Hi Bharat,
Please add the IOMMU list on your next posting
On Mon, Mar 23, 2020 at 02:11:08PM +0530, 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 <bbhushan2@xxxxxxxxxxx>
> ---
> drivers/iommu/virtio-iommu.c | 24 ++++++++++++++++++++----
> include/uapi/linux/virtio_iommu.h | 6 ++++++
> 2 files changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
> index cce329d71fba..e69347ca4ee6 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_head resv_regions;
> + u64 pgsize_bitmap;
> };
>
> struct viommu_request {
> @@ -415,6 +416,14 @@ 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)
> +
> +{
> + vdev->pgsize_bitmap = mask->pgsize_bitmap;
We need to read this through le64_to_cpu(). Also check that the length of
the field provided by the device is >= sizeof(mask) (like
viommu_add_resv_mem() does)
> + return 0;
> +}
> +
> static int viommu_add_resv_mem(struct viommu_endpoint *vdev,
> struct virtio_iommu_probe_resv_mem *mem,
> size_t len)
> @@ -494,11 +503,13 @@ 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);
> -
> 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);
> + break;
> default:
> dev_err(dev, "unknown viommu prop 0x%x\n", type);
> }
> @@ -607,16 +618,21 @@ static struct iommu_domain *viommu_domain_alloc(unsigned type)
> return &vdomain->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;
> + if (vdev->pgsize_bitmap)
> + domain->pgsize_bitmap = vdev->pgsize_bitmap;
> + else
> + domain->pgsize_bitmap = viommu->pgsize_bitmap;
> +
nit: it could be nicer to initialize vdev->pgsize_bitmap in add_device(),
override it in probe_endpoint(), and just copy it here.
> domain->geometry = viommu->geometry;
>
> ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain,
> @@ -657,7 +673,7 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev)
> * Properly initialize the domain now that we know which viommu
> * owns it.
> */
> - ret = viommu_domain_finalise(vdev->viommu, domain);
> + ret = viommu_domain_finalise(vdev, domain);
Attaching additional endpoints with different masks to the domain should
return an error
> } else if (vdomain->viommu != vdev->viommu) {
> dev_err(dev, "cannot attach to foreign vIOMMU\n");
> ret = -EXDEV;
> diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h
> index 237e36a280cb..aff3db0ef54b 100644
> --- a/include/uapi/linux/virtio_iommu.h
> +++ b/include/uapi/linux/virtio_iommu.h
> @@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap {
>
> #define VIRTIO_IOMMU_PROBE_T_NONE 0
> #define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1
> +#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2
>
> #define VIRTIO_IOMMU_PROBE_T_MASK 0xfff
>
> @@ -119,6 +120,11 @@ struct virtio_iommu_probe_property {
> __le16 length;
> };
>
> +struct virtio_iommu_probe_pgsize_mask {
> + struct virtio_iommu_probe_property head;
Compilers will introduce 4 bytes of padding here, to align the next field.
We need to make them explicit by adding a 4-bytes 'reserved' field.
> + uint64_t pgsize_bitmap;
__le64
Thanks,
Jean
> +};
> +
> #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0
> #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1
>
> --
> 2.17.1
>
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