v4.19.13 snapshot.
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
new file mode 100644
index 0000000..16eb9b3
--- /dev/null
+++ b/drivers/hv/channel_mgmt.c
@@ -0,0 +1,1406 @@
+/*
+ * 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 <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/hyperv.h>
+#include <asm/mshyperv.h>
+
+#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);
+
+ 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);
+}
+
+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;
+
+ /*
+ * 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.
+ */
+ while (1) {
+ if (completion_done(&vmbus_connection.unload_event))
+ break;
+
+ 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);
+ }
+
+ mdelay(10);
+ }
+
+ /*
+ * 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;
+
+ /* 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);
+ }
+ }
+ 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 },
+};
+
+/*
+ * 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;
+ int size;
+
+ hdr = (struct vmbus_channel_message_header *)msg->u.payload;
+ size = msg->header.payload_size;
+
+ trace_vmbus_on_message(hdr);
+
+ if (hdr->msgtype >= CHANNELMSG_COUNT) {
+ pr_err("Received invalid channel message type %d size %d\n",
+ hdr->msgtype, size);
+ print_hex_dump_bytes("", DUMP_PREFIX_NONE,
+ (unsigned char *)msg->u.payload, size);
+ return;
+ }
+
+ if (channel_message_table[hdr->msgtype].message_handler)
+ channel_message_table[hdr->msgtype].message_handler(hdr);
+ else
+ pr_err("Unhandled channel message type %d\n", hdr->msgtype);
+}
+
+/*
+ * 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);