/* * 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 #include #include "hyperv_vmbus.h" static void init_vp_index(struct vmbus_channel *channel, u16 dev_type); static const struct vmbus_device vmbus_devs[] = { /* IDE */ { .dev_type = HV_IDE, HV_IDE_GUID, .perf_device = true, }, /* SCSI */ { .dev_type = HV_SCSI, HV_SCSI_GUID, .perf_device = true, }, /* Fibre Channel */ { .dev_type = HV_FC, HV_SYNTHFC_GUID, .perf_device = true, }, /* Synthetic NIC */ { .dev_type = HV_NIC, HV_NIC_GUID, .perf_device = true, }, /* Network Direct */ { .dev_type = HV_ND, HV_ND_GUID, .perf_device = true, }, /* PCIE */ { .dev_type = HV_PCIE, HV_PCIE_GUID, .perf_device = false, }, /* Synthetic Frame Buffer */ { .dev_type = HV_FB, HV_SYNTHVID_GUID, .perf_device = false, }, /* Synthetic Keyboard */ { .dev_type = HV_KBD, HV_KBD_GUID, .perf_device = false, }, /* Synthetic MOUSE */ { .dev_type = HV_MOUSE, HV_MOUSE_GUID, .perf_device = false, }, /* KVP */ { .dev_type = HV_KVP, HV_KVP_GUID, .perf_device = false, }, /* Time Synch */ { .dev_type = HV_TS, HV_TS_GUID, .perf_device = false, }, /* Heartbeat */ { .dev_type = HV_HB, HV_HEART_BEAT_GUID, .perf_device = false, }, /* Shutdown */ { .dev_type = HV_SHUTDOWN, HV_SHUTDOWN_GUID, .perf_device = false, }, /* File copy */ { .dev_type = HV_FCOPY, HV_FCOPY_GUID, .perf_device = false, }, /* Backup */ { .dev_type = HV_BACKUP, HV_VSS_GUID, .perf_device = false, }, /* Dynamic Memory */ { .dev_type = HV_DM, HV_DM_GUID, .perf_device = false, }, /* Unknown GUID */ { .dev_type = HV_UNKNOWN, .perf_device = false, }, }; static const struct { uuid_le guid; } vmbus_unsupported_devs[] = { { HV_AVMA1_GUID }, { HV_AVMA2_GUID }, { HV_RDV_GUID }, }; /* * The rescinded channel may be blocked waiting for a response from the host; * take care of that. */ static void vmbus_rescind_cleanup(struct vmbus_channel *channel) { struct vmbus_channel_msginfo *msginfo; unsigned long flags; spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); channel->rescind = true; list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, msglistentry) { if (msginfo->waiting_channel == channel) { complete(&msginfo->waitevent); break; } } spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); } static bool is_unsupported_vmbus_devs(const uuid_le *guid) { int i; for (i = 0; i < ARRAY_SIZE(vmbus_unsupported_devs); i++) if (!uuid_le_cmp(*guid, vmbus_unsupported_devs[i].guid)) return true; return false; } static u16 hv_get_dev_type(const struct vmbus_channel *channel) { const uuid_le *guid = &channel->offermsg.offer.if_type; u16 i; if (is_hvsock_channel(channel) || is_unsupported_vmbus_devs(guid)) return HV_UNKNOWN; for (i = HV_IDE; i < HV_UNKNOWN; i++) { if (!uuid_le_cmp(*guid, vmbus_devs[i].guid)) return i; } pr_info("Unknown GUID: %pUl\n", guid); return i; } /** * vmbus_prep_negotiate_resp() - Create default response for Hyper-V Negotiate message * @icmsghdrp: Pointer to msg header structure * @icmsg_negotiate: Pointer to negotiate message structure * @buf: Raw buffer channel data * * @icmsghdrp is of type &struct icmsg_hdr. * Set up and fill in default negotiate response message. * * The fw_version and fw_vercnt specifies the framework version that * we can support. * * The srv_version and srv_vercnt specifies the service * versions we can support. * * Versions are given in decreasing order. * * nego_fw_version and nego_srv_version store the selected protocol versions. * * Mainly used by Hyper-V drivers. */ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf, const int *fw_version, int fw_vercnt, const int *srv_version, int srv_vercnt, int *nego_fw_version, int *nego_srv_version) { int icframe_major, icframe_minor; int icmsg_major, icmsg_minor; int fw_major, fw_minor; int srv_major, srv_minor; int i, j; bool found_match = false; struct icmsg_negotiate *negop; icmsghdrp->icmsgsize = 0x10; negop = (struct icmsg_negotiate *)&buf[ sizeof(struct vmbuspipe_hdr) + sizeof(struct icmsg_hdr)]; icframe_major = negop->icframe_vercnt; icframe_minor = 0; icmsg_major = negop->icmsg_vercnt; icmsg_minor = 0; /* * Select the framework version number we will * support. */ for (i = 0; i < fw_vercnt; i++) { fw_major = (fw_version[i] >> 16); fw_minor = (fw_version[i] & 0xFFFF); for (j = 0; j < negop->icframe_vercnt; j++) { if ((negop->icversion_data[j].major == fw_major) && (negop->icversion_data[j].minor == fw_minor)) { icframe_major = negop->icversion_data[j].major; icframe_minor = negop->icversion_data[j].minor; found_match = true; break; } } if (found_match) break; } if (!found_match) goto fw_error; found_match = false; for (i = 0; i < srv_vercnt; i++) { srv_major = (srv_version[i] >> 16); srv_minor = (srv_version[i] & 0xFFFF); for (j = negop->icframe_vercnt; (j < negop->icframe_vercnt + negop->icmsg_vercnt); j++) { if ((negop->icversion_data[j].major == srv_major) && (negop->icversion_data[j].minor == srv_minor)) { icmsg_major = negop->icversion_data[j].major; icmsg_minor = negop->icversion_data[j].minor; found_match = true; break; } } if (found_match) break; } /* * Respond with the framework and service * version numbers we can support. */ fw_error: if (!found_match) { negop->icframe_vercnt = 0; negop->icmsg_vercnt = 0; } else { negop->icframe_vercnt = 1; negop->icmsg_vercnt = 1; } if (nego_fw_version) *nego_fw_version = (icframe_major << 16) | icframe_minor; if (nego_srv_version) *nego_srv_version = (icmsg_major << 16) | icmsg_minor; negop->icversion_data[0].major = icframe_major; negop->icversion_data[0].minor = icframe_minor; negop->icversion_data[1].major = icmsg_major; negop->icversion_data[1].minor = icmsg_minor; return found_match; } EXPORT_SYMBOL_GPL(vmbus_prep_negotiate_resp); /* * alloc_channel - Allocate and initialize a vmbus channel object */ static struct vmbus_channel *alloc_channel(void) { struct vmbus_channel *channel; channel = kzalloc(sizeof(*channel), GFP_ATOMIC); if (!channel) return NULL; spin_lock_init(&channel->lock); init_completion(&channel->rescind_event); INIT_LIST_HEAD(&channel->sc_list); INIT_LIST_HEAD(&channel->percpu_list); tasklet_init(&channel->callback_event, vmbus_on_event, (unsigned long)channel); return channel; } /* * free_channel - Release the resources used by the vmbus channel object */ static void free_channel(struct vmbus_channel *channel) { tasklet_kill(&channel->callback_event); vmbus_remove_channel_attr_group(channel); kobject_put(&channel->kobj); } static void percpu_channel_enq(void *arg) { struct vmbus_channel *channel = arg; struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context); list_add_tail_rcu(&channel->percpu_list, &hv_cpu->chan_list); } static void percpu_channel_deq(void *arg) { struct vmbus_channel *channel = arg; list_del_rcu(&channel->percpu_list); } static void vmbus_release_relid(u32 relid) { struct vmbus_channel_relid_released msg; int ret; memset(&msg, 0, sizeof(struct vmbus_channel_relid_released)); msg.child_relid = relid; msg.header.msgtype = CHANNELMSG_RELID_RELEASED; ret = vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released), true); trace_vmbus_release_relid(&msg, ret); } void hv_process_channel_removal(u32 relid) { unsigned long flags; struct vmbus_channel *primary_channel, *channel; BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex)); /* * Make sure channel is valid as we may have raced. */ channel = relid2channel(relid); if (!channel) return; BUG_ON(!channel->rescind); if (channel->target_cpu != get_cpu()) { put_cpu(); smp_call_function_single(channel->target_cpu, percpu_channel_deq, channel, true); } else { percpu_channel_deq(channel); put_cpu(); } if (channel->primary_channel == NULL) { list_del(&channel->listentry); primary_channel = channel; } else { primary_channel = channel->primary_channel; spin_lock_irqsave(&primary_channel->lock, flags); list_del(&channel->sc_list); primary_channel->num_sc--; spin_unlock_irqrestore(&primary_channel->lock, flags); } /* * We need to free the bit for init_vp_index() to work in the case * of sub-channel, when we reload drivers like hv_netvsc. */ if (channel->affinity_policy == HV_LOCALIZED) cpumask_clear_cpu(channel->target_cpu, &primary_channel->alloced_cpus_in_node); vmbus_release_relid(relid); free_channel(channel); } void vmbus_free_channels(void) { struct vmbus_channel *channel, *tmp; list_for_each_entry_safe(channel, tmp, &vmbus_connection.chn_list, listentry) { /* hv_process_channel_removal() needs this */ channel->rescind = true; vmbus_device_unregister(channel->device_obj); } } /* Note: the function can run concurrently for primary/sub channels. */ static void vmbus_add_channel_work(struct work_struct *work) { struct vmbus_channel *newchannel = container_of(work, struct vmbus_channel, add_channel_work); struct vmbus_channel *primary_channel = newchannel->primary_channel; unsigned long flags; u16 dev_type; int ret; dev_type = hv_get_dev_type(newchannel); init_vp_index(newchannel, dev_type); if (newchannel->target_cpu != get_cpu()) { put_cpu(); smp_call_function_single(newchannel->target_cpu, percpu_channel_enq, newchannel, true); } else { percpu_channel_enq(newchannel); put_cpu(); } /* * This state is used to indicate a successful open * so that when we do close the channel normally, we * can cleanup properly. */ newchannel->state = CHANNEL_OPEN_STATE; if (primary_channel != NULL) { /* newchannel is a sub-channel. */ struct hv_device *dev = primary_channel->device_obj; if (vmbus_add_channel_kobj(dev, newchannel)) goto err_deq_chan; if (primary_channel->sc_creation_callback != NULL) primary_channel->sc_creation_callback(newchannel); newchannel->probe_done = true; return; } /* * Start the process of binding the primary channel to the driver */ newchannel->device_obj = vmbus_device_create( &newchannel->offermsg.offer.if_type, &newchannel->offermsg.offer.if_instance, newchannel); if (!newchannel->device_obj) goto err_deq_chan; newchannel->device_obj->device_id = dev_type; /* * Add the new device to the bus. This will kick off device-driver * binding which eventually invokes the device driver's AddDevice() * method. */ ret = vmbus_device_register(newchannel->device_obj); if (ret != 0) { pr_err("unable to add child device object (relid %d)\n", newchannel->offermsg.child_relid); kfree(newchannel->device_obj); goto err_deq_chan; } newchannel->probe_done = true; return; err_deq_chan: mutex_lock(&vmbus_connection.channel_mutex); /* * We need to set the flag, otherwise * vmbus_onoffer_rescind() can be blocked. */ newchannel->probe_done = true; if (primary_channel == NULL) { list_del(&newchannel->listentry); } else { spin_lock_irqsave(&primary_channel->lock, flags); list_del(&newchannel->sc_list); spin_unlock_irqrestore(&primary_channel->lock, flags); } mutex_unlock(&vmbus_connection.channel_mutex); if (newchannel->target_cpu != get_cpu()) { put_cpu(); smp_call_function_single(newchannel->target_cpu, percpu_channel_deq, newchannel, true); } else { percpu_channel_deq(newchannel); put_cpu(); } vmbus_release_relid(newchannel->offermsg.child_relid); free_channel(newchannel); } /* * vmbus_process_offer - Process the offer by creating a channel/device * associated with this offer */ static void vmbus_process_offer(struct vmbus_channel *newchannel) { struct vmbus_channel *channel; struct workqueue_struct *wq; unsigned long flags; bool fnew = true; mutex_lock(&vmbus_connection.channel_mutex); /* * Now that we have acquired the channel_mutex, * we can release the potentially racing rescind thread. */ atomic_dec(&vmbus_connection.offer_in_progress); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { if (!uuid_le_cmp(channel->offermsg.offer.if_type, newchannel->offermsg.offer.if_type) && !uuid_le_cmp(channel->offermsg.offer.if_instance, newchannel->offermsg.offer.if_instance)) { fnew = false; break; } } if (fnew) list_add_tail(&newchannel->listentry, &vmbus_connection.chn_list); else { /* * Check to see if this is a valid sub-channel. */ if (newchannel->offermsg.offer.sub_channel_index == 0) { mutex_unlock(&vmbus_connection.channel_mutex); /* * Don't call free_channel(), because newchannel->kobj * is not initialized yet. */ kfree(newchannel); WARN_ON_ONCE(1); return; } /* * Process the sub-channel. */ newchannel->primary_channel = channel; spin_lock_irqsave(&channel->lock, flags); list_add_tail(&newchannel->sc_list, &channel->sc_list); spin_unlock_irqrestore(&channel->lock, flags); } mutex_unlock(&vmbus_connection.channel_mutex); /* * vmbus_process_offer() mustn't call channel->sc_creation_callback() * directly for sub-channels, because sc_creation_callback() -> * vmbus_open() may never get the host's response to the * OPEN_CHANNEL message (the host may rescind a channel at any time, * e.g. in the case of hot removing a NIC), and vmbus_onoffer_rescind() * may not wake up the vmbus_open() as it's blocked due to a non-zero * vmbus_connection.offer_in_progress, and finally we have a deadlock. * * The above is also true for primary channels, if the related device * drivers use sync probing mode by default. * * And, usually the handling of primary channels and sub-channels can * depend on each other, so we should offload them to different * workqueues to avoid possible deadlock, e.g. in sync-probing mode, * NIC1's netvsc_subchan_work() can race with NIC2's netvsc_probe() -> * rtnl_lock(), and causes deadlock: the former gets the rtnl_lock * and waits for all the sub-channels to appear, but the latter * can't get the rtnl_lock and this blocks the handling of * sub-channels. */ INIT_WORK(&newchannel->add_channel_work, vmbus_add_channel_work); wq = fnew ? vmbus_connection.handle_primary_chan_wq : vmbus_connection.handle_sub_chan_wq; queue_work(wq, &newchannel->add_channel_work); } /* * We use this state to statically distribute the channel interrupt load. */ static int next_numa_node_id; /* * init_vp_index() accesses global variables like next_numa_node_id, and * it can run concurrently for primary channels and sub-channels: see * vmbus_process_offer(), so we need the lock to protect the global * variables. */ static DEFINE_SPINLOCK(bind_channel_to_cpu_lock); /* * Starting with Win8, we can statically distribute the incoming * channel interrupt load by binding a channel to VCPU. * We distribute the interrupt loads to one or more NUMA nodes based on * the channel's affinity_policy. * * For pre-win8 hosts or non-performance critical channels we assign the * first CPU in the first NUMA node. */ static void init_vp_index(struct vmbus_channel *channel, u16 dev_type) { u32 cur_cpu; bool perf_chn = vmbus_devs[dev_type].perf_device; struct vmbus_channel *primary = channel->primary_channel; int next_node; cpumask_var_t available_mask; struct cpumask *alloced_mask; if ((vmbus_proto_version == VERSION_WS2008) || (vmbus_proto_version == VERSION_WIN7) || (!perf_chn) || !alloc_cpumask_var(&available_mask, GFP_KERNEL)) { /* * Prior to win8, all channel interrupts are * delivered on cpu 0. * Also if the channel is not a performance critical * channel, bind it to cpu 0. * In case alloc_cpumask_var() fails, bind it to cpu 0. */ channel->numa_node = 0; channel->target_cpu = 0; channel->target_vp = hv_cpu_number_to_vp_number(0); return; } spin_lock(&bind_channel_to_cpu_lock); /* * Based on the channel affinity policy, we will assign the NUMA * nodes. */ if ((channel->affinity_policy == HV_BALANCED) || (!primary)) { while (true) { next_node = next_numa_node_id++; if (next_node == nr_node_ids) { next_node = next_numa_node_id = 0; continue; } if (cpumask_empty(cpumask_of_node(next_node))) continue; break; } channel->numa_node = next_node; primary = channel; } alloced_mask = &hv_context.hv_numa_map[primary->numa_node]; if (cpumask_weight(alloced_mask) == cpumask_weight(cpumask_of_node(primary->numa_node))) { /* * We have cycled through all the CPUs in the node; * reset the alloced map. */ cpumask_clear(alloced_mask); } cpumask_xor(available_mask, alloced_mask, cpumask_of_node(primary->numa_node)); cur_cpu = -1; if (primary->affinity_policy == HV_LOCALIZED) { /* * Normally Hyper-V host doesn't create more subchannels * than there are VCPUs on the node but it is possible when not * all present VCPUs on the node are initialized by guest. * Clear the alloced_cpus_in_node to start over. */ if (cpumask_equal(&primary->alloced_cpus_in_node, cpumask_of_node(primary->numa_node))) cpumask_clear(&primary->alloced_cpus_in_node); } while (true) { cur_cpu = cpumask_next(cur_cpu, available_mask); if (cur_cpu >= nr_cpu_ids) { cur_cpu = -1; cpumask_copy(available_mask, cpumask_of_node(primary->numa_node)); continue; } if (primary->affinity_policy == HV_LOCALIZED) { /* * NOTE: in the case of sub-channel, we clear the * sub-channel related bit(s) in * primary->alloced_cpus_in_node in * hv_process_channel_removal(), so when we * reload drivers like hv_netvsc in SMP guest, here * we're able to re-allocate * bit from primary->alloced_cpus_in_node. */ if (!cpumask_test_cpu(cur_cpu, &primary->alloced_cpus_in_node)) { cpumask_set_cpu(cur_cpu, &primary->alloced_cpus_in_node); cpumask_set_cpu(cur_cpu, alloced_mask); break; } } else { cpumask_set_cpu(cur_cpu, alloced_mask); break; } } channel->target_cpu = cur_cpu; channel->target_vp = hv_cpu_number_to_vp_number(cur_cpu); spin_unlock(&bind_channel_to_cpu_lock); free_cpumask_var(available_mask); } #define UNLOAD_DELAY_UNIT_MS 10 /* 10 milliseconds */ #define UNLOAD_WAIT_MS (100*1000) /* 100 seconds */ #define UNLOAD_WAIT_LOOPS (UNLOAD_WAIT_MS/UNLOAD_DELAY_UNIT_MS) #define UNLOAD_MSG_MS (5*1000) /* Every 5 seconds */ #define UNLOAD_MSG_LOOPS (UNLOAD_MSG_MS/UNLOAD_DELAY_UNIT_MS) static void vmbus_wait_for_unload(void) { int cpu; void *page_addr; struct hv_message *msg; struct vmbus_channel_message_header *hdr; u32 message_type, i; /* * CHANNELMSG_UNLOAD_RESPONSE is always delivered to the CPU which was * used for initial contact or to CPU0 depending on host version. When * we're crashing on a different CPU let's hope that IRQ handler on * the cpu which receives CHANNELMSG_UNLOAD_RESPONSE is still * functional and vmbus_unload_response() will complete * vmbus_connection.unload_event. If not, the last thing we can do is * read message pages for all CPUs directly. * * Wait up to 100 seconds since an Azure host must writeback any dirty * data in its disk cache before the VMbus UNLOAD request will * complete. This flushing has been empirically observed to take up * to 50 seconds in cases with a lot of dirty data, so allow additional * leeway and for inaccuracies in mdelay(). But eventually time out so * that the panic path can't get hung forever in case the response * message isn't seen. */ for (i = 1; i <= UNLOAD_WAIT_LOOPS; i++) { if (completion_done(&vmbus_connection.unload_event)) goto completed; for_each_online_cpu(cpu) { struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); page_addr = hv_cpu->synic_message_page; msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; message_type = READ_ONCE(msg->header.message_type); if (message_type == HVMSG_NONE) continue; hdr = (struct vmbus_channel_message_header *) msg->u.payload; if (hdr->msgtype == CHANNELMSG_UNLOAD_RESPONSE) complete(&vmbus_connection.unload_event); vmbus_signal_eom(msg, message_type); } /* * Give a notice periodically so someone watching the * serial output won't think it is completely hung. */ if (!(i % UNLOAD_MSG_LOOPS)) pr_notice("Waiting for VMBus UNLOAD to complete\n"); mdelay(UNLOAD_DELAY_UNIT_MS); } pr_err("Continuing even though VMBus UNLOAD did not complete\n"); completed: /* * We're crashing and already got the UNLOAD_RESPONSE, cleanup all * maybe-pending messages on all CPUs to be able to receive new * messages after we reconnect. */ for_each_online_cpu(cpu) { struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); page_addr = hv_cpu->synic_message_page; msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; msg->header.message_type = HVMSG_NONE; } } /* * vmbus_unload_response - Handler for the unload response. */ static void vmbus_unload_response(struct vmbus_channel_message_header *hdr) { /* * This is a global event; just wakeup the waiting thread. * Once we successfully unload, we can cleanup the monitor state. */ complete(&vmbus_connection.unload_event); } void vmbus_initiate_unload(bool crash) { struct vmbus_channel_message_header hdr; if (xchg(&vmbus_connection.conn_state, DISCONNECTED) == DISCONNECTED) return; /* Pre-Win2012R2 hosts don't support reconnect */ if (vmbus_proto_version < VERSION_WIN8_1) return; init_completion(&vmbus_connection.unload_event); memset(&hdr, 0, sizeof(struct vmbus_channel_message_header)); hdr.msgtype = CHANNELMSG_UNLOAD; vmbus_post_msg(&hdr, sizeof(struct vmbus_channel_message_header), !crash); /* * vmbus_initiate_unload() is also called on crash and the crash can be * happening in an interrupt context, where scheduling is impossible. */ if (!crash) wait_for_completion(&vmbus_connection.unload_event); else vmbus_wait_for_unload(); } /* * vmbus_onoffer - Handler for channel offers from vmbus in parent partition. * */ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr) { struct vmbus_channel_offer_channel *offer; struct vmbus_channel *newchannel; offer = (struct vmbus_channel_offer_channel *)hdr; trace_vmbus_onoffer(offer); /* Allocate the channel object and save this offer. */ newchannel = alloc_channel(); if (!newchannel) { vmbus_release_relid(offer->child_relid); atomic_dec(&vmbus_connection.offer_in_progress); pr_err("Unable to allocate channel object\n"); return; } /* * Setup state for signalling the host. */ newchannel->sig_event = VMBUS_EVENT_CONNECTION_ID; if (vmbus_proto_version != VERSION_WS2008) { newchannel->is_dedicated_interrupt = (offer->is_dedicated_interrupt != 0); newchannel->sig_event = offer->connection_id; } memcpy(&newchannel->offermsg, offer, sizeof(struct vmbus_channel_offer_channel)); newchannel->monitor_grp = (u8)offer->monitorid / 32; newchannel->monitor_bit = (u8)offer->monitorid % 32; vmbus_process_offer(newchannel); } /* * vmbus_onoffer_rescind - Rescind offer handler. * * We queue a work item to process this offer synchronously */ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) { struct vmbus_channel_rescind_offer *rescind; struct vmbus_channel *channel; struct device *dev; rescind = (struct vmbus_channel_rescind_offer *)hdr; trace_vmbus_onoffer_rescind(rescind); /* * The offer msg and the corresponding rescind msg * from the host are guranteed to be ordered - * offer comes in first and then the rescind. * Since we process these events in work elements, * and with preemption, we may end up processing * the events out of order. Given that we handle these * work elements on the same CPU, this is possible only * in the case of preemption. In any case wait here * until the offer processing has moved beyond the * point where the channel is discoverable. */ while (atomic_read(&vmbus_connection.offer_in_progress) != 0) { /* * We wait here until any channel offer is currently * being processed. */ msleep(1); } mutex_lock(&vmbus_connection.channel_mutex); channel = relid2channel(rescind->child_relid); mutex_unlock(&vmbus_connection.channel_mutex); if (channel == NULL) { /* * We failed in processing the offer message; * we would have cleaned up the relid in that * failure path. */ return; } /* * Before setting channel->rescind in vmbus_rescind_cleanup(), we * should make sure the channel callback is not running any more. */ vmbus_reset_channel_cb(channel); /* * Now wait for offer handling to complete. */ vmbus_rescind_cleanup(channel); while (READ_ONCE(channel->probe_done) == false) { /* * We wait here until any channel offer is currently * being processed. */ msleep(1); } /* * At this point, the rescind handling can proceed safely. */ if (channel->device_obj) { if (channel->chn_rescind_callback) { channel->chn_rescind_callback(channel); return; } /* * We will have to unregister this device from the * driver core. */ dev = get_device(&channel->device_obj->device); if (dev) { vmbus_device_unregister(channel->device_obj); put_device(dev); } } else if (channel->primary_channel != NULL) { /* * Sub-channel is being rescinded. Following is the channel * close sequence when initiated from the driveri (refer to * vmbus_close() for details): * 1. Close all sub-channels first * 2. Then close the primary channel. */ mutex_lock(&vmbus_connection.channel_mutex); if (channel->state == CHANNEL_OPEN_STATE) { /* * The channel is currently not open; * it is safe for us to cleanup the channel. */ hv_process_channel_removal(rescind->child_relid); } else { complete(&channel->rescind_event); } mutex_unlock(&vmbus_connection.channel_mutex); } } void vmbus_hvsock_device_unregister(struct vmbus_channel *channel) { BUG_ON(!is_hvsock_channel(channel)); /* We always get a rescind msg when a connection is closed. */ while (!READ_ONCE(channel->probe_done) || !READ_ONCE(channel->rescind)) msleep(1); vmbus_device_unregister(channel->device_obj); } EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister); /* * vmbus_onoffers_delivered - * This is invoked when all offers have been delivered. * * Nothing to do here. */ static void vmbus_onoffers_delivered( struct vmbus_channel_message_header *hdr) { } /* * vmbus_onopen_result - Open result handler. * * This is invoked when we received a response to our channel open request. * Find the matching request, copy the response and signal the requesting * thread. */ static void vmbus_onopen_result(struct vmbus_channel_message_header *hdr) { struct vmbus_channel_open_result *result; struct vmbus_channel_msginfo *msginfo; struct vmbus_channel_message_header *requestheader; struct vmbus_channel_open_channel *openmsg; unsigned long flags; result = (struct vmbus_channel_open_result *)hdr; trace_vmbus_onopen_result(result); /* * Find the open msg, copy the result and signal/unblock the wait event */ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, msglistentry) { requestheader = (struct vmbus_channel_message_header *)msginfo->msg; if (requestheader->msgtype == CHANNELMSG_OPENCHANNEL) { openmsg = (struct vmbus_channel_open_channel *)msginfo->msg; if (openmsg->child_relid == result->child_relid && openmsg->openid == result->openid) { memcpy(&msginfo->response.open_result, result, sizeof( struct vmbus_channel_open_result)); complete(&msginfo->waitevent); break; } } } spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); } /* * vmbus_ongpadl_created - GPADL created handler. * * This is invoked when we received a response to our gpadl create request. * Find the matching request, copy the response and signal the requesting * thread. */ static void vmbus_ongpadl_created(struct vmbus_channel_message_header *hdr) { struct vmbus_channel_gpadl_created *gpadlcreated; struct vmbus_channel_msginfo *msginfo; struct vmbus_channel_message_header *requestheader; struct vmbus_channel_gpadl_header *gpadlheader; unsigned long flags; gpadlcreated = (struct vmbus_channel_gpadl_created *)hdr; trace_vmbus_ongpadl_created(gpadlcreated); /* * Find the establish msg, copy the result and signal/unblock the wait * event */ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, msglistentry) { requestheader = (struct vmbus_channel_message_header *)msginfo->msg; if (requestheader->msgtype == CHANNELMSG_GPADL_HEADER) { gpadlheader = (struct vmbus_channel_gpadl_header *)requestheader; if ((gpadlcreated->child_relid == gpadlheader->child_relid) && (gpadlcreated->gpadl == gpadlheader->gpadl)) { memcpy(&msginfo->response.gpadl_created, gpadlcreated, sizeof( struct vmbus_channel_gpadl_created)); complete(&msginfo->waitevent); break; } } } spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); } /* * vmbus_ongpadl_torndown - GPADL torndown handler. * * This is invoked when we received a response to our gpadl teardown request. * Find the matching request, copy the response and signal the requesting * thread. */ static void vmbus_ongpadl_torndown( struct vmbus_channel_message_header *hdr) { struct vmbus_channel_gpadl_torndown *gpadl_torndown; struct vmbus_channel_msginfo *msginfo; struct vmbus_channel_message_header *requestheader; struct vmbus_channel_gpadl_teardown *gpadl_teardown; unsigned long flags; gpadl_torndown = (struct vmbus_channel_gpadl_torndown *)hdr; trace_vmbus_ongpadl_torndown(gpadl_torndown); /* * Find the open msg, copy the result and signal/unblock the wait event */ spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, msglistentry) { requestheader = (struct vmbus_channel_message_header *)msginfo->msg; if (requestheader->msgtype == CHANNELMSG_GPADL_TEARDOWN) { gpadl_teardown = (struct vmbus_channel_gpadl_teardown *)requestheader; if (gpadl_torndown->gpadl == gpadl_teardown->gpadl) { memcpy(&msginfo->response.gpadl_torndown, gpadl_torndown, sizeof( struct vmbus_channel_gpadl_torndown)); complete(&msginfo->waitevent); break; } } } spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); } /* * vmbus_onversion_response - Version response handler * * This is invoked when we received a response to our initiate contact request. * Find the matching request, copy the response and signal the requesting * thread. */ static void vmbus_onversion_response( struct vmbus_channel_message_header *hdr) { struct vmbus_channel_msginfo *msginfo; struct vmbus_channel_message_header *requestheader; struct vmbus_channel_version_response *version_response; unsigned long flags; version_response = (struct vmbus_channel_version_response *)hdr; trace_vmbus_onversion_response(version_response); spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags); list_for_each_entry(msginfo, &vmbus_connection.chn_msg_list, msglistentry) { requestheader = (struct vmbus_channel_message_header *)msginfo->msg; if (requestheader->msgtype == CHANNELMSG_INITIATE_CONTACT) { memcpy(&msginfo->response.version_response, version_response, sizeof(struct vmbus_channel_version_response)); complete(&msginfo->waitevent); } } spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags); } /* Channel message dispatch table */ const struct vmbus_channel_message_table_entry channel_message_table[CHANNELMSG_COUNT] = { { CHANNELMSG_INVALID, 0, NULL }, { CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer }, { CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind }, { CHANNELMSG_REQUESTOFFERS, 0, NULL }, { CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered }, { CHANNELMSG_OPENCHANNEL, 0, NULL }, { CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result }, { CHANNELMSG_CLOSECHANNEL, 0, NULL }, { CHANNELMSG_GPADL_HEADER, 0, NULL }, { CHANNELMSG_GPADL_BODY, 0, NULL }, { CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created }, { CHANNELMSG_GPADL_TEARDOWN, 0, NULL }, { CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown }, { CHANNELMSG_RELID_RELEASED, 0, NULL }, { CHANNELMSG_INITIATE_CONTACT, 0, NULL }, { CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response }, { CHANNELMSG_UNLOAD, 0, NULL }, { CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response }, { CHANNELMSG_18, 0, NULL }, { CHANNELMSG_19, 0, NULL }, { CHANNELMSG_20, 0, NULL }, { CHANNELMSG_TL_CONNECT_REQUEST, 0, NULL }, { CHANNELMSG_22, 0, NULL }, { CHANNELMSG_TL_CONNECT_RESULT, 0, NULL }, }; /* * vmbus_onmessage - Handler for channel protocol messages. * * This is invoked in the vmbus worker thread context. */ void vmbus_onmessage(void *context) { struct hv_message *msg = context; struct vmbus_channel_message_header *hdr; hdr = (struct vmbus_channel_message_header *)msg->u.payload; trace_vmbus_on_message(hdr); /* * vmbus_on_msg_dpc() makes sure the hdr->msgtype here can not go * out of bound and the message_handler pointer can not be NULL. */ channel_message_table[hdr->msgtype].message_handler(hdr); } /* * vmbus_request_offers - Send a request to get all our pending offers. */ int vmbus_request_offers(void) { struct vmbus_channel_message_header *msg; struct vmbus_channel_msginfo *msginfo; int ret; msginfo = kmalloc(sizeof(*msginfo) + sizeof(struct vmbus_channel_message_header), GFP_KERNEL); if (!msginfo) return -ENOMEM; msg = (struct vmbus_channel_message_header *)msginfo->msg; msg->msgtype = CHANNELMSG_REQUESTOFFERS; ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_message_header), true); trace_vmbus_request_offers(ret); if (ret != 0) { pr_err("Unable to request offers - %d\n", ret); goto cleanup; } cleanup: kfree(msginfo); return ret; } /* * Retrieve the (sub) channel on which to send an outgoing request. * When a primary channel has multiple sub-channels, we try to * distribute the load equally amongst all available channels. */ struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary) { struct list_head *cur, *tmp; int cur_cpu; struct vmbus_channel *cur_channel; struct vmbus_channel *outgoing_channel = primary; int next_channel; int i = 1; if (list_empty(&primary->sc_list)) return outgoing_channel; next_channel = primary->next_oc++; if (next_channel > (primary->num_sc)) { primary->next_oc = 0; return outgoing_channel; } cur_cpu = hv_cpu_number_to_vp_number(smp_processor_id()); list_for_each_safe(cur, tmp, &primary->sc_list) { cur_channel = list_entry(cur, struct vmbus_channel, sc_list); if (cur_channel->state != CHANNEL_OPENED_STATE) continue; if (cur_channel->target_vp == cur_cpu) return cur_channel; if (i == next_channel) return cur_channel; i++; } return outgoing_channel; } EXPORT_SYMBOL_GPL(vmbus_get_outgoing_channel); static void invoke_sc_cb(struct vmbus_channel *primary_channel) { struct list_head *cur, *tmp; struct vmbus_channel *cur_channel; if (primary_channel->sc_creation_callback == NULL) return; list_for_each_safe(cur, tmp, &primary_channel->sc_list) { cur_channel = list_entry(cur, struct vmbus_channel, sc_list); primary_channel->sc_creation_callback(cur_channel); } } void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, void (*sc_cr_cb)(struct vmbus_channel *new_sc)) { primary_channel->sc_creation_callback = sc_cr_cb; } EXPORT_SYMBOL_GPL(vmbus_set_sc_create_callback); bool vmbus_are_subchannels_present(struct vmbus_channel *primary) { bool ret; ret = !list_empty(&primary->sc_list); if (ret) { /* * Invoke the callback on sub-channel creation. * This will present a uniform interface to the * clients. */ invoke_sc_cb(primary); } return ret; } EXPORT_SYMBOL_GPL(vmbus_are_subchannels_present); void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel, void (*chn_rescind_cb)(struct vmbus_channel *)) { channel->chn_rescind_callback = chn_rescind_cb; } EXPORT_SYMBOL_GPL(vmbus_set_chn_rescind_callback);