Drivers: hv: vmbus: Resume after fixing up old primary channels (d8bd2d44) · Commits · 戴 / test

drivers/hv/channel_mgmt.c

+65 −20

Original line number	Diff line number	Diff line
		@@ -407,6 +407,14 @@ void hv_process_channel_removal(struct vmbus_channel *channel)
		cpumask_clear_cpu(channel->target_cpu,
		&primary_channel->alloced_cpus_in_node);

		/*
		* Upon suspend, an in-use hv_sock channel is marked as "rescinded" and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);
		}

drivers/hv/connection.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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);

drivers/hv/hyperv_vmbus.h

+14 −0

Original line number	Diff line number	Diff line
		@@ -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;
		};

drivers/hv/vmbus_drv.c

+17 −0

Original line number	Diff line number	Diff line
		@@ -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);

include/linux/hyperv.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -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;

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