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Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 1c72f3819eb1..e81a2db42df7 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -20,6 +20,7 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/kexec.h>
+#include <linux/i8253.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
#include <asm/hyperv-tlfs.h>
@@ -295,6 +296,16 @@ static void __init ms_hyperv_init_platform(void)
if (efi_enabled(EFI_BOOT))
x86_platform.get_nmi_reason = hv_get_nmi_reason;
+ /*
+ * Hyper-V VMs have a PIT emulation quirk such that zeroing the
+ * counter register during PIT shutdown restarts the PIT. So it
+ * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
+ * to false tells pit_shutdown() not to zero the counter so that
+ * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
+ * and setting this value has no effect.
+ */
+ i8253_clear_counter_on_shutdown = false;
+
#if IS_ENABLED(CONFIG_HYPERV)
/*
* Setup the hook to get control post apic initialization.