blob: 95be2f9c68e82486f68ef10b3bce08c465ec6272 [file] [log] [blame]
From 591271512dfe2e330e4dc73ac9800e8d7c66b76b Mon Sep 17 00:00:00 2001
From: Tianyu Lan <Tianyu.Lan@microsoft.com>
Date: Mon, 6 Apr 2020 08:53:29 -0700
Subject: [PATCH] x86/Hyper-V: Report crash register data or kmsg before
running crash kernel
commit a11589563e96bf262767294b89b25a9d44e7303b upstream.
We want to notify Hyper-V when a Linux guest VM crash occurs, so
there is a record of the crash even when kdump is enabled. But
crash_kexec_post_notifiers defaults to "false", so the kdump kernel
runs before the notifiers and Hyper-V never gets notified. Fix this by
always setting crash_kexec_post_notifiers to be true for Hyper-V VMs.
Fixes: 81b18bce48af ("Drivers: HV: Send one page worth of kmsg dump over Hyper-V during panic")
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/20200406155331.2105-5-Tianyu.Lan@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 39490b46c9e2..861acf818d7c 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -256,6 +256,16 @@ static void __init ms_hyperv_init_platform(void)
cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
}
+ /*
+ * Hyper-V expects to get crash register data or kmsg when
+ * crash enlightment is available and system crashes. Set
+ * crash_kexec_post_notifiers to be true to make sure that
+ * calling crash enlightment interface before running kdump
+ * kernel.
+ */
+ if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
+ crash_kexec_post_notifiers = true;
+
#ifdef CONFIG_X86_LOCAL_APIC
if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS &&
ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
--
2.7.4