| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| K. Y. Srinivasan | 1178 | 23.22% | 33 | 21.43% |
| Dexuan Cui | 1106 | 21.80% | 21 | 13.64% |
| Hank Janssen | 648 | 12.77% | 4 | 2.60% |
| Andrea Parri | 596 | 11.75% | 15 | 9.74% |
| Haiyang Zhang | 366 | 7.21% | 10 | 6.49% |
| Vitaly Kuznetsov | 351 | 6.92% | 25 | 16.23% |
| Greg Kroah-Hartman | 326 | 6.42% | 18 | 11.69% |
| Alex Ng | 152 | 3.00% | 1 | 0.65% |
| Stephen Hemminger | 94 | 1.85% | 5 | 3.25% |
| Michael Kelley | 70 | 1.38% | 4 | 2.60% |
| Andres Beltran | 64 | 1.26% | 1 | 0.65% |
| Saurabh Sengar | 47 | 0.93% | 2 | 1.30% |
| Bill Pemberton | 17 | 0.34% | 3 | 1.95% |
| Lan Tianyu | 15 | 0.30% | 1 | 0.65% |
| Andy Shevchenko | 13 | 0.26% | 1 | 0.65% |
| Kimberly Brown | 10 | 0.20% | 2 | 1.30% |
| Timo Teräs | 10 | 0.20% | 1 | 0.65% |
| Tejun Heo | 3 | 0.06% | 1 | 0.65% |
| Thomas Gleixner | 2 | 0.04% | 1 | 0.65% |
| Vasanth | 2 | 0.04% | 1 | 0.65% |
| Yang Yingliang | 1 | 0.02% | 1 | 0.65% |
| Julia Lawall | 1 | 0.02% | 1 | 0.65% |
| Nicholas Mc Guire | 1 | 0.02% | 1 | 0.65% |
| Juan Vazquez | 1 | 0.02% | 1 | 0.65% |
| Total | 5074 | 154 |
// 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/interrupt.h> #include <linux/sched.h> #include <linux/wait.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/list.h> #include <linux/module.h> #include <linux/completion.h> #include <linux/delay.h> #include <linux/cpu.h> #include <linux/hyperv.h> #include <asm/mshyperv.h> #include <linux/sched/isolation.h> #include "hyperv_vmbus.h" static void init_vp_index(struct vmbus_channel *channel); const struct vmbus_device vmbus_devs[] = { /* IDE */ { .dev_type = HV_IDE, HV_IDE_GUID, .perf_device = true, .allowed_in_isolated = false, }, /* SCSI */ { .dev_type = HV_SCSI, HV_SCSI_GUID, .perf_device = true, .allowed_in_isolated = true, }, /* Fibre Channel */ { .dev_type = HV_FC, HV_SYNTHFC_GUID, .perf_device = true, .allowed_in_isolated = false, }, /* Synthetic NIC */ { .dev_type = HV_NIC, HV_NIC_GUID, .perf_device = true, .allowed_in_isolated = true, }, /* Network Direct */ { .dev_type = HV_ND, HV_ND_GUID, .perf_device = true, .allowed_in_isolated = false, }, /* PCIE */ { .dev_type = HV_PCIE, HV_PCIE_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Synthetic Frame Buffer */ { .dev_type = HV_FB, HV_SYNTHVID_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Synthetic Keyboard */ { .dev_type = HV_KBD, HV_KBD_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Synthetic MOUSE */ { .dev_type = HV_MOUSE, HV_MOUSE_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* KVP */ { .dev_type = HV_KVP, HV_KVP_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Time Synch */ { .dev_type = HV_TS, HV_TS_GUID, .perf_device = false, .allowed_in_isolated = true, }, /* Heartbeat */ { .dev_type = HV_HB, HV_HEART_BEAT_GUID, .perf_device = false, .allowed_in_isolated = true, }, /* Shutdown */ { .dev_type = HV_SHUTDOWN, HV_SHUTDOWN_GUID, .perf_device = false, .allowed_in_isolated = true, }, /* File copy */ { .dev_type = HV_FCOPY, HV_FCOPY_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Backup */ { .dev_type = HV_BACKUP, HV_VSS_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Dynamic Memory */ { .dev_type = HV_DM, HV_DM_GUID, .perf_device = false, .allowed_in_isolated = false, }, /* Unknown GUID */ { .dev_type = HV_UNKNOWN, .perf_device = false, .allowed_in_isolated = false, }, }; static const struct { guid_t guid; } vmbus_unsupported_devs[] = { { HV_AVMA1_GUID }, { HV_AVMA2_GUID }, { HV_RDV_GUID }, { HV_IMC_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 guid_t *guid) { int i; for (i = 0; i < ARRAY_SIZE(vmbus_unsupported_devs); i++) if (guid_equal(guid, &vmbus_unsupported_devs[i].guid)) return true; return false; } static u16 hv_get_dev_type(const struct vmbus_channel *channel) { const guid_t *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 (guid_equal(guid, &vmbus_devs[i].guid)) return i; } pr_info("Unknown GUID: %pUl\n", guid); return i; } /** * vmbus_prep_negotiate_resp() - Create default response for Negotiate message * @icmsghdrp: Pointer to msg header structure * @buf: Raw buffer channel data * @buflen: Length of the raw buffer channel data. * @fw_version: The framework versions we can support. * @fw_vercnt: The size of @fw_version. * @srv_version: The service versions we can support. * @srv_vercnt: The size of @srv_version. * @nego_fw_version: The selected framework version. * @nego_srv_version: The selected service version. * * Note: Versions are given in decreasing order. * * Set up and fill in default negotiate response message. * Mainly used by Hyper-V drivers. */ bool vmbus_prep_negotiate_resp(struct icmsg_hdr *icmsghdrp, u8 *buf, u32 buflen, 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; /* Check that there's enough space for icframe_vercnt, icmsg_vercnt */ if (buflen < ICMSG_HDR + offsetof(struct icmsg_negotiate, reserved)) { pr_err_ratelimited("Invalid icmsg negotiate\n"); return false; } icmsghdrp->icmsgsize = 0x10; negop = (struct icmsg_negotiate *)&buf[ICMSG_HDR]; icframe_major = negop->icframe_vercnt; icframe_minor = 0; icmsg_major = negop->icmsg_vercnt; icmsg_minor = 0; /* Validate negop packet */ if (icframe_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT || icmsg_major > IC_VERSION_NEGOTIATION_MAX_VER_COUNT || ICMSG_NEGOTIATE_PKT_SIZE(icframe_major, icmsg_major) > buflen) { pr_err_ratelimited("Invalid icmsg negotiate - icframe_major: %u, icmsg_major: %u\n", icframe_major, icmsg_major); goto fw_error; } /* * 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->sched_lock); init_completion(&channel->rescind_event); INIT_LIST_HEAD(&channel->sc_list); tasklet_init(&channel->callback_event, vmbus_on_event, (unsigned long)channel); hv_ringbuffer_pre_init(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); } void vmbus_channel_map_relid(struct vmbus_channel *channel) { if (WARN_ON(channel->offermsg.child_relid >= MAX_CHANNEL_RELIDS)) return; /* * The mapping of the channel's relid is visible from the CPUs that * execute vmbus_chan_sched() by the time that vmbus_chan_sched() will * execute: * * (a) In the "normal (i.e., not resuming from hibernation)" path, * the full barrier in virt_store_mb() guarantees that the store * is propagated to all CPUs before the add_channel_work work * is queued. In turn, add_channel_work is queued before the * channel's ring buffer is allocated/initialized and the * OPENCHANNEL message for the channel is sent in vmbus_open(). * Hyper-V won't start sending the interrupts for the channel * before the OPENCHANNEL message is acked. The memory barrier * in vmbus_chan_sched() -> sync_test_and_clear_bit() ensures * that vmbus_chan_sched() must find the channel's relid in * recv_int_page before retrieving the channel pointer from the * array of channels. * * (b) In the "resuming from hibernation" path, the virt_store_mb() * guarantees that the store is propagated to all CPUs before * the VMBus connection is marked as ready for the resume event * (cf. check_ready_for_resume_event()). The interrupt handler * of the VMBus driver and vmbus_chan_sched() can not run before * vmbus_bus_resume() has completed execution (cf. resume_noirq). */ virt_store_mb( vmbus_connection.channels[channel->offermsg.child_relid], channel); } void vmbus_channel_unmap_relid(struct vmbus_channel *channel) { if (WARN_ON(channel->offermsg.child_relid >= MAX_CHANNEL_RELIDS)) return; WRITE_ONCE( vmbus_connection.channels[channel->offermsg.child_relid], NULL); } 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(struct vmbus_channel *channel) { lockdep_assert_held(&vmbus_connection.channel_mutex); BUG_ON(!channel->rescind); /* * hv_process_channel_removal() could find INVALID_RELID only for * hv_sock channels. See the inline comments in vmbus_onoffer(). */ WARN_ON(channel->offermsg.child_relid == INVALID_RELID && !is_hvsock_channel(channel)); /* * Upon suspend, an in-use hv_sock channel is removed from the array of * channels and the relid is invalidated. After hibernation, when the * user-space application destroys the channel, it's unnecessary and * unsafe to remove the channel from the array of channels. See also * the inline comments before the call of vmbus_release_relid() below. */ if (channel->offermsg.child_relid != INVALID_RELID) vmbus_channel_unmap_relid(channel); if (channel->primary_channel == NULL) list_del(&channel->listentry); else list_del(&channel->sc_list); /* * If this is a "perf" channel, updates the hv_numa_map[] masks so that * init_vp_index() can (re-)use the CPU. */ if (hv_is_perf_channel(channel)) hv_clear_allocated_cpu(channel->target_cpu); /* * Upon suspend, an in-use hv_sock channel is marked as "rescinded" and * the relid is invalidated; after hibernation, when the user-space app * destroys the channel, the relid is INVALID_RELID, and in this case * it's unnecessary and unsafe to release the old relid, since the same * relid can refer to a completely different channel now. */ if (channel->offermsg.child_relid != INVALID_RELID) vmbus_release_relid(channel->offermsg.child_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; int ret; /* * 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 = newchannel->device_id; /* * Add the new device to the bus. This will kick off device-driver * binding which eventually invokes the device driver's AddDevice() * method. * * If vmbus_device_register() fails, the 'device_obj' is freed in * vmbus_device_release() as called by device_unregister() in the * error path of vmbus_device_register(). In the outside error * path, there's no need to free it. */ 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); 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 list_del(&newchannel->sc_list); /* vmbus_process_offer() has mapped the channel. */ vmbus_channel_unmap_relid(newchannel); mutex_unlock(&vmbus_connection.channel_mutex); 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; bool fnew = true; /* * Synchronize vmbus_process_offer() and CPU hotplugging: * * CPU1 CPU2 * * [vmbus_process_offer()] [Hot removal of the CPU] * * CPU_READ_LOCK CPUS_WRITE_LOCK * LOAD cpu_online_mask SEARCH chn_list * STORE target_cpu LOAD target_cpu * INSERT chn_list STORE cpu_online_mask * CPUS_READ_UNLOCK CPUS_WRITE_UNLOCK * * Forbids: CPU1's LOAD from *not* seing CPU2's STORE && * CPU2's SEARCH from *not* seeing CPU1's INSERT * * Forbids: CPU2's SEARCH from seeing CPU1's INSERT && * CPU2's LOAD from *not* seing CPU1's STORE */ cpus_read_lock(); /* * Serializes the modifications of the chn_list list as well as * the accesses to next_numa_node_id in init_vp_index(). */ mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { if (guid_equal(&channel->offermsg.offer.if_type, &newchannel->offermsg.offer.if_type) && guid_equal(&channel->offermsg.offer.if_instance, &newchannel->offermsg.offer.if_instance)) { fnew = false; newchannel->primary_channel = channel; break; } } init_vp_index(newchannel); /* Remember the channels that should be cleaned up upon suspend. */ if (is_hvsock_channel(newchannel) || is_sub_channel(newchannel)) atomic_inc(&vmbus_connection.nr_chan_close_on_suspend); /* * Now that we have acquired the channel_mutex, * we can release the potentially racing rescind thread. */ atomic_dec(&vmbus_connection.offer_in_progress); 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); cpus_read_unlock(); /* * Don't call free_channel(), because newchannel->kobj * is not initialized yet. */ kfree(newchannel); WARN_ON_ONCE(1); return; } /* * Process the sub-channel. */ list_add_tail(&newchannel->sc_list, &channel->sc_list); } vmbus_channel_map_relid(newchannel); mutex_unlock(&vmbus_connection.channel_mutex); cpus_read_unlock(); /* * 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); } /* * Check if CPUs used by other channels of the same device. * It should only be called by init_vp_index(). */ static bool hv_cpuself_used(u32 cpu, struct vmbus_channel *chn) { struct vmbus_channel *primary = chn->primary_channel; struct vmbus_channel *sc; lockdep_assert_held(&vmbus_connection.channel_mutex); if (!primary) return false; if (primary->target_cpu == cpu) return true; list_for_each_entry(sc, &primary->sc_list, sc_list) if (sc != chn && sc->target_cpu == cpu) return true; return false; } /* * We use this state to statically distribute the channel interrupt load. */ static int next_numa_node_id; /* * We can statically distribute the incoming channel interrupt load * by binding a channel to VCPU. * * For non-performance critical channels we assign the VMBUS_CONNECT_CPU. * Performance critical channels will be distributed evenly among all * the available NUMA nodes. Once the node is assigned, we will assign * the CPU based on a simple round robin scheme. */ static void init_vp_index(struct vmbus_channel *channel) { bool perf_chn = hv_is_perf_channel(channel); u32 i, ncpu = num_online_cpus(); cpumask_var_t available_mask; struct cpumask *allocated_mask; const struct cpumask *hk_mask = housekeeping_cpumask(HK_TYPE_MANAGED_IRQ); u32 target_cpu; int numa_node; if (!perf_chn || !alloc_cpumask_var(&available_mask, GFP_KERNEL) || cpumask_empty(hk_mask)) { /* * If the channel is not a performance critical * channel, bind it to VMBUS_CONNECT_CPU. * In case alloc_cpumask_var() fails, bind it to * VMBUS_CONNECT_CPU. * If all the cpus are isolated, bind it to * VMBUS_CONNECT_CPU. */ channel->target_cpu = VMBUS_CONNECT_CPU; if (perf_chn) hv_set_allocated_cpu(VMBUS_CONNECT_CPU); return; } for (i = 1; i <= ncpu + 1; i++) { while (true) { numa_node = next_numa_node_id++; if (numa_node == nr_node_ids) { next_numa_node_id = 0; continue; } if (cpumask_empty(cpumask_of_node(numa_node))) continue; break; } allocated_mask = &hv_context.hv_numa_map[numa_node]; retry: cpumask_xor(available_mask, allocated_mask, cpumask_of_node(numa_node)); cpumask_and(available_mask, available_mask, hk_mask); if (cpumask_empty(available_mask)) { /* * We have cycled through all the CPUs in the node; * reset the allocated map. */ cpumask_clear(allocated_mask); goto retry; } target_cpu = cpumask_first(available_mask); cpumask_set_cpu(target_cpu, allocated_mask); if (channel->offermsg.offer.sub_channel_index >= ncpu || i > ncpu || !hv_cpuself_used(target_cpu, channel)) break; } channel->target_cpu = target_cpu; 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. * * NB. A malicious or compromised Hyper-V could send a spurious * message of type CHANNELMSG_UNLOAD_RESPONSE, and trigger a call * of the complete() below. Make sure that unload_event has been * initialized by the time this complete() is executed. */ 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; reinit_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(); } static void check_ready_for_resume_event(void) { /* * If all the old primary channels have been fixed up, then it's safe * to resume. */ if (atomic_dec_and_test(&vmbus_connection.nr_chan_fixup_on_resume)) complete(&vmbus_connection.ready_for_resume_event); } static void vmbus_setup_channel_state(struct vmbus_channel *channel, struct vmbus_channel_offer_channel *offer) { /* * Setup state for signalling the host. */ channel->sig_event = VMBUS_EVENT_CONNECTION_ID; channel->is_dedicated_interrupt = (offer->is_dedicated_interrupt != 0); channel->sig_event = offer->connection_id; memcpy(&channel->offermsg, offer, sizeof(struct vmbus_channel_offer_channel)); channel->monitor_grp = (u8)offer->monitorid / 32; channel->monitor_bit = (u8)offer->monitorid % 32; channel->device_id = hv_get_dev_type(channel); } /* * find_primary_channel_by_offer - Get the channel object given the new offer. * This is only used in the resume path of hibernation. */ static struct vmbus_channel * find_primary_channel_by_offer(const struct vmbus_channel_offer_channel *offer) { struct vmbus_channel *channel = NULL, *iter; const guid_t *inst1, *inst2; /* Ignore sub-channel offers. */ if (offer->offer.sub_channel_index != 0) return NULL; mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(iter, &vmbus_connection.chn_list, listentry) { inst1 = &iter->offermsg.offer.if_instance; inst2 = &offer->offer.if_instance; if (guid_equal(inst1, inst2)) { channel = iter; break; } } mutex_unlock(&vmbus_connection.channel_mutex); return channel; } static bool vmbus_is_valid_offer(const struct vmbus_channel_offer_channel *offer) { const guid_t *guid = &offer->offer.if_type; u16 i; if (!hv_is_isolation_supported()) return true; if (is_hvsock_offer(offer)) return true; for (i = 0; i < ARRAY_SIZE(vmbus_devs); i++) { if (guid_equal(guid, &vmbus_devs[i].guid)) return vmbus_devs[i].allowed_in_isolated; } return false; } /* * 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 *oldchannel, *newchannel; size_t offer_sz; offer = (struct vmbus_channel_offer_channel *)hdr; trace_vmbus_onoffer(offer); if (!vmbus_is_valid_offer(offer)) { pr_err_ratelimited("Invalid offer %d from the host supporting isolation\n", offer->child_relid); atomic_dec(&vmbus_connection.offer_in_progress); return; } oldchannel = find_primary_channel_by_offer(offer); if (oldchannel != NULL) { /* * We're resuming from hibernation: all the sub-channel and * hv_sock channels we had before the hibernation should have * been cleaned up, and now we must be seeing a re-offered * primary channel that we had before the hibernation. */ /* * { Initially: channel relid = INVALID_RELID, * channels[valid_relid] = NULL } * * CPU1 CPU2 * * [vmbus_onoffer()] [vmbus_device_release()] * * LOCK channel_mutex LOCK channel_mutex * STORE channel relid = valid_relid LOAD r1 = channel relid * MAP_RELID channel if (r1 != INVALID_RELID) * UNLOCK channel_mutex UNMAP_RELID channel * UNLOCK channel_mutex * * Forbids: r1 == valid_relid && * channels[valid_relid] == channel * * Note. r1 can be INVALID_RELID only for an hv_sock channel. * None of the hv_sock channels which were present before the * suspend are re-offered upon the resume. See the WARN_ON() * in hv_process_channel_removal(). */ mutex_lock(&vmbus_connection.channel_mutex); atomic_dec(&vmbus_connection.offer_in_progress); WARN_ON(oldchannel->offermsg.child_relid != INVALID_RELID); /* Fix up the relid. */ oldchannel->offermsg.child_relid = offer->child_relid; offer_sz = sizeof(*offer); if (memcmp(offer, &oldchannel->offermsg, offer_sz) != 0) { /* * This is not an error, since the host can also change * the other field(s) of the offer, e.g. on WS RS5 * (Build 17763), the offer->connection_id of the * Mellanox VF vmbus device can change when the host * reoffers the device upon resume. */ pr_debug("vmbus offer changed: relid=%d\n", offer->child_relid); print_hex_dump_debug("Old vmbus offer: ", DUMP_PREFIX_OFFSET, 16, 4, &oldchannel->offermsg, offer_sz, false); print_hex_dump_debug("New vmbus offer: ", DUMP_PREFIX_OFFSET, 16, 4, offer, offer_sz, false); /* Fix up the old channel. */ vmbus_setup_channel_state(oldchannel, offer); } /* Add the channel back to the array of channels. */ vmbus_channel_map_relid(oldchannel); check_ready_for_resume_event(); mutex_unlock(&vmbus_connection.channel_mutex); return; } /* 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; } vmbus_setup_channel_state(newchannel, offer); vmbus_process_offer(newchannel); } static void check_ready_for_suspend_event(void) { /* * If all the sub-channels or hv_sock channels have been cleaned up, * then it's safe to suspend. */ if (atomic_dec_and_test(&vmbus_connection.nr_chan_close_on_suspend)) complete(&vmbus_connection.ready_for_suspend_event); } /* * 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; bool clean_up_chan_for_suspend; 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. We rely on the synchronization * provided by offer_in_progress and by channel_mutex for * ordering these events: * * { Initially: offer_in_progress = 1 } * * CPU1 CPU2 * * [vmbus_onoffer()] [vmbus_onoffer_rescind()] * * LOCK channel_mutex WAIT_ON offer_in_progress == 0 * DECREMENT offer_in_progress LOCK channel_mutex * STORE channels[] LOAD channels[] * UNLOCK channel_mutex UNLOCK channel_mutex * * Forbids: CPU2's LOAD from *not* seeing CPU1's STORE */ 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); if (channel != NULL) { /* * Guarantee that no other instance of vmbus_onoffer_rescind() * has got a reference to the channel object. Synchronize on * &vmbus_connection.channel_mutex. */ if (channel->rescind_ref) { mutex_unlock(&vmbus_connection.channel_mutex); return; } channel->rescind_ref = true; } 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; } clean_up_chan_for_suspend = is_hvsock_channel(channel) || is_sub_channel(channel); /* * 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); if (clean_up_chan_for_suspend) check_ready_for_suspend_event(); 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(channel); } else { complete(&channel->rescind_event); } mutex_unlock(&vmbus_connection.channel_mutex); } /* The "channel" may have been freed. Do not access it any longer. */ if (clean_up_chan_for_suspend) check_ready_for_suspend_event(); } 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_onmodifychannel_response - Modify Channel response handler. * * This is invoked when we received a response to our channel modify request. * Find the matching request, copy the response and signal the requesting thread. */ static void vmbus_onmodifychannel_response(struct vmbus_channel_message_header *hdr) { struct vmbus_channel_modifychannel_response *response; struct vmbus_channel_msginfo *msginfo; unsigned long flags; response = (struct vmbus_channel_modifychannel_response *)hdr; trace_vmbus_onmodifychannel_response(response); /* * Find the modify msg, copy the response 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) { struct vmbus_channel_message_header *responseheader = (struct vmbus_channel_message_header *)msginfo->msg; if (responseheader->msgtype == CHANNELMSG_MODIFYCHANNEL) { struct vmbus_channel_modifychannel *modifymsg; modifymsg = (struct vmbus_channel_modifychannel *)msginfo->msg; if (modifymsg->child_relid == response->child_relid) { memcpy(&msginfo->response.modify_response, response, sizeof(*response)); 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, 0}, { CHANNELMSG_OFFERCHANNEL, 0, vmbus_onoffer, sizeof(struct vmbus_channel_offer_channel)}, { CHANNELMSG_RESCIND_CHANNELOFFER, 0, vmbus_onoffer_rescind, sizeof(struct vmbus_channel_rescind_offer) }, { CHANNELMSG_REQUESTOFFERS, 0, NULL, 0}, { CHANNELMSG_ALLOFFERS_DELIVERED, 1, vmbus_onoffers_delivered, 0}, { CHANNELMSG_OPENCHANNEL, 0, NULL, 0}, { CHANNELMSG_OPENCHANNEL_RESULT, 1, vmbus_onopen_result, sizeof(struct vmbus_channel_open_result)}, { CHANNELMSG_CLOSECHANNEL, 0, NULL, 0}, { CHANNELMSG_GPADL_HEADER, 0, NULL, 0}, { CHANNELMSG_GPADL_BODY, 0, NULL, 0}, { CHANNELMSG_GPADL_CREATED, 1, vmbus_ongpadl_created, sizeof(struct vmbus_channel_gpadl_created)}, { CHANNELMSG_GPADL_TEARDOWN, 0, NULL, 0}, { CHANNELMSG_GPADL_TORNDOWN, 1, vmbus_ongpadl_torndown, sizeof(struct vmbus_channel_gpadl_torndown) }, { CHANNELMSG_RELID_RELEASED, 0, NULL, 0}, { CHANNELMSG_INITIATE_CONTACT, 0, NULL, 0}, { CHANNELMSG_VERSION_RESPONSE, 1, vmbus_onversion_response, sizeof(struct vmbus_channel_version_response)}, { CHANNELMSG_UNLOAD, 0, NULL, 0}, { CHANNELMSG_UNLOAD_RESPONSE, 1, vmbus_unload_response, 0}, { CHANNELMSG_18, 0, NULL, 0}, { CHANNELMSG_19, 0, NULL, 0}, { CHANNELMSG_20, 0, NULL, 0}, { CHANNELMSG_TL_CONNECT_REQUEST, 0, NULL, 0}, { CHANNELMSG_MODIFYCHANNEL, 0, NULL, 0}, { CHANNELMSG_TL_CONNECT_RESULT, 0, NULL, 0}, { CHANNELMSG_MODIFYCHANNEL_RESPONSE, 1, vmbus_onmodifychannel_response, sizeof(struct vmbus_channel_modifychannel_response)}, }; /* * vmbus_onmessage - Handler for channel protocol messages. * * This is invoked in the vmbus worker thread context. */ void vmbus_onmessage(struct vmbus_channel_message_header *hdr) { 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 = kzalloc(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; } 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); 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);
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