Commit eaa03d34 authored by Andrea Parri (Microsoft)'s avatar Andrea Parri (Microsoft) Committed by Wei Liu
Browse files

Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb() 



Following the recommendation in Documentation/memory-barriers.txt for
virtual machine guests.

Fixes: 8b6a877c ("Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels")
Signed-off-by: default avatarAndrea Parri (Microsoft) <parri.andrea@gmail.com>
Link: https://lore.kernel.org/r/20220328154457.100872-1-parri.andrea@gmail.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent be580279

drivers/hv/channel_mgmt.c

+3 −3
Original line number Diff line number Diff line
@@ -380,7 +380,7 @@ void vmbus_channel_map_relid(struct vmbus_channel *channel) 
	 * execute:

	 *

	 *  (a) In the "normal (i.e., not resuming from hibernation)" path,

	 *      the full barrier in smp_store_mb() guarantees that the store

	 *      the full barrier in virt_store_mb() guarantees that the store

	 *      is propagated to all CPUs before the add_channel_work work

	 *      is queued.  In turn, add_channel_work is queued before the

	 *      channel's ring buffer is allocated/initialized and the
@@ -392,14 +392,14 @@ void vmbus_channel_map_relid(struct vmbus_channel *channel) 
	 *      recv_int_page before retrieving the channel pointer from the

	 *      array of channels.

	 *

	 *  (b) In the "resuming from hibernation" path, the smp_store_mb()

	 *  (b) In the "resuming from hibernation" path, the virt_store_mb()

	 *      guarantees that the store is propagated to all CPUs before

	 *      the VMBus connection is marked as ready for the resume event

	 *      (cf. check_ready_for_resume_event()).  The interrupt handler

	 *      of the VMBus driver and vmbus_chan_sched() can not run before

	 *      vmbus_bus_resume() has completed execution (cf. resume_noirq).

	 */

	smp_store_mb(

	virt_store_mb(

		vmbus_connection.channels[channel->offermsg.child_relid],

		channel);

}