[PATCH] Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb()

[PATCH] Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb()

[Andrea Parri (Microsoft)]

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

Fixes: 8b6a877c060ed ("Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels")
Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>
---
 drivers/hv/channel_mgmt.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 60375879612f3..67be81208a2d9 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -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);
 }
-- 
2.25.1

Re: [PATCH] Drivers: hv: vmbus: Replace smp_store_mb() with virt_store_mb()

[Wei Liu]

On Mon, Mar 28, 2022 at 05:44:57PM +0200, Andrea Parri (Microsoft) wrote:
> Following the recommendation in Documentation/memory-barriers.txt for
> virtual machine guests.
> 
> Fixes: 8b6a877c060ed ("Drivers: hv: vmbus: Replace the per-CPU channel lists with a global array of channels")
> Signed-off-by: Andrea Parri (Microsoft) <parri.andrea@gmail.com>

Applied to hyperv-fixes. Thanks.