Re: [PATCH v5 11/19] iommufd: IOCTLs for the io_pagetable

Eric Auger
2022-11-27T17:49:42Z

Hi Jason,

On 11/16/22 22:00, Jason Gunthorpe wrote:
> Connect the IOAS to its IOCTL interface. This exposes most of the
> functionality in the io_pagetable to userspace.
>
> This is intended to be the core of the generic interface that IOMMUFD will
> provide. Every IOMMU driver should be able to implement an iommu_domain
> that is compatible with this generic mechanism.
>
> It is also designed to be easy to use for simple non virtual machine
> monitor users, like DPDK:
> - Universal simple support for all IOMMUs (no PPC special path)
> - An IOVA allocator that considers the aperture and the allowed/reserved
> ranges
> - io_pagetable allows any number of iommu_domains to be connected to the
> IOAS
> - Automatic allocation and re-use of iommu_domains
>
> Along with room in the design to add non-generic features to cater to
> specific HW functionality.
>
> Tested-by: Nicolin Chen <nicolinc@nvidia.com>
> Tested-by: Yi Liu <yi.l.liu@intel.com>
> Tested-by: Lixiao Yang <lixiao.yang@intel.com>
> Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> ---
> drivers/iommu/iommufd/Makefile | 1 +
> drivers/iommu/iommufd/ioas.c | 384 ++++++++++++++++++++++++
> drivers/iommu/iommufd/iommufd_private.h | 33 ++
> drivers/iommu/iommufd/main.c | 45 +++
> include/uapi/linux/iommufd.h | 246 ++++++++++++++-
> 5 files changed, 708 insertions(+), 1 deletion(-)
> create mode 100644 drivers/iommu/iommufd/ioas.c
>
> diff --git a/drivers/iommu/iommufd/Makefile b/drivers/iommu/iommufd/Makefile
> index b66a8c47ff55ec..2b4f36f1b72f9d 100644
> --- a/drivers/iommu/iommufd/Makefile
> +++ b/drivers/iommu/iommufd/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0-only
> iommufd-y := \
> io_pagetable.o \
> + ioas.o \
> main.o \
> pages.o
>
> diff --git a/drivers/iommu/iommufd/ioas.c b/drivers/iommu/iommufd/ioas.c
> new file mode 100644
> index 00000000000000..7671456e86413a
> --- /dev/null
> +++ b/drivers/iommu/iommufd/ioas.c
> @@ -0,0 +1,384 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
> + */
> +#include <linux/interval_tree.h>
> +#include <linux/iommufd.h>
> +#include <linux/iommu.h>
> +#include <uapi/linux/iommufd.h>
> +
> +#include "io_pagetable.h"
> +
> +void iommufd_ioas_destroy(struct iommufd_object *obj)
> +{
> + struct iommufd_ioas *ioas = container_of(obj, struct iommufd_ioas, obj);
> + int rc;
> +
> + rc = iopt_unmap_all(&ioas->iopt, NULL);
> + WARN_ON(rc && rc != -ENOENT);
> + iopt_destroy_table(&ioas->iopt);
> +}
> +
> +struct iommufd_ioas *iommufd_ioas_alloc(struct iommufd_ctx *ictx)
> +{
> + struct iommufd_ioas *ioas;
> +
> + ioas = iommufd_object_alloc(ictx, ioas, IOMMUFD_OBJ_IOAS);
> + if (IS_ERR(ioas))
> + return ioas;
> +
> + iopt_init_table(&ioas->iopt);
> + return ioas;
> +}
> +
> +int iommufd_ioas_alloc_ioctl(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_ioas_alloc *cmd = ucmd->cmd;
> + struct iommufd_ioas *ioas;
> + int rc;
> +
> + if (cmd->flags)
> + return -EOPNOTSUPP;
> +
> + ioas = iommufd_ioas_alloc(ucmd->ictx);
> + if (IS_ERR(ioas))
> + return PTR_ERR(ioas);
> +
> + cmd->out_ioas_id = ioas->obj.id;
> + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
> + if (rc)
> + goto out_table;
> + iommufd_object_finalize(ucmd->ictx, &ioas->obj);
> + return 0;
> +
> +out_table:
> + iommufd_object_abort_and_destroy(ucmd->ictx, &ioas->obj);
> + return rc;
> +}
> +
> +int iommufd_ioas_iova_ranges(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_iova_range __user *ranges;
> + struct iommu_ioas_iova_ranges *cmd = ucmd->cmd;
> + struct iommufd_ioas *ioas;
> + struct interval_tree_span_iter span;
> + u32 max_iovas;
> + int rc;
> +
> + if (cmd->__reserved)
> + return -EOPNOTSUPP;
> +
> + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
> + if (IS_ERR(ioas))
> + return PTR_ERR(ioas);
> +
> + down_read(&ioas->iopt.iova_rwsem);
> + max_iovas = cmd->num_iovas;
> + ranges = u64_to_user_ptr(cmd->allowed_iovas);
> + cmd->num_iovas = 0;
> + cmd->out_iova_alignment = ioas->iopt.iova_alignment;
> + interval_tree_for_each_span(&span, &ioas->iopt.reserved_itree, 0,
> + ULONG_MAX) {
> + if (!span.is_hole)
> + continue;
> + if (cmd->num_iovas < max_iovas) {
> + struct iommu_iova_range elm = {
> + .start = span.start_hole,
> + .last = span.last_hole,
> + };
> +
> + 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:
> + up_read(&ioas->iopt.iova_rwsem);
> + iommufd_put_object(&ioas->obj);
> + return rc;
> +}
> +
> +static int iommufd_ioas_load_iovas(struct rb_root_cached *itree,
> + struct iommu_iova_range __user *ranges,
> + u32 num)
> +{
> + u32 i;
> +
> + for (i = 0; i != num; i++) {
shouldn't it be < ?
> + struct iommu_iova_range range;
> + struct iopt_allowed *allowed;
> +
> + if (copy_from_user(&range, ranges + i, sizeof(range)))
> + return -EFAULT;
> +
> + if (range.start >= range.last)
> + return -EINVAL;
> +
> + if (interval_tree_iter_first(itree, range.start, range.last))
> + return -EINVAL;
> +
> + allowed = kzalloc(sizeof(*allowed), GFP_KERNEL_ACCOUNT);
> + if (!allowed)
> + return -ENOMEM;
> + allowed->node.start = range.start;
> + allowed->node.last = range.last;
> +
> + interval_tree_insert(&allowed->node, itree);
> + }
> + return 0;
> +}
> +
> +int iommufd_ioas_allow_iovas(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_ioas_allow_iovas *cmd = ucmd->cmd;
> + struct rb_root_cached allowed_iova = RB_ROOT_CACHED;
> + struct interval_tree_node *node;
> + struct iommufd_ioas *ioas;
> + struct io_pagetable *iopt;
> + int rc = 0;
> +
> + if (cmd->__reserved)
> + return -EOPNOTSUPP;
> +
> + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
> + if (IS_ERR(ioas))
> + return PTR_ERR(ioas);
> + iopt = &ioas->iopt;
> +
> + rc = iommufd_ioas_load_iovas(&allowed_iova,
> + u64_to_user_ptr(cmd->allowed_iovas),
> + cmd->num_iovas);
> + if (rc)
> + goto out_free;
> +
> + rc = iopt_set_allow_iova(iopt, &allowed_iova);
Please can you add a comment about why you need to proceed in 2 steps,
ie. add the ranges in a first tree and then 'swap' to the
iopt->allowed_tree (and eventually delete the first tree)?
> +out_free:
> + while ((node = interval_tree_iter_first(&allowed_iova, 0, ULONG_MAX))) {
> + interval_tree_remove(node, &allowed_iova);
> + kfree(container_of(node, struct iopt_allowed, node));
> + }
> + iommufd_put_object(&ioas->obj);
> + return rc;
> +}
> +
> +static int conv_iommu_prot(u32 map_flags)
> +{
> + int iommu_prot;
> +
> + /*
> + * We provide no manual cache coherency ioctls to userspace and most
> + * architectures make the CPU ops for cache flushing privileged.
> + * Therefore we require the underlying IOMMU to support CPU coherent
> + * operation. Support for IOMMU_CACHE is enforced by the
> + * IOMMU_CAP_CACHE_COHERENCY test during bind.
> + */
> + iommu_prot = IOMMU_CACHE;
at init?
> + if (map_flags & IOMMU_IOAS_MAP_WRITEABLE)
> + iommu_prot |= IOMMU_WRITE;
> + if (map_flags & IOMMU_IOAS_MAP_READABLE)
> + iommu_prot |= IOMMU_READ;
> + return iommu_prot;
> +}
> +
> +int iommufd_ioas_map(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_ioas_map *cmd = ucmd->cmd;
> + struct iommufd_ioas *ioas;
> + unsigned int flags = 0;
> + unsigned long iova;
> + int rc;
> +
> + if ((cmd->flags &
> + ~(IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE |
> + IOMMU_IOAS_MAP_READABLE)) ||
> + cmd->__reserved)
> + return -EOPNOTSUPP;
> + if (cmd->iova >= ULONG_MAX || cmd->length >= ULONG_MAX)
> + return -EOVERFLOW;
> +
> + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
> + if (IS_ERR(ioas))
> + return PTR_ERR(ioas);
> +
> + if (!(cmd->flags & IOMMU_IOAS_MAP_FIXED_IOVA))
> + flags = IOPT_ALLOC_IOVA;
> + iova = cmd->iova;
can be done either at initialization or only if MAP_FIXED_IOVA.
> + rc = iopt_map_user_pages(ucmd->ictx, &ioas->iopt, &iova,
> + u64_to_user_ptr(cmd->user_va), cmd->length,
> + conv_iommu_prot(cmd->flags), flags);
> + if (rc)
> + goto out_put;
> +
> + cmd->iova = iova;
> + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
> +out_put:
> + iommufd_put_object(&ioas->obj);
> + return rc;
> +}
> +
> +int iommufd_ioas_copy(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_ioas_copy *cmd = ucmd->cmd;
> + struct iommufd_ioas *src_ioas;
> + struct iommufd_ioas *dst_ioas;
> + unsigned int flags = 0;
> + LIST_HEAD(pages_list);
> + unsigned long iova;
> + int rc;
> +
> + if ((cmd->flags &
> + ~(IOMMU_IOAS_MAP_FIXED_IOVA | IOMMU_IOAS_MAP_WRITEABLE |
> + IOMMU_IOAS_MAP_READABLE)))
> + return -EOPNOTSUPP;
> + if (cmd->length >= ULONG_MAX || cmd->src_iova >= ULONG_MAX ||
> + cmd->dst_iova >= ULONG_MAX)
> + return -EOVERFLOW;
> +
> + src_ioas = iommufd_get_ioas(ucmd, cmd->src_ioas_id);
> + if (IS_ERR(src_ioas))
> + return PTR_ERR(src_ioas);
> + rc = iopt_get_pages(&src_ioas->iopt, cmd->src_iova, cmd->length,
> + &pages_list);
> + iommufd_put_object(&src_ioas->obj);
> + if (rc)
> + return rc;
> +
> + dst_ioas = iommufd_get_ioas(ucmd, cmd->dst_ioas_id);
> + if (IS_ERR(dst_ioas)) {
> + rc = PTR_ERR(dst_ioas);
> + goto out_pages;
> + }
> +
> + if (!(cmd->flags & IOMMU_IOAS_MAP_FIXED_IOVA))
> + flags = IOPT_ALLOC_IOVA;
> + iova = cmd->dst_iova;
> + rc = iopt_map_pages(&dst_ioas->iopt, &pages_list, cmd->length, &iova,
> + conv_iommu_prot(cmd->flags), flags);
> + if (rc)
> + goto out_put_dst;
> +
> + cmd->dst_iova = iova;
> + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
> +out_put_dst:
> + iommufd_put_object(&dst_ioas->obj);
> +out_pages:
> + iopt_free_pages_list(&pages_list);
> + return rc;
> +}
> +
> +int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_ioas_unmap *cmd = ucmd->cmd;
> + struct iommufd_ioas *ioas;
> + unsigned long unmapped = 0;
> + int rc;
> +
> + ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
> + if (IS_ERR(ioas))
> + return PTR_ERR(ioas);
> +
> + if (cmd->iova == 0 && cmd->length == U64_MAX) {
> + rc = iopt_unmap_all(&ioas->iopt, &unmapped);
> + if (rc)
> + goto out_put;
> + } else {
> + if (cmd->iova >= ULONG_MAX || cmd->length >= ULONG_MAX) {
> + rc = -EOVERFLOW;
> + goto out_put;
> + }
> + rc = iopt_unmap_iova(&ioas->iopt, cmd->iova, cmd->length,
> + &unmapped);
> + if (rc)
> + goto out_put;
> + }
> +
> + cmd->length = unmapped;
> + rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
> +
> +out_put:
> + iommufd_put_object(&ioas->obj);
> + return rc;
> +}
> +
> +int iommufd_option_rlimit_mode(struct iommu_option *cmd,
> + struct iommufd_ctx *ictx)
> +{
*object_id  and __reserved should be checked as per the uapi doc*
> + if (cmd->op == IOMMU_OPTION_OP_GET) {
> + cmd->val64 = ictx->account_mode == IOPT_PAGES_ACCOUNT_MM;
> + return 0;
> + }
> + if (cmd->op == IOMMU_OPTION_OP_SET) {
> + int rc = 0;
> +
> + if (!capable(CAP_SYS_RESOURCE))
> + return -EPERM;
> +
> + xa_lock(&ictx->objects);
> + if (!xa_empty(&ictx->objects)) {
> + rc = -EBUSY;
> + } else {
> + if (cmd->val64 == 0)
> + ictx->account_mode = IOPT_PAGES_ACCOUNT_USER;
> + else if (cmd->val64 == 1)
> + ictx->account_mode = IOPT_PAGES_ACCOUNT_MM;
> + else
> + rc = -EINVAL;
> + }
> + xa_unlock(&ictx->objects);
> +
> + return rc;
> + }
> + return -EOPNOTSUPP;
> +}
> +
> +static int iommufd_ioas_option_huge_pages(struct iommu_option *cmd,
> + struct iommufd_ioas *ioas)
> +{
> + if (cmd->op == IOMMU_OPTION_OP_GET) {
> + cmd->val64 = !ioas->iopt.disable_large_pages;
> + return 0;
> + }
> + if (cmd->op == IOMMU_OPTION_OP_SET) {
> + if (cmd->val64 == 0)
> + return iopt_disable_large_pages(&ioas->iopt);
> + if (cmd->val64 == 1) {
> + iopt_enable_large_pages(&ioas->iopt);
> + return 0;
> + }
> + return -EINVAL;
> + }
> + return -EOPNOTSUPP;
> +}
> +
> +int iommufd_ioas_option(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_option *cmd = ucmd->cmd;
> + struct iommufd_ioas *ioas;
> + int rc = 0;
> +
> + if (cmd->__reserved)
> + return -EOPNOTSUPP;
> +
> + ioas = iommufd_get_ioas(ucmd, cmd->object_id);
> + if (IS_ERR(ioas))
> + return PTR_ERR(ioas);
> +
> + switch (cmd->option_id) {
> + case IOMMU_OPTION_HUGE_PAGES:
> + rc = iommufd_ioas_option_huge_pages(cmd, ioas);
> + break;
> + default:
> + rc = -EOPNOTSUPP;
> + }
> +
> + iommufd_put_object(&ioas->obj);
> + return rc;
> +}
> diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
> index dadd90cae543ba..6721332dbbba03 100644
> --- a/drivers/iommu/iommufd/iommufd_private.h
> +++ b/drivers/iommu/iommufd/iommufd_private.h
> @@ -11,6 +11,7 @@
>
> struct iommu_domain;
> struct iommu_group;
> +struct iommu_option;
>
> struct iommufd_ctx {
> struct file *file;
> @@ -102,6 +103,7 @@ static inline int iommufd_ucmd_respond(struct iommufd_ucmd *ucmd,
> enum iommufd_object_type {
> IOMMUFD_OBJ_NONE,
> IOMMUFD_OBJ_ANY = IOMMUFD_OBJ_NONE,
> + IOMMUFD_OBJ_IOAS,
> };
>
> /* Base struct for all objects with a userspace ID handle. */
> @@ -174,6 +176,37 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
> type), \
> typeof(*(ptr)), obj)
>
> +/*
> + * The IO Address Space (IOAS) pagetable is a virtual page table backed by the
> + * io_pagetable object. It is a user controlled mapping of IOVA -> PFNs. The
> + * mapping is copied into all of the associated domains and made available to
> + * in-kernel users.
> + */
> +struct iommufd_ioas {
> + struct iommufd_object obj;
> + struct io_pagetable iopt;
> +};
> +
> +static inline struct iommufd_ioas *iommufd_get_ioas(struct iommufd_ucmd *ucmd,
> + u32 id)
> +{
> + return container_of(iommufd_get_object(ucmd->ictx, id,
> + IOMMUFD_OBJ_IOAS),
> + struct iommufd_ioas, obj);
> +}
> +
> +struct iommufd_ioas *iommufd_ioas_alloc(struct iommufd_ctx *ictx);
> +int iommufd_ioas_alloc_ioctl(struct iommufd_ucmd *ucmd);
> +void iommufd_ioas_destroy(struct iommufd_object *obj);
> +int iommufd_ioas_iova_ranges(struct iommufd_ucmd *ucmd);
> +int iommufd_ioas_allow_iovas(struct iommufd_ucmd *ucmd);
> +int iommufd_ioas_map(struct iommufd_ucmd *ucmd);
> +int iommufd_ioas_copy(struct iommufd_ucmd *ucmd);
> +int iommufd_ioas_unmap(struct iommufd_ucmd *ucmd);
> +int iommufd_ioas_option(struct iommufd_ucmd *ucmd);
> +int iommufd_option_rlimit_mode(struct iommu_option *cmd,
> + struct iommufd_ctx *ictx);
> +
> struct iommufd_access {
> unsigned long iova_alignment;
> u32 iopt_access_list_id;
> diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
> index 3a705cadb85020..266109045537ed 100644
> --- a/drivers/iommu/iommufd/main.c
> +++ b/drivers/iommu/iommufd/main.c
> @@ -202,8 +202,36 @@ static int iommufd_fops_release(struct inode *inode, struct file *filp)
> return 0;
> }
>
> +static int iommufd_option(struct iommufd_ucmd *ucmd)
> +{
> + struct iommu_option *cmd = ucmd->cmd;
> + int rc;
__reserved can be checked here instead.
> + switch (cmd->option_id) {
> + case IOMMU_OPTION_RLIMIT_MODE:
> + rc = iommufd_option_rlimit_mode(cmd, ucmd->ictx);
> + break;
> + case IOMMU_OPTION_HUGE_PAGES:
> + rc = iommufd_ioas_option(ucmd);
> + break;
> + default:
> + return -EOPNOTSUPP;
> + }
> + if (rc)
> + return rc;
> + if (copy_to_user(&((struct iommu_option __user *)ucmd->ubuffer)->val64,
> + &cmd->val64, sizeof(cmd->val64)))
> + return -EFAULT;
> + return 0;
> +}
> +
> union ucmd_buffer {
> struct iommu_destroy destroy;
> + struct iommu_ioas_alloc alloc;
> + struct iommu_ioas_allow_iovas allow_iovas;
> + struct iommu_ioas_iova_ranges iova_ranges;
> + struct iommu_ioas_map map;
> + struct iommu_ioas_unmap unmap;
> };
>
> struct iommufd_ioctl_op {
> @@ -224,6 +252,20 @@ struct iommufd_ioctl_op {
> }
> static const struct iommufd_ioctl_op iommufd_ioctl_ops[] = {
> IOCTL_OP(IOMMU_DESTROY, iommufd_destroy, struct iommu_destroy, id),
> + IOCTL_OP(IOMMU_IOAS_ALLOC, iommufd_ioas_alloc_ioctl,
> + struct iommu_ioas_alloc, out_ioas_id),
> + IOCTL_OP(IOMMU_IOAS_ALLOW_IOVAS, iommufd_ioas_allow_iovas,
> + struct iommu_ioas_allow_iovas, allowed_iovas),
> + IOCTL_OP(IOMMU_IOAS_COPY, iommufd_ioas_copy, struct iommu_ioas_copy,
> + src_iova),
> + IOCTL_OP(IOMMU_IOAS_IOVA_RANGES, iommufd_ioas_iova_ranges,
> + struct iommu_ioas_iova_ranges, out_iova_alignment),
> + IOCTL_OP(IOMMU_IOAS_MAP, iommufd_ioas_map, struct iommu_ioas_map,
> + iova),
> + IOCTL_OP(IOMMU_IOAS_UNMAP, iommufd_ioas_unmap, struct iommu_ioas_unmap,
> + length),
> + IOCTL_OP(IOMMU_OPTION, iommufd_option, struct iommu_option,
> + val64),
> };
>
> static long iommufd_fops_ioctl(struct file *filp, unsigned int cmd,
> @@ -310,6 +352,9 @@ void iommufd_ctx_put(struct iommufd_ctx *ictx)
> EXPORT_SYMBOL_NS_GPL(iommufd_ctx_put, IOMMUFD);
>
> static const struct iommufd_object_ops iommufd_object_ops[] = {
> + [IOMMUFD_OBJ_IOAS] = {
> + .destroy = iommufd_ioas_destroy,
> + },
> };
>
> static struct miscdevice iommu_misc_dev = {
> diff --git a/include/uapi/linux/iommufd.h b/include/uapi/linux/iommufd.h
> index 2ad06b27a35fe5..9e9250dfc4fb1b 100644
> --- a/include/uapi/linux/iommufd.h
> +++ b/include/uapi/linux/iommufd.h
> @@ -37,12 +37,19 @@
> enum {
> IOMMUFD_CMD_BASE = 0x80,
> IOMMUFD_CMD_DESTROY = IOMMUFD_CMD_BASE,
> + IOMMUFD_CMD_IOAS_ALLOC,
> + IOMMUFD_CMD_IOAS_ALLOW_IOVAS,
> + IOMMUFD_CMD_IOAS_COPY,
> + IOMMUFD_CMD_IOAS_IOVA_RANGES,
> + IOMMUFD_CMD_IOAS_MAP,
> + IOMMUFD_CMD_IOAS_UNMAP,
> + IOMMUFD_CMD_OPTION,
> };
>
> /**
> * struct iommu_destroy - ioctl(IOMMU_DESTROY)
> * @size: sizeof(struct iommu_destroy)
> - * @id: iommufd object ID to destroy. Can by any destroyable object type.
> + * @id: iommufd object ID to destroy. Can be any destroyable object type.
> *
> * Destroy any object held within iommufd.
> */
> @@ -52,4 +59,241 @@ struct iommu_destroy {
> };
> #define IOMMU_DESTROY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_DESTROY)
>
> +/**
> + * struct iommu_ioas_alloc - ioctl(IOMMU_IOAS_ALLOC)
> + * @size: sizeof(struct iommu_ioas_alloc)
> + * @flags: Must be 0
> + * @out_ioas_id: Output IOAS ID for the allocated object
> + *
> + * Allocate an IO Address Space (IOAS) which holds an IO Virtual Address (IOVA)
> + * to memory mapping.
> + */
> +struct iommu_ioas_alloc {
> + __u32 size;
> + __u32 flags;
> + __u32 out_ioas_id;
> +};
> +#define IOMMU_IOAS_ALLOC _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOC)
> +
> +/**
> + * struct iommu_iova_range - ioctl(IOMMU_IOVA_RANGE)
> + * @start: First IOVA
> + * @last: Inclusive last IOVA
> + *
> + * An interval in IOVA space.
> + */
> +struct iommu_iova_range {
> + __aligned_u64 start;
> + __aligned_u64 last;
> +};
> +
> +/**
> + * struct iommu_ioas_iova_ranges - ioctl(IOMMU_IOAS_IOVA_RANGES)
> + * @size: sizeof(struct iommu_ioas_iova_ranges)
> + * @ioas_id: IOAS ID to read ranges from
> + * @num_iovas: Input/Output total number of ranges in the IOAS
> + * @__reserved: Must be 0
> + * @allowed_iovas: Pointer to the output array of struct iommu_iova_range
> + * @out_iova_alignment: Minimum alignment required for mapping IOVA
> + *
> + * Query an IOAS for ranges of allowed IOVAs. Mapping IOVA outside these ranges
> + * is not allowed. num_iovas will be set to the total number of iovas and
> + * the allowed_iovas[] will be filled in as space permits.
> + *
> + * The allowed ranges are dependent on the HW path the DMA operation takes, and
> + * can change during the lifetime of the IOAS. A fresh empty IOAS will have a
> + * full range, and each attached device will narrow the ranges based on that
> + * device's HW restrictions. Detatching a device can widen the ranges. Userspace
detaching
> + * should query ranges after every attach/detatch to know what IOVAs are valid
detach
> + * for mapping.
> + *
> + * On input num_iovas is the length of the allowed_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.
> + */
> +struct iommu_ioas_iova_ranges {
> + __u32 size;
> + __u32 ioas_id;
> + __u32 num_iovas;
> + __u32 __reserved;
> + __aligned_u64 allowed_iovas;
> + __aligned_u64 out_iova_alignment;
document @out_iova_alignment?
> +};
> +#define IOMMU_IOAS_IOVA_RANGES _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_IOVA_RANGES)
> +
> +/**
> + * struct iommu_ioas_allow_iovas - ioctl(IOMMU_IOAS_ALLOW_IOVAS)
> + * @size: sizeof(struct iommu_ioas_allow_iovas)
> + * @ioas_id: IOAS ID to allow IOVAs from
> + * @num_iovas: Input/Output total number of ranges in the IOAS
> + * @__reserved: Must be 0
> + * @allowed_iovas: Pointer to array of struct iommu_iova_range
> + *
> + * Ensure a range of IOVAs are always available for allocation. If this call
> + * succeeds then IOMMU_IOAS_IOVA_RANGES will never return a list of IOVA ranges
> + * that are narrower than the ranges provided here. This call will fail if
> + * IOMMU_IOAS_IOVA_RANGES is currently narrower than the given ranges.
> + *
> + * When an IOAS is first created the IOVA_RANGES will be maximally sized, and as
> + * devices are attached the IOVA will narrow based on the device restrictions.
> + * When an allowed range is specified any narrowing will be refused, ie device
> + * attachment can fail if the device requires limiting within the allowed range.
> + *
> + * Automatic IOVA allocation is also impacted by this call. MAP will only
> + * allocate within the allowed IOVAs if they are present.
> + *
> + * This call replaces the entire allowed list with the given list.
> + */
> +struct iommu_ioas_allow_iovas {
> + __u32 size;
> + __u32 ioas_id;
> + __u32 num_iovas;
> + __u32 __reserved;
> + __aligned_u64 allowed_iovas;
> +};
> +#define IOMMU_IOAS_ALLOW_IOVAS _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_ALLOW_IOVAS)
> +
> +/**
> + * enum iommufd_ioas_map_flags - Flags for map and copy
> + * @IOMMU_IOAS_MAP_FIXED_IOVA: If clear the kernel will compute an appropriate
> + * IOVA to place the mapping at
> + * @IOMMU_IOAS_MAP_WRITEABLE: DMA is allowed to write to this mapping
> + * @IOMMU_IOAS_MAP_READABLE: DMA is allowed to read from this mapping
> + */
> +enum iommufd_ioas_map_flags {
> + IOMMU_IOAS_MAP_FIXED_IOVA = 1 << 0,
> + IOMMU_IOAS_MAP_WRITEABLE = 1 << 1,
> + IOMMU_IOAS_MAP_READABLE = 1 << 2,
> +};
> +
> +/**
> + * struct iommu_ioas_map - ioctl(IOMMU_IOAS_MAP)
> + * @size: sizeof(struct iommu_ioas_map)
> + * @flags: Combination of enum iommufd_ioas_map_flags
> + * @ioas_id: IOAS ID to change the mapping of
> + * @__reserved: Must be 0
> + * @user_va: Userspace pointer to start mapping from
> + * @length: Number of bytes to map
> + * @iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is set
> + * then this must be provided as input.
> + *
> + * Set an IOVA mapping from a user pointer. If FIXED_IOVA is specified then the
> + * mapping will be established at iova, otherwise a suitable location based on
> + * the reserved and allowed lists will be automatically selected and returned in
> + * iova.
You do not mention anything about the fact the IOCTL cannot be called
twice for a given @user_va w/ FIXED_IOVA
Refering to VFIO_DMA_MAP_FLAG_VADDR.
> + */
> +struct iommu_ioas_map {
> + __u32 size;
> + __u32 flags;
> + __u32 ioas_id;
> + __u32 __reserved;
> + __aligned_u64 user_va;
> + __aligned_u64 length;
> + __aligned_u64 iova;
> +};
> +#define IOMMU_IOAS_MAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_MAP)
> +
> +/**
> + * struct iommu_ioas_copy - ioctl(IOMMU_IOAS_COPY)
> + * @size: sizeof(struct iommu_ioas_copy)
> + * @flags: Combination of enum iommufd_ioas_map_flags
> + * @dst_ioas_id: IOAS ID to change the mapping of
> + * @src_ioas_id: IOAS ID to copy from
> + * @length: Number of bytes to copy and map
> + * @dst_iova: IOVA the mapping was placed at. If IOMMU_IOAS_MAP_FIXED_IOVA is
> + * set then this must be provided as input.
> + * @src_iova: IOVA to start the copy
> + *
> + * Copy an already existing mapping from src_ioas_id and establish it in
> + * dst_ioas_id. The src iova/length must exactly match a range used with
> + * IOMMU_IOAS_MAP.
> + *
> + * This may be used to efficiently clone a subset of an IOAS to another, or as a
> + * kind of 'cache' to speed up mapping. Copy has an effciency advantage over
efficiency
> + * establishing equivalent new mappings, as internal resources are shared, and
> + * the kernel will pin the user memory only once.
> + */
> +struct iommu_ioas_copy {
> + __u32 size;
> + __u32 flags;
> + __u32 dst_ioas_id;
> + __u32 src_ioas_id;
is src_ioas_id == dst_ioas_id allowed?
> + __aligned_u64 length;
> + __aligned_u64 dst_iova;
> + __aligned_u64 src_iova;
> +};
> +#define IOMMU_IOAS_COPY _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_COPY)
> +
> +/**
> + * struct iommu_ioas_unmap - ioctl(IOMMU_IOAS_UNMAP)
> + * @size: sizeof(struct iommu_ioas_unmap)
> + * @ioas_id: IOAS ID to change the mapping of
> + * @iova: IOVA to start the unmapping at
> + * @length: Number of bytes to unmap, and return back the bytes unmapped
> + *
> + * Unmap an IOVA range. The iova/length must be a superset of a previously
> + * mapped range used with IOMMU_IOAS_MAP or IOMMU_IOAS_COPY. Splitting or
> + * truncating ranges is not allowed. The values 0 to U64_MAX will unmap
> + * everything.
> + */
> +struct iommu_ioas_unmap {
> + __u32 size;
> + __u32 ioas_id;
> + __aligned_u64 iova;
> + __aligned_u64 length;
> +};
> +#define IOMMU_IOAS_UNMAP _IO(IOMMUFD_TYPE, IOMMUFD_CMD_IOAS_UNMAP)
> +
> +/**
> + * enum iommufd_option - ioctl(IOMMU_OPTION_RLIMIT_MODE) and
> + * ioctl(IOMMU_OPTION_HUGE_PAGES)
> + * @IOMMU_OPTION_RLIMIT_MODE:
> + * Change how RLIMIT_MEMLOCK accounting works. The caller must have privilege
> + * to invoke this. Value 0 (default) is user based accouting, 1 uses process
> + * based accounting. Global option, object_id must be 0
> + * @IOMMU_OPTION_HUGE_PAGES:
> + * Value 1 (default) allows contiguous pages to be combined when generating
> + * iommu mappings. Value 0 disables combining, everything is mapped to
> + * PAGE_SIZE. This can be useful for benchmarking. This is a per-IOAS
> + * option, the object_id must be the IOAS ID.
> + */
> +enum iommufd_option {
> + IOMMU_OPTION_RLIMIT_MODE = 0,
> + IOMMU_OPTION_HUGE_PAGES = 1,
> +};
> +
> +/**
> + * enum iommufd_option_ops - ioctl(IOMMU_OPTION_OP_SET) and
> + * ioctl(IOMMU_OPTION_OP_GET)
> + * @IOMMU_OPTION_OP_SET: Set the option's value
> + * @IOMMU_OPTION_OP_GET: Get the option's value
> + */
> +enum iommufd_option_ops {
> + IOMMU_OPTION_OP_SET = 0,
> + IOMMU_OPTION_OP_GET = 1,
> +};
> +
> +/**
> + * struct iommu_option - iommu option multiplexer
> + * @size: sizeof(struct iommu_option)
> + * @option_id: One of enum iommufd_option
> + * @op: One of enum iommufd_option_ops
> + * @__reserved: Must be 0
> + * @object_id: ID of the object if required
> + * @val64: Option value to set or value returned on get
> + *
> + * Change a simple option value. This multiplexor allows controlling a options
s/a options/options
> + * on objects. IOMMU_OPTION_OP_SET will load an option and IOMMU_OPTION_OP_GET
> + * will return the current value.
> + */
> +struct iommu_option {
> + __u32 size;
> + __u32 option_id;
> + __u16 op;
> + __u16 __reserved;
> + __u32 object_id;
> + __aligned_u64 val64;
> +};
> +#define IOMMU_OPTION _IO(IOMMUFD_TYPE, IOMMUFD_CMD_OPTION)
> #endif
Thanks

Eric