Commit 1a06d017 authored by Dexuan Cui's avatar Dexuan Cui Committed by Wei Liu
Browse files

Drivers: hv: vmbus: Fix Suspend-to-Idle for Generation-2 VM 



Before the hibernation patchset (e.g. f53335e3), in a Generation-2
Linux VM on Hyper-V, the user can run "echo freeze > /sys/power/state" to
freeze the system, i.e. Suspend-to-Idle. The user can press the keyboard
or move the mouse to wake up the VM.

With the hibernation patchset, Linux VM on Hyper-V can hibernate to disk,
but Suspend-to-Idle is broken: when the synthetic keyboard/mouse are
suspended, there is no way to wake up the VM.

Fix the issue by not suspending and resuming the vmbus devices upon
Suspend-to-Idle.

Fixes: f53335e3 ("Drivers: hv: vmbus: Suspend/resume the vmbus itself for hibernation")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
Signed-off-by: default avatarDexuan Cui <decui@microsoft.com>
Link: https://lore.kernel.org/r/1586663435-36243-1-git-send-email-decui@microsoft.com


Signed-off-by: default avatarWei Liu <wei.liu@kernel.org>
parent f3a99e76

drivers/hv/vmbus_drv.c

+34 −9
Original line number Diff line number Diff line
@@ -978,6 +978,9 @@ static int vmbus_resume(struct device *child_device) 


	return drv->resume(dev);

}

#else

#define vmbus_suspend NULL

#define vmbus_resume NULL

#endif /* CONFIG_PM_SLEEP */



/*
@@ -997,11 +1000,22 @@ static void vmbus_device_release(struct device *device) 
}



/*

 * Note: we must use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS rather than

 * SET_SYSTEM_SLEEP_PM_OPS: see the comment before vmbus_bus_pm.

 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.

 *

 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we

 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there

 * is no way to wake up a Generation-2 VM.

 *

 * The other 4 ops are for hibernation.

 */



static const struct dev_pm_ops vmbus_pm = {

	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(vmbus_suspend, vmbus_resume)

	.suspend_noirq	= NULL,

	.resume_noirq	= NULL,

	.freeze_noirq	= vmbus_suspend,

	.thaw_noirq	= vmbus_resume,

	.poweroff_noirq	= vmbus_suspend,

	.restore_noirq	= vmbus_resume,

};



/* The one and only one */
@@ -2281,6 +2295,9 @@ static int vmbus_bus_resume(struct device *dev) 


	return 0;

}

#else

#define vmbus_bus_suspend NULL

#define vmbus_bus_resume NULL

#endif /* CONFIG_PM_SLEEP */



static const struct acpi_device_id vmbus_acpi_device_ids[] = {
@@ -2291,16 +2308,24 @@ static const struct acpi_device_id vmbus_acpi_device_ids[] = { 
MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);



/*

 * Note: we must use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS rather than

 * SET_SYSTEM_SLEEP_PM_OPS, otherwise NIC SR-IOV can not work, because the

 * "pci_dev_pm_ops" uses the "noirq" callbacks: in the resume path, the

 * pci "noirq" restore callback runs before "non-noirq" callbacks (see

 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with

 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in

 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see

 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->

 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's

 * resume callback must also run via the "noirq" callbacks.

 * resume callback must also run via the "noirq" ops.

 *

 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment

 * earlier in this file before vmbus_pm.

 */



static const struct dev_pm_ops vmbus_bus_pm = {

	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(vmbus_bus_suspend, vmbus_bus_resume)

	.suspend_noirq	= NULL,

	.resume_noirq	= NULL,

	.freeze_noirq	= vmbus_bus_suspend,

	.thaw_noirq	= vmbus_bus_resume,

	.poweroff_noirq	= vmbus_bus_suspend,

	.restore_noirq	= vmbus_bus_resume

};



static struct acpi_driver vmbus_acpi_driver = {

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