linux/drivers/hv/channel_mgmt.c

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/*
* 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 cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#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 = true,
},
/* 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);
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_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);
kfree_rcu(channel, rcu);
}
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;
memset(&msg, 0, sizeof(struct vmbus_channel_relid_released));
msg.child_relid = relid;
msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released),
true);
}
void hv_process_channel_removal(struct vmbus_channel *channel, u32 relid)
{
unsigned long flags;
struct vmbus_channel *primary_channel;
BUG_ON(!channel->rescind);
BUG_ON(!mutex_is_locked(&vmbus_connection.channel_mutex));
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);
}
}
/*
* 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;
bool fnew = true;
unsigned long flags;
u16 dev_type;
int ret;
/* Make sure this is a new offer */
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);
mutex_unlock(&vmbus_connection.channel_mutex);
if (!fnew) {
/*
* Check to see if this is a sub-channel.
*/
if (newchannel->offermsg.offer.sub_channel_index != 0) {
/*
* Process the sub-channel.
*/
newchannel->primary_channel = channel;
spin_lock_irqsave(&channel->lock, flags);
list_add_tail(&newchannel->sc_list, &channel->sc_list);
channel->num_sc++;
spin_unlock_irqrestore(&channel->lock, flags);
} else {
goto err_free_chan;
}
}
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 (!fnew) {
if (channel->sc_creation_callback != NULL)
channel->sc_creation_callback(newchannel);
return;
}
/*
* Start the process of binding this offer to the driver
* We need to set the DeviceObject field before calling
* vmbus_child_dev_add()
*/
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);
list_del(&newchannel->listentry);
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);
err_free_chan:
free_channel(newchannel);
}
/*
* We use this state to statically distribute the channel interrupt load.
*/
static int next_numa_node_id;
/*
* Starting with Win8, we can statically distribute the incoming
* channel interrupt load by binding a channel to VCPU.
* We do this in a hierarchical fashion:
* First distribute the primary channels across available NUMA nodes
* and then distribute the subchannels amongst the CPUs in the NUMA
* node assigned to the primary channel.
*
* 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;
struct cpumask available_mask;
struct cpumask *alloced_mask;
if ((vmbus_proto_version == VERSION_WS2008) ||
(vmbus_proto_version == VERSION_WIN7) || (!perf_chn)) {
/*
* 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.
*/
channel->numa_node = 0;
channel->target_cpu = 0;
channel->target_vp = hv_cpu_number_to_vp_number(0);
return;
}
/*
* 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);
}
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;
/* 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;
unsigned long flags;
struct device *dev;
rescind = (struct vmbus_channel_rescind_offer *)hdr;
/*
* 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;
}
spin_lock_irqsave(&channel->lock, flags);
channel->rescind = true;
spin_unlock_irqrestore(&channel->lock, flags);
/*
* Now that we have posted the rescind state, perform
* rescind related cleanup.
*/
vmbus_rescind_cleanup(channel);
/*
* Now wait for offer handling to complete.
*/
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.
*/
if (channel->state == CHANNEL_OPEN_STATE) {
/*
* The channel is currently not open;
* it is safe for us to cleanup the channel.
*/
mutex_lock(&vmbus_connection.channel_mutex);
hv_process_channel_removal(channel,
channel->offermsg.child_relid);
mutex_unlock(&vmbus_connection.channel_mutex);
}
}
}
void vmbus_hvsock_device_unregister(struct vmbus_channel *channel)
{
mutex_lock(&vmbus_connection.channel_mutex);
BUG_ON(!is_hvsock_channel(channel));
channel->rescind = true;
vmbus_device_unregister(channel->device_obj);
mutex_unlock(&vmbus_connection.channel_mutex);
}
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;
/*
* 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;
/*
* 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;
/*
* 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;
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;
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);
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);