Messages in this thread Patch in this message | | | From | Bharat Bhushan <> | Subject | [PATCH v6] iommu/virtio: Use page size bitmap supported by endpoint | Date | Thu, 14 May 2020 13:21:51 +0530 |
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Different endpoint can support different page size, probe endpoint if it supports specific page size otherwise use global page sizes.
Device attached to domain should support a minimum of domain supported page sizes. If device supports more than domain supported page sizes then device is limited to use domain supported page sizes only.
Signed-off-by: Bharat Bhushan <bbhushan2@marvell.com> --- v5->v6 - property length before dereference - Error out on no supported page sizes (page-size-mask is zero) - Allow device to attach to domain even it supports minimum of domain supported page sizes. In that case device will use domain page sizes only. - added format of pgsize_bitmap
v4->v5: - Rebase to Linux v5.7-rc4
v3->v4: - Fix whitespace error
v2->v3: - Fixed error return for incompatible endpoint - __u64 changed to __le64 in header file
drivers/iommu/virtio-iommu.c | 63 ++++++++++++++++++++++++++++--- include/uapi/linux/virtio_iommu.h | 14 ++++++- 2 files changed, 71 insertions(+), 6 deletions(-)
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index 4e1d11af23c8..cbac3047a781 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 +416,23 @@ 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; + + if (len < sizeof(*mask)) + return -EINVAL; + + pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap); + if (!pgsize_bitmap) + 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) @@ -499,6 +517,9 @@ static int viommu_probe_endpoint(struct viommu_dev *viommu, struct device *dev) 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); } @@ -615,7 +636,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev, struct viommu_dev *viommu = vdev->viommu; struct viommu_domain *vdomain = to_viommu_domain(domain); - viommu_page_size = 1UL << __ffs(viommu->pgsize_bitmap); + viommu_page_size = 1UL << __ffs(vdev->pgsize_bitmap); if (viommu_page_size > PAGE_SIZE) { dev_err(vdev->dev, "granule 0x%lx larger than system page size 0x%lx\n", @@ -630,7 +651,7 @@ static int viommu_domain_finalise(struct viommu_endpoint *vdev, vdomain->id = (unsigned int)ret; - domain->pgsize_bitmap = viommu->pgsize_bitmap; + domain->pgsize_bitmap = vdev->pgsize_bitmap; domain->geometry = viommu->geometry; vdomain->map_flags = viommu->map_flags; @@ -654,6 +675,38 @@ static void viommu_domain_free(struct iommu_domain *domain) kfree(vdomain); } +/* + * Check whether the endpoint's capabilities are compatible with other + * endpoints in the domain. Report any inconsistency. + */ +static bool viommu_endpoint_is_compatible(struct viommu_endpoint *vdev, + struct viommu_domain *vdomain) +{ + struct device *dev = vdev->dev; + u64 pgsize_bitmap; + + if (vdomain->viommu != vdev->viommu) { + dev_err(dev, "cannot attach to foreign vIOMMU\n"); + return false; + } + + pgsize_bitmap = vdomain->domain.pgsize_bitmap & vdev->pgsize_bitmap; + + if (pgsize_bitmap != vdomain->domain.pgsize_bitmap) { + dev_err(dev, "incompatible domain bitmap 0x%lx != 0x%llx\n", + vdomain->domain.pgsize_bitmap, vdev->pgsize_bitmap); + return false; + } + + /* Domain pagesize bitmap is subset of device pagesize bitmap */ + if (pgsize_bitmap != vdev->pgsize_bitmap) { + dev_info(dev, "page size bitmap used %llx, supported %llx\n", + pgsize_bitmap, vdev->pgsize_bitmap); + vdev->pgsize_bitmap = pgsize_bitmap; + } + return true; +} + static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) { int i; @@ -670,9 +723,8 @@ static int viommu_attach_dev(struct iommu_domain *domain, struct device *dev) * owns it. */ ret = viommu_domain_finalise(vdev, domain); - } else if (vdomain->viommu != vdev->viommu) { - dev_err(dev, "cannot attach to foreign vIOMMU\n"); - ret = -EXDEV; + } else if (!viommu_endpoint_is_compatible(vdev, vdomain)) { + ret = -EINVAL; } mutex_unlock(&vdomain->mutex); @@ -886,6 +938,7 @@ static int viommu_add_device(struct device *dev) vdev->dev = dev; vdev->viommu = viommu; + vdev->pgsize_bitmap = viommu->pgsize_bitmap; INIT_LIST_HEAD(&vdev->resv_regions); dev_iommu_priv_set(dev, vdev); diff --git a/include/uapi/linux/virtio_iommu.h b/include/uapi/linux/virtio_iommu.h index 48e3c29223b5..15a8327ffef5 100644 --- a/include/uapi/linux/virtio_iommu.h +++ b/include/uapi/linux/virtio_iommu.h @@ -28,7 +28,11 @@ struct virtio_iommu_range_32 { }; struct virtio_iommu_config { - /* Supported page sizes */ + /* + * Bitmap of supported page sizes. The least significant bit + * indicates the smallest granularity and the other bits are + * hints indicating optimal block sizes. + */ __u64 page_size_mask; /* Supported IOVA range */ struct virtio_iommu_range_64 input_range; @@ -111,6 +115,7 @@ 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 +124,13 @@ struct virtio_iommu_probe_property { __le16 length; }; +struct virtio_iommu_probe_pgsize_mask { + struct virtio_iommu_probe_property head; + __u8 reserved[4]; + /* Same format as virtio_iommu_config::page_size_mask */ + __le64 pgsize_bitmap; +}; + #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0 #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1 -- 2.17.1
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