon_sc.to_ack_queue)) { reqp = STAILQ_FIRST(&sc->daemon_sc.to_ack_queue); STAILQ_REMOVE_HEAD(&sc->daemon_sc.to_ack_queue, slink); free(reqp, M_DEVBUF); } while (!STAILQ_EMPTY(&sc->app_sc.to_notify_queue)) { reqp = STAILQ_FIRST(&sc->app_sc.to_notify_queue); STAILQ_REMOVE_HEAD(&sc->app_sc.to_notify_queue, slink); free(reqp, M_DEVBUF); } while (!STAILQ_EMPTY(&sc->app_sc.to_ack_queue)) { reqp = STAILQ_FIRST(&sc->app_sc.to_ack_queue); STAILQ_REMOVE_HEAD(&sc->app_sc.to_ack_queue, slink); free(reqp, M_DEVBUF); } return (0); } static int hv_vss_attach(device_t dev) { int error; struct sysctl_oid_list *child; struct sysctl_ctx_list *ctx; hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev); sc->dev = dev; mtx_init(&sc->pending_mutex, "hv_vss pending mutex", NULL, MTX_DEF); ctx = device_get_sysctl_ctx(dev); child = SYSCTL_CHILDREN(device_get_sysctl_tree(dev)); SYSCTL_ADD_INT(ctx, child, OID_AUTO, "hv_vss_log", CTLFLAG_RWTUN, &hv_vss_log, 0, "Hyperv VSS service log level"); TASK_INIT(&sc->task, 0, hv_vss_process_request, sc); hv_vss_init_send_receive_queue(dev); /* create character device for file system freeze/thaw */ error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &sc->hv_vss_dev, &hv_vss_cdevsw, 0, UID_ROOT, GID_WHEEL, 0640, FS_VSS_DEV_NAME); if (error != 0) { hv_vss_log_info("Fail to create '%s': %d\n", FS_VSS_DEV_NAME, error); return (error); } sc->hv_vss_dev->si_drv1 = &sc->daemon_sc; sc->daemon_sc.sc = sc; /* create character device for application freeze/thaw */ error = make_dev_p(MAKEDEV_CHECKNAME | MAKEDEV_WAITOK, &sc->hv_appvss_dev, &hv_appvss_cdevsw, 0, UID_ROOT, GID_WHEEL, 0640, APP_VSS_DEV_NAME); if (error != 0) { hv_vss_log_info("Fail to create '%s': %d\n", APP_VSS_DEV_NAME, error); return (error); } sc->hv_appvss_dev->si_drv1 = &sc->app_sc; sc->app_sc.sc = sc; return (vmbus_ic_attach(dev, hv_vss_callback)); } static int hv_vss_detach(device_t dev) { hv_vss_sc *sc = (hv_vss_sc*)device_get_softc(dev); mtx_destroy(&sc->pending_mutex); if (sc->daemon_sc.proc_task != NULL) { PROC_LOCK(sc->daemon_sc.proc_task); kern_psignal(sc->daemon_sc.proc_task, SIGKILL); PROC_UNLOCK(sc->daemon_sc.proc_task); } if (sc->app_sc.proc_task != NULL) { PROC_LOCK(sc->app_sc.proc_task); kern_psignal(sc->app_sc.proc_task, SIGKILL); PROC_UNLOCK(sc->app_sc.proc_task); } hv_vss_destroy_send_receive_queue(dev); destroy_dev(sc->hv_vss_dev); destroy_dev(sc->hv_appvss_dev); return (vmbus_ic_detach(dev)); } static device_method_t vss_methods[] = { /* Device interface */ DEVMETHOD(device_probe, hv_vss_probe), DEVMETHOD(device_attach, hv_vss_attach), DEVMETHOD(device_detach, hv_vss_detach), { 0, 0 } }; static driver_t vss_driver = { "hvvss", vss_methods, sizeof(hv_vss_sc)}; DRIVER_MODULE(hv_vss, vmbus, vss_driver, NULL, NULL); MODULE_VERSION(hv_vss, 1); MODULE_DEPEND(hv_vss, vmbus, 1, 1, 1);