* [PATCH v3 1/2] hyperv: Add definitions for MSHV sleep state configuration
2025-10-27 20:28 [PATCH v3 0/2] Add support for clean shutdown with MSHV Praveen K Paladugu
@ 2025-10-27 20:28 ` Praveen K Paladugu
2025-10-27 20:28 ` [PATCH v3 2/2] hyperv: Enable clean shutdown for root partition with MSHV Praveen K Paladugu
2025-10-27 20:56 ` [PATCH v3 0/2] Add support for clean shutdown " Easwar Hariharan
2 siblings, 0 replies; 7+ messages in thread
From: Praveen K Paladugu @ 2025-10-27 20:28 UTC (permalink / raw)
To: kys, haiyangz, wei.liu, decui, tglx, mingo, linux-hyperv,
linux-kernel, bp, dave.hansen, x86, hpa, arnd
Cc: anbelski, prapal, easwar.hariharan, nunodasneves, skinsburskii
Add the definitions required to configure sleep states in mshv hypervsior.
Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com>
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
---
include/hyperv/hvgdk_mini.h | 4 +++-
include/hyperv/hvhdk_mini.h | 33 +++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+), 1 deletion(-)
diff --git a/include/hyperv/hvgdk_mini.h b/include/hyperv/hvgdk_mini.h
index 7499a679e60a..b43fa1c9ed2c 100644
--- a/include/hyperv/hvgdk_mini.h
+++ b/include/hyperv/hvgdk_mini.h
@@ -465,19 +465,21 @@ union hv_vp_assist_msr_contents { /* HV_REGISTER_VP_ASSIST_PAGE */
#define HVCALL_RESET_DEBUG_SESSION 0x006b
#define HVCALL_MAP_STATS_PAGE 0x006c
#define HVCALL_UNMAP_STATS_PAGE 0x006d
+#define HVCALL_SET_SYSTEM_PROPERTY 0x006f
#define HVCALL_ADD_LOGICAL_PROCESSOR 0x0076
#define HVCALL_GET_SYSTEM_PROPERTY 0x007b
#define HVCALL_MAP_DEVICE_INTERRUPT 0x007c
#define HVCALL_UNMAP_DEVICE_INTERRUPT 0x007d
#define HVCALL_RETARGET_INTERRUPT 0x007e
#define HVCALL_NOTIFY_PARTITION_EVENT 0x0087
+#define HVCALL_ENTER_SLEEP_STATE 0x0084
#define HVCALL_NOTIFY_PORT_RING_EMPTY 0x008b
#define HVCALL_REGISTER_INTERCEPT_RESULT 0x0091
#define HVCALL_ASSERT_VIRTUAL_INTERRUPT 0x0094
#define HVCALL_CREATE_PORT 0x0095
#define HVCALL_CONNECT_PORT 0x0096
#define HVCALL_START_VP 0x0099
-#define HVCALL_GET_VP_INDEX_FROM_APIC_ID 0x009a
+#define HVCALL_GET_VP_INDEX_FROM_APIC_ID 0x009a
#define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_SPACE 0x00af
#define HVCALL_FLUSH_GUEST_PHYSICAL_ADDRESS_LIST 0x00b0
#define HVCALL_SIGNAL_EVENT_DIRECT 0x00c0
diff --git a/include/hyperv/hvhdk_mini.h b/include/hyperv/hvhdk_mini.h
index f2d7b50de7a4..06cf30deb319 100644
--- a/include/hyperv/hvhdk_mini.h
+++ b/include/hyperv/hvhdk_mini.h
@@ -140,6 +140,7 @@ enum hv_snp_status {
enum hv_system_property {
/* Add more values when needed */
+ HV_SYSTEM_PROPERTY_SLEEP_STATE = 3,
HV_SYSTEM_PROPERTY_SCHEDULER_TYPE = 15,
HV_DYNAMIC_PROCESSOR_FEATURE_PROPERTY = 21,
HV_SYSTEM_PROPERTY_CRASHDUMPAREA = 47,
@@ -155,6 +156,19 @@ union hv_pfn_range { /* HV_SPA_PAGE_RANGE */
} __packed;
};
+enum hv_sleep_state {
+ HV_SLEEP_STATE_S1 = 1,
+ HV_SLEEP_STATE_S2 = 2,
+ HV_SLEEP_STATE_S3 = 3,
+ HV_SLEEP_STATE_S4 = 4,
+ HV_SLEEP_STATE_S5 = 5,
+ /*
+ * After hypervisor has received this, any follow up sleep
+ * state registration requests will be rejected.
+ */
+ HV_SLEEP_STATE_LOCK = 6
+};
+
enum hv_dynamic_processor_feature_property {
/* Add more values when needed */
HV_X64_DYNAMIC_PROCESSOR_FEATURE_MAX_ENCRYPTED_PARTITIONS = 13,
@@ -184,6 +198,25 @@ struct hv_output_get_system_property {
};
} __packed;
+struct hv_sleep_state_info {
+ u32 sleep_state; /* enum hv_sleep_state */
+ u8 pm1a_slp_typ;
+ u8 pm1b_slp_typ;
+} __packed;
+
+struct hv_input_set_system_property {
+ u32 property_id; /* enum hv_system_property */
+ u32 reserved;
+ union {
+ /* More fields to be filled in when needed */
+ struct hv_sleep_state_info set_sleep_state_info;
+ };
+} __packed;
+
+struct hv_input_enter_sleep_state { /* HV_INPUT_ENTER_SLEEP_STATE */
+ u32 sleep_state; /* enum hv_sleep_state */
+} __packed;
+
struct hv_input_map_stats_page {
u32 type; /* enum hv_stats_object_type */
u32 padding;
--
2.51.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH v3 2/2] hyperv: Enable clean shutdown for root partition with MSHV
2025-10-27 20:28 [PATCH v3 0/2] Add support for clean shutdown with MSHV Praveen K Paladugu
2025-10-27 20:28 ` [PATCH v3 1/2] hyperv: Add definitions for MSHV sleep state configuration Praveen K Paladugu
@ 2025-10-27 20:28 ` Praveen K Paladugu
2025-10-27 21:19 ` Easwar Hariharan
2025-10-27 20:56 ` [PATCH v3 0/2] Add support for clean shutdown " Easwar Hariharan
2 siblings, 1 reply; 7+ messages in thread
From: Praveen K Paladugu @ 2025-10-27 20:28 UTC (permalink / raw)
To: kys, haiyangz, wei.liu, decui, tglx, mingo, linux-hyperv,
linux-kernel, bp, dave.hansen, x86, hpa, arnd
Cc: anbelski, prapal, easwar.hariharan, nunodasneves, skinsburskii
Without configuing sleep state info within mshv, if a root partition is
shut down, it will try to shutdown by writing to ACPI regions. These
writes are intercepted by mshv and will result in a Machine Check
Exception (MCE).
Root eventually panics with a trace similar to:
[ 81.306348] reboot: Power down
[ 81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001
[ 81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9
[ 81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff
[ 81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
[ 81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt
[ 81.314717] Kernel panic - not syncing: Fatal machine check
To prevent this, properly configure sleep states within MSHV, enable a
reboot notifier, allowing the root partition to cleanly shut down without
any panics. Only S5 sleep state is enabled for now.
Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com>
Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
---
arch/x86/hyperv/hv_init.c | 8 +++
arch/x86/include/asm/mshyperv.h | 2 +
drivers/hv/mshv_common.c | 103 ++++++++++++++++++++++++++++++++
3 files changed, 113 insertions(+)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index e28737ec7054..0a8856009792 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -555,6 +555,14 @@ void __init hyperv_init(void)
hv_remap_tsc_clocksource();
hv_root_crash_init();
+
+ /*
+ * The notifier registration might fail at various hops.
+ * Corresponding error messages will land in dmesg. There is
+ * otherwise nothing that can be specifically done to handle
+ * failures here.
+ */
+ hv_sleep_notifiers_register();
} else {
hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
wrmsrq(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 1342d55c2545..fbc1233175ce 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -181,8 +181,10 @@ int hyperv_fill_flush_guest_mapping_list(
void hv_apic_init(void);
void __init hv_init_spinlocks(void);
bool hv_vcpu_is_preempted(int vcpu);
+void hv_sleep_notifiers_register(void);
#else
static inline void hv_apic_init(void) {}
+static inline void hv_sleep_notifiers_register(void) {};
#endif
struct irq_domain *hv_create_pci_msi_domain(void);
diff --git a/drivers/hv/mshv_common.c b/drivers/hv/mshv_common.c
index aa2be51979fd..12b248ea3498 100644
--- a/drivers/hv/mshv_common.c
+++ b/drivers/hv/mshv_common.c
@@ -14,6 +14,9 @@
#include <asm/mshyperv.h>
#include <linux/resume_user_mode.h>
#include <linux/export.h>
+#include <linux/acpi.h>
+#include <linux/notifier.h>
+#include <linux/reboot.h>
#include "mshv.h"
@@ -138,3 +141,103 @@ int hv_call_get_partition_property(u64 partition_id,
return 0;
}
EXPORT_SYMBOL_GPL(hv_call_get_partition_property);
+
+#if IS_ENABLED(CONFIG_ACPI)
+/*
+ * Corresponding sleep states have to be initialized in order for a subsequent
+ * HVCALL_ENTER_SLEEP_STATE call to succeed. Currently only S5 state as per
+ * ACPI 6.4 chapter 7.4.2 is relevant, while S1, S2 and S3 can be supported.
+ *
+ * ACPI should be initialized and should support S5 sleep state when this method
+ * is called, so that it can extract correct PM values and pass them to hv.
+ */
+static int hv_initialize_sleep_states(void)
+{
+ u64 status;
+ unsigned long flags;
+ struct hv_input_set_system_property *in;
+ acpi_status acpi_status;
+ u8 sleep_type_a, sleep_type_b;
+
+ if (!acpi_sleep_state_supported(ACPI_STATE_S5)) {
+ pr_err("%s: S5 sleep state not supported.\n", __func__);
+ return -ENODEV;
+ }
+
+ acpi_status = acpi_get_sleep_type_data(ACPI_STATE_S5, &sleep_type_a,
+ &sleep_type_b);
+ if (ACPI_FAILURE(acpi_status))
+ return -ENODEV;
+
+ local_irq_save(flags);
+ in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ memset(in, 0, sizeof(*in));
+
+ in->property_id = HV_SYSTEM_PROPERTY_SLEEP_STATE;
+ in->set_sleep_state_info.sleep_state = HV_SLEEP_STATE_S5;
+ in->set_sleep_state_info.pm1a_slp_typ = sleep_type_a;
+ in->set_sleep_state_info.pm1b_slp_typ = sleep_type_b;
+
+ status = hv_do_hypercall(HVCALL_SET_SYSTEM_PROPERTY, in, NULL);
+ local_irq_restore(flags);
+
+ if (!hv_result_success(status)) {
+ hv_status_err(status, "\n");
+ return hv_result_to_errno(status);
+ }
+
+ return 0;
+}
+
+static int hv_call_enter_sleep_state(u32 sleep_state)
+{
+ u64 status;
+ int ret;
+ unsigned long flags;
+ struct hv_input_enter_sleep_state *in;
+
+ ret = hv_initialize_sleep_states();
+ if (ret)
+ return ret;
+
+ local_irq_save(flags);
+ in = *this_cpu_ptr(hyperv_pcpu_input_arg);
+ in->sleep_state = sleep_state;
+
+ status = hv_do_hypercall(HVCALL_ENTER_SLEEP_STATE, in, NULL);
+ local_irq_restore(flags);
+
+ if (!hv_result_success(status)) {
+ hv_status_err(status, "\n");
+ return hv_result_to_errno(status);
+ }
+
+ return 0;
+}
+
+static int hv_reboot_notifier_handler(struct notifier_block *this,
+ unsigned long code, void *another)
+{
+ int ret = 0;
+
+ if (code == SYS_HALT || code == SYS_POWER_OFF)
+ ret = hv_call_enter_sleep_state(HV_SLEEP_STATE_S5);
+
+ return ret ? NOTIFY_DONE : NOTIFY_OK;
+}
+
+static struct notifier_block hv_reboot_notifier = {
+ .notifier_call = hv_reboot_notifier_handler,
+ .priority = INT_MIN, /* may not return */
+};
+
+void hv_sleep_notifiers_register(void)
+{
+ int ret;
+
+ ret = register_reboot_notifier(&hv_reboot_notifier);
+ if (ret)
+ pr_err("%s: cannot register reboot notifier %d\n", __func__,
+ ret);
+}
+#endif
--
2.51.0
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH v3 2/2] hyperv: Enable clean shutdown for root partition with MSHV
2025-10-27 20:28 ` [PATCH v3 2/2] hyperv: Enable clean shutdown for root partition with MSHV Praveen K Paladugu
@ 2025-10-27 21:19 ` Easwar Hariharan
0 siblings, 0 replies; 7+ messages in thread
From: Easwar Hariharan @ 2025-10-27 21:19 UTC (permalink / raw)
To: Praveen K Paladugu
Cc: kys, haiyangz, wei.liu, decui, tglx, mingo, linux-hyperv,
linux-kernel, bp, dave.hansen, x86, hpa, arnd, easwar.hariharan,
anbelski, nunodasneves, skinsburskii
On 10/27/2025 1:28 PM, Praveen K Paladugu wrote:
> Without configuing sleep state info within mshv, if a root partition is
> shut down, it will try to shutdown by writing to ACPI regions. These
> writes are intercepted by mshv and will result in a Machine Check
> Exception (MCE).
>
> Root eventually panics with a trace similar to:
>
> [ 81.306348] reboot: Power down
> [ 81.314709] mce: [Hardware Error]: CPU 0: Machine Check Exception: 4 Bank 0: b2000000c0060001
> [ 81.314711] mce: [Hardware Error]: TSC 3b8cb60a66 PPIN 11d98332458e4ea9
> [ 81.314713] mce: [Hardware Error]: PROCESSOR 0:606a6 TIME 1759339405 SOCKET 0 APIC 0 microcode ffffffff
> [ 81.314715] mce: [Hardware Error]: Run the above through 'mcelog --ascii'
> [ 81.314716] mce: [Hardware Error]: Machine check: Processor context corrupt
> [ 81.314717] Kernel panic - not syncing: Fatal machine check
>
> To prevent this, properly configure sleep states within MSHV, enable a
> reboot notifier, allowing the root partition to cleanly shut down without
> any panics. Only S5 sleep state is enabled for now.
>
> Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
> Co-developed-by: Anatol Belski <anbelski@linux.microsoft.com>
> Signed-off-by: Anatol Belski <anbelski@linux.microsoft.com>
> ---
> arch/x86/hyperv/hv_init.c | 8 +++
> arch/x86/include/asm/mshyperv.h | 2 +
> drivers/hv/mshv_common.c | 103 ++++++++++++++++++++++++++++++++
> 3 files changed, 113 insertions(+)
>
Reviewed-by: Easwar Hariharan <easwar.hariharan@linux.microsoft.com>
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 0/2] Add support for clean shutdown with MSHV
2025-10-27 20:28 [PATCH v3 0/2] Add support for clean shutdown with MSHV Praveen K Paladugu
2025-10-27 20:28 ` [PATCH v3 1/2] hyperv: Add definitions for MSHV sleep state configuration Praveen K Paladugu
2025-10-27 20:28 ` [PATCH v3 2/2] hyperv: Enable clean shutdown for root partition with MSHV Praveen K Paladugu
@ 2025-10-27 20:56 ` Easwar Hariharan
2025-10-27 21:11 ` Praveen K Paladugu
2 siblings, 1 reply; 7+ messages in thread
From: Easwar Hariharan @ 2025-10-27 20:56 UTC (permalink / raw)
To: Praveen K Paladugu
Cc: kys, haiyangz, wei.liu, decui, tglx, mingo, linux-hyperv,
linux-kernel, bp, dave.hansen, x86, hpa, arnd, easwar.hariharan,
anbelski, nunodasneves, skinsburskii
On 10/27/2025 1:28 PM, Praveen K Paladugu wrote:
> Add support for clean shutdown of the root partition when running on MSHV
> hypervisor.
>
> v3:
> - Dropped acpi_sleep handlers as they are not used on mshv
> - Applied ordering for hv_reboot_notifier
> - Fixed build issues on i386, arm64 architectures
>
> v2:
> - Addressed review comments from v1.
> - Moved all sleep state handling methods under CONFIG_ACPI stub
> - - This fixes build issues on non-x86 architectures.
>
> Praveen K Paladugu (2):
> hyperv: Add definitions for MSHV sleep state configuration
> hyperv: Enable clean shutdown for root partition with MSHV
>
> arch/x86/hyperv/hv_init.c | 8 +++
> arch/x86/include/asm/mshyperv.h | 2 +
> drivers/hv/mshv_common.c | 103 ++++++++++++++++++++++++++++++++
> include/hyperv/hvgdk_mini.h | 4 +-
> include/hyperv/hvhdk_mini.h | 33 ++++++++++
> 5 files changed, 149 insertions(+), 1 deletion(-)
>
This series seems to assume that Mukesh's hypervisor crash series has been merged, but that's not the case.
I don't see any code context or logical dependency on that series, but correct me if I'm wrong. If there's no
dependency, can you send a v4 based on Linus' tree or hyperv-next to avoid a merge conflict?
Thanks,
Easwar (he/him)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 0/2] Add support for clean shutdown with MSHV
2025-10-27 20:56 ` [PATCH v3 0/2] Add support for clean shutdown " Easwar Hariharan
@ 2025-10-27 21:11 ` Praveen K Paladugu
2025-10-27 21:13 ` Easwar Hariharan
0 siblings, 1 reply; 7+ messages in thread
From: Praveen K Paladugu @ 2025-10-27 21:11 UTC (permalink / raw)
To: Easwar Hariharan
Cc: kys, haiyangz, wei.liu, decui, tglx, mingo, linux-hyperv,
linux-kernel, bp, dave.hansen, x86, hpa, arnd, anbelski,
nunodasneves, skinsburskii
On 10/27/2025 3:56 PM, Easwar Hariharan wrote:
> On 10/27/2025 1:28 PM, Praveen K Paladugu wrote:
>> Add support for clean shutdown of the root partition when running on MSHV
>> hypervisor.
>>
>> v3:
>> - Dropped acpi_sleep handlers as they are not used on mshv
>> - Applied ordering for hv_reboot_notifier
>> - Fixed build issues on i386, arm64 architectures
>>
>> v2:
>> - Addressed review comments from v1.
>> - Moved all sleep state handling methods under CONFIG_ACPI stub
>> - - This fixes build issues on non-x86 architectures.
>>
>> Praveen K Paladugu (2):
>> hyperv: Add definitions for MSHV sleep state configuration
>> hyperv: Enable clean shutdown for root partition with MSHV
>>
>> arch/x86/hyperv/hv_init.c | 8 +++
>> arch/x86/include/asm/mshyperv.h | 2 +
>> drivers/hv/mshv_common.c | 103 ++++++++++++++++++++++++++++++++
>> include/hyperv/hvgdk_mini.h | 4 +-
>> include/hyperv/hvhdk_mini.h | 33 ++++++++++
>> 5 files changed, 149 insertions(+), 1 deletion(-)
>>
>
> This series seems to assume that Mukesh's hypervisor crash series has been merged, but that's not the case.
> I don't see any code context or logical dependency on that series, but correct me if I'm wrong. If there's no
> dependency, can you send a v4 based on Linus' tree or hyperv-next to avoid a merge conflict?
>
I rebased this patchset on top of hyperv/hyperv-next branch, which has
crashdump patches:
https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/log/?h=hyperv-next
Let me know if I missed/misunderstood anything.
> Thanks,
> Easwar (he/him)
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v3 0/2] Add support for clean shutdown with MSHV
2025-10-27 21:11 ` Praveen K Paladugu
@ 2025-10-27 21:13 ` Easwar Hariharan
0 siblings, 0 replies; 7+ messages in thread
From: Easwar Hariharan @ 2025-10-27 21:13 UTC (permalink / raw)
To: Praveen K Paladugu
Cc: easwar.hariharan, kys, haiyangz, wei.liu, decui, tglx, mingo,
linux-hyperv, linux-kernel, bp, dave.hansen, x86, hpa, arnd,
anbelski, nunodasneves, skinsburskii
On 10/27/2025 2:11 PM, Praveen K Paladugu wrote:
>
>
> On 10/27/2025 3:56 PM, Easwar Hariharan wrote:
>> On 10/27/2025 1:28 PM, Praveen K Paladugu wrote:
>>> Add support for clean shutdown of the root partition when running on MSHV
>>> hypervisor.
>>>
>>> v3:
>>> - Dropped acpi_sleep handlers as they are not used on mshv
>>> - Applied ordering for hv_reboot_notifier
>>> - Fixed build issues on i386, arm64 architectures
>>>
>>> v2:
>>> - Addressed review comments from v1.
>>> - Moved all sleep state handling methods under CONFIG_ACPI stub
>>> - - This fixes build issues on non-x86 architectures.
>>>
>>> Praveen K Paladugu (2):
>>> hyperv: Add definitions for MSHV sleep state configuration
>>> hyperv: Enable clean shutdown for root partition with MSHV
>>>
>>> arch/x86/hyperv/hv_init.c | 8 +++
>>> arch/x86/include/asm/mshyperv.h | 2 +
>>> drivers/hv/mshv_common.c | 103 ++++++++++++++++++++++++++++++++
>>> include/hyperv/hvgdk_mini.h | 4 +-
>>> include/hyperv/hvhdk_mini.h | 33 ++++++++++
>>> 5 files changed, 149 insertions(+), 1 deletion(-)
>>>
>>
>> This series seems to assume that Mukesh's hypervisor crash series has been merged, but that's not the case.
>> I don't see any code context or logical dependency on that series, but correct me if I'm wrong. If there's no
>> dependency, can you send a v4 based on Linus' tree or hyperv-next to avoid a merge conflict?
>>
>
> I rebased this patchset on top of hyperv/hyperv-next branch, which has crashdump patches: https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/log/?h=hyperv-next
>
> Let me know if I missed/misunderstood anything.
>
Nope, a miss on my part. Sorry about the noise.
Thanks,
Easwar (he/him)
^ permalink raw reply [flat|nested] 7+ messages in thread