| Message ID | 1526640912-894-1-git-send-email-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Geert, On 05/18/2018 12:55 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. I fail to apply this on master branch? > > Note that while more fine-grained power management could be implemented > on the guest side, if exported by the host, this would be inherently > unsafe, as abusing it may take down the whole system. I think I would prefer we get rid of the above paragraph. Thanks Eric > > Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> > Reviewed-by: Simon Horman <horms+renesas@verge.net.au> > --- > v2: > - Improve wording, > - Add Reviewed-by. > --- > drivers/vfio/platform/vfio_platform_common.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c > index b60bb5326668498c..41f862f055054543 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> > @@ -233,6 +234,8 @@ static void vfio_platform_release(void *device_data) > const char *extra_dbg = NULL; > int ret; > > + pm_runtime_put(vdev->device); > + > 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 release (%d) %s\n", > @@ -275,6 +278,10 @@ static int vfio_platform_open(void *device_data) > ret, extra_dbg ? extra_dbg : ""); > goto err_rst; > } > + > + ret = pm_runtime_get_sync(vdev->device); > + if (ret < 0) > + goto err_rst; > } > > vdev->refcnt++; > @@ -690,6 +697,7 @@ 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 +715,7 @@ 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); > } >
Hi Eric, On Mon, May 28, 2018 at 4:54 PM, Auger Eric <eric.auger@redhat.com> wrote: > On 05/18/2018 12:55 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. > > I fail to apply this on master branch? It's against git://github.com/awilliam/linux-vfio.git#next. >> Note that while more fine-grained power management could be implemented >> on the guest side, if exported by the host, this would be inherently >> unsafe, as abusing it may take down the whole system. > I think I would prefer we get rid of the above paragraph. OK, I will drop it. But you've been warned ;-) Gr{oetje,eeting}s, Geert
diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c index b60bb5326668498c..41f862f055054543 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> @@ -233,6 +234,8 @@ static void vfio_platform_release(void *device_data) const char *extra_dbg = NULL; int ret; + pm_runtime_put(vdev->device); + 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 release (%d) %s\n", @@ -275,6 +278,10 @@ static int vfio_platform_open(void *device_data) ret, extra_dbg ? extra_dbg : ""); goto err_rst; } + + ret = pm_runtime_get_sync(vdev->device); + if (ret < 0) + goto err_rst; } vdev->refcnt++; @@ -690,6 +697,7 @@ 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 +715,7 @@ 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); }