From 5647dbf8f0807a35421bd0232247b02413ef2cab Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Sat, 28 Jan 2017 12:37:15 -0700 Subject: [PATCH] Drivers: hv: restore TSC page cleanup before kexec We need to cleanup the TSC page before doing kexec/kdump or the new kernel may crash if it tries to use it. Fixes: 63ed4e0c67df ("Drivers: hv: vmbus: Consolidate all Hyper-V specific clocksource code") Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- arch/x86/hyperv/hv_init.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index d6b018b..b371d0e 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -178,6 +178,10 @@ void hyperv_cleanup(void) /* Reset the hypercall page */ hypercall_msr.as_uint64 = 0; wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); + + /* Reset the TSC page */ + hypercall_msr.as_uint64 = 0; + wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64); } EXPORT_SYMBOL_GPL(hyperv_cleanup); -- 2.7.4