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-rw-r--r--drivers/hv/channel.c50
-rw-r--r--drivers/hv/channel_mgmt.c119
-rw-r--r--drivers/hv/connection.c14
-rw-r--r--include/linux/hyperv.h62
4 files changed, 236 insertions, 9 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 0b122f8c7005..6de6c98ce6eb 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -116,6 +116,15 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
unsigned long flags;
int ret, t, err = 0;
+ spin_lock_irqsave(&newchannel->sc_lock, flags);
+ if (newchannel->state == CHANNEL_OPEN_STATE) {
+ newchannel->state = CHANNEL_OPENING_STATE;
+ } else {
+ spin_unlock_irqrestore(&newchannel->sc_lock, flags);
+ return -EINVAL;
+ }
+ spin_unlock_irqrestore(&newchannel->sc_lock, flags);
+
newchannel->onchannel_callback = onchannelcallback;
newchannel->channel_callback_context = context;
@@ -216,6 +225,9 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
list_del(&open_info->msglistentry);
spin_unlock_irqrestore(&vmbus_connection.channelmsg_lock, flags);
+ if (err == 0)
+ newchannel->state = CHANNEL_OPENED_STATE;
+
kfree(open_info);
return err;
@@ -500,15 +512,14 @@ int vmbus_teardown_gpadl(struct vmbus_channel *channel, u32 gpadl_handle)
}
EXPORT_SYMBOL_GPL(vmbus_teardown_gpadl);
-/*
- * vmbus_close - Close the specified channel
- */
-void vmbus_close(struct vmbus_channel *channel)
+static void vmbus_close_internal(struct vmbus_channel *channel)
{
struct vmbus_channel_close_channel *msg;
int ret;
unsigned long flags;
+ channel->state = CHANNEL_OPEN_STATE;
+ channel->sc_creation_callback = NULL;
/* Stop callback and cancel the timer asap */
spin_lock_irqsave(&channel->inbound_lock, flags);
channel->onchannel_callback = NULL;
@@ -538,6 +549,37 @@ void vmbus_close(struct vmbus_channel *channel)
}
+
+/*
+ * vmbus_close - Close the specified channel
+ */
+void vmbus_close(struct vmbus_channel *channel)
+{
+ struct list_head *cur, *tmp;
+ struct vmbus_channel *cur_channel;
+
+ if (channel->primary_channel != NULL) {
+ /*
+ * We will only close sub-channels when
+ * the primary is closed.
+ */
+ return;
+ }
+ /*
+ * Close all the sub-channels first and then close the
+ * primary channel.
+ */
+ list_for_each_safe(cur, tmp, &channel->sc_list) {
+ cur_channel = list_entry(cur, struct vmbus_channel, sc_list);
+ if (cur_channel->state != CHANNEL_OPENED_STATE)
+ continue;
+ vmbus_close_internal(cur_channel);
+ }
+ /*
+ * Now close the primary.
+ */
+ vmbus_close_internal(channel);
+}
EXPORT_SYMBOL_GPL(vmbus_close);
/**
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 21ef68934a20..0df75908200e 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -115,6 +115,9 @@ static struct vmbus_channel *alloc_channel(void)
return NULL;
spin_lock_init(&channel->inbound_lock);
+ spin_lock_init(&channel->sc_lock);
+
+ INIT_LIST_HEAD(&channel->sc_list);
channel->controlwq = create_workqueue("hv_vmbus_ctl");
if (!channel->controlwq) {
@@ -166,6 +169,7 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
struct vmbus_channel,
work);
unsigned long flags;
+ struct vmbus_channel *primary_channel;
struct vmbus_channel_relid_released msg;
vmbus_device_unregister(channel->device_obj);
@@ -174,9 +178,16 @@ static void vmbus_process_rescind_offer(struct work_struct *work)
msg.header.msgtype = CHANNELMSG_RELID_RELEASED;
vmbus_post_msg(&msg, sizeof(struct vmbus_channel_relid_released));
- spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
- list_del(&channel->listentry);
- spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+ if (channel->primary_channel == NULL) {
+ spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
+ list_del(&channel->listentry);
+ spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
+ } else {
+ primary_channel = channel->primary_channel;
+ spin_lock_irqsave(&primary_channel->sc_lock, flags);
+ list_del(&channel->listentry);
+ spin_unlock_irqrestore(&primary_channel->sc_lock, flags);
+ }
free_channel(channel);
}
@@ -228,6 +239,24 @@ static void vmbus_process_offer(struct work_struct *work)
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
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->sc_lock, flags);
+ list_add_tail(&newchannel->sc_list, &channel->sc_list);
+ spin_unlock_irqrestore(&channel->sc_lock, flags);
+ newchannel->state = CHANNEL_OPEN_STATE;
+ if (channel->sc_creation_callback != NULL)
+ channel->sc_creation_callback(newchannel);
+
+ return;
+ }
+
free_channel(newchannel);
return;
}
@@ -685,4 +714,86 @@ cleanup:
return ret;
}
-/* eof */
+/*
+ * Retrieve the (sub) channel on which to send an outgoing request.
+ * When a primary channel has multiple sub-channels, we choose a
+ * channel whose VCPU binding is closest to the VCPU on which
+ * this call is being made.
+ */
+struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary)
+{
+ struct list_head *cur, *tmp;
+ int cur_cpu = hv_context.vp_index[smp_processor_id()];
+ struct vmbus_channel *cur_channel;
+ struct vmbus_channel *outgoing_channel = primary;
+ int cpu_distance, new_cpu_distance;
+
+ if (list_empty(&primary->sc_list))
+ return outgoing_channel;
+
+ 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;
+
+ cpu_distance = ((outgoing_channel->target_vp > cur_cpu) ?
+ (outgoing_channel->target_vp - cur_cpu) :
+ (cur_cpu - outgoing_channel->target_vp));
+
+ new_cpu_distance = ((cur_channel->target_vp > cur_cpu) ?
+ (cur_channel->target_vp - cur_cpu) :
+ (cur_cpu - cur_channel->target_vp));
+
+ if (cpu_distance < new_cpu_distance)
+ continue;
+
+ outgoing_channel = cur_channel;
+ }
+
+ 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);
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 253a74ba245c..ec3b8cdf1e04 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -246,12 +246,26 @@ struct vmbus_channel *relid2channel(u32 relid)
struct vmbus_channel *channel;
struct vmbus_channel *found_channel = NULL;
unsigned long flags;
+ struct list_head *cur, *tmp;
+ struct vmbus_channel *cur_sc;
spin_lock_irqsave(&vmbus_connection.channel_lock, flags);
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;
+ }
+ }
}
}
spin_unlock_irqrestore(&vmbus_connection.channel_lock, flags);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c2559847d7ee..405e05a28e65 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -909,6 +909,7 @@ enum vmbus_channel_state {
CHANNEL_OFFER_STATE,
CHANNEL_OPENING_STATE,
CHANNEL_OPEN_STATE,
+ CHANNEL_OPENED_STATE,
};
struct vmbus_channel_debug_info {
@@ -1046,6 +1047,38 @@ struct vmbus_channel {
* preserve the earlier behavior.
*/
u32 target_vp;
+ /*
+ * Support for sub-channels. For high performance devices,
+ * it will be useful to have multiple sub-channels to support
+ * a scalable communication infrastructure with the host.
+ * The support for sub-channels is implemented as an extention
+ * to the current infrastructure.
+ * The initial offer is considered the primary channel and this
+ * offer message will indicate if the host supports sub-channels.
+ * The guest is free to ask for sub-channels to be offerred and can
+ * open these sub-channels as a normal "primary" channel. However,
+ * all sub-channels will have the same type and instance guids as the
+ * primary channel. Requests sent on a given channel will result in a
+ * response on the same channel.
+ */
+
+ /*
+ * Sub-channel creation callback. This callback will be called in
+ * process context when a sub-channel offer is received from the host.
+ * The guest can open the sub-channel in the context of this callback.
+ */
+ void (*sc_creation_callback)(struct vmbus_channel *new_sc);
+
+ spinlock_t sc_lock;
+ /*
+ * All Sub-channels of a primary channel are linked here.
+ */
+ struct list_head sc_list;
+ /*
+ * The primary channel this sub-channel belongs to.
+ * This will be NULL for the primary channel.
+ */
+ struct vmbus_channel *primary_channel;
};
static inline void set_channel_read_state(struct vmbus_channel *c, bool state)
@@ -1057,6 +1090,34 @@ void vmbus_onmessage(void *context);
int vmbus_request_offers(void);
+/*
+ * APIs for managing sub-channels.
+ */
+
+void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel,
+ void (*sc_cr_cb)(struct vmbus_channel *new_sc));
+
+/*
+ * Retrieve the (sub) channel on which to send an outgoing request.
+ * When a primary channel has multiple sub-channels, we choose a
+ * channel whose VCPU binding is closest to the VCPU on which
+ * this call is being made.
+ */
+struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary);
+
+/*
+ * Check if sub-channels have already been offerred. This API will be useful
+ * when the driver is unloaded after establishing sub-channels. In this case,
+ * when the driver is re-loaded, the driver would have to check if the
+ * subchannels have already been established before attempting to request
+ * the creation of sub-channels.
+ * This function returns TRUE to indicate that subchannels have already been
+ * created.
+ * This function should be invoked after setting the callback function for
+ * sub-channel creation.
+ */
+bool vmbus_are_subchannels_present(struct vmbus_channel *primary);
+
/* The format must be the same as struct vmdata_gpa_direct */
struct vmbus_channel_packet_page_buffer {
u16 type;
@@ -1327,7 +1388,6 @@ void vmbus_driver_unregister(struct hv_driver *hv_driver);
0x8e, 0x77, 0x05, 0x58, 0xeb, 0x10, 0x73, 0xf8 \
}
-
/*
* Common header for Hyper-V ICs
*/

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