This reports device's reserved IOVA regions to userspace. This is needed in the nested translation as userspace owns stage-1 HWPT, and userspace needs to exclude the reserved IOVA regions in the stage-1 HWPT hence exclude them in the device's DMA address space.
This can also be used to figure out allowed IOVAs of an IOAS.
Signed-off-by: Yi Liu yi.l.liu@intel.com --- drivers/iommu/iommufd/main.c | 54 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/iommufd.h | 46 ++++++++++++++++++++++++++++++ 2 files changed, 100 insertions(+)
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index bd3efc1d8509..510db114fc61 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -250,6 +250,57 @@ static int iommufd_get_hw_info(struct iommufd_ucmd *ucmd) return rc; }
+static int iommufd_resv_iova_ranges(struct iommufd_ucmd *ucmd) +{ + struct iommu_resv_iova_ranges *cmd = ucmd->cmd; + struct iommu_resv_iova_range __user *ranges; + struct iommu_resv_region *resv; + struct iommufd_device *idev; + LIST_HEAD(resv_regions); + u32 max_iovas; + int rc; + + if (cmd->__reserved) + return -EOPNOTSUPP; + + idev = iommufd_get_device(ucmd, cmd->dev_id); + if (IS_ERR(idev)) + return PTR_ERR(idev); + + max_iovas = cmd->num_iovas; + ranges = u64_to_user_ptr(cmd->resv_iovas); + cmd->num_iovas = 0; + + iommu_get_resv_regions(idev->dev, &resv_regions); + + list_for_each_entry(resv, &resv_regions, list) { + if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE) + continue; + if (cmd->num_iovas < max_iovas) { + struct iommu_resv_iova_range elm = { + .start = resv->start, + .last = resv->length - 1 + resv->start, + }; + + if (copy_to_user(&ranges[cmd->num_iovas], &elm, + sizeof(elm))) { + rc = -EFAULT; + goto out_put; + } + } + cmd->num_iovas++; + } + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + if (rc) + goto out_put; + if (cmd->num_iovas > max_iovas) + rc = -EMSGSIZE; +out_put: + iommu_put_resv_regions(idev->dev, &resv_regions); + iommufd_put_object(&idev->obj); + return rc; +} + static int iommufd_fops_open(struct inode *inode, struct file *filp) { struct iommufd_ctx *ictx; @@ -347,6 +398,7 @@ union ucmd_buffer { struct iommu_ioas_map map; struct iommu_ioas_unmap unmap; struct iommu_option option; + struct iommu_resv_iova_ranges resv_ranges; struct iommu_vfio_ioas vfio_ioas; #ifdef CONFIG_IOMMUFD_TEST struct iommu_test_cmd test; @@ -389,6 +441,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { length), IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option, val64), + IOCTL_OP(IOMMU_RESV_IOVA_RANGES, iommufd_resv_iova_ranges, + struct iommu_resv_iova_ranges, resv_iovas), IOCTL_OP(IOMMU_VFIO_IOAS, iommufd_vfio_ioas, struct iommu_vfio_ioas, __reserved), #ifdef CONFIG_IOMMUFD_TEST diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index d38bc54fd5f2..f2026cde2d64 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -47,6 +47,7 @@ enum { IOMMUFD_CMD_VFIO_IOAS, IOMMUFD_CMD_HWPT_ALLOC, IOMMUFD_CMD_GET_HW_INFO, + IOMMUFD_CMD_RESV_IOVA_RANGES, };
/** @@ -422,4 +423,49 @@ struct iommu_hw_info { __u32 __reserved; }; #define IOMMU_GET_HW_INFO _IO(IOMMUFD_TYPE, IOMMUFD_CMD_GET_HW_INFO) + +/** + * struct iommu_resv_iova_range - ioctl(IOMMU_RESV_IOVA_RANGE) + * @start: First IOVA + * @last: Inclusive last IOVA + * + * An interval in IOVA space. + */ +struct iommu_resv_iova_range { + __aligned_u64 start; + __aligned_u64 last; +}; + +/** + * struct iommu_resv_iova_ranges - ioctl(IOMMU_RESV_IOVA_RANGES) + * @size: sizeof(struct iommu_resv_iova_ranges) + * @dev_id: device to read resv iova ranges for + * @num_iovas: Input/Output total number of resv ranges for the device + * @__reserved: Must be 0 + * @resv_iovas: Pointer to the output array of struct iommu_resv_iova_range + * + * Query a device for ranges of reserved IOVAs. num_iovas will be set to the + * total number of iovas and the resv_iovas[] will be filled in as space + * permits. + * + * On input num_iovas is the length of the resv_iovas array. On output it is + * the total number of iovas filled in. The ioctl will return -EMSGSIZE and + * set num_iovas to the required value if num_iovas is too small. In this + * case the caller should allocate a larger output array and re-issue the + * ioctl. + * + * Under nested translation, userspace should query the reserved IOVAs for a + * given device, and report it to the stage-1 I/O page table owner to exclude + * the reserved IOVAs. The reserved IOVAs can also be used to figure out the + * allowed IOVA ranges for the IOAS that the device is attached to. For detail + * see ioctl IOMMU_IOAS_IOVA_RANGES. + */ +struct iommu_resv_iova_ranges { + __u32 size; + __u32 dev_id; + __u32 num_iovas; + __u32 __reserved; + __aligned_u64 resv_iovas; +}; +#define IOMMU_RESV_IOVA_RANGES _IO(IOMMUFD_TYPE, IOMMUFD_CMD_RESV_IOVA_RANGES) #endif