diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h index 06b8c2e2d9e6..dcd609573244 100644 --- a/drivers/iommu/iommufd/iommufd_private.h +++ b/drivers/iommu/iommufd/iommufd_private.h @@ -652,6 +652,8 @@ int iommufd_viommu_alloc_ioctl(struct iommufd_ucmd *ucmd); void iommufd_viommu_destroy(struct iommufd_object *obj); int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd); void iommufd_vdevice_destroy(struct iommufd_object *obj); +int iommufd_hw_queue_alloc_ioctl(struct iommufd_ucmd *ucmd); +void iommufd_hw_queue_destroy(struct iommufd_object *obj); #ifdef CONFIG_IOMMUFD_TEST int iommufd_test(struct iommufd_ucmd *ucmd); diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c index 778694d7c207..4e8dbbfac890 100644 --- a/drivers/iommu/iommufd/main.c +++ b/drivers/iommu/iommufd/main.c @@ -354,6 +354,7 @@ union ucmd_buffer { struct iommu_destroy destroy; struct iommu_fault_alloc fault; struct iommu_hw_info info; + struct iommu_hw_queue_alloc hw_queue; struct iommu_hwpt_alloc hwpt; struct iommu_hwpt_get_dirty_bitmap get_dirty_bitmap; struct iommu_hwpt_invalidate cache; @@ -396,6 +397,8 @@ static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = { struct iommu_fault_alloc, out_fault_fd), IOCTL_OP(IOMMU_GET_HW_INFO, iommufd_get_hw_info, struct iommu_hw_info, __reserved), + IOCTL_OP(IOMMU_HW_QUEUE_ALLOC, iommufd_hw_queue_alloc_ioctl, + struct iommu_hw_queue_alloc, length), IOCTL_OP(IOMMU_HWPT_ALLOC, iommufd_hwpt_alloc, struct iommu_hwpt_alloc, __reserved), IOCTL_OP(IOMMU_HWPT_GET_DIRTY_BITMAP, iommufd_hwpt_get_dirty_bitmap, @@ -559,6 +562,9 @@ static const struct iommufd_object_ops iommufd_object_ops[] = { [IOMMUFD_OBJ_FAULT] = { .destroy = iommufd_fault_destroy, }, + [IOMMUFD_OBJ_HW_QUEUE] = { + .destroy = iommufd_hw_queue_destroy, + }, [IOMMUFD_OBJ_HWPT_PAGING] = { .destroy = iommufd_hwpt_paging_destroy, .abort = iommufd_hwpt_paging_abort, diff --git a/drivers/iommu/iommufd/viommu.c b/drivers/iommu/iommufd/viommu.c index 081ee6697a11..91339f799916 100644 --- a/drivers/iommu/iommufd/viommu.c +++ b/drivers/iommu/iommufd/viommu.c @@ -201,3 +201,183 @@ int iommufd_vdevice_alloc_ioctl(struct iommufd_ucmd *ucmd) iommufd_put_object(ucmd->ictx, &viommu->obj); return rc; } + +static void iommufd_hw_queue_destroy_access(struct iommufd_ctx *ictx, + struct iommufd_access *access, + u64 base_iova, size_t length) +{ + u64 aligned_iova = PAGE_ALIGN_DOWN(base_iova); + u64 offset = base_iova - aligned_iova; + + iommufd_access_unpin_pages(access, aligned_iova, + PAGE_ALIGN(length + offset)); + iommufd_access_detach_internal(access); + iommufd_access_destroy_internal(ictx, access); +} + +void iommufd_hw_queue_destroy(struct iommufd_object *obj) +{ + struct iommufd_hw_queue *hw_queue = + container_of(obj, struct iommufd_hw_queue, obj); + + if (hw_queue->destroy) + hw_queue->destroy(hw_queue); + if (hw_queue->access) + iommufd_hw_queue_destroy_access(hw_queue->viommu->ictx, + hw_queue->access, + hw_queue->base_addr, + hw_queue->length); + if (hw_queue->viommu) + refcount_dec(&hw_queue->viommu->obj.users); +} + +/* + * When the HW accesses the guest queue via physical addresses, the underlying + * physical pages of the guest queue must be contiguous. Also, for the security + * concern that IOMMUFD_CMD_IOAS_UNMAP could potentially remove the mappings of + * the guest queue from the nesting parent iopt while the HW is still accessing + * the guest queue memory physically, such a HW queue must require an access to + * pin the underlying pages and prevent that from happening. + */ +static struct iommufd_access * +iommufd_hw_queue_alloc_phys(struct iommu_hw_queue_alloc *cmd, + struct iommufd_viommu *viommu, phys_addr_t *base_pa) +{ + u64 aligned_iova = PAGE_ALIGN_DOWN(cmd->nesting_parent_iova); + u64 offset = cmd->nesting_parent_iova - aligned_iova; + struct iommufd_access *access; + struct page **pages; + size_t max_npages; + size_t length; + size_t i; + int rc; + + /* max_npages = DIV_ROUND_UP(offset + cmd->length, PAGE_SIZE) */ + if (check_add_overflow(offset, cmd->length, &length)) + return ERR_PTR(-ERANGE); + if (check_add_overflow(length, PAGE_SIZE - 1, &length)) + return ERR_PTR(-ERANGE); + max_npages = length / PAGE_SIZE; + /* length needs to be page aligned too */ + length = max_npages * PAGE_SIZE; + + /* + * Use kvcalloc() to avoid memory fragmentation for a large page array. + * Set __GFP_NOWARN to avoid syzkaller blowups + */ + pages = kvcalloc(max_npages, sizeof(*pages), GFP_KERNEL | __GFP_NOWARN); + if (!pages) + return ERR_PTR(-ENOMEM); + + access = iommufd_access_create_internal(viommu->ictx); + if (IS_ERR(access)) { + rc = PTR_ERR(access); + goto out_free; + } + + rc = iommufd_access_attach_internal(access, viommu->hwpt->ioas); + if (rc) + goto out_destroy; + + rc = iommufd_access_pin_pages(access, aligned_iova, length, pages, 0); + if (rc) + goto out_detach; + + /* Validate if the underlying physical pages are contiguous */ + for (i = 1; i < max_npages; i++) { + if (page_to_pfn(pages[i]) == page_to_pfn(pages[i - 1]) + 1) + continue; + rc = -EFAULT; + goto out_unpin; + } + + *base_pa = (page_to_pfn(pages[0]) << PAGE_SHIFT) + offset; + kfree(pages); + return access; + +out_unpin: + iommufd_access_unpin_pages(access, aligned_iova, length); +out_detach: + iommufd_access_detach_internal(access); +out_destroy: + iommufd_access_destroy_internal(viommu->ictx, access); +out_free: + kfree(pages); + return ERR_PTR(rc); +} + +int iommufd_hw_queue_alloc_ioctl(struct iommufd_ucmd *ucmd) +{ + struct iommu_hw_queue_alloc *cmd = ucmd->cmd; + struct iommufd_hw_queue *hw_queue; + struct iommufd_viommu *viommu; + struct iommufd_access *access; + size_t hw_queue_size; + phys_addr_t base_pa; + u64 last; + int rc; + + if (cmd->flags || cmd->type == IOMMU_HW_QUEUE_TYPE_DEFAULT) + return -EOPNOTSUPP; + if (!cmd->length) + return -EINVAL; + if (check_add_overflow(cmd->nesting_parent_iova, cmd->length - 1, + &last)) + return -EOVERFLOW; + + viommu = iommufd_get_viommu(ucmd, cmd->viommu_id); + if (IS_ERR(viommu)) + return PTR_ERR(viommu); + + if (!viommu->ops || !viommu->ops->get_hw_queue_size || + !viommu->ops->hw_queue_init_phys) { + rc = -EOPNOTSUPP; + goto out_put_viommu; + } + + hw_queue_size = viommu->ops->get_hw_queue_size(viommu, cmd->type); + if (!hw_queue_size) { + rc = -EOPNOTSUPP; + goto out_put_viommu; + } + + /* + * It is a driver bug for providing a hw_queue_size smaller than the + * core HW queue structure size + */ + if (WARN_ON_ONCE(hw_queue_size < sizeof(*hw_queue))) { + rc = -EOPNOTSUPP; + goto out_put_viommu; + } + + hw_queue = (struct iommufd_hw_queue *)_iommufd_object_alloc_ucmd( + ucmd, hw_queue_size, IOMMUFD_OBJ_HW_QUEUE); + if (IS_ERR(hw_queue)) { + rc = PTR_ERR(hw_queue); + goto out_put_viommu; + } + + access = iommufd_hw_queue_alloc_phys(cmd, viommu, &base_pa); + if (IS_ERR(access)) { + rc = PTR_ERR(access); + goto out_put_viommu; + } + + hw_queue->viommu = viommu; + refcount_inc(&viommu->obj.users); + hw_queue->access = access; + hw_queue->type = cmd->type; + hw_queue->length = cmd->length; + hw_queue->base_addr = cmd->nesting_parent_iova; + + rc = viommu->ops->hw_queue_init_phys(hw_queue, cmd->index, base_pa); + if (rc) + goto out_put_viommu; + + cmd->out_hw_queue_id = hw_queue->obj.id; + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd)); + +out_put_viommu: + iommufd_put_object(ucmd->ictx, &viommu->obj); + return rc; +} diff --git a/include/linux/iommufd.h b/include/linux/iommufd.h index f13f3ca6adb5..ce4011a2fc27 100644 --- a/include/linux/iommufd.h +++ b/include/linux/iommufd.h @@ -123,6 +123,7 @@ struct iommufd_vdevice { struct iommufd_hw_queue { struct iommufd_object obj; struct iommufd_viommu *viommu; + struct iommufd_access *access; u64 base_addr; /* in guest physical address space */ size_t length; diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h index 640a8b5147c2..b928c1ed2395 100644 --- a/include/uapi/linux/iommufd.h +++ b/include/uapi/linux/iommufd.h @@ -56,6 +56,7 @@ enum { IOMMUFD_CMD_VDEVICE_ALLOC = 0x91, IOMMUFD_CMD_IOAS_CHANGE_PROCESS = 0x92, IOMMUFD_CMD_VEVENTQ_ALLOC = 0x93, + IOMMUFD_CMD_HW_QUEUE_ALLOC = 0x94, }; /** @@ -1156,4 +1157,37 @@ enum iommu_hw_queue_type { IOMMU_HW_QUEUE_TYPE_DEFAULT = 0, }; +/** + * struct iommu_hw_queue_alloc - ioctl(IOMMU_HW_QUEUE_ALLOC) + * @size: sizeof(struct iommu_hw_queue_alloc) + * @flags: Must be 0 + * @viommu_id: Virtual IOMMU ID to associate the HW queue with + * @type: One of enum iommu_hw_queue_type + * @index: The logical index to the HW queue per virtual IOMMU for a multi-queue + * model + * @out_hw_queue_id: The ID of the new HW queue + * @nesting_parent_iova: Base address of the queue memory in the guest physical + * address space + * @length: Length of the queue memory + * + * Allocate a HW queue object for a vIOMMU-specific HW-accelerated queue, which + * allows HW to access a guest queue memory described using @nesting_parent_iova + * and @length. + * + * A vIOMMU can allocate multiple queues, but it must use a different @index per + * type to separate each allocation, e.g:: + * + * Type1 HW queue0, Type1 HW queue1, Type2 HW queue0, ... + */ +struct iommu_hw_queue_alloc { + __u32 size; + __u32 flags; + __u32 viommu_id; + __u32 type; + __u32 index; + __u32 out_hw_queue_id; + __aligned_u64 nesting_parent_iova; + __aligned_u64 length; +}; +#define IOMMU_HW_QUEUE_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_HW_QUEUE_ALLOC) #endif