gregkh at linuxfoundation.org
2018-Nov-19 13:00 UTC
Patch "x86/hyper-v: Enable PIT shutdown quirk" has been added to the 4.19-stable tree
This is a note to let you know that I've just added the patch titled
x86/hyper-v: Enable PIT shutdown quirk
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
x86-hyper-v-enable-pit-shutdown-quirk.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable at vger.kernel.org> know about it.
>From 1de72c706488b7be664a601cf3843bd01e327e58 Mon Sep 17 00:00:00 2001
From: Michael Kelley <mikelley at microsoft.com>
Date: Sun, 4 Nov 2018 03:48:57 +0000
Subject: x86/hyper-v: Enable PIT shutdown quirk
From: Michael Kelley <mikelley at microsoft.com>
commit 1de72c706488b7be664a601cf3843bd01e327e58 upstream.
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 <mikelley at microsoft.com>
Signed-off-by: Thomas Gleixner <tglx at linutronix.de>
Cc: "gregkh at linuxfoundation.org" <gregkh at
linuxfoundation.org>
Cc: "devel at linuxdriverproject.org" <devel at
linuxdriverproject.org>
Cc: "daniel.lezcano at linaro.org" <daniel.lezcano at
linaro.org>
Cc: "virtualization at lists.linux-foundation.org" <virtualization
at lists.linux-foundation.org>
Cc: "jgross at suse.com" <jgross at suse.com>
Cc: "akataria at vmware.com" <akataria at vmware.com>
Cc: "olaf at aepfle.de" <olaf at aepfle.de>
Cc: "apw at canonical.com" <apw at canonical.com>
Cc: vkuznets <vkuznets at redhat.com>
Cc: "jasowang at redhat.com" <jasowang at redhat.com>
Cc: "marcelo.cerri at canonical.com" <marcelo.cerri at
canonical.com>
Cc: KY Srinivasan <kys at microsoft.com>
Cc: stable at vger.kernel.org
Link: https://lkml.kernel.org/r/1541303219-11142-3-git-send-email-mikelley at
microsoft.com
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
arch/x86/kernel/cpu/mshyperv.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--- 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>
@@ -285,6 +286,16 @@ static void __init ms_hyperv_init_platfo
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.
Patches currently in stable-queue which might be from mikelley at microsoft.com
are
queue-4.19/x86-hyper-v-enable-pit-shutdown-quirk.patch
queue-4.19/clockevents-drivers-i8253-add-support-for-pit-shutdown-quirk.patch
kbuild test robot
2018-Nov-19 20:44 UTC
Patch "x86/hyper-v: Enable PIT shutdown quirk" has been added to the 4.19-stable tree
Hi gregkh,
I love your patch! Yet something to improve:
[auto build test ERROR on tip/x86/core]
[cannot apply to v4.20-rc3 next-20181119]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/gregkh-linuxfoundation-org/Patch-x86-hyper-v-Enable-PIT-shutdown-quirk-has-been-added-to-the-4-19-stable-tree/20181120-042611
config: i386-randconfig-x019-201846 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=i386
All errors (new ones prefixed by >>):
arch/x86/kernel/cpu/mshyperv.c: In function
'ms_hyperv_init_platform':>> arch/x86/kernel/cpu/mshyperv.c:297:2: error:
'i8253_clear_counter_on_shutdown' undeclared (first use in this
function)
i8253_clear_counter_on_shutdown = false;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/kernel/cpu/mshyperv.c:297:2: note: each undeclared identifier is
reported only once for each function it appears in
vim +/i8253_clear_counter_on_shutdown +297 arch/x86/kernel/cpu/mshyperv.c
275
276 #if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
277 machine_ops.shutdown = hv_machine_shutdown;
278 machine_ops.crash_shutdown = hv_machine_crash_shutdown;
279 #endif
280 mark_tsc_unstable("running on Hyper-V");
281
282 /*
283 * Generation 2 instances don't support reading the NMI status from
284 * 0x61 port.
285 */
286 if (efi_enabled(EFI_BOOT))
287 x86_platform.get_nmi_reason = hv_get_nmi_reason;
288
289 /*
290 * Hyper-V VMs have a PIT emulation quirk such that zeroing the
291 * counter register during PIT shutdown restarts the PIT. So it
292 * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
293 * to false tells pit_shutdown() not to zero the counter so that
294 * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
295 * and setting this value has no effect.
296 */
> 297 i8253_clear_counter_on_shutdown = false;
298
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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kbuild test robot
2018-Nov-20 18:47 UTC
Patch "x86/hyper-v: Enable PIT shutdown quirk" has been added to the 4.19-stable tree
Hi gregkh,
I love your patch! Yet something to improve:
[auto build test ERROR on tip/x86/core]
[cannot apply to v4.20-rc3 next-20181120]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system]
url:
https://github.com/0day-ci/linux/commits/gregkh-linuxfoundation-org/Patch-x86-hyper-v-Enable-PIT-shutdown-quirk-has-been-added-to-the-4-19-stable-tree/20181120-042611
config: x86_64-allmodconfig (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All error/warnings (new ones prefixed by >>):
>> arch/x86/kernel/cpu/mshyperv.c:297:9: error: undefined identifier
'i8253_clear_counter_on_shutdown'
arch/x86/kernel/cpu/mshyperv.c:320:41: warning: symbol
'x86_hyper_ms_hyperv' was not declared. Should it be
static?>> arch/x86/kernel/cpu/mshyperv.c:297:9: warning: generating address of
non-lvalue (3)
arch/x86/kernel/cpu/mshyperv.c: In function
'ms_hyperv_init_platform':
arch/x86/kernel/cpu/mshyperv.c:297:2: error:
'i8253_clear_counter_on_shutdown' undeclared (first use in this
function)
i8253_clear_counter_on_shutdown = false;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/kernel/cpu/mshyperv.c:297:2: note: each undeclared identifier is
reported only once for each function it appears in
vim +/i8253_clear_counter_on_shutdown +297 arch/x86/kernel/cpu/mshyperv.c
275
276 #if IS_ENABLED(CONFIG_HYPERV) && defined(CONFIG_KEXEC_CORE)
277 machine_ops.shutdown = hv_machine_shutdown;
278 machine_ops.crash_shutdown = hv_machine_crash_shutdown;
279 #endif
280 mark_tsc_unstable("running on Hyper-V");
281
282 /*
283 * Generation 2 instances don't support reading the NMI status from
284 * 0x61 port.
285 */
286 if (efi_enabled(EFI_BOOT))
287 x86_platform.get_nmi_reason = hv_get_nmi_reason;
288
289 /*
290 * Hyper-V VMs have a PIT emulation quirk such that zeroing the
291 * counter register during PIT shutdown restarts the PIT. So it
292 * continues to interrupt @18.2 HZ. Setting i8253_clear_counter
293 * to false tells pit_shutdown() not to zero the counter so that
294 * the PIT really is shutdown. Generation 2 VMs don't have a PIT,
295 * and setting this value has no effect.
296 */
> 297 i8253_clear_counter_on_shutdown = false;
298
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
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