This is a note to let you know that I've just added the patch titled
Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drivers-hv-vmbus-fix-crash-handler-reset-of-hyper-v-.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 25f7596802de2c2869ace152344d924ba42959c2
Author: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Date: Thu Nov 14 06:32:01 2019 +0000
Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
[ Upstream commit 7a1323b5dfe44a9013a2cc56ef2973034a00bf88 ]
The crash handler calls hv_synic_cleanup() to shutdown the
Hyper-V synthetic interrupt controller. But if the CPU
that calls hv_synic_cleanup() has a VMbus channel interrupt
assigned to it (which is likely the case in smaller VM sizes),
hv_synic_cleanup() returns an error and the synthetic
interrupt controller isn't shutdown. While the lack of
being shutdown hasn't caused a known problem, it still
should be fixed for highest reliability.
So directly call hv_synic_disable_regs() instead of
hv_synic_cleanup(), which ensures that the synic is always
shutdown.
Signed-off-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Reviewed-by: Dexuan Cui <decui@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 53a60c81e220..05ead1735c6e 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2308,7 +2308,7 @@ static void hv_crash_handler(struct pt_regs *regs)
vmbus_connection.conn_state = DISCONNECTED;
cpu = smp_processor_id();
hv_stimer_cleanup(cpu);
- hv_synic_cleanup(cpu);
+ hv_synic_disable_regs(cpu);
hyperv_cleanup();
};
