diff options
| author | Michael Kelley <[email protected]> | 2018-11-04 03:48:57 +0000 |
|---|---|---|
| committer | Thomas Gleixner <[email protected]> | 2018-11-04 11:04:46 +0100 |
| commit | 1de72c706488b7be664a601cf3843bd01e327e58 (patch) | |
| tree | 9541096f9fec1f07998816bbdbc8d4c289e48df9 | |
| parent | 35b69a420bfb56b7b74cb635ea903db05e357bec (diff) | |
x86/hyper-v: Enable PIT shutdown quirk
Hyper-V emulation of the PIT has a quirk such that the normal PIT shutdown
path doesn't work, because clearing the counter register restarts the
timer.
Disable the counter clearing on PIT shutdown.
Signed-off-by: Michael Kelley <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: vkuznets <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: "[email protected]" <[email protected]>
Cc: KY Srinivasan <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
| -rw-r--r-- | arch/x86/kernel/cpu/mshyperv.c | 11 |
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. |