diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 5518d031f62a818e195be7b44c58158e5569fe66..8eb167540b4f66e658e7977858635f6dc8139700 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -407,7 +407,15 @@ void hv_process_channel_removal(struct vmbus_channel *channel)
cpumask_clear_cpu(channel->target_cpu,
&primary_channel->alloced_cpus_in_node);
- vmbus_release_relid(channel->offermsg.child_relid);
+ /*
+ * Upon suspend, an in-use hv_sock channel is marked as "rescinded" and
+ * the relid is invalidated; after hibernation, when the user-space app
+ * destroys the channel, the relid is INVALID_RELID, and in this case
+ * it's unnecessary and unsafe to release the old relid, since the same
+ * relid can refer to a completely different channel now.
+ */
+ if (channel->offermsg.child_relid != INVALID_RELID)
+ vmbus_release_relid(channel->offermsg.child_relid);
free_channel(channel);
}
@@ -851,6 +859,36 @@ void vmbus_initiate_unload(bool crash)
vmbus_wait_for_unload();
}
+static void check_ready_for_resume_event(void)
+{
+ /*
+ * If all the old primary channels have been fixed up, then it's safe
+ * to resume.
+ */
+ if (atomic_dec_and_test(&vmbus_connection.nr_chan_fixup_on_resume))
+ complete(&vmbus_connection.ready_for_resume_event);
+}
+
+static void vmbus_setup_channel_state(struct vmbus_channel *channel,
+ struct vmbus_channel_offer_channel *offer)
+{
+ /*
+ * Setup state for signalling the host.
+ */
+ channel->sig_event = VMBUS_EVENT_CONNECTION_ID;
+
+ if (vmbus_proto_version != VERSION_WS2008) {
+ channel->is_dedicated_interrupt =
+ (offer->is_dedicated_interrupt != 0);
+ channel->sig_event = offer->connection_id;
+ }
+
+ memcpy(&channel->offermsg, offer,
+ sizeof(struct vmbus_channel_offer_channel));
+ channel->monitor_grp = (u8)offer->monitorid / 32;
+ channel->monitor_bit = (u8)offer->monitorid % 32;
+}
+
/*
* find_primary_channel_by_offer - Get the channel object given the new offer.
* This is only used in the resume path of hibernation.
@@ -902,14 +940,29 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
atomic_dec(&vmbus_connection.offer_in_progress);
/*
- * We're resuming from hibernation: we expect the host to send
- * exactly the same offers that we had before the hibernation.
+ * We're resuming from hibernation: all the sub-channel and
+ * hv_sock channels we had before the hibernation should have
+ * been cleaned up, and now we must be seeing a re-offered
+ * primary channel that we had before the hibernation.
*/
+
+ WARN_ON(oldchannel->offermsg.child_relid != INVALID_RELID);
+ /* Fix up the relid. */
+ oldchannel->offermsg.child_relid = offer->child_relid;
+
offer_sz = sizeof(*offer);
- if (memcmp(offer, &oldchannel->offermsg, offer_sz) == 0)
+ if (memcmp(offer, &oldchannel->offermsg, offer_sz) == 0) {
+ check_ready_for_resume_event();
return;
+ }
- pr_debug("Mismatched offer from the host (relid=%d)\n",
+ /*
+ * This is not an error, since the host can also change the
+ * other field(s) of the offer, e.g. on WS RS5 (Build 17763),
+ * the offer->connection_id of the Mellanox VF vmbus device
+ * can change when the host reoffers the device upon resume.
+ */
+ pr_debug("vmbus offer changed: relid=%d\n",
offer->child_relid);
print_hex_dump_debug("Old vmbus offer: ", DUMP_PREFIX_OFFSET,
@@ -917,6 +970,12 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
false);
print_hex_dump_debug("New vmbus offer: ", DUMP_PREFIX_OFFSET,
16, 4, offer, offer_sz, false);
+
+ /* Fix up the old channel. */
+ vmbus_setup_channel_state(oldchannel, offer);
+
+ check_ready_for_resume_event();
+
return;
}
@@ -929,21 +988,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
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_setup_channel_state(newchannel, offer);
vmbus_process_offer(newchannel);
}
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 99851ea682eb26515a826d469a8c64893bd9e1b3..6e4c015783ffca5ec063c59ff5a478d2dc93de46 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -29,6 +29,8 @@ struct vmbus_connection vmbus_connection = {
.ready_for_suspend_event= COMPLETION_INITIALIZER(
vmbus_connection.ready_for_suspend_event),
+ .ready_for_resume_event = COMPLETION_INITIALIZER(
+ vmbus_connection.ready_for_resume_event),
};
EXPORT_SYMBOL_GPL(vmbus_connection);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 974b747ca1fc03c1d3bf989fa5acc7c7e5c46418..f7a5f5615f34cb47b116fbcc2e5f82b40b40d8bd 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -272,6 +272,20 @@ struct vmbus_connection {
* drop to zero.
*/
struct completion ready_for_suspend_event;
+
+ /*
+ * The number of primary channels that should be "fixed up"
+ * upon resume: these channels are re-offered upon resume, and some
+ * fields of the channel offers (i.e. child_relid and connection_id)
+ * can change, so the old offermsg must be fixed up, before the resume
+ * callbacks of the VSC drivers start to further touch the channels.
+ */
+ atomic_t nr_chan_fixup_on_resume;
+ /*
+ * vmbus_bus_resume() waits for "nr_chan_fixup_on_resume" to
+ * drop to zero.
+ */
+ struct completion ready_for_resume_event;
};
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 32ec951d334f61bfd193451eb56a35ab152e79ce..391f0b225c9ae4698c3cc3d9958b10873cf861a0 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2164,9 +2164,17 @@ static int vmbus_bus_suspend(struct device *dev)
if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
wait_for_completion(&vmbus_connection.ready_for_suspend_event);
+ WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0);
+
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
+ /*
+ * Invalidate the field. Upon resume, vmbus_onoffer() will fix
+ * up the field, and the other fields (if necessary).
+ */
+ channel->offermsg.child_relid = INVALID_RELID;
+
if (is_hvsock_channel(channel)) {
if (!channel->rescind) {
pr_err("hv_sock channel not rescinded!\n");
@@ -2181,6 +2189,8 @@ static int vmbus_bus_suspend(struct device *dev)
WARN_ON_ONCE(1);
}
spin_unlock_irqrestore(&channel->lock, flags);
+
+ atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
}
mutex_unlock(&vmbus_connection.channel_mutex);
@@ -2189,6 +2199,9 @@ static int vmbus_bus_suspend(struct device *dev)
vmbus_connection.conn_state = DISCONNECTED;
+ /* Reset the event for the next resume. */
+ reinit_completion(&vmbus_connection.ready_for_resume_event);
+
return 0;
}
@@ -2223,8 +2236,12 @@ static int vmbus_bus_resume(struct device *dev)
if (ret != 0)
return ret;
+ WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
+
vmbus_request_offers();
+ wait_for_completion(&vmbus_connection.ready_for_resume_event);
+
/* Reset the event for the next suspend. */
reinit_completion(&vmbus_connection.ready_for_suspend_event);
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 8a60e7766037d669db5ce65475af076af0fbf190..a3aa9e9ef6f23d6c491b169b8f6a4fc445ebbe7f 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -426,6 +426,9 @@ enum vmbus_channel_message_type {
CHANNELMSG_COUNT
};
+/* Hyper-V supports about 2048 channels, and the RELIDs start with 1. */
+#define INVALID_RELID U32_MAX
+
struct vmbus_channel_message_header {
enum vmbus_channel_message_type msgtype;
u32 padding;