On Tue, 29 May 2018 21:06:08 +0200
Auger Eric <eric.auger@xxxxxxxxxx> wrote:
> Hi,
> On 05/29/2018 07:15 PM, Geert Uytterhoeven wrote:
> > If a device is part of a PM Domain (e.g. power and/or clock domain), its
> > power state is managed using Runtime PM. Without Runtime PM, the device
> > may not be powered up or clocked, causing subtle failures, crashes, or
> > system lock-ups when the device is accessed by the guest.
> >
> > Fix this by adding Runtime PM support, powering the device when the VFIO
> > device is opened by the guest.
> >
> > Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> > Reviewed-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> Acked-by: Eric Auger <eric.auger@xxxxxxxxxx>
Looks ok to me too, applied with Eric's ack to vfio next branch for
v4.18. Thanks,
Alex
> > ---
> > Against linux-vfio/next
> >
> > v4:
> > - Keep device powered while issuing reset,
> >
> > v3:
> > - Drop controversial note about unsafeness of exporting fine-grained
> > power management from host to guest,
> >
> > v2:
> > - Improve wording,
> > - Add Reviewed-by.
> > ---
> > drivers/vfio/platform/vfio_platform_common.c | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
> > index b60bb5326668498c..c0cd824be2b767be 100644
> > --- a/drivers/vfio/platform/vfio_platform_common.c
> > +++ b/drivers/vfio/platform/vfio_platform_common.c
> > @@ -17,6 +17,7 @@
> > #include <linux/iommu.h>
> > #include <linux/module.h>
> > #include <linux/mutex.h>
> > +#include <linux/pm_runtime.h>
> > #include <linux/slab.h>
> > #include <linux/types.h>
> > #include <linux/uaccess.h>
> > @@ -239,6 +240,7 @@ static void vfio_platform_release(void *device_data)
> > ret, extra_dbg ? extra_dbg : "");
> > WARN_ON(1);
> > }
> > + pm_runtime_put(vdev->device);
> > vfio_platform_regions_cleanup(vdev);
> > vfio_platform_irq_cleanup(vdev);
> > }
> > @@ -269,6 +271,10 @@ static int vfio_platform_open(void *device_data)
> > if (ret)
> > goto err_irq;
> >
> > + ret = pm_runtime_get_sync(vdev->device);
> > + if (ret < 0)
> > + goto err_pm;
> > +
> > ret = vfio_platform_call_reset(vdev, &extra_dbg);
> > if (ret && vdev->reset_required) {
> > dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
> > @@ -283,6 +289,8 @@ static int vfio_platform_open(void *device_data)
> > return 0;
> >
> > err_rst:
> > + pm_runtime_put(vdev->device);
> > +err_pm:
> > vfio_platform_irq_cleanup(vdev);
> > err_irq:
> > vfio_platform_regions_cleanup(vdev);
> > @@ -690,6 +698,7 @@ int vfio_platform_probe_common(struct vfio_platform_device *vdev,
> >
> > mutex_init(&vdev->igate);
> >
> > + pm_runtime_enable(vdev->device);
> > return 0;
> >
> > put_iommu:
> > @@ -707,6 +716,7 @@ struct vfio_platform_device *vfio_platform_remove_common(struct device *dev)
> > vdev = vfio_del_group_dev(dev);
> >
> > if (vdev) {
> > + pm_runtime_disable(vdev->device);
> > vfio_platform_put_reset(vdev);
> > vfio_iommu_group_put(dev->iommu_group, dev);
> > }
> >
