// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2009, Microsoft Corporation. * * Authors: * Haiyang Zhang <haiyangz@microsoft.com> * Hank Janssen <hjanssen@microsoft.com> */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/kernel.h> #include <linux/sched.h> #include <linux/wait.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/hyperv.h> #include <linux/uio.h> #include <linux/interrupt.h> #include <asm/page.h> #include <asm/mshyperv.h> #include "hyperv_vmbus.h" /* * hv_gpadl_size - Return the real size of a gpadl, the size that Hyper-V uses * * For BUFFER gpadl, Hyper-V uses the exact same size as the guest does. * * For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the header * (because of the alignment requirement), however, the hypervisor only * uses the first HV_HYP_PAGE_SIZE as the header, therefore leaving a * (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. And since there are two rings in a * ringbuffer, the total size for a RING gpadl that Hyper-V uses is the * total size that the guest uses minus twice of the gap size. */ static inline u32 hv_gpadl_size(enum hv_gpadl_type type, u32 size) { switch (type) { case HV_GPADL_BUFFER: return size; case HV_GPADL_RING: /* The size of a ringbuffer must be page-aligned */ BUG_ON(size % PAGE_SIZE); /* * Two things to notice here: * 1) We're processing two ring buffers as a unit * 2) We're skipping any space larger than HV_HYP_PAGE_SIZE in * the first guest-size page of each of the two ring buffers. * So we effectively subtract out two guest-size pages, and add * back two Hyper-V size pages. */ return size - 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE); } BUG(); return 0; } /* * hv_ring_gpadl_send_hvpgoffset - Calculate the send offset (in unit of * HV_HYP_PAGE) in a ring gpadl based on the * offset in the guest * * @offset: the offset (in bytes) where the send ringbuffer starts in the * virtual address space of the guest */ static inline u32 hv_ring_gpadl_send_hvpgoffset(u32 offset) { /* * For RING gpadl, in each ring, the guest uses one PAGE_SIZE as the * header (because of the alignment requirement), however, the * hypervisor only uses the first HV_HYP_PAGE_SIZE as the header, * therefore leaving a (PAGE_SIZE - HV_HYP_PAGE_SIZE) gap. * * And to calculate the effective send offset in gpadl, we need to * substract this gap. */ return (offset - (PAGE_SIZE - HV_HYP_PAGE_SIZE)) >> HV_HYP_PAGE_SHIFT; } /* * hv_gpadl_hvpfn - Return the Hyper-V page PFN of the @i th Hyper-V page in * the gpadl * * @type: the type of the gpadl * @kbuffer: the pointer to the gpadl in the guest * @size: the total size (in bytes) of the gpadl * @send_offset: the offset (in bytes) where the send ringbuffer starts in the * virtual address space of the guest * @i: the index */ static inline u64 hv_gpadl_hvpfn(enum hv_gpadl_type type, void *kbuffer, u32 size, u32 send_offset, int i) { int send_idx = hv_ring_gpadl_send_hvpgoffset(send_offset); unsigned long delta = 0UL; switch (type) { case HV_GPADL_BUFFER: break; case HV_GPADL_RING: if (i == 0) delta = 0; else if (i <= send_idx) delta = PAGE_SIZE - HV_HYP_PAGE_SIZE; else delta = 2 * (PAGE_SIZE - HV_HYP_PAGE_SIZE); break; default: BUG(); break; } return virt_to_hvpfn(kbuffer + delta + (HV_HYP_PAGE_SIZE * i)); } /* * vmbus_setevent- Trigger an event notification on the specified * channel. */ void vmbus_setevent(struct vmbus_channel *channel) { struct hv_monitor_page *monitorpage; trace_vmbus_setevent(channel); /* * For channels marked as in "low latency" mode * bypass the monitor page mechanism. */ if (channel->offermsg.monitor_allocated && !channel->low_latency) { vmbus_send_interrupt(channel->offermsg.child_relid); /* Get the child to parent monitor page */ monitorpage = vmbus_connection.monitor_pages[1]; sync_set_bit(channel->monitor_bit, (unsigned long *)&monitorpage->trigger_group [channel->monitor_grp].pending); } else { vmbus_set_event(channel); } } EXPORT_SYMBOL_GPL(vmbus_setevent); /* vmbus_free_ring - drop mapping of ring buffer */ void vmbus_free_ring(struct vmbus_channel *channel) { hv_ringbuffer_cleanup(&channel->outbound); hv_ringbuffer_cleanup(&channel->inbound); if (channel->ringbuffer_page) { __free_pages(channel->ringbuffer_page, get_order(channel->ringbuffer_pagecount << PAGE_SHIFT)); channel->ringbuffer_page = NULL; } } EXPORT_SYMBOL_GPL(vmbus_free_ring); /* vmbus_alloc_ring - allocate and map pages for ring buffer */ int vmbus_alloc_ring(struct vmbus_channel *newchannel, u32 send_size, u32 recv_size) { struct page *page; int order; if (send_size % PAGE_SIZE || recv_size % PAGE_SIZE) return -EINVAL; /* Allocate the ring buffer */ order = get_order(send_size + recv_size); page = alloc_pages_node(cpu_to_node(newchannel->target_cpu), GFP_KERNEL|__GFP_ZERO, order); if (!page) page = alloc_pages(GFP_KERNEL|__GFP_ZERO, order); if (!page) return -ENOMEM; newchannel->ringbuffer_page = page; newchannel->ringbuffer_pagecount = (send_size + recv_size) >> PAGE_SHIFT; newchannel->ringbuffer_send_offset = send_size >> PAGE_SHIFT; return 0; } EXPORT_SYMBOL_GPL(vmbus_alloc_ring); /* Used for Hyper-V Socket: a guest client's connect() to the host */ int vmbus_send_tl_connect_request(const guid_t *shv_guest_servie_id, const guid_t *shv_host_servie_id) { struct vmbus_channel_tl_connect_request conn_msg; int ret; memset(&conn_msg, 0, sizeof(conn_msg)); conn_msg.header.msgtype = CHANNELMSG_TL_CONNECT_REQUEST; conn_msg.guest_endpoint_id = *shv_guest_servie_id; conn_msg.host_service_id = *shv_host_servie_id; ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true); trace_vmbus_send_tl_connect_request(&conn_msg, ret); return ret; } EXPORT_SYMBOL_GPL(vmbus_send_tl_connect_request); /* * Set/change the vCPU (@target_vp) the channel (@child_relid) will interrupt. * * CHANNELMSG_MODIFYCHANNEL messages are aynchronous. Also, Hyper-V does not * ACK such messages. IOW we can't know when the host will stop interrupting * the "old" vCPU and start interrupting the "new" vCPU for the given channel. * * The CHANNELMSG_MODIFYCHANNEL message type is supported since VMBus version * VERSION_WIN10_V4_1. */ int vmbus_send_modifychannel(u32 child_relid, u32 target_vp) { struct vmbus_channel_modifychannel conn_msg; int ret; memset(&conn_msg, 0, sizeof(conn_msg)); conn_msg.header.msgtype = CHANNELMSG_MODIFYCHANNEL; conn_msg.child_relid = child_relid; conn_msg.target_vp = target_vp; ret = vmbus_post_msg(&conn_msg, sizeof(conn_msg), true); trace_vmbus_send_modifychannel(&conn_msg, ret); return ret; } EXPORT_SYMBOL_GPL(vmbus_send_modifychannel); /* * create_gpadl_header - Creates a gpadl for the specified buffer */ static int create_gpadl_header(enum hv_gpadl_type type, void *kbuffer, u32 size, u32 send_offset, struct vmbus_channel_msginfo **msginfo) { int i; int pagecount; struct vmbus_channel_gpadl_header *gpadl_header; struct vmbus_channel_gpadl_body *gpadl_body; struct vmbus_channel_msginfo *msgheader; struct vmbus_channel_msginfo *msgbody = NULL; u32 msgsize; int pfnsum, pfncount, pfnleft, pfncurr, pfnsize; pagecount = hv_gpadl_size(type, size) >> HV_HYP_PAGE_SHIFT; /* do we need a gpadl body msg */ pfnsize = MAX_SIZE_CHANNEL_MESSAGE - sizeof(struct vmbus_channel_gpadl_header) - sizeof(struct gpa_range); pfncount = pfnsize / sizeof(u64); if (pagecount > pfncount) { /* we need a gpadl body */ /* fill in the header */ msgsize = sizeof(struct vmbus_channel_msginfo) + sizeof(struct vmbus_channel_gpadl_header) + sizeof(struct gpa_range) + pfncount * sizeof(u64); msgheader = kzalloc(msgsize, GFP_KERNEL); if (!msgheader) goto nomem; INIT_LIST_HEAD(&msgheader->submsglist); msgheader->msgsize = msgsize; gpadl_header = (struct vmbus_channel_gpadl_header *) msgheader->msg; gpadl_header->rangecount = 1; gpadl_header->range_buflen = sizeof(struct gpa_range) + pagecount * sizeof(u64); gpadl_header->range[0].byte_offset = 0; gpadl_header->range[0].byte_count = hv_gpadl_size(type, size); for (i = 0; i < pfncount; i++) gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn( type, kbuffer, size, send_offset, i); *msginfo = msgheader; pfnsum = pfncount; pfnleft = pagecount - pfncount; /* how many pfns can we fit */ pfnsize = MAX_SIZE_CHANNEL_MESSAGE - sizeof(struct vmbus_channel_gpadl_body); pfncount = pfnsize / sizeof(u64); /* fill in the body */ while (pfnleft) { if (pfnleft > pfncount) pfncurr = pfncount; else pfncurr = pfnleft; msgsize = sizeof(struct vmbus_channel_msginfo) + sizeof(struct vmbus_channel_gpadl_body) + pfncurr * sizeof(u64); msgbody = kzalloc(msgsize, GFP_KERNEL); if (!msgbody) { struct vmbus_channel_msginfo *pos = NULL; struct vmbus_channel_msginfo *tmp = NULL; /* * Free up all the allocated messages. */ list_for_each_entry_safe(pos, tmp, &msgheader->submsglist, msglistentry) { list_del(&pos->msglistentry); kfree(pos); } goto nomem; } msgbody->msgsize = msgsize; gpadl_body = (struct vmbus_channel_gpadl_body *)msgbody->msg; /* * Gpadl is u32 and we are using a pointer which could * be 64-bit * This is governed by the guest/host protocol and * so the hypervisor guarantees that this is ok. */ for (i = 0; i < pfncurr; i++) gpadl_body->pfn[i] = hv_gpadl_hvpfn(type, kbuffer, size, send_offset, pfnsum + i); /* add to msg header */ list_add_tail(&msgbody->msglistentry, &msgheader->submsglist); pfnsum += pfncurr; pfnleft -= pfncurr; } } else { /* everything fits in a header */ msgsize = sizeof(struct vmbus_channel_msginfo) + sizeof(struct vmbus_channel_gpadl_header) + sizeof(struct gpa_range) + pagecount * sizeof(u64); msgheader = kzalloc(msgsize, GFP_KERNEL); if (msgheader == NULL) goto nomem; INIT_LIST_HEAD(&msgheader->submsglist); msgheader->msgsize = msgsize; gpadl_header = (struct vmbus_channel_gpadl_header *) msgheader->msg; gpadl_header->rangecount = 1; gpadl_header->range_buflen = sizeof(struct gpa_range) + pagecount * sizeof(u64); gpadl_header->range[0].byte_offset = 0; gpadl_header->range[0].byte_count = hv_gpadl_size(type, size); for (i = 0; i < pagecount; i++) gpadl_header->range[0].pfn_array[i] = hv_gpadl_hvpfn( type, kbuffer, size, send_offset, i); *msginfo = msgheader; } return 0; nomem: kfree(msgheader); kfree(msgbody); return -ENOMEM; } /* * __vmbus_establish_gpadl - Establish a GPADL for a buffer or ringbuffer * * @channel: a channel * @type: the type of the corresponding GPADL, only meaningful for the guest. * @kbuffer: from kmalloc or vmalloc * @size: page-size multiple * @send_offset: the offset (in bytes) where the send ring buffer starts, * should be 0 for BUFFER type gpadl * @gpadl_handle: some funky thing */ static int __vmbus_establish_gpadl(struct vmbus_channel *channel, enum hv_gpadl_type type, void *kbuffer, u32 size, u32 send_offset, u32 *gpadl_handle) { struct vmbus_channel_gpadl_header *gpadlmsg; struct vmbus_channel_gpadl_body *gpadl_body; struct vmbus_channel_msginfo *msginfo = NULL; struct vmbus_channel_msginfo *submsginfo, *tmp; struct list_head *curr; u32 next_gpadl_handle; unsigned long flags; int ret = 0; next_gpadl_handle = (atomic_inc_return(&vmbus_connection.next_gpadl_handle) - 1); ret = create_gpadl_header(type, kbuffer, size, send_offset, &msginfo); if (ret) return ret; init_completion(&msginfo->waitevent); msginfo->waiting_channel = channel; gpadlmsg = (struct vmbus_channel_gpadl_header *)msginfo->msg; gpadlmsg->header.msgtype = CHANNELMSG_GPADL_HEADER; gpadlmsg->child_relid = channel->offermsg.child_relid; gpadlmsg->gpadl = next_gpadl_handle; spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_add_tail(&msginfo->msglistentry, &vmbus_connection.chn_msg_list); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); if (channel->rescind) { ret = -ENODEV; goto cleanup; } ret = vmbus_post_msg(gpadlmsg, msginfo->msgsize - sizeof(*msginfo), true); trace_vmbus_establish_gpadl_header(gpadlmsg, ret); if (ret != 0) goto cleanup; list_for_each(curr, &msginfo->submsglist) { submsginfo = (struct vmbus_channel_msginfo *)curr; gpadl_body = (struct vmbus_channel_gpadl_body *)submsginfo->msg; gpadl_body->header.msgtype = CHANNELMSG_GPADL_BODY; gpadl_body->gpadl = next_gpadl_handle; ret = vmbus_post_msg(gpadl_body, submsginfo->msgsize - sizeof(*submsginfo), true); trace_vmbus_establish_gpadl_body(gpadl_body, ret); if (ret != 0) goto cleanup; } wait_for_completion(&msginfo->waitevent); if (msginfo->response.gpadl_created.creation_status != 0) { pr_err("Failed to establish GPADL: err = 0x%x\n", msginfo->response.gpadl_created.creation_status); ret = -EDQUOT; goto cleanup; } if (channel->rescind) { ret = -ENODEV; goto cleanup; } /* At this point, we received the gpadl created msg */ *gpadl_handle = gpadlmsg->gpadl; cleanup: spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&msginfo->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); list_for_each_entry_safe(submsginfo, tmp, &msginfo->submsglist, msglistentry) { kfree(submsginfo); } kfree(msginfo); return ret; } /* * vmbus_establish_gpadl - Establish a GPADL for the specified buffer * * @channel: a channel * @kbuffer: from kmalloc or vmalloc * @size: page-size multiple * @gpadl_handle: some funky thing */ int vmbus_establish_gpadl(struct vmbus_channel *channel, void *kbuffer, u32 size, u32 *gpadl_handle) { return __vmbus_establish_gpadl(channel, HV_GPADL_BUFFER, kbuffer, size, 0U, gpadl_handle); } EXPORT_SYMBOL_GPL(vmbus_establish_gpadl); /** * request_arr_init - Allocates memory for the requestor array. Each slot * keeps track of the next available slot in the array. Initially, each * slot points to the next one (as in a Linked List). The last slot * does not point to anything, so its value is U64_MAX by default. * @size The size of the array */ static u64 *request_arr_init(u32 size) { int i; u64 *req_arr; req_arr = kcalloc(size, sizeof(u64), GFP_KERNEL); if (!req_arr) return NULL; for (i = 0; i < size - 1; i++) req_arr[i] = i + 1; /* Last slot (no more available slots) */ req_arr[i] = U64_MAX; return req_arr; } /* * vmbus_alloc_requestor - Initializes @rqstor's fields. * Index 0 is the first free slot * @size: Size of the requestor array */ static int vmbus_alloc_requestor(struct vmbus_requestor *rqstor, u32 size) { u64 *rqst_arr; unsigned long *bitmap; rqst_arr = request_arr_init(size); if (!rqst_arr) return -ENOMEM; bitmap = bitmap_zalloc(size, GFP_KERNEL); if (!bitmap) { kfree(rqst_arr); return -ENOMEM; } rqstor->req_arr = rqst_arr; rqstor->req_bitmap = bitmap; rqstor->size = size; rqstor->next_request_id = 0; spin_lock_init(&rqstor->req_lock); return 0; } /* * vmbus_free_requestor - Frees memory allocated for @rqstor * @rqstor: Pointer to the requestor struct */ static void vmbus_free_requestor(struct vmbus_requestor *rqstor) { kfree(rqstor->req_arr); bitmap_free(rqstor->req_bitmap); } static int __vmbus_open(struct vmbus_channel *newchannel, void *userdata, u32 userdatalen, void (*onchannelcallback)(void *context), void *context) { struct vmbus_channel_open_channel *open_msg; struct vmbus_channel_msginfo *open_info = NULL; struct page *page = newchannel->ringbuffer_page; u32 send_pages, recv_pages; unsigned long flags; int err; if (userdatalen > MAX_USER_DEFINED_BYTES) return -EINVAL; send_pages = newchannel->ringbuffer_send_offset; recv_pages = newchannel->ringbuffer_pagecount - send_pages; if (newchannel->state != CHANNEL_OPEN_STATE) return -EINVAL; /* Create and init requestor */ if (newchannel->rqstor_size) { if (vmbus_alloc_requestor(&newchannel->requestor, newchannel->rqstor_size)) return -ENOMEM; } newchannel->state = CHANNEL_OPENING_STATE; newchannel->onchannel_callback = onchannelcallback; newchannel->channel_callback_context = context; err = hv_ringbuffer_init(&newchannel->outbound, page, send_pages); if (err) goto error_clean_ring; err = hv_ringbuffer_init(&newchannel->inbound, &page[send_pages], recv_pages); if (err) goto error_clean_ring; /* Establish the gpadl for the ring buffer */ newchannel->ringbuffer_gpadlhandle = 0; err = __vmbus_establish_gpadl(newchannel, HV_GPADL_RING, page_address(newchannel->ringbuffer_page), (send_pages + recv_pages) << PAGE_SHIFT, newchannel->ringbuffer_send_offset << PAGE_SHIFT, &newchannel->ringbuffer_gpadlhandle); if (err) goto error_clean_ring; /* Create and init the channel open message */ open_info = kzalloc(sizeof(*open_info) + sizeof(struct vmbus_channel_open_channel), GFP_KERNEL); if (!open_info) { err = -ENOMEM; goto error_free_gpadl; } init_completion(&open_info->waitevent); open_info->waiting_channel = newchannel; open_msg = (struct vmbus_channel_open_channel *)open_info->msg; open_msg->header.msgtype = CHANNELMSG_OPENCHANNEL; open_msg->openid = newchannel->offermsg.child_relid; open_msg->child_relid = newchannel->offermsg.child_relid; open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle; /* * The unit of ->downstream_ringbuffer_pageoffset is HV_HYP_PAGE and * the unit of ->ringbuffer_send_offset (i.e. send_pages) is PAGE, so * here we calculate it into HV_HYP_PAGE. */ open_msg->downstream_ringbuffer_pageoffset = hv_ring_gpadl_send_hvpgoffset(send_pages << PAGE_SHIFT); open_msg->target_vp = hv_cpu_number_to_vp_number(newchannel->target_cpu); if (userdatalen) memcpy(open_msg->userdata, userdata, userdatalen); spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_add_tail(&open_info->msglistentry, &vmbus_connection.chn_msg_list); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); if (newchannel->rescind) { err = -ENODEV; goto error_free_info; } err = vmbus_post_msg(open_msg, sizeof(struct vmbus_channel_open_channel), true); trace_vmbus_open(open_msg, err); if (err != 0) goto error_clean_msglist; wait_for_completion(&open_info->waitevent); spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&open_info->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); if (newchannel->rescind) { err = -ENODEV; goto error_free_info; } if (open_info->response.open_result.status) { err = -EAGAIN; goto error_free_info; } newchannel->state = CHANNEL_OPENED_STATE; kfree(open_info); return 0; error_clean_msglist: spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&open_info->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); error_free_info: kfree(open_info); error_free_gpadl: vmbus_teardown_gpadl(newchannel, newchannel->ringbuffer_gpadlhandle); newchannel->ringbuffer_gpadlhandle = 0; error_clean_ring: hv_ringbuffer_cleanup(&newchannel->outbound); hv_ringbuffer_cleanup(&newchannel->inbound); vmbus_free_requestor(&newchannel->requestor); newchannel->state = CHANNEL_OPEN_STATE; return err; } /* * vmbus_connect_ring - Open the channel but reuse ring buffer */ int vmbus_connect_ring(struct vmbus_channel *newchannel, void (*onchannelcallback)(void *context), void *context) { return __vmbus_open(newchannel, NULL, 0, onchannelcallback, context); } EXPORT_SYMBOL_GPL(vmbus_connect_ring); /* * vmbus_open - Open the specified channel. */ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size, u32 recv_ringbuffer_size, void *userdata, u32 userdatalen, void (*onchannelcallback)(void *context), void *context) { int err; err = vmbus_alloc_ring(newchannel, send_ringbuffer_size, recv_ringbuffer_size); if (err) return err; err = __vmbus_open(newchannel, userdata, userdatalen, onchannelcallback, context); if (err) vmbus_free_ring(newchannel); return err; } EXPORT_SYMBOL_GPL(vmbus_open); /* * vmbus_teardown_gpadl -Teardown the specified GPADL handle */ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle) { struct vmbus_channel_gpadl_teardown *msg; struct vmbus_channel_msginfo *info; unsigned long flags; int ret; info = kzalloc(sizeof(*info) + sizeof(struct vmbus_channel_gpadl_teardown), GFP_KERNEL); if (!info) return -ENOMEM; init_completion(&info->waitevent); info->waiting_channel = channel; msg = (struct vmbus_channel_gpadl_teardown *)info->msg; msg->header.msgtype = CHANNELMSG_GPADL_TEARDOWN; msg->child_relid = channel->offermsg.child_relid; msg->gpadl = gpadl_handle; spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_add_tail(&info->msglistentry, &vmbus_connection.chn_msg_list); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); if (channel->rescind) goto post_msg_err; ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_gpadl_teardown), true); trace_vmbus_teardown_gpadl(msg, ret); if (ret) goto post_msg_err; wait_for_completion(&info->waitevent); post_msg_err: /* * If the channel has been rescinded; * we will be awakened by the rescind * handler; set the error code to zero so we don't leak memory. */ if (channel->rescind) ret = 0; spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&info->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); kfree(info); return ret; } EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl); void vmbus_reset_channel_cb(struct vmbus_channel *channel) { unsigned long flags; /* * vmbus_on_event(), running in the per-channel tasklet, can race * with vmbus_close_internal() in the case of SMP guest, e.g., when * the former is accessing channel->inbound.ring_buffer, the latter * could be freeing the ring_buffer pages, so here we must stop it * first. * * vmbus_chan_sched() might call the netvsc driver callback function * that ends up scheduling NAPI work that accesses the ring buffer. * At this point, we have to ensure that any such work is completed * and that the channel ring buffer is no longer being accessed, cf. * the calls to napi_disable() in netvsc_device_remove(). */ tasklet_disable(&channel->callback_event); /* See the inline comments in vmbus_chan_sched(). */ spin_lock_irqsave(&channel->sched_lock, flags); channel->onchannel_callback = NULL; spin_unlock_irqrestore(&channel->sched_lock, flags); channel->sc_creation_callback = NULL; /* Re-enable tasklet for use on re-open */ tasklet_enable(&channel->callback_event); } static int vmbus_close_internal(struct vmbus_channel *channel) { struct vmbus_channel_close_channel *msg; int ret; vmbus_reset_channel_cb(channel); /* * In case a device driver's probe() fails (e.g., * util_probe() -> vmbus_open() returns -ENOMEM) and the device is * rescinded later (e.g., we dynamically disable an Integrated Service * in Hyper-V Manager), the driver's remove() invokes vmbus_close(): * here we should skip most of the below cleanup work. */ if (channel->state != CHANNEL_OPENED_STATE) return -EINVAL; channel->state = CHANNEL_OPEN_STATE; /* Send a closing message */ msg = &channel->close_msg.msg; msg->header.msgtype = CHANNELMSG_CLOSECHANNEL; msg->child_relid = channel->offermsg.child_relid; ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_close_channel), true); trace_vmbus_close_internal(msg, ret); if (ret) { pr_err("Close failed: close post msg return is %d\n", ret); /* * If we failed to post the close msg, * it is perhaps better to leak memory. */ } /* Tear down the gpadl for the channel's ring buffer */ else if (channel->ringbuffer_gpadlhandle) { ret = vmbus_teardown_gpadl(channel, channel->ringbuffer_gpadlhandle); if (ret) { pr_err("Close failed: teardown gpadl return %d\n", ret); /* * If we failed to teardown gpadl, * it is perhaps better to leak memory. */ } channel->ringbuffer_gpadlhandle = 0; } if (!ret) vmbus_free_requestor(&channel->requestor); return ret; } /* disconnect ring - close all channels */ int vmbus_disconnect_ring(struct vmbus_channel *channel) { struct vmbus_channel *cur_channel, *tmp; int ret; if (channel->primary_channel != NULL) return -EINVAL; list_for_each_entry_safe(cur_channel, tmp, &channel->sc_list, sc_list) { if (cur_channel->rescind) wait_for_completion(&cur_channel->rescind_event); mutex_lock(&vmbus_connection.channel_mutex); if (vmbus_close_internal(cur_channel) == 0) { vmbus_free_ring(cur_channel); if (cur_channel->rescind) hv_process_channel_removal(cur_channel); } mutex_unlock(&vmbus_connection.channel_mutex); } /* * Now close the primary. */ mutex_lock(&vmbus_connection.channel_mutex); ret = vmbus_close_internal(channel); mutex_unlock(&vmbus_connection.channel_mutex); return ret; } EXPORT_SYMBOL_GPL(vmbus_disconnect_ring); /* * vmbus_close - Close the specified channel */ void vmbus_close(struct vmbus_channel *channel) { if (vmbus_disconnect_ring(channel) == 0) vmbus_free_ring(channel); } EXPORT_SYMBOL_GPL(vmbus_close); /** * vmbus_sendpacket() - Send the specified buffer on the given channel * @channel: Pointer to vmbus_channel structure * @buffer: Pointer to the buffer you want to send the data from. * @bufferlen: Maximum size of what the buffer holds. * @requestid: Identifier of the request * @type: Type of packet that is being sent e.g. negotiate, time * packet etc. * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED * * Sends data in @buffer directly to Hyper-V via the vmbus. * This will send the data unparsed to Hyper-V. * * Mainly used by Hyper-V drivers. */ int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer, u32 bufferlen, u64 requestid, enum vmbus_packet_type type, u32 flags) { struct vmpacket_descriptor desc; u32 packetlen = sizeof(struct vmpacket_descriptor) + bufferlen; u32 packetlen_aligned = ALIGN(packetlen, sizeof(u64)); struct kvec bufferlist[3]; u64 aligned_data = 0; int num_vecs = ((bufferlen != 0) ? 3 : 1); /* Setup the descriptor */ desc.type = type; /* VmbusPacketTypeDataInBand; */ desc.flags = flags; /* VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; */ /* in 8-bytes granularity */ desc.offset8 = sizeof(struct vmpacket_descriptor) >> 3; desc.len8 = (u16)(packetlen_aligned >> 3); desc.trans_id = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */ bufferlist[0].iov_base = &desc; bufferlist[0].iov_len = sizeof(struct vmpacket_descriptor); bufferlist[1].iov_base = buffer; bufferlist[1].iov_len = bufferlen; bufferlist[2].iov_base = &aligned_data; bufferlist[2].iov_len = (packetlen_aligned - packetlen); return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid); } EXPORT_SYMBOL(vmbus_sendpacket); /* * vmbus_sendpacket_pagebuffer - Send a range of single-page buffer * packets using a GPADL Direct packet type. This interface allows you * to control notifying the host. This will be useful for sending * batched data. Also the sender can control the send flags * explicitly. */ int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, struct hv_page_buffer pagebuffers[], u32 pagecount, void *buffer, u32 bufferlen, u64 requestid) { int i; struct vmbus_channel_packet_page_buffer desc; u32 descsize; u32 packetlen; u32 packetlen_aligned; struct kvec bufferlist[3]; u64 aligned_data = 0; if (pagecount > MAX_PAGE_BUFFER_COUNT) return -EINVAL; /* * Adjust the size down since vmbus_channel_packet_page_buffer is the * largest size we support */ descsize = sizeof(struct vmbus_channel_packet_page_buffer) - ((MAX_PAGE_BUFFER_COUNT - pagecount) * sizeof(struct hv_page_buffer)); packetlen = descsize + bufferlen; packetlen_aligned = ALIGN(packetlen, sizeof(u64)); /* Setup the descriptor */ desc.type = VM_PKT_DATA_USING_GPA_DIRECT; desc.flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; desc.dataoffset8 = descsize >> 3; /* in 8-bytes granularity */ desc.length8 = (u16)(packetlen_aligned >> 3); desc.transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */ desc.reserved = 0; desc.rangecount = pagecount; for (i = 0; i < pagecount; i++) { desc.range[i].len = pagebuffers[i].len; desc.range[i].offset = pagebuffers[i].offset; desc.range[i].pfn = pagebuffers[i].pfn; } bufferlist[0].iov_base = &desc; bufferlist[0].iov_len = descsize; bufferlist[1].iov_base = buffer; bufferlist[1].iov_len = bufferlen; bufferlist[2].iov_base = &aligned_data; bufferlist[2].iov_len = (packetlen_aligned - packetlen); return hv_ringbuffer_write(channel, bufferlist, 3, requestid); } EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer); /* * vmbus_sendpacket_multipagebuffer - Send a multi-page buffer packet * using a GPADL Direct packet type. * The buffer includes the vmbus descriptor. */ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel, struct vmbus_packet_mpb_array *desc, u32 desc_size, void *buffer, u32 bufferlen, u64 requestid) { u32 packetlen; u32 packetlen_aligned; struct kvec bufferlist[3]; u64 aligned_data = 0; packetlen = desc_size + bufferlen; packetlen_aligned = ALIGN(packetlen, sizeof(u64)); /* Setup the descriptor */ desc->type = VM_PKT_DATA_USING_GPA_DIRECT; desc->flags = VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED; desc->dataoffset8 = desc_size >> 3; /* in 8-bytes granularity */ desc->length8 = (u16)(packetlen_aligned >> 3); desc->transactionid = VMBUS_RQST_ERROR; /* will be updated in hv_ringbuffer_write() */ desc->reserved = 0; desc->rangecount = 1; bufferlist[0].iov_base = desc; bufferlist[0].iov_len = desc_size; bufferlist[1].iov_base = buffer; bufferlist[1].iov_len = bufferlen; bufferlist[2].iov_base = &aligned_data; bufferlist[2].iov_len = (packetlen_aligned - packetlen); return hv_ringbuffer_write(channel, bufferlist, 3, requestid); } EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc); /** * __vmbus_recvpacket() - Retrieve the user packet on the specified channel * @channel: Pointer to vmbus_channel structure * @buffer: Pointer to the buffer you want to receive the data into. * @bufferlen: Maximum size of what the buffer can hold. * @buffer_actual_len: The actual size of the data after it was received. * @requestid: Identifier of the request * @raw: true means keep the vmpacket_descriptor header in the received data. * * Receives directly from the hyper-v vmbus and puts the data it received * into Buffer. This will receive the data unparsed from hyper-v. * * Mainly used by Hyper-V drivers. */ static inline int __vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, u32 bufferlen, u32 *buffer_actual_len, u64 *requestid, bool raw) { return hv_ringbuffer_read(channel, buffer, bufferlen, buffer_actual_len, requestid, raw); } int vmbus_recvpacket(struct vmbus_channel *channel, void *buffer, u32 bufferlen, u32 *buffer_actual_len, u64 *requestid) { return __vmbus_recvpacket(channel, buffer, bufferlen, buffer_actual_len, requestid, false); } EXPORT_SYMBOL(vmbus_recvpacket); /* * vmbus_recvpacket_raw - Retrieve the raw packet on the specified channel */ int vmbus_recvpacket_raw(struct vmbus_channel *channel, void *buffer, u32 bufferlen, u32 *buffer_actual_len, u64 *requestid) { return __vmbus_recvpacket(channel, buffer, bufferlen, buffer_actual_len, requestid, true); } EXPORT_SYMBOL_GPL(vmbus_recvpacket_raw); /* * vmbus_next_request_id - Returns a new request id. It is also * the index at which the guest memory address is stored. * Uses a spin lock to avoid race conditions. * @rqstor: Pointer to the requestor struct * @rqst_add: Guest memory address to be stored in the array */ u64 vmbus_next_request_id(struct vmbus_requestor *rqstor, u64 rqst_addr) { unsigned long flags; u64 current_id; const struct vmbus_channel *channel = container_of(rqstor, const struct vmbus_channel, requestor); /* Check rqstor has been initialized */ if (!channel->rqstor_size) return VMBUS_NO_RQSTOR; spin_lock_irqsave(&rqstor->req_lock, flags); current_id = rqstor->next_request_id; /* Requestor array is full */ if (current_id >= rqstor->size) { spin_unlock_irqrestore(&rqstor->req_lock, flags); return VMBUS_RQST_ERROR; } rqstor->next_request_id = rqstor->req_arr[current_id]; rqstor->req_arr[current_id] = rqst_addr; /* The already held spin lock provides atomicity */ bitmap_set(rqstor->req_bitmap, current_id, 1); spin_unlock_irqrestore(&rqstor->req_lock, flags); /* * Cannot return an ID of 0, which is reserved for an unsolicited * message from Hyper-V. */ return current_id + 1; } EXPORT_SYMBOL_GPL(vmbus_next_request_id); /* * vmbus_request_addr - Returns the memory address stored at @trans_id * in @rqstor. Uses a spin lock to avoid race conditions. * @rqstor: Pointer to the requestor struct * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's * next request id. */ u64 vmbus_request_addr(struct vmbus_requestor *rqstor, u64 trans_id) { unsigned long flags; u64 req_addr; const struct vmbus_channel *channel = container_of(rqstor, const struct vmbus_channel, requestor); /* Check rqstor has been initialized */ if (!channel->rqstor_size) return VMBUS_NO_RQSTOR; /* Hyper-V can send an unsolicited message with ID of 0 */ if (!trans_id) return trans_id; spin_lock_irqsave(&rqstor->req_lock, flags); /* Data corresponding to trans_id is stored at trans_id - 1 */ trans_id--; /* Invalid trans_id */ if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap)) { spin_unlock_irqrestore(&rqstor->req_lock, flags); return VMBUS_RQST_ERROR; } req_addr = rqstor->req_arr[trans_id]; rqstor->req_arr[trans_id] = rqstor->next_request_id; rqstor->next_request_id = trans_id; /* The already held spin lock provides atomicity */ bitmap_clear(rqstor->req_bitmap, trans_id, 1); spin_unlock_irqrestore(&rqstor->req_lock, flags); return req_addr; } EXPORT_SYMBOL_GPL(vmbus_request_addr);