> -Original Message-
> From: Jean-Philippe Brucker
> Sent: Wednesday, April 1, 2020 9:20 PM
> To: Robin Murphy
> Cc: Bharat Bhushan ; j...@8bytes.org;
> m...@redhat.com; jasow...@redhat.com; virtualization@lists.linux-
> foundation.org; iommu@lists.linux-foundation.org;
> linux-ker...@vger.kernel.org;
> eric.auger@gmail.com; eric.au...@redhat.com
> Subject: [EXT] Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap
> supported by
> endpoint
>
> External Email
>
> --
> On Wed, Apr 01, 2020 at 02:00:13PM +0100, Robin Murphy wrote:
> > On 2020-04-01 12:38 pm, Bharat Bhushan wrote:
> > > Different endpoint can support different page size, probe endpoint
> > > if it supports specific page size otherwise use global page sizes.
> > >
> > > Signed-off-by: Bharat Bhushan
> > > ---
> > > drivers/iommu/virtio-iommu.c | 33 +++
> > > include/uapi/linux/virtio_iommu.h | 7 +++
> > > 2 files changed, 36 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/iommu/virtio-iommu.c
> > > b/drivers/iommu/virtio-iommu.c index cce329d71fba..c794cb5b7b3e
> > > 100644
> > > --- a/drivers/iommu/virtio-iommu.c
> > > +++ b/drivers/iommu/virtio-iommu.c
> > > @@ -78,6 +78,7 @@ struct viommu_endpoint {
> > > struct viommu_dev *viommu;
> > > struct viommu_domain*vdomain;
> > > struct list_headresv_regions;
> > > + u64 pgsize_bitmap;
> > > };
> > > struct viommu_request {
> > > @@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct
> viommu_domain *vdomain)
> > > return ret;
> > > }
> > > +static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev,
> > > + struct virtio_iommu_probe_pgsize_mask *mask,
> > > + size_t len)
> > > +
> > > +{
> > > + u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap);
> > > +
> > > + if (len < sizeof(*mask))
> > > + return -EINVAL;
> > > +
> > > + vdev->pgsize_bitmap = pgsize_bitmap;
> > > + return 0;
> > > +}
> > > +
> > > static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
> > > struct virtio_iommu_probe_resv_mem *mem,
> > > size_t len)
> > > @@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct
> viommu_dev *viommu, struct device *dev)
> > > while (type != VIRTIO_IOMMU_PROBE_T_NONE &&
> > > cur < viommu->probe_size) {
> > > len = le16_to_cpu(prop->length) + sizeof(*prop);
> > > -
>
> Whitespace change
>
> > > switch (type) {
> > > case VIRTIO_IOMMU_PROBE_T_RESV_MEM:
> > > ret = viommu_add_resv_mem(vdev, (void *)prop,
> > > len);
> > > break;
> > > + case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK:
> > > + ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len);
> > > + break;
> > > default:
> > > dev_err(dev, "unknown viommu prop 0x%x\n",
> > > type);
> > > }
> > > @@ -607,16 +624,23 @@ static struct iommu_domain
> *viommu_domain_alloc(unsigned type)
> > > return >domain;
> > > }
> > > -static int viommu_domain_finalise(struct viommu_dev *viommu,
> > > +static int viommu_domain_finalise(struct viommu_endpoint *vdev,
> > > struct iommu_domain *domain)
> > > {
> > > int ret;
> > > struct viommu_domain *vdomain = to_viommu_domain(domain);
> > > + struct viommu_dev *viommu = vdev->viommu;
> > > vdomain->viommu = viommu;
> > > vdomain->map_flags = viommu->map_flags;
> > > - domain->pgsize_bitmap = viommu->pgsize_bitmap;
> > > + /* Devices in same domain must support same size pages */
> >
> > AFAICS what the code appears to do is enforce that the first endpoint
> > attached to any domain has the same pgsize_bitmap as the most recently
> > probed viommu_dev i
