Re: FAILED: patch "[PATCH] x86/Hyper-V: Trigger crash enlightenment only once during" failed to apply to 4.19-stable tree

[Sasha Levin <sashal@kernel.org>]

On Tue, Apr 21, 2020 at 07:12:03PM +0200, gregkh@linuxfoundation.org wrote:
>
>The patch below does not apply to the 4.19-stable tree.
>If someone wants it applied there, or to any other stable or longterm
>tree, then please email the backport, including the original git commit
>id to <stable@vger.kernel.org>.
>
>thanks,
>
>greg k-h
>
>------------------ original commit in Linus's tree ------------------
>
>From 73f26e526f19afb3a06b76b970a76bcac2cafd05 Mon Sep 17 00:00:00 2001
>From: Tianyu Lan <Tianyu.Lan@microsoft.com>
>Date: Mon, 6 Apr 2020 08:53:28 -0700
>Subject: [PATCH] x86/Hyper-V: Trigger crash enlightenment only once during
> system crash.
>
>When a guest VM panics, Hyper-V should be notified only once via the
>crash synthetic MSRs.  Current Linux code might write these crash MSRs
>twice during a system panic:
>1) hyperv_panic/die_event() calling hyperv_report_panic()
>2) hv_kmsg_dump() calling hyperv_report_panic_msg()
>
>Fix this by not calling hyperv_report_panic() if a kmsg dump has been
>successfully registered.  The notification will happen later via
>hyperv_report_panic_msg().
>
>Fixes: 7ed4325a44ea ("Drivers: hv: vmbus: Make panic reporting to be more useful")
>Reviewed-by: Michael Kelley <mikelley@microsoft.com>
>Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
>Link: https://lore.kernel.org/r/20200406155331.2105-4-Tianyu.Lan@microsoft.com
>Signed-off-by: Wei Liu <wei.liu@kernel.org>

This patch builds on 74347a99e73a ("x86/Hyper-V: Unload vmbus channel in
hv panic callback") which previously failed to apply. Once that issue
was resolved we can grab this patch too.

-- 
Thanks,
Sasha