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 <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index d6b018b86c424cfd6d54806e7f2d2592f649306f..b371d0e984a988729c19d29ce09098a972d7fbb7 100644 (file)
--- 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);