diff options
Diffstat (limited to 'drivers/hv/channel.c')
| -rw-r--r-- | drivers/hv/channel.c | 1044 |
1 files changed, 1044 insertions, 0 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c new file mode 100644 index 000000000..f064fa6ef --- /dev/null +++ b/drivers/hv/channel.c @@ -0,0 +1,1044 @@ +// 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); + +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; + + 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 = kmalloc(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_clean_msglist; + } + + 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); + 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 = kmalloc(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; + } + + 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 = requestid; + + 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); +} +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 = requestid; + 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); +} +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 = requestid; + 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); +} +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); |