blob: 514494a0025b99079ff188b54f0bc136ad0d7951 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
*/
#include <linux/file.h>
#include <linux/interval_tree.h>
#include <linux/iommu.h>
#include <linux/iommufd.h>
#include <linux/slab.h>
#include <linux/vfio.h>
#include <uapi/linux/vfio.h>
#include <uapi/linux/iommufd.h>
#include "iommufd_private.h"
static struct iommufd_ioas *get_compat_ioas(struct iommufd_ctx *ictx)
{
struct iommufd_ioas *ioas = ERR_PTR(-ENODEV);
xa_lock(&ictx->objects);
if (!ictx->vfio_ioas || !iommufd_lock_obj(&ictx->vfio_ioas->obj))
goto out_unlock;
ioas = ictx->vfio_ioas;
out_unlock:
xa_unlock(&ictx->objects);
return ioas;
}
/**
* iommufd_vfio_compat_ioas_get_id - Ensure a compat IOAS exists
* @ictx: Context to operate on
* @out_ioas_id: The IOAS ID of the compatibility IOAS
*
* Return the ID of the current compatibility IOAS. The ID can be passed into
* other functions that take an ioas_id.
*/
int iommufd_vfio_compat_ioas_get_id(struct iommufd_ctx *ictx, u32 *out_ioas_id)
{
struct iommufd_ioas *ioas;
ioas = get_compat_ioas(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
*out_ioas_id = ioas->obj.id;
iommufd_put_object(&ioas->obj);
return 0;
}
EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_get_id, IOMMUFD_VFIO);
/**
* iommufd_vfio_compat_set_no_iommu - Called when a no-iommu device is attached
* @ictx: Context to operate on
*
* This allows selecting the VFIO_NOIOMMU_IOMMU and blocks normal types.
*/
int iommufd_vfio_compat_set_no_iommu(struct iommufd_ctx *ictx)
{
int ret;
xa_lock(&ictx->objects);
if (!ictx->vfio_ioas) {
ictx->no_iommu_mode = 1;
ret = 0;
} else {
ret = -EINVAL;
}
xa_unlock(&ictx->objects);
return ret;
}
EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_set_no_iommu, IOMMUFD_VFIO);
/**
* iommufd_vfio_compat_ioas_create - Ensure the compat IOAS is created
* @ictx: Context to operate on
*
* The compatibility IOAS is the IOAS that the vfio compatibility ioctls operate
* on since they do not have an IOAS ID input in their ABI. Only attaching a
* group should cause a default creation of the internal ioas, this does nothing
* if an existing ioas has already been assigned somehow.
*/
int iommufd_vfio_compat_ioas_create(struct iommufd_ctx *ictx)
{
struct iommufd_ioas *ioas = NULL;
int ret;
ioas = iommufd_ioas_alloc(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
xa_lock(&ictx->objects);
/*
* VFIO won't allow attaching a container to both iommu and no iommu
* operation
*/
if (ictx->no_iommu_mode) {
ret = -EINVAL;
goto out_abort;
}
if (ictx->vfio_ioas && iommufd_lock_obj(&ictx->vfio_ioas->obj)) {
ret = 0;
iommufd_put_object(&ictx->vfio_ioas->obj);
goto out_abort;
}
ictx->vfio_ioas = ioas;
xa_unlock(&ictx->objects);
/*
* An automatically created compat IOAS is treated as a userspace
* created object. Userspace can learn the ID via IOMMU_VFIO_IOAS_GET,
* and if not manually destroyed it will be destroyed automatically
* at iommufd release.
*/
iommufd_object_finalize(ictx, &ioas->obj);
return 0;
out_abort:
xa_unlock(&ictx->objects);
iommufd_object_abort(ictx, &ioas->obj);
return ret;
}
EXPORT_SYMBOL_NS_GPL(iommufd_vfio_compat_ioas_create, IOMMUFD_VFIO);
int iommufd_vfio_ioas(struct iommufd_ucmd *ucmd)
{
struct iommu_vfio_ioas *cmd = ucmd->cmd;
struct iommufd_ioas *ioas;
if (cmd->__reserved)
return -EOPNOTSUPP;
switch (cmd->op) {
case IOMMU_VFIO_IOAS_GET:
ioas = get_compat_ioas(ucmd->ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
cmd->ioas_id = ioas->obj.id;
iommufd_put_object(&ioas->obj);
return iommufd_ucmd_respond(ucmd, sizeof(*cmd));
case IOMMU_VFIO_IOAS_SET:
ioas = iommufd_get_ioas(ucmd, cmd->ioas_id);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
xa_lock(&ucmd->ictx->objects);
ucmd->ictx->vfio_ioas = ioas;
xa_unlock(&ucmd->ictx->objects);
iommufd_put_object(&ioas->obj);
return 0;
case IOMMU_VFIO_IOAS_CLEAR:
xa_lock(&ucmd->ictx->objects);
ucmd->ictx->vfio_ioas = NULL;
xa_unlock(&ucmd->ictx->objects);
return 0;
default:
return -EOPNOTSUPP;
}
}
static int iommufd_vfio_map_dma(struct iommufd_ctx *ictx, unsigned int cmd,
void __user *arg)
{
u32 supported_flags = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE;
size_t minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
struct vfio_iommu_type1_dma_map map;
int iommu_prot = IOMMU_CACHE;
struct iommufd_ioas *ioas;
unsigned long iova;
int rc;
if (copy_from_user(&map, arg, minsz))
return -EFAULT;
if (map.argsz < minsz || map.flags & ~supported_flags)
return -EINVAL;
if (map.flags & VFIO_DMA_MAP_FLAG_READ)
iommu_prot |= IOMMU_READ;
if (map.flags & VFIO_DMA_MAP_FLAG_WRITE)
iommu_prot |= IOMMU_WRITE;
ioas = get_compat_ioas(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
/*
* Maps created through the legacy interface always use VFIO compatible
* rlimit accounting. If the user wishes to use the faster user based
* rlimit accounting then they must use the new interface.
*/
iova = map.iova;
rc = iopt_map_user_pages(ictx, &ioas->iopt, &iova, u64_to_user_ptr(map.vaddr),
map.size, iommu_prot, 0);
iommufd_put_object(&ioas->obj);
return rc;
}
static int iommufd_vfio_unmap_dma(struct iommufd_ctx *ictx, unsigned int cmd,
void __user *arg)
{
size_t minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
/*
* VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP is obsoleted by the new
* dirty tracking direction:
* https://lore.kernel.org/kvm/20220731125503.142683-1-yishaih@nvidia.com/
* https://lore.kernel.org/kvm/20220428210933.3583-1-joao.m.martins@oracle.com/
*/
u32 supported_flags = VFIO_DMA_UNMAP_FLAG_ALL;
struct vfio_iommu_type1_dma_unmap unmap;
unsigned long unmapped = 0;
struct iommufd_ioas *ioas;
int rc;
if (copy_from_user(&unmap, arg, minsz))
return -EFAULT;
if (unmap.argsz < minsz || unmap.flags & ~supported_flags)
return -EINVAL;
ioas = get_compat_ioas(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
if (unmap.flags & VFIO_DMA_UNMAP_FLAG_ALL) {
if (unmap.iova != 0 || unmap.size != 0) {
rc = -EINVAL;
goto err_put;
}
rc = iopt_unmap_all(&ioas->iopt, &unmapped);
} else {
if (READ_ONCE(ioas->iopt.disable_large_pages)) {
/*
* Create cuts at the start and last of the requested
* range. If the start IOVA is 0 then it doesn't need to
* be cut.
*/
unsigned long iovas[] = { unmap.iova + unmap.size - 1,
unmap.iova - 1 };
rc = iopt_cut_iova(&ioas->iopt, iovas,
unmap.iova ? 2 : 1);
if (rc)
goto err_put;
}
rc = iopt_unmap_iova(&ioas->iopt, unmap.iova, unmap.size,
&unmapped);
}
unmap.size = unmapped;
if (copy_to_user(arg, &unmap, minsz))
rc = -EFAULT;
err_put:
iommufd_put_object(&ioas->obj);
return rc;
}
static int iommufd_vfio_cc_iommu(struct iommufd_ctx *ictx)
{
struct iommufd_hw_pagetable *hwpt;
struct iommufd_ioas *ioas;
int rc = 1;
ioas = get_compat_ioas(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
mutex_lock(&ioas->mutex);
list_for_each_entry(hwpt, &ioas->hwpt_list, hwpt_item) {
if (!hwpt->enforce_cache_coherency) {
rc = 0;
break;
}
}
mutex_unlock(&ioas->mutex);
iommufd_put_object(&ioas->obj);
return rc;
}
static int iommufd_vfio_check_extension(struct iommufd_ctx *ictx,
unsigned long type)
{
switch (type) {
case VFIO_TYPE1_IOMMU:
case VFIO_TYPE1v2_IOMMU:
case VFIO_UNMAP_ALL:
return 1;
case VFIO_NOIOMMU_IOMMU:
return IS_ENABLED(CONFIG_VFIO_NOIOMMU);
case VFIO_DMA_CC_IOMMU:
return iommufd_vfio_cc_iommu(ictx);
/*
* This is obsolete, and to be removed from VFIO. It was an incomplete
* idea that got merged.
* https://lore.kernel.org/kvm/0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com/
*/
case VFIO_TYPE1_NESTING_IOMMU:
return 0;
/*
* VFIO_DMA_MAP_FLAG_VADDR
* https://lore.kernel.org/kvm/1611939252-7240-1-git-send-email-steven.sistare@oracle.com/
* https://lore.kernel.org/all/Yz777bJZjTyLrHEQ@nvidia.com/
*
* It is hard to see how this could be implemented safely.
*/
case VFIO_UPDATE_VADDR:
default:
return 0;
}
}
static int iommufd_vfio_set_iommu(struct iommufd_ctx *ictx, unsigned long type)
{
bool no_iommu_mode = READ_ONCE(ictx->no_iommu_mode);
struct iommufd_ioas *ioas = NULL;
int rc = 0;
/*
* Emulation for NOIOMMU is imperfect in that VFIO blocks almost all
* other ioctls. We let them keep working but they mostly fail since no
* IOAS should exist.
*/
if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) && type == VFIO_NOIOMMU_IOMMU &&
no_iommu_mode) {
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
return 0;
}
if ((type != VFIO_TYPE1_IOMMU && type != VFIO_TYPE1v2_IOMMU) ||
no_iommu_mode)
return -EINVAL;
/* VFIO fails the set_iommu if there is no group */
ioas = get_compat_ioas(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
/*
* The difference between TYPE1 and TYPE1v2 is the ability to unmap in
* the middle of mapped ranges. This is complicated by huge page support
* which creates single large IOPTEs that cannot be split by the iommu
* driver. TYPE1 is very old at this point and likely nothing uses it,
* however it is simple enough to emulate by simply disabling the
* problematic large IOPTEs. Then we can safely unmap within any range.
*/
if (type == VFIO_TYPE1_IOMMU)
rc = iopt_disable_large_pages(&ioas->iopt);
iommufd_put_object(&ioas->obj);
return rc;
}
static unsigned long iommufd_get_pagesizes(struct iommufd_ioas *ioas)
{
struct io_pagetable *iopt = &ioas->iopt;
unsigned long pgsize_bitmap = ULONG_MAX;
struct iommu_domain *domain;
unsigned long index;
down_read(&iopt->domains_rwsem);
xa_for_each(&iopt->domains, index, domain)
pgsize_bitmap &= domain->pgsize_bitmap;
/* See vfio_update_pgsize_bitmap() */
if (pgsize_bitmap & ~PAGE_MASK) {
pgsize_bitmap &= PAGE_MASK;
pgsize_bitmap |= PAGE_SIZE;
}
pgsize_bitmap = max(pgsize_bitmap, ioas->iopt.iova_alignment);
up_read(&iopt->domains_rwsem);
return pgsize_bitmap;
}
static int iommufd_fill_cap_iova(struct iommufd_ioas *ioas,
struct vfio_info_cap_header __user *cur,
size_t avail)
{
struct vfio_iommu_type1_info_cap_iova_range __user *ucap_iovas =
container_of(cur,
struct vfio_iommu_type1_info_cap_iova_range __user,
header);
struct vfio_iommu_type1_info_cap_iova_range cap_iovas = {
.header = {
.id = VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE,
.version = 1,
},
};
struct interval_tree_span_iter span;
interval_tree_for_each_span(&span, &ioas->iopt.reserved_itree, 0,
ULONG_MAX) {
struct vfio_iova_range range;
if (!span.is_hole)
continue;
range.start = span.start_hole;
range.end = span.last_hole;
if (avail >= struct_size(&cap_iovas, iova_ranges,
cap_iovas.nr_iovas + 1) &&
copy_to_user(&ucap_iovas->iova_ranges[cap_iovas.nr_iovas],
&range, sizeof(range)))
return -EFAULT;
cap_iovas.nr_iovas++;
}
if (avail >= struct_size(&cap_iovas, iova_ranges, cap_iovas.nr_iovas) &&
copy_to_user(ucap_iovas, &cap_iovas, sizeof(cap_iovas)))
return -EFAULT;
return struct_size(&cap_iovas, iova_ranges, cap_iovas.nr_iovas);
}
static int iommufd_fill_cap_dma_avail(struct iommufd_ioas *ioas,
struct vfio_info_cap_header __user *cur,
size_t avail)
{
struct vfio_iommu_type1_info_dma_avail cap_dma = {
.header = {
.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL,
.version = 1,
},
/*
* iommufd's limit is based on the cgroup's memory limit.
* Normally vfio would return U16_MAX here, and provide a module
* parameter to adjust it. Since S390 qemu userspace actually
* pays attention and needs a value bigger than U16_MAX return
* U32_MAX.
*/
.avail = U32_MAX,
};
if (avail >= sizeof(cap_dma) &&
copy_to_user(cur, &cap_dma, sizeof(cap_dma)))
return -EFAULT;
return sizeof(cap_dma);
}
static int iommufd_vfio_iommu_get_info(struct iommufd_ctx *ictx,
void __user *arg)
{
typedef int (*fill_cap_fn)(struct iommufd_ioas *ioas,
struct vfio_info_cap_header __user *cur,
size_t avail);
static const fill_cap_fn fill_fns[] = {
iommufd_fill_cap_dma_avail,
iommufd_fill_cap_iova,
};
size_t minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
struct vfio_info_cap_header __user *last_cap = NULL;
struct vfio_iommu_type1_info info = {};
struct iommufd_ioas *ioas;
size_t total_cap_size;
int rc;
int i;
if (copy_from_user(&info, arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
minsz = min_t(size_t, info.argsz, sizeof(info));
ioas = get_compat_ioas(ictx);
if (IS_ERR(ioas))
return PTR_ERR(ioas);
info.flags = VFIO_IOMMU_INFO_PGSIZES;
info.iova_pgsizes = iommufd_get_pagesizes(ioas);
info.cap_offset = 0;
down_read(&ioas->iopt.iova_rwsem);
total_cap_size = sizeof(info);
for (i = 0; i != ARRAY_SIZE(fill_fns); i++) {
int cap_size;
if (info.argsz > total_cap_size)
cap_size = fill_fns[i](ioas, arg + total_cap_size,
info.argsz - total_cap_size);
else
cap_size = fill_fns[i](ioas, NULL, 0);
if (cap_size < 0) {
rc = cap_size;
goto out_put;
}
if (last_cap && info.argsz >= total_cap_size &&
put_user(total_cap_size, &last_cap->next)) {
rc = -EFAULT;
goto out_put;
}
last_cap = arg + total_cap_size;
total_cap_size += cap_size;
}
/*
* If the user did not provide enough space then only some caps are
* returned and the argsz will be updated to the correct amount to get
* all caps.
*/
if (info.argsz >= total_cap_size)
info.cap_offset = sizeof(info);
info.argsz = total_cap_size;
info.flags |= VFIO_IOMMU_INFO_CAPS;
if (copy_to_user(arg, &info, minsz)) {
rc = -EFAULT;
goto out_put;
}
rc = 0;
out_put:
up_read(&ioas->iopt.iova_rwsem);
iommufd_put_object(&ioas->obj);
return rc;
}
int iommufd_vfio_ioctl(struct iommufd_ctx *ictx, unsigned int cmd,
unsigned long arg)
{
void __user *uarg = (void __user *)arg;
switch (cmd) {
case VFIO_GET_API_VERSION:
return VFIO_API_VERSION;
case VFIO_SET_IOMMU:
return iommufd_vfio_set_iommu(ictx, arg);
case VFIO_CHECK_EXTENSION:
return iommufd_vfio_check_extension(ictx, arg);
case VFIO_IOMMU_GET_INFO:
return iommufd_vfio_iommu_get_info(ictx, uarg);
case VFIO_IOMMU_MAP_DMA:
return iommufd_vfio_map_dma(ictx, cmd, uarg);
case VFIO_IOMMU_UNMAP_DMA:
return iommufd_vfio_unmap_dma(ictx, cmd, uarg);
case VFIO_IOMMU_DIRTY_PAGES:
default:
return -ENOIOCTLCMD;
}
return -ENOIOCTLCMD;
}