diff mbox series

[1/3] Drivers: hv: vmbus: Disable Suspend-to-Idle for VMBus

Message ID 1726176470-13133-2-git-send-email-ernis@linux.microsoft.com
State New
Headers show
Series Disable Suspend-to-Idle in Hyper-V and Fix Hibernation Interruptions | expand

Commit Message

Erni Sri Satya Vennela Sept. 12, 2024, 9:27 p.m. UTC 
If the Virtual Machine Connection window is focused,
a Hyper-V VM user can unintentionally touch the keyboard/mouse
when the VM is hibernating or resuming, and consequently the
hibernation or resume operation can be aborted unexpectedly.
Fix the issue by no longer registering the keyboard/mouse as
wakeup devices (see the other two patches for the
changes to drivers/input/serio/hyperv-keyboard.c and
drivers/hid/hid-hyperv.c).

The keyboard/mouse were registered as wakeup devices because the
VM needs to be woken up from the Suspend-to-Idle state after
a user runs "echo freeze > /sys/power/state". It seems like
the Suspend-to-Idle feature has no real users in practice, so
let's no longer support that by returning -EOPNOTSUPP if a
user tries to use that.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
---
 drivers/hv/vmbus_drv.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

Comments

Saurabh Singh Sengar Sept. 13, 2024, 6:38 a.m. UTC | #1 
On Thu, Sep 12, 2024 at 02:27:48PM -0700, Erni Sri Satya Vennela wrote:
> If the Virtual Machine Connection window is focused,
> a Hyper-V VM user can unintentionally touch the keyboard/mouse
> when the VM is hibernating or resuming, and consequently the
> hibernation or resume operation can be aborted unexpectedly.
> Fix the issue by no longer registering the keyboard/mouse as
> wakeup devices (see the other two patches for the
> changes to drivers/input/serio/hyperv-keyboard.c and
> drivers/hid/hid-hyperv.c).
> 
> The keyboard/mouse were registered as wakeup devices because the
> VM needs to be woken up from the Suspend-to-Idle state after
> a user runs "echo freeze > /sys/power/state". It seems like
> the Suspend-to-Idle feature has no real users in practice, so
> let's no longer support that by returning -EOPNOTSUPP if a
> user tries to use that.
> 
> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>

Can we have a fixes tag ?
My vote is to backport this upto this commit atleast:
https://lore.kernel.org/all/1586663435-36243-1-git-send-email-decui@microsoft.com/

- Saurabh

> ---
>  drivers/hv/vmbus_drv.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 965d2a4efb7e..4efd8856392f 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -900,6 +900,19 @@ static void vmbus_shutdown(struct device *child_device)
>  }
>  
>  #ifdef CONFIG_PM_SLEEP
> +/*
> + * vmbus_freeze - Suspend-to-Idle
> + */
> +static int vmbus_freeze(struct device *child_device)
> +{
> +/*
> + * Do not support Suspend-to-Idle ("echo freeze > /sys/power/state") as
> + * that would require registering the Hyper-V synthetic mouse/keyboard
> + * devices as wakeup devices, which can abort hibernation/resume unexpectedly.
> + */
> +	return -EOPNOTSUPP;
> +}
> +
>  /*
>   * vmbus_suspend - Suspend a vmbus device
>   */
> @@ -969,7 +982,7 @@ static void vmbus_device_release(struct device *device)
>   */
>  
>  static const struct dev_pm_ops vmbus_pm = {
> -	.suspend_noirq	= NULL,
> +	.suspend_noirq  = vmbus_freeze,
>  	.resume_noirq	= NULL,
>  	.freeze_noirq	= vmbus_suspend,
>  	.thaw_noirq	= vmbus_resume,
> -- 
> 2.34.1
Naman Jain Sept. 13, 2024, 7:19 a.m. UTC | #2 
On 9/13/2024 2:57 AM, Erni Sri Satya Vennela wrote:
> If the Virtual Machine Connection window is focused,
> a Hyper-V VM user can unintentionally touch the keyboard/mouse
> when the VM is hibernating or resuming, and consequently the
> hibernation or resume operation can be aborted unexpectedly.
> Fix the issue by no longer registering the keyboard/mouse as
> wakeup devices (see the other two patches for the
> changes to drivers/input/serio/hyperv-keyboard.c and
> drivers/hid/hid-hyperv.c).
> 
> The keyboard/mouse were registered as wakeup devices because the
> VM needs to be woken up from the Suspend-to-Idle state after
> a user runs "echo freeze > /sys/power/state". It seems like
> the Suspend-to-Idle feature has no real users in practice, so
> let's no longer support that by returning -EOPNOTSUPP if a
> user tries to use that.
> 

Maybe it would be good to capture here the kind of VMs that this is
going to be not supported - HyperV based VMs. You mentioned it in cover
letter, but it would be good to add it here as well, as cover letter
does not go to git log.

Also, the subject suggests that we are disabling suspend-to-idle for
vmbus specifically, but from commit description, it suggests that
"suspend to idle" feature itself is no longer supported on these
particular VMs. Please rephrase it based on what exactly we are trying
to do here. IIUC, we are now returning an error (EOPNOTSUPP) in vmbus
driver callback, which insures that we don't support Suspend-to-Idle in
these VMs.

> Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
> Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
> ---
>   drivers/hv/vmbus_drv.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
> index 965d2a4efb7e..4efd8856392f 100644
> --- a/drivers/hv/vmbus_drv.c
> +++ b/drivers/hv/vmbus_drv.c
> @@ -900,6 +900,19 @@ static void vmbus_shutdown(struct device *child_device)
>   }
>   
>   #ifdef CONFIG_PM_SLEEP
> +/*
> + * vmbus_freeze - Suspend-to-Idle
> + */
> +static int vmbus_freeze(struct device *child_device)
> +{
> +/*
> + * Do not support Suspend-to-Idle ("echo freeze > /sys/power/state") as
> + * that would require registering the Hyper-V synthetic mouse/keyboard
> + * devices as wakeup devices, which can abort hibernation/resume unexpectedly.
> + */
> +	return -EOPNOTSUPP;
> +}
> +
>   /*
>    * vmbus_suspend - Suspend a vmbus device
>    */
> @@ -969,7 +982,7 @@ static void vmbus_device_release(struct device *device)
>    */
>   
>   static const struct dev_pm_ops vmbus_pm = {
> -	.suspend_noirq	= NULL,
> +	.suspend_noirq  = vmbus_freeze,
>   	.resume_noirq	= NULL,
>   	.freeze_noirq	= vmbus_suspend,

I am not sure if this is OK or how it works, but this naming scheme
seems a bit confusing to me -
*suspend* -> vmbus_*freeze*
*freeze* -> vmbus_*suspend*
and we are removing support for "freeze" by returning EOPNOTSUPP in
suspend callback.

I'll try to understand more on this, but just see if its OK.

>   	.thaw_noirq	= vmbus_resume,

Regards,
Naman
kernel test robot Sept. 13, 2024, 5:01 p.m. UTC | #3 
Hi Erni,

kernel test robot noticed the following build errors:

[auto build test ERROR on hid/for-next]
[also build test ERROR on dtor-input/next dtor-input/for-linus linus/master v6.11-rc7 next-20240913]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Erni-Sri-Satya-Vennela/Drivers-hv-vmbus-Disable-Suspend-to-Idle-for-VMBus/20240913-053127
base:   https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git for-next
patch link:    https://lore.kernel.org/r/1726176470-13133-2-git-send-email-ernis%40linux.microsoft.com
patch subject: [PATCH 1/3] Drivers: hv: vmbus: Disable Suspend-to-Idle for VMBus
config: x86_64-randconfig-161-20240913 (https://download.01.org/0day-ci/archive/20240914/202409140042.imFE8dSL-lkp@intel.com/config)
compiler: clang version 18.1.8 (https://github.com/llvm/llvm-project 3b5b5c1ec4a3095ab096dd780e84d7ab81f3d7ff)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240914/202409140042.imFE8dSL-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409140042.imFE8dSL-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/hv/vmbus_drv.c:985:20: error: use of undeclared identifier 'vmbus_freeze'
     985 |         .suspend_noirq  = vmbus_freeze,
         |                           ^
   drivers/hv/vmbus_drv.c:1913:42: warning: shift count >= width of type [-Wshift-count-overflow]
    1913 |         dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
         |                                                 ^~~~~~~~~~~~~~~~
   include/linux/dma-mapping.h:77:54: note: expanded from macro 'DMA_BIT_MASK'
      77 | #define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
         |                                                      ^ ~~~
   1 warning and 1 error generated.


vim +/vmbus_freeze +985 drivers/hv/vmbus_drv.c

   973	
   974	/*
   975	 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
   976	 *
   977	 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
   978	 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
   979	 * is no way to wake up a Generation-2 VM.
   980	 *
   981	 * The other 4 ops are for hibernation.
   982	 */
   983	
   984	static const struct dev_pm_ops vmbus_pm = {
 > 985		.suspend_noirq  = vmbus_freeze,
   986		.resume_noirq	= NULL,
   987		.freeze_noirq	= vmbus_suspend,
   988		.thaw_noirq	= vmbus_resume,
   989		.poweroff_noirq	= vmbus_suspend,
   990		.restore_noirq	= vmbus_resume,
   991	};
   992
kernel test robot Sept. 13, 2024, 5:43 p.m. UTC | #4 
Hi Erni,

kernel test robot noticed the following build errors:

[auto build test ERROR on hid/for-next]
[also build test ERROR on dtor-input/next dtor-input/for-linus linus/master v6.11-rc7 next-20240913]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Erni-Sri-Satya-Vennela/Drivers-hv-vmbus-Disable-Suspend-to-Idle-for-VMBus/20240913-053127
base:   https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git for-next
patch link:    https://lore.kernel.org/r/1726176470-13133-2-git-send-email-ernis%40linux.microsoft.com
patch subject: [PATCH 1/3] Drivers: hv: vmbus: Disable Suspend-to-Idle for VMBus
config: i386-randconfig-003-20240913 (https://download.01.org/0day-ci/archive/20240914/202409140137.5jZxplAp-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240914/202409140137.5jZxplAp-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409140137.5jZxplAp-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/hv/vmbus_drv.c:985:27: error: 'vmbus_freeze' undeclared here (not in a function); did you mean 'vmbus_remove'?
     985 |         .suspend_noirq  = vmbus_freeze,
         |                           ^~~~~~~~~~~~
         |                           vmbus_remove


vim +985 drivers/hv/vmbus_drv.c

   973	
   974	/*
   975	 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
   976	 *
   977	 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
   978	 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
   979	 * is no way to wake up a Generation-2 VM.
   980	 *
   981	 * The other 4 ops are for hibernation.
   982	 */
   983	
   984	static const struct dev_pm_ops vmbus_pm = {
 > 985		.suspend_noirq  = vmbus_freeze,
   986		.resume_noirq	= NULL,
   987		.freeze_noirq	= vmbus_suspend,
   988		.thaw_noirq	= vmbus_resume,
   989		.poweroff_noirq	= vmbus_suspend,
   990		.restore_noirq	= vmbus_resume,
   991	};
   992
diff mbox series

Patch

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 965d2a4efb7e..4efd8856392f 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -900,6 +900,19 @@  static void vmbus_shutdown(struct device *child_device)
 }
 
 #ifdef CONFIG_PM_SLEEP
+/*
+ * vmbus_freeze - Suspend-to-Idle
+ */
+static int vmbus_freeze(struct device *child_device)
+{
+/*
+ * Do not support Suspend-to-Idle ("echo freeze > /sys/power/state") as
+ * that would require registering the Hyper-V synthetic mouse/keyboard
+ * devices as wakeup devices, which can abort hibernation/resume unexpectedly.
+ */
+	return -EOPNOTSUPP;
+}
+
 /*
  * vmbus_suspend - Suspend a vmbus device
  */
@@ -969,7 +982,7 @@  static void vmbus_device_release(struct device *device)
  */
 
 static const struct dev_pm_ops vmbus_pm = {
-	.suspend_noirq	= NULL,
+	.suspend_noirq  = vmbus_freeze,
 	.resume_noirq	= NULL,
 	.freeze_noirq	= vmbus_suspend,
 	.thaw_noirq	= vmbus_resume,