/* * * Copyright (c) 2009, Microsoft Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 59 Temple * Place - Suite 330, Boston, MA 02111-1307 USA. * * Authors: * Haiyang Zhang * Hank Janssen * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include "hyperv_vmbus.h" struct vmbus_connection vmbus_connection = { .conn_state = DISCONNECTED, .next_gpadl_handle = ATOMIC_INIT(0xE1E10), }; /* * Negotiated protocol version with the host. */ __u32 vmbus_proto_version; EXPORT_SYMBOL_GPL(vmbus_proto_version); static __u32 vmbus_get_next_version(__u32 current_version) { switch (current_version) { case (VERSION_WIN7): return VERSION_WS2008; case (VERSION_WIN8): return VERSION_WIN7; case (VERSION_WIN8_1): return VERSION_WIN8; case (VERSION_WS2008): default: return VERSION_INVAL; } } static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, __u32 version) { int ret = 0; struct vmbus_channel_initiate_contact *msg; unsigned long flags; init_completion(&msginfo->waitevent); msg = (struct vmbus_channel_initiate_contact *)msginfo->msg; msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT; msg->vmbus_version_requested = version; msg->interrupt_page = virt_to_phys(vmbus_connection.int_page); msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]); msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]); if (version == VERSION_WIN8_1) { msg->target_vcpu = hv_context.vp_index[get_cpu()]; put_cpu(); } /* * Add to list before we send the request since we may * receive the response before returning from this routine */ 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); ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_initiate_contact)); if (ret != 0) { spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&msginfo->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); return ret; } /* Wait for the connection response */ wait_for_completion(&msginfo->waitevent); spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_del(&msginfo->msglistentry); spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); /* Check if successful */ if (msginfo->response.version_response.version_supported) { vmbus_connection.conn_state = CONNECTED; } else { return -ECONNREFUSED; } return ret; } /* * vmbus_connect - Sends a connect request on the partition service connection */ int vmbus_connect(void) { int ret = 0; struct vmbus_channel_msginfo *msginfo = NULL; __u32 version; /* Initialize the vmbus connection */ vmbus_connection.conn_state = CONNECTING; vmbus_connection.work_queue = create_workqueue("hv_vmbus_con"); if (!vmbus_connection.work_queue) { ret = -ENOMEM; goto cleanup; } INIT_LIST_HEAD(&vmbus_connection.chn_msg_list); spin_lock_init(&vmbus_connection.channelmsg_lock); INIT_LIST_HEAD(&vmbus_connection.chn_list); spin_lock_init(&vmbus_connection.channel_lock); /* * Setup the vmbus event connection for channel interrupt * abstraction stuff */ vmbus_connection.int_page = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0); if (vmbus_connection.int_page == NULL) { ret = -ENOMEM; goto cleanup; } vmbus_connection.recv_int_page = vmbus_connection.int_page; vmbus_connection.send_int_page = (void *)((unsigned long)vmbus_connection.int_page + (PAGE_SIZE >> 1)); /* * Setup the monitor notification facility. The 1st page for * parent->child and the 2nd page for child->parent */ vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0); if ((vmbus_connection.monitor_pages[0] == NULL) || (vmbus_connection.monitor_pages[1] == NULL)) { ret = -ENOMEM; goto cleanup; } msginfo = kzalloc(sizeof(*msginfo) + sizeof(struct vmbus_channel_initiate_contact), GFP_KERNEL); if (msginfo == NULL) { ret = -ENOMEM; goto cleanup; } /* * Negotiate a compatible VMBUS version number with the * host. We start with the highest number we can support * and work our way down until we negotiate a compatible * version. */ version = VERSION_CURRENT; do { ret = vmbus_negotiate_version(msginfo, version); if (ret == -ETIMEDOUT) goto cleanup; if (vmbus_connection.conn_state == CONNECTED) break; version = vmbus_get_next_version(version); } while (version != VERSION_INVAL); if (version == VERSION_INVAL) goto cleanup; vmbus_proto_version = version; pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d; Vmbus version:%d.%d\n", host_info_eax, host_info_ebx >> 16, host_info_ebx & 0xFFFF, host_info_ecx, host_info_edx >> 24, host_info_edx & 0xFFFFFF, version >> 16, version & 0xFFFF); kfree(msginfo); return 0; cleanup: pr_err("Unable to connect to host\n"); vmbus_connection.conn_state = DISCONNECTED; vmbus_disconnect(); kfree(msginfo); return ret; } void vmbus_disconnect(void) { if (vmbus_connection.work_queue) { drain_workqueue(vmbus_connection.work_queue); destroy_workqueue(vmbus_connection.work_queue); } if (vmbus_connection.int_page) { free_pages((unsigned long)vmbus_connection.int_page, 0); vmbus_connection.int_page = NULL; } free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0); free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0); vmbus_connection.monitor_pages[0] = NULL; vmbus_connection.monitor_pages[1] = NULL; } /* * Map the given relid to the corresponding channel based on the * per-cpu list of channels that have been affinitized to this CPU. * This will be used in the channel callback path as we can do this * mapping in a lock-free fashion. */ static struct vmbus_channel *pcpu_relid2channel(u32 relid) { struct vmbus_channel *channel; struct vmbus_channel *found_channel = NULL; int cpu = smp_processor_id(); struct list_head *pcpu_head = &hv_context.percpu_list[cpu]; list_for_each_entry(channel, pcpu_head, percpu_list) { if (channel->offermsg.child_relid == relid) { found_channel = channel; break; } } return found_channel; } /* * relid2channel - Get the channel object given its * child relative id (ie channel id) */ struct vmbus_channel *relid2channel(u32 relid, bool rescind) { struct vmbus_channel *channel; struct vmbus_channel *found_channel = NULL; unsigned long flags; struct list_head *cur, *tmp; struct vmbus_channel *cur_sc; spin_lock_irqsave(&vmbus_connection.channel_lock, flags); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { if (channel->offermsg.child_relid == relid) { found_channel = channel; if (rescind) found_channel->rescind = true; break; } else if (!list_empty(&channel->sc_list)) { /* * Deal with sub-channels. */ list_for_each_safe(cur, tmp, &channel->sc_list) { cur_sc = list_entry(cur, struct vmbus_channel, sc_list); if (cur_sc->offermsg.child_relid == relid) { found_channel = cur_sc; if (rescind) found_channel->rescind = true; break; } } } } spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags); return found_channel; } /* * process_chn_event - Process a channel event notification */ static void process_chn_event(u32 relid) { struct vmbus_channel *channel; void *arg; bool read_state; u32 bytes_to_read; /* * Find the channel based on this relid and invokes the * channel callback to process the event */ channel = pcpu_relid2channel(relid); if (!channel) return; /* * A channel once created is persistent even when there * is no driver handling the device. An unloading driver * sets the onchannel_callback to NULL on the same CPU * as where this interrupt is handled (in an interrupt context). * Thus, checking and invoking the driver specific callback takes * care of orderly unloading of the driver. */ if (channel->onchannel_callback != NULL) { arg = channel->channel_callback_context; read_state = channel->batched_reading; /* * This callback reads the messages sent by the host. * We can optimize host to guest signaling by ensuring: * 1. While reading the channel, we disable interrupts from * host. * 2. Ensure that we process all posted messages from the host * before returning from this callback. * 3. Once we return, enable signaling from the host. Once this * state is set we check to see if additional packets are * available to read. In this case we repeat the process. */ do { if (read_state) hv_begin_read(&channel->inbound); channel->onchannel_callback(arg); if (read_state) bytes_to_read = hv_end_read(&channel->inbound); else bytes_to_read = 0; } while (read_state && (bytes_to_read != 0)); } } /* * vmbus_on_event - Handler for events */ void vmbus_on_event(unsigned long data) { u32 dword; u32 maxdword; int bit; u32 relid; u32 *recv_int_page = NULL; void *page_addr; int cpu = smp_processor_id(); union hv_synic_event_flags *event; if ((vmbus_proto_version == VERSION_WS2008) || (vmbus_proto_version == VERSION_WIN7)) { maxdword = MAX_NUM_CHANNELS_SUPPORTED >> 5; recv_int_page = vmbus_connection.recv_int_page; } else { /* * When the host is win8 and beyond, the event page * can be directly checked to get the id of the channel * that has the interrupt pending. */ maxdword = HV_EVENT_FLAGS_DWORD_COUNT; page_addr = hv_context.synic_event_page[cpu]; event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT; recv_int_page = event->flags32; } /* Check events */ if (!recv_int_page) return; for (dword = 0; dword < maxdword; dword++) { if (!recv_int_page[dword]) continue; for (bit = 0; bit < 32; bit++) { if (sync_test_and_clear_bit(bit, (unsigned long *)&recv_int_page[dword])) { relid = (dword << 5) + bit; if (relid == 0) /* * Special case - vmbus * channel protocol msg */ continue; process_chn_event(relid); } } } } /* * vmbus_post_msg - Send a msg on the vmbus's message connection */ int vmbus_post_msg(void *buffer, size_t buflen) { union hv_connection_id conn_id; int ret = 0; int retries = 0; conn_id.asu32 = 0; conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID; /* * hv_post_message() can have transient failures because of * insufficient resources. Retry the operation a couple of * times before giving up. */ while (retries < 10) { ret = hv_post_message(conn_id, 1, buffer, buflen); switch (ret) { case HV_STATUS_INVALID_CONNECTION_ID: /* * We could get this if we send messages too * frequently. */ ret = -EAGAIN; break; case HV_STATUS_INSUFFICIENT_MEMORY: case HV_STATUS_INSUFFICIENT_BUFFERS: ret = -ENOMEM; break; case HV_STATUS_SUCCESS: return ret; default: pr_err("hv_post_msg() failed; error code:%d\n", ret); return -EINVAL; } retries++; msleep(1000); } return ret; } /* * vmbus_set_event - Send an event notification to the parent */ int vmbus_set_event(struct vmbus_channel *channel) { u32 child_relid = channel->offermsg.child_relid; if (!channel->is_dedicated_interrupt) { /* Each u32 represents 32 channels */ sync_set_bit(child_relid & 31, (unsigned long *)vmbus_connection.send_int_page + (child_relid >> 5)); } return hv_signal_event(channel->sig_event); }