On Wed, 27 Mar 2019 14:17:57 +0000 Parav Pandit <[email protected]> wrote:
> > -----Original Message----- > > From: [email protected] <linux-kernel- > > [email protected]> On Behalf Of Kirti Wankhede > > Sent: Tuesday, March 26, 2019 4:33 AM > > To: Lu Baolu <[email protected]>; Joerg Roedel <[email protected]>; > > David Woodhouse <[email protected]>; Alex Williamson > > <[email protected]> > > Cc: [email protected]; [email protected]; > > [email protected]; [email protected]; Jean-Philippe Brucker <jean- > > > > [email protected]>; [email protected]; [email protected]; > > [email protected]; [email protected]; [email protected]; > > [email protected]; [email protected]; linux- > > [email protected]; Jacob Pan <[email protected]>; Neo Jia > > <[email protected]> > > Subject: Re: [PATCH v8 7/9] vfio/mdev: Add iommu related member in > > mdev_device > > > > > > > > On 3/25/2019 7:00 AM, Lu Baolu wrote: > > > A parent device might create different types of mediated devices. For > > > example, a mediated device could be created by the parent device with > > > full isolation and protection provided by the IOMMU. One usage case > > > could be found on Intel platforms where a mediated device is an > > > assignable subset of a PCI, the DMA requests on behalf of it are all > > > tagged with a PASID. Since IOMMU supports PASID-granular translations > > > (scalable mode in VT-d 3.0), this mediated device could be > > > individually protected and isolated by an IOMMU. > > > > > > This patch adds a new member in the struct mdev_device to indicate > > > that the mediated device represented by mdev could be isolated and > > > protected by attaching a domain to a device represented by > > > mdev->iommu_device. It also adds a helper to add or set the iommu > > > device. > > > > > > * mdev_device->iommu_device > > > - This, if set, indicates that the mediated device could > > > be fully isolated and protected by IOMMU via attaching > > > an iommu domain to this device. If empty, it indicates > > > using vendor defined isolation, hence bypass IOMMU. > > > > > > * mdev_set/get_iommu_device(dev, iommu_device) > > > - Set or get the iommu device which represents this mdev > > > in IOMMU's device scope. Drivers don't need to set the > > > iommu device if it uses vendor defined isolation. > > > > > > Cc: Ashok Raj <[email protected]> > > > Cc: Jacob Pan <[email protected]> > > > Cc: Kevin Tian <[email protected]> > > > Cc: Liu Yi L <[email protected]> > > > Suggested-by: Kevin Tian <[email protected]> > > > Suggested-by: Alex Williamson <[email protected]> > > > Signed-off-by: Lu Baolu <[email protected]> > > > Reviewed-by: Jean-Philippe Brucker <[email protected]> > > > --- > > > drivers/vfio/mdev/mdev_core.c | 18 ++++++++++++++++++ > > > drivers/vfio/mdev/mdev_private.h | 1 + > > > include/linux/mdev.h | 14 ++++++++++++++ > > > 3 files changed, 33 insertions(+) > > > > > > diff --git a/drivers/vfio/mdev/mdev_core.c > > > b/drivers/vfio/mdev/mdev_core.c index b96fedc77ee5..1b6435529166 > > > 100644 > > > --- a/drivers/vfio/mdev/mdev_core.c > > > +++ b/drivers/vfio/mdev/mdev_core.c > > > @@ -390,6 +390,24 @@ int mdev_device_remove(struct device *dev, bool > > force_remove) > > > return 0; > > > } > > > > > > +int mdev_set_iommu_device(struct device *dev, struct device > > > +*iommu_device) { > > > + struct mdev_device *mdev = to_mdev_device(dev); > > > + > > > + mdev->iommu_device = iommu_device; > > > + > > > + return 0; > > > +} > > > +EXPORT_SYMBOL(mdev_set_iommu_device); > > > + > > > +struct device *mdev_get_iommu_device(struct device *dev) { > > > + struct mdev_device *mdev = to_mdev_device(dev); > > > + > > > + return mdev->iommu_device; > > > +} > > > +EXPORT_SYMBOL(mdev_get_iommu_device); > > > + > > > static int __init mdev_init(void) > > > { > > > return mdev_bus_register(); > > > diff --git a/drivers/vfio/mdev/mdev_private.h > > > b/drivers/vfio/mdev/mdev_private.h > > > index 379758c52b1b..bfb7b22a7cb6 100644 > > > --- a/drivers/vfio/mdev/mdev_private.h > > > +++ b/drivers/vfio/mdev/mdev_private.h > > > @@ -34,6 +34,7 @@ struct mdev_device { > > > struct list_head next; > > > struct kobject *type_kobj; > > > bool active; > > > + struct device *iommu_device; > > > }; > > > > This is not a performance path, but it is a good practice to create naturally > aligned/packed structures. > You should define struct device *iommu_device; before bool active. Agreed, if someone wants to fixup before commit or if there's another spin please do so, otherwise we can adjust it in a trivial follow-up patch. Thanks, Alex _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
