Release 4.17 drivers/hv/connection.c
/*
*
* 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/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/hyperv.h>
#include <linux/export.h>
#include <asm/mshyperv.h>
#include "hyperv_vmbus.h"
struct vmbus_connection vmbus_connection = {
.conn_state = DISCONNECTED,
.next_gpadl_handle = ATOMIC_INIT(0xE1E10),
};
EXPORT_SYMBOL_GPL(vmbus_connection);
/*
* Negotiated protocol version with the host.
*/
__u32 vmbus_proto_version;
EXPORT_SYMBOL_GPL(vmbus_proto_version);
static __u32 vmbus_get_next_version(__u32 current_version)
{
switch (current_version) {
case (VERSION_WIN7):
return VERSION_WS2008;
case (VERSION_WIN8):
return VERSION_WIN7;
case (VERSION_WIN8_1):
return VERSION_WIN8;
case (VERSION_WIN10):
return VERSION_WIN8_1;
case (VERSION_WS2008):
default:
return VERSION_INVAL;
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 45 | 80.36% | 2 | 40.00% |
| Keith Mange | 8 | 14.29% | 1 | 20.00% |
| Greg Kroah-Hartman | 2 | 3.57% | 1 | 20.00% |
| Hank Janssen | 1 | 1.79% | 1 | 20.00% |
| Total | 56 | 100.00% | 5 | 100.00% |
static int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo,
__u32 version)
{
int ret = 0;
struct vmbus_channel_initiate_contact *msg;
unsigned long flags;
init_completion(&msginfo->waitevent);
msg = (struct vmbus_channel_initiate_contact *)msginfo->msg;
msg->header.msgtype = CHANNELMSG_INITIATE_CONTACT;
msg->vmbus_version_requested = version;
msg->interrupt_page = virt_to_phys(vmbus_connection.int_page);
msg->monitor_page1 = virt_to_phys(vmbus_connection.monitor_pages[0]);
msg->monitor_page2 = virt_to_phys(vmbus_connection.monitor_pages[1]);
/*
* We want all channel messages to be delivered on CPU 0.
* This has been the behavior pre-win8. This is not
* perf issue and having all channel messages delivered on CPU 0
* would be ok.
* For post win8 hosts, we support receiving channel messagges on
* all the CPUs. This is needed for kexec to work correctly where
* the CPU attempting to connect may not be CPU 0.
*/
if (version >= VERSION_WIN8_1) {
msg->target_vcpu =
hv_cpu_number_to_vp_number(smp_processor_id());
vmbus_connection.connect_cpu = smp_processor_id();
} else {
msg->target_vcpu = 0;
vmbus_connection.connect_cpu = 0;
}
/*
* Add to list before we send the request since we may
* receive the response before returning from this routine
*/
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_add_tail(&msginfo->msglistentry,
&vmbus_connection.chn_msg_list);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
ret = vmbus_post_msg(msg,
sizeof(struct vmbus_channel_initiate_contact),
true);
trace_vmbus_negotiate_version(msg, ret);
if (ret != 0) {
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&msginfo->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock,
flags);
return ret;
}
/* Wait for the connection response */
wait_for_completion(&msginfo->waitevent);
spin_lock_irqsave(&vmbus_connection.channelmsg_lock, flags);
list_del(&msginfo->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
/* Check if successful */
if (msginfo->response.version_response.version_supported) {
vmbus_connection.conn_state = CONNECTED;
} else {
return -ECONNREFUSED;
}
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 188 | 62.25% | 7 | 33.33% |
| Hank Janssen | 54 | 17.88% | 1 | 4.76% |
| Greg Kroah-Hartman | 22 | 7.28% | 6 | 28.57% |
| Alex Ng | 14 | 4.64% | 1 | 4.76% |
| Vitaly Kuznetsov | 12 | 3.97% | 3 | 14.29% |
| Haiyang Zhang | 9 | 2.98% | 1 | 4.76% |
| Bill Pemberton | 2 | 0.66% | 1 | 4.76% |
| Stephen Hemminger | 1 | 0.33% | 1 | 4.76% |
| Total | 302 | 100.00% | 21 | 100.00% |
/*
* vmbus_connect - Sends a connect request on the partition service connection
*/
int vmbus_connect(void)
{
int ret = 0;
struct vmbus_channel_msginfo *msginfo = NULL;
__u32 version;
/* Initialize the vmbus connection */
vmbus_connection.conn_state = CONNECTING;
vmbus_connection.work_queue = create_workqueue("hv_vmbus_con");
if (!vmbus_connection.work_queue) {
ret = -ENOMEM;
goto cleanup;
}
INIT_LIST_HEAD(&vmbus_connection.chn_msg_list);
spin_lock_init(&vmbus_connection.channelmsg_lock);
INIT_LIST_HEAD(&vmbus_connection.chn_list);
mutex_init(&vmbus_connection.channel_mutex);
/*
* Setup the vmbus event connection for channel interrupt
* abstraction stuff
*/
vmbus_connection.int_page =
(void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
if (vmbus_connection.int_page == NULL) {
ret = -ENOMEM;
goto cleanup;
}
vmbus_connection.recv_int_page = vmbus_connection.int_page;
vmbus_connection.send_int_page =
(void *)((unsigned long)vmbus_connection.int_page +
(PAGE_SIZE >> 1));
/*
* Setup the monitor notification facility. The 1st page for
* parent->child and the 2nd page for child->parent
*/
vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
if ((vmbus_connection.monitor_pages[0] == NULL) ||
(vmbus_connection.monitor_pages[1] == NULL)) {
ret = -ENOMEM;
goto cleanup;
}
msginfo = kzalloc(sizeof(*msginfo) +
sizeof(struct vmbus_channel_initiate_contact),
GFP_KERNEL);
if (msginfo == NULL) {
ret = -ENOMEM;
goto cleanup;
}
/*
* Negotiate a compatible VMBUS version number with the
* host. We start with the highest number we can support
* and work our way down until we negotiate a compatible
* version.
*/
version = VERSION_CURRENT;
do {
ret = vmbus_negotiate_version(msginfo, version);
if (ret == -ETIMEDOUT)
goto cleanup;
if (vmbus_connection.conn_state == CONNECTED)
break;
version = vmbus_get_next_version(version);
} while (version != VERSION_INVAL);
if (version == VERSION_INVAL)
goto cleanup;
vmbus_proto_version = version;
pr_info("Vmbus version:%d.%d\n",
version >> 16, version & 0xFFFF);
kfree(msginfo);
return 0;
cleanup:
pr_err("Unable to connect to host\n");
vmbus_connection.conn_state = DISCONNECTED;
vmbus_disconnect();
kfree(msginfo);
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 241 | 63.93% | 9 | 50.00% |
| Hank Janssen | 64 | 16.98% | 1 | 5.56% |
| Greg Kroah-Hartman | 44 | 11.67% | 2 | 11.11% |
| Haiyang Zhang | 12 | 3.18% | 2 | 11.11% |
| Vitaly Kuznetsov | 12 | 3.18% | 1 | 5.56% |
| Bill Pemberton | 2 | 0.53% | 2 | 11.11% |
| Dexuan Cui | 2 | 0.53% | 1 | 5.56% |
| Total | 377 | 100.00% | 18 | 100.00% |
void vmbus_disconnect(void)
{
/*
* First send the unload request to the host.
*/
vmbus_initiate_unload(false);
if (vmbus_connection.work_queue) {
drain_workqueue(vmbus_connection.work_queue);
destroy_workqueue(vmbus_connection.work_queue);
}
if (vmbus_connection.int_page) {
free_pages((unsigned long)vmbus_connection.int_page, 0);
vmbus_connection.int_page = NULL;
}
free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0);
free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0);
vmbus_connection.monitor_pages[0] = NULL;
vmbus_connection.monitor_pages[1] = NULL;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Hank Janssen | 30 | 26.79% | 1 | 10.00% |
| Greg Kroah-Hartman | 27 | 24.11% | 1 | 10.00% |
| Vitaly Kuznetsov | 18 | 16.07% | 2 | 20.00% |
| Haiyang Zhang | 16 | 14.29% | 2 | 20.00% |
| K. Y. Srinivasan | 14 | 12.50% | 2 | 20.00% |
| Bill Pemberton | 5 | 4.46% | 1 | 10.00% |
| Radim Krčmář | 2 | 1.79% | 1 | 10.00% |
| Total | 112 | 100.00% | 10 | 100.00% |
/*
* relid2channel - Get the channel object given its
* child relative id (ie channel id)
*/
struct vmbus_channel *relid2channel(u32 relid)
{
struct vmbus_channel *channel;
struct vmbus_channel *found_channel = NULL;
struct list_head *cur, *tmp;
struct vmbus_channel *cur_sc;
BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
if (channel->offermsg.child_relid == relid) {
found_channel = channel;
break;
} else if (!list_empty(&channel->sc_list)) {
/*
* Deal with sub-channels.
*/
list_for_each_safe(cur, tmp, &channel->sc_list) {
cur_sc = list_entry(cur, struct vmbus_channel,
sc_list);
if (cur_sc->offermsg.child_relid == relid) {
found_channel = cur_sc;
break;
}
}
}
}
return found_channel;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 67 | 51.15% | 1 | 8.33% |
| Hank Janssen | 36 | 27.48% | 1 | 8.33% |
| Haiyang Zhang | 11 | 8.40% | 4 | 33.33% |
| Greg Kroah-Hartman | 8 | 6.11% | 3 | 25.00% |
| Dexuan Cui | 6 | 4.58% | 2 | 16.67% |
| Bill Pemberton | 3 | 2.29% | 1 | 8.33% |
| Total | 131 | 100.00% | 12 | 100.00% |
/*
* vmbus_on_event - Process a channel event notification
*
* For batched channels (default) optimize host to guest signaling
* by ensuring:
* 1. While reading the channel, we disable interrupts from host.
* 2. Ensure that we process all posted messages from the host
* before returning from this callback.
* 3. Once we return, enable signaling from the host. Once this
* state is set we check to see if additional packets are
* available to read. In this case we repeat the process.
* If this tasklet has been running for a long time
* then reschedule ourselves.
*/
void vmbus_on_event(unsigned long data)
{
struct vmbus_channel *channel = (void *) data;
unsigned long time_limit = jiffies + 2;
trace_vmbus_on_event(channel);
do {
void (*callback_fn)(void *);
/* A channel once created is persistent even when
* there is no driver handling the device. An
* unloading driver sets the onchannel_callback to NULL.
*/
callback_fn = READ_ONCE(channel->onchannel_callback);
if (unlikely(callback_fn == NULL))
return;
(*callback_fn)(channel->channel_callback_context);
if (channel->callback_mode != HV_CALL_BATCHED)
return;
if (likely(hv_end_read(&channel->inbound) == 0))
return;
hv_begin_read(&channel->inbound);
} while (likely(time_before(jiffies, time_limit)));
/* The time limit (2 jiffies) has been reached */
tasklet_schedule(&channel->callback_event);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Stephen Hemminger | 85 | 64.89% | 3 | 30.00% |
| K. Y. Srinivasan | 27 | 20.61% | 4 | 40.00% |
| Hank Janssen | 12 | 9.16% | 1 | 10.00% |
| Vitaly Kuznetsov | 5 | 3.82% | 1 | 10.00% |
| Greg Kroah-Hartman | 2 | 1.53% | 1 | 10.00% |
| Total | 131 | 100.00% | 10 | 100.00% |
/*
* vmbus_post_msg - Send a msg on the vmbus's message connection
*/
int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
{
union hv_connection_id conn_id;
int ret = 0;
int retries = 0;
u32 usec = 1;
conn_id.asu32 = 0;
conn_id.u.id = VMBUS_MESSAGE_CONNECTION_ID;
/*
* hv_post_message() can have transient failures because of
* insufficient resources. Retry the operation a couple of
* times before giving up.
*/
while (retries < 100) {
ret = hv_post_message(conn_id, 1, buffer, buflen);
switch (ret) {
case HV_STATUS_INVALID_CONNECTION_ID:
/*
* We could get this if we send messages too
* frequently.
*/
ret = -EAGAIN;
break;
case HV_STATUS_INSUFFICIENT_MEMORY:
case HV_STATUS_INSUFFICIENT_BUFFERS:
ret = -ENOBUFS;
break;
case HV_STATUS_SUCCESS:
return ret;
default:
pr_err("hv_post_msg() failed; error code:%d\n", ret);
return -EINVAL;
}
retries++;
if (can_sleep && usec > 1000)
msleep(usec / 1000);
else if (usec < MAX_UDELAY_MS * 1000)
udelay(usec);
else
mdelay(usec / 1000);
if (retries < 22)
usec *= 2;
}
return ret;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 69 | 40.83% | 5 | 29.41% |
| Vitaly Kuznetsov | 36 | 21.30% | 1 | 5.88% |
| Hank Janssen | 25 | 14.79% | 1 | 5.88% |
| Haiyang Zhang | 21 | 12.43% | 5 | 29.41% |
| Dexuan Cui | 12 | 7.10% | 1 | 5.88% |
| Greg Kroah-Hartman | 6 | 3.55% | 4 | 23.53% |
| Total | 169 | 100.00% | 17 | 100.00% |
/*
* vmbus_set_event - Send an event notification to the parent
*/
void vmbus_set_event(struct vmbus_channel *channel)
{
u32 child_relid = channel->offermsg.child_relid;
if (!channel->is_dedicated_interrupt)
vmbus_send_interrupt(child_relid);
++channel->sig_events;
hv_do_fast_hypercall8(HVCALL_SIGNAL_EVENT, channel->sig_event);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 29 | 64.44% | 4 | 40.00% |
| Hank Janssen | 7 | 15.56% | 1 | 10.00% |
| Stephen Hemminger | 6 | 13.33% | 2 | 20.00% |
| Haiyang Zhang | 2 | 4.44% | 2 | 20.00% |
| Vitaly Kuznetsov | 1 | 2.22% | 1 | 10.00% |
| Total | 45 | 100.00% | 10 | 100.00% |
EXPORT_SYMBOL_GPL(vmbus_set_event);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| K. Y. Srinivasan | 709 | 50.39% | 34 | 40.00% |
| Hank Janssen | 249 | 17.70% | 2 | 2.35% |
| Greg Kroah-Hartman | 122 | 8.67% | 15 | 17.65% |
| Stephen Hemminger | 98 | 6.97% | 7 | 8.24% |
| Vitaly Kuznetsov | 87 | 6.18% | 8 | 9.41% |
| Haiyang Zhang | 79 | 5.61% | 7 | 8.24% |
| Dexuan Cui | 20 | 1.42% | 3 | 3.53% |
| Bill Pemberton | 16 | 1.14% | 5 | 5.88% |
| Alex Ng | 14 | 1.00% | 1 | 1.18% |
| Keith Mange | 8 | 0.57% | 1 | 1.18% |
| Tejun Heo | 3 | 0.21% | 1 | 1.18% |
| Radim Krčmář | 2 | 0.14% | 1 | 1.18% |
| Total | 1407 | 100.00% | 85 | 100.00% |
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