// SPDX-License-Identifier: GPL-2.0-only
/*
* VFIO: IOMMU DMA mapping support for Type1 IOMMU
*
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
* Author: Alex Williamson <[email protected]>
*
* Derived from original vfio:
* Copyright 2010 Cisco Systems, Inc. All rights reserved.
* Author: Tom Lyon, [email protected]
*
* We arbitrarily define a Type1 IOMMU as one matching the below code.
* It could be called the x86 IOMMU as it's designed for AMD-Vi & Intel
* VT-d, but that makes it harder to re-use as theoretically anyone
* implementing a similar IOMMU could make use of this. We expect the
* IOMMU to support the IOMMU API and have few to no restrictions around
* the IOVA range that can be mapped. The Type1 IOMMU is currently
* optimized for relatively static mappings of a userspace process with
* userspace pages pinned into memory. We also assume devices and IOMMU
* domains are PCI based as the IOMMU API is still centered around a
* device/bus interface rather than a group interface.
*/
#include <linux/compat.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/highmem.h>
#include <linux/iommu.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/kthread.h>
#include <linux/rbtree.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/vfio.h>
#include <linux/workqueue.h>
#include <linux/notifier.h>
#include "vfio.h"
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <[email protected]>"
#define DRIVER_DESC "Type1 IOMMU driver for VFIO"
static bool allow_unsafe_interrupts;
module_param_named(allow_unsafe_interrupts,
allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(allow_unsafe_interrupts,
"Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
static bool disable_hugepages;
module_param_named(disable_hugepages,
disable_hugepages, bool, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(disable_hugepages,
"Disable VFIO IOMMU support for IOMMU hugepages.");
static unsigned int dma_entry_limit __read_mostly = U16_MAX;
module_param_named(dma_entry_limit, dma_entry_limit, uint, 0644);
MODULE_PARM_DESC(dma_entry_limit,
"Maximum number of user DMA mappings per container (65535).");
struct vfio_iommu {
struct list_head domain_list;
struct list_head iova_list;
struct mutex lock;
struct rb_root dma_list;
struct list_head device_list;
struct mutex device_list_lock;
unsigned int dma_avail;
unsigned int vaddr_invalid_count;
uint64_t pgsize_bitmap;
uint64_t num_non_pinned_groups;
bool v2;
bool nesting;
bool dirty_page_tracking;
struct list_head emulated_iommu_groups;
};
struct vfio_domain {
struct iommu_domain *domain;
struct list_head next;
struct list_head group_list;
bool fgsp : 1; /* Fine-grained super pages */
bool enforce_cache_coherency : 1;
};
struct vfio_dma {
struct rb_node node;
dma_addr_t iova; /* Device address */
unsigned long vaddr; /* Process virtual addr */
size_t size; /* Map size (bytes) */
int prot; /* IOMMU_READ/WRITE */
bool iommu_mapped;
bool lock_cap; /* capable(CAP_IPC_LOCK) */
bool vaddr_invalid;
struct task_struct *task;
struct rb_root pfn_list; /* Ex-user pinned pfn list */
unsigned long *bitmap;
struct mm_struct *mm;
size_t locked_vm;
};
struct vfio_batch {
struct page **pages; /* for pin_user_pages_remote */
struct page *fallback_page; /* if pages alloc fails */
int capacity; /* length of pages array */
int size; /* of batch currently */
int offset; /* of next entry in pages */
};
struct vfio_iommu_group {
struct iommu_group *iommu_group;
struct list_head next;
bool pinned_page_dirty_scope;
};
struct vfio_iova {
struct list_head list;
dma_addr_t start;
dma_addr_t end;
};
/*
* Guest RAM pinning working set or DMA target
*/
struct vfio_pfn {
struct rb_node node;
dma_addr_t iova; /* Device address */
unsigned long pfn; /* Host pfn */
unsigned int ref_count;
};
struct vfio_regions {
struct list_head list;
dma_addr_t iova;
phys_addr_t phys;
size_t len;
};
#define DIRTY_BITMAP_BYTES(n) (ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE)
/*
* Input argument of number of bits to bitmap_set() is unsigned integer, which
* further casts to signed integer for unaligned multi-bit operation,
* __bitmap_set().
* Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte,
* that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page
* system.
*/
#define DIRTY_BITMAP_PAGES_MAX ((u64)INT_MAX)
#define DIRTY_BITMAP_SIZE_MAX DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)
static int put_pfn(unsigned long pfn, int prot);
static struct vfio_iommu_group*
vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
struct iommu_group *iommu_group);
/*
* This code handles mapping and unmapping of user data buffers
* into DMA'ble space using the IOMMU
*/
static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
dma_addr_t start, size_t size)
{
struct rb_node *node = iommu->dma_list.rb_node;
while (node) {
struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
if (start + size <= dma->iova)
node = node->rb_left;
else if (start >= dma->iova + dma->size)
node = node->rb_right;
else
return dma;
}
return NULL;
}
static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu,
dma_addr_t start, u64 size)
{
struct rb_node *res = NULL;
struct rb_node *node = iommu->dma_list.rb_node;
struct vfio_dma *dma_res = NULL;
while (node) {
struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
if (start < dma->iova + dma->size) {
res = node;
dma_res = dma;
if (start >= dma->iova)
break;
node = node->rb_left;
} else {
node = node->rb_right;
}
}
if (res && size && dma_res->iova >= start + size)
res = NULL;
return res;
}
static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
{
struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
struct vfio_dma *dma;
while (*link) {
parent = *link;
dma = rb_entry(parent, struct vfio_dma, node);
if (new->iova + new->size <= dma->iova)
link = &(*link)->rb_left;
else
link = &(*link)->rb_right;
}
rb_link_node(&new->node, parent, link);
rb_insert_color(&new->node, &iommu->dma_list);
}
static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
{
rb_erase(&old->node, &iommu->dma_list);
}
static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize)
{
uint64_t npages = dma->size / pgsize;
if (npages > DIRTY_BITMAP_PAGES_MAX)
return -EINVAL;
/*
* Allocate extra 64 bits that are used to calculate shift required for
* bitmap_shift_left() to manipulate and club unaligned number of pages
* in adjacent vfio_dma ranges.
*/
dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64),
GFP_KERNEL);
if (!dma->bitmap)
return -ENOMEM;
return 0;
}
static void vfio_dma_bitmap_free(struct vfio_dma *dma)
{
kvfree(dma->bitmap);
dma->bitmap = NULL;
}
static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize)
{
struct rb_node *p;
unsigned long pgshift = __ffs(pgsize);
for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) {
struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node);
bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1);
}
}
static void vfio_iommu_populate_bitmap_full(struct vfio_iommu *iommu)
{
struct rb_node *n;
unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
bitmap_set(dma->bitmap, 0, dma->size >> pgshift);
}
}
static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize)
{
struct rb_node *n;
for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
int ret;
ret = vfio_dma_bitmap_alloc(dma, pgsize);
if (ret) {
struct rb_node *p;
for (p = rb_prev(n); p; p = rb_prev(p)) {
struct vfio_dma *dma = rb_entry(n,
struct vfio_dma, node);
vfio_dma_bitmap_free(dma);
}
return ret;
}
vfio_dma_populate_bitmap(dma, pgsize);
}
return 0;
}
static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu)
{
struct rb_node *n;
for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
vfio_dma_bitmap_free(dma);
}
}
/*
* Helper Functions for host iova-pfn list
*/
static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
{
struct vfio_pfn *vpfn;
struct rb_node *node = dma->pfn_list.rb_node;
while (node) {
vpfn = rb_entry(node, struct vfio_pfn, node);
if (iova < vpfn->iova)
node = node->rb_left;
else if (iova > vpfn->iova)
node = node->rb_right;
else
return vpfn;
}
return NULL;
}
static void vfio_link_pfn(struct vfio_dma *dma,
struct vfio_pfn *new)
{
struct rb_node **link, *parent = NULL;
struct vfio_pfn *vpfn;
link = &dma->pfn_list.rb_node;
while (*link) {
parent = *link;
vpfn = rb_entry(parent, struct vfio_pfn, node);
if (new->iova < vpfn->iova)
link = &(*link)->rb_left;
else
link = &(*link)->rb_right;
}
rb_link_node(&new->node, parent, link);
rb_insert_color(&new->node, &dma->pfn_list);
}
static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
{
rb_erase(&old->node, &dma->pfn_list);
}
static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
unsigned long pfn)
{
struct vfio_pfn *vpfn;
vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
if (!vpfn)
return -ENOMEM;
vpfn->iova = iova;
vpfn->pfn = pfn;
vpfn->ref_count = 1;
vfio_link_pfn(dma, vpfn);
return 0;
}
static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
struct vfio_pfn *vpfn)
{
vfio_unlink_pfn(dma, vpfn);
kfree(vpfn);
}
static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
unsigned long iova)
{
struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
if (vpfn)
vpfn->ref_count++;
return vpfn;
}
static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
{
int ret = 0;
vpfn->ref_count--;
if (!vpfn->ref_count) {
ret = put_pfn(vpfn->pfn, dma->prot);
vfio_remove_from_pfn_list(dma, vpfn);
}
return ret;
}
static int mm_lock_acct(struct task_struct *task, struct mm_struct *mm,
bool lock_cap, long npage)
{
int ret = mmap_write_lock_killable(mm);
if (ret)
return ret;
ret = __account_locked_vm(mm, abs(npage), npage > 0, task, lock_cap);
mmap_write_unlock(mm);
return ret;
}
static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
{
struct mm_struct *mm;
int ret;
if (!npage)
return 0;
mm = dma->mm;
if (async && !mmget_not_zero(mm))
return -ESRCH; /* process exited */
ret = mm_lock_acct(dma->task, mm, dma->lock_cap, npage);
if (!ret)
dma->locked_vm += npage;
if (async)
mmput(mm);
return ret;
}
/*
* Some mappings aren't backed by a struct page, for example an mmap'd
* MMIO range for our own or another device. These use a different
* pfn conversion and shouldn't be tracked as locked pages.
* For compound pages, any driver that sets the reserved bit in head
* page needs to set the reserved bit in all subpages to be safe.
*/
static bool is_invalid_reserved_pfn(unsigned long pfn)
{
if (pfn_valid(pfn))
return PageReserved(pfn_to_page(pfn));
return true;
}
static int put_pfn(unsigned long pfn, int prot)
{
if (!is_invalid_reserved_pfn(pfn)) {
struct page *page = pfn_to_page(pfn);
unpin_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE);
return 1;
}
return 0;
}
#define VFIO_BATCH_MAX_CAPACITY (PAGE_SIZE / sizeof(struct page *))
static void vfio_batch_init(struct vfio_batch *batch)
{
batch->size = 0;
batch->offset = 0;
if (unlikely(disable_hugepages))
goto fallback;
batch->pages = (struct page **) __get_free_page(GFP_KERNEL);
if (!batch->pages)
goto fallback;
batch->capacity = VFIO_BATCH_MAX_CAPACITY;
return;
fallback:
batch->pages = &batch->fallback_page;
batch->capacity = 1;
}
static void vfio_batch_unpin(struct vfio_batch *batch, struct vfio_dma *dma)
{
while (batch->size) {
unsigned long pfn = page_to_pfn(batch->pages[batch->offset]);
put_pfn(pfn, dma->prot);
batch->offset++;
batch->size--;
}
}
static void vfio_batch_fini(struct vfio_batch *batch)
{
if (batch->capacity == VFIO_BATCH_MAX_CAPACITY)
free_page((unsigned long)batch->pages);
}
static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
unsigned long vaddr, unsigned long *pfn,
bool write_fault)
{
struct follow_pfnmap_args args = { .vma = vma, .address = vaddr };
int ret;
ret = follow_pfnmap_start(&args);
if (ret) {
bool unlocked = false;
ret = fixup_user_fault(mm, vaddr,
FAULT_FLAG_REMOTE |
(write_fault ? FAULT_FLAG_WRITE : 0),
&unlocked);
if (unlocked)
return -EAGAIN;
if (ret)
return ret;
ret = follow_pfnmap_start(&args);
if (ret)
return ret;
}
if (write_fault && !args.writable)
ret = -EFAULT;
else
*pfn = args.pfn;
follow_pfnmap_end(&args);
return ret;
}
/*
* Returns the positive number of pfns successfully obtained or a negative
* error code.
*/
static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
long npages, int prot, unsigned long *pfn,
struct page **pages)
{
struct vm_area_struct *vma;
unsigned int flags = 0;
int ret;
if (prot & IOMMU_WRITE)
flags |= FOLL_WRITE;
mmap_read_lock(mm);
ret = pin_user_pages_remote(mm, vaddr, npages, flags | FOLL_LONGTERM,
pages, NULL);
if (ret > 0) {
*pfn = page_to_pfn(pages[0]);
goto done;
}
vaddr = untagged_addr_remote(mm, vaddr);
retry:
vma = vma_lookup(mm, vaddr);
if (vma && vma->vm_flags & VM_PFNMAP) {
ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE);
if (ret == -EAGAIN)
goto retry;
if (!ret) {
if (is_invalid_reserved_pfn(*pfn))
ret = 1;
else
ret = -EFAULT;
}
}
done:
mmap_read_unlock(mm);
return ret;
}
/*
* Attempt to pin pages. We really don't want to track all the pfns and
* the iommu can only map chunks of consecutive pfns anyway, so get the
* first page and all consecutive pages with the same locking.
*/
static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
long npage, unsigned long *pfn_base,
unsigned long limit, struct vfio_batch *batch)
{
unsigned long pfn;
struct mm_struct *mm = current->mm;
long ret, pinned = 0, lock_acct = 0;
bool rsvd;
dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
/* This code path is only user initiated */
if (!mm)
return -ENODEV;
if (batch->size) {
/* Leftover pages in batch from an earlier call. */
*pfn_base = page_to_pfn(batch->pages[batch->offset]);
pfn = *pfn_base;
rsvd = is_invalid_reserved_pfn(*pfn_base);
} else {
*pfn_base = 0;
}
while (npage) {
if (!batch->size) {
/* Empty batch, so refill it. */
long req_pages = min_t(long, npage, batch->capacity);
ret = vaddr_get_pfns(mm, vaddr, req_pages, dma->prot,
&pfn, batch->pages);
if (ret < 0)
goto unpin_out;
batch->size = ret;
batch->offset = 0;
if (!*pfn_base) {
*pfn_base = pfn;
rsvd = is_invalid_reserved_pfn(*pfn_base);
}
}
/*
* pfn is preset for the first iteration of this inner loop and
* updated at the end to handle a VM_PFNMAP pfn. In that case,
* batch->pages isn't valid (there's no struct page), so allow
* batch->pages to be touched only when there's more than one
* pfn to check, which guarantees the pfns are from a
* !VM_PFNMAP vma.
*/
while (true) {
if (pfn != *pfn_base + pinned ||
rsvd != is_invalid_reserved_pfn(pfn))
goto out;
/*
* Reserved pages aren't counted against the user,
* externally pinned pages are already counted against
* the user.
*/
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
if (!dma->lock_cap &&
mm->locked_vm + lock_acct + 1 > limit) {
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, limit << PAGE_SHIFT);
ret = -ENOMEM;
goto unpin_out;
}
lock_acct++;
}
pinned++;
npage--;
vaddr += PAGE_SIZE;
iova += PAGE_SIZE;
batch->offset++;
batch->size--;
if (!batch->size)
break;
pfn = page_to_pfn(batch->pages[batch->offset]);
}
if (unlikely(disable_hugepages))
break;
}
out:
ret = vfio_lock_acct(dma, lock_acct, false);
unpin_out:
if (batch->size == 1 && !batch->offset) {
/* May be a VM_PFNMAP pfn, which the batch can't remember. */
put_pfn(pfn, dma->prot);
batch->size = 0;
}
if (ret < 0) {
if (pinned && !rsvd) {
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
}
vfio_batch_unpin(batch, dma);
return ret;
}
return pinned;
}
static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
unsigned long pfn, long npage,
bool do_accounting)
{
long unlocked = 0, locked = 0;
long i;
for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
if (put_pfn(pfn++, dma->prot)) {
unlocked++;
if (vfio_find_vpfn(dma, iova))
locked++;
}
}
if (do_accounting)
vfio_lock_acct(dma, locked - unlocked, true);
return unlocked;
}
static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
unsigned long *pfn_base, bool do_accounting)
{
struct page *pages[1];
struct mm_struct *mm;
int ret;
mm = dma->mm;
if (!mmget_not_zero(mm))
return -ENODEV;
ret = vaddr_get_pfns(mm, vaddr, 1, dma->prot, pfn_base, pages);
if (ret != 1)
goto out;
ret = 0;
if (do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
ret = vfio_lock_acct(dma, 1, false);
if (ret) {
put_pfn(*pfn_base, dma->prot);
if (ret == -ENOMEM)
pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK "
"(%ld) exceeded\n", __func__,
dma->task->comm, task_pid_nr(dma->task),
task_rlimit(dma->task, RLIMIT_MEMLOCK));
}
}
out:
mmput(mm);
return ret;
}
static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
bool do_accounting)
{
int unlocked;
struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
if (!vpfn)
return 0;
unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
if (do_accounting)
vfio_lock_acct(dma, -unlocked, true);
return unlocked;
}
static int vfio_iommu_type1_pin_pages(void *iommu_data,
struct iommu_group *iommu_group,
dma_addr_t user_iova,
int npage, int prot,
struct page **pages)
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_iommu_group *group;
int i, j, ret;
unsigned long remote_vaddr;
struct vfio_dma *dma;
bool do_accounting;
if (!iommu || !pages)
return -EINVAL;
/* Supported for v2 version only */
if (!iommu->v2)
return -EACCES;
mutex_lock(&iommu->lock);
if (WARN_ONCE(iommu->vaddr_invalid_count,
"vfio_pin_pages not allowed with VFIO_UPDATE_VADDR\n")) {
ret = -EBUSY;
goto pin_done;
}
/* Fail if no dma_umap notifier is registered */
if (list_empty(&iommu->device_list)) {
ret = -EINVAL;
goto pin_done;
}
/*
* If iommu capable domain exist in the container then all pages are
* already pinned and accounted. Accounting should be done if there is no
* iommu capable domain in the container.
*/
do_accounting = list_empty(&iommu->domain_list);
for (i = 0; i < npage; i++) {
unsigned long phys_pfn;
dma_addr_t iova;
struct vfio_pfn *vpfn;
iova = user_iova + PAGE_SIZE * i;
dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
if (!dma) {
ret = -EINVAL;
goto pin_unwind;
}
if ((dma->prot & prot) != prot) {
ret = -EPERM;
goto pin_unwind;
}
vpfn = vfio_iova_get_vfio_pfn(dma, iova);
if (vpfn) {
pages[i] = pfn_to_page(vpfn->pfn);
continue;
}
remote_vaddr = dma->vaddr + (iova - dma->iova);
ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn,
do_accounting);
if (ret)
goto pin_unwind;
if (!pfn_valid(phys_pfn)) {
ret = -EINVAL;
goto pin_unwind;
}
ret = vfio_add_to_pfn_list(dma, iova, phys_pfn);
if (ret) {
if (put_pfn(phys_pfn, dma->prot) && do_accounting)
vfio_lock_acct(dma, -1, true);
goto pin_unwind;
}
pages[i] = pfn_to_page(phys_pfn);
if (iommu->dirty_page_tracking) {
unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
/*
* Bitmap populated with the smallest supported page
* size
*/
bitmap_set(dma->bitmap,
(iova - dma->iova) >> pgshift, 1);
}
}
ret = i;
group = vfio_iommu_find_iommu_group(iommu, iommu_group);
if (!group->pinned_page_dirty_scope) {
group->pinned_page_dirty_scope = true;
iommu->num_non_pinned_groups--;
}
goto pin_done;
pin_unwind:
pages[i] = NULL;
for (j = 0; j < i; j++) {
dma_addr_t iova;
iova = user_iova + PAGE_SIZE * j;
dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
vfio_unpin_page_external(dma, iova, do_accounting);
pages[j] = NULL;
}
pin_done:
mutex_unlock(&iommu->lock);
return ret;
}
static void vfio_iommu_type1_unpin_pages(void *iommu_data,
dma_addr_t user_iova, int npage)
{
struct vfio_iommu *iommu = iommu_data;
bool do_accounting;
int i;
/* Supported for v2 version only */
if (WARN_ON(!iommu->v2))
return;
mutex_lock(&iommu->lock);
do_accounting = list_empty(&iommu->domain_list);
for (i = 0; i < npage; i++) {
dma_addr_t iova = user_iova + PAGE_SIZE * i;
struct vfio_dma *dma;
dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
if (!dma)
break;
vfio_unpin_page_external(dma, iova, do_accounting);
}
mutex_unlock(&iommu->lock);
WARN_ON(i != npage);
}
static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
struct list_head *regions,
struct iommu_iotlb_gather *iotlb_gather)
{
long unlocked = 0;
struct vfio_regions *entry, *next;
iommu_iotlb_sync(domain->domain, iotlb_gather);
list_for_each_entry_safe(entry, next, regions, list) {
unlocked += vfio_unpin_pages_remote(dma,
entry->iova,
entry->phys >> PAGE_SHIFT,
entry->len >> PAGE_SHIFT,
false);
list_del(&entry->list);
kfree(entry);
}
cond_resched();
return unlocked;
}
/*
* Generally, VFIO needs to unpin remote pages after each IOTLB flush.
* Therefore, when using IOTLB flush sync interface, VFIO need to keep track
* of these regions (currently using a list).
*
* This value specifies maximum number of regions for each IOTLB flush sync.
*/
#define VFIO_IOMMU_TLB_SYNC_MAX 512
static size_t unmap_unpin_fast(struct vfio_domain *domain,
struct vfio_dma *dma, dma_addr_t *iova,
size_t len, phys_addr_t phys, long *unlocked,
struct list_head *unmapped_list,
int *unmapped_cnt,
struct iommu_iotlb_gather *iotlb_gather)
{
size_t unmapped = 0;
struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry) {
unmapped = iommu_unmap_fast(domain->domain, *iova, len,
iotlb_gather);
if (!unmapped) {
kfree(entry);
} else {
entry->iova = *iova;
entry->phys = phys;
entry->len = unmapped;
list_add_tail(&entry->list, unmapped_list);
*iova += unmapped;
(*unmapped_cnt)++;
}
}
/*
* Sync if the number of fast-unmap regions hits the limit
* or in case of errors.
*/
if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) {
*unlocked += vfio_sync_unpin(dma, domain, unmapped_list,
iotlb_gather);
*unmapped_cnt = 0;
}
return unmapped;
}
static size_t unmap_unpin_slow(struct vfio_domain *domain,
struct vfio_dma *dma, dma_addr_t *iova,
size_t len, phys_addr_t phys,
long *unlocked)
{
size_t unmapped = iommu_unmap(domain->domain, *iova, len);
if (unmapped) {
*unlocked += vfio_unpin_pages_remote(dma, *iova,
phys >> PAGE_SHIFT,
unmapped >> PAGE_SHIFT,
false);
*iova += unmapped;
cond_resched();
}
return unmapped;
}
static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
bool do_accounting)
{
dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
struct vfio_domain *domain, *d;
LIST_HEAD(unmapped_region_list);
struct iommu_iotlb_gather iotlb_gather;
int unmapped_region_cnt = 0;
long unlocked = 0;
if (!dma->size)
return 0;
if (list_empty(&iommu->domain_list))
return 0;
/*
* We use the IOMMU to track the physical addresses, otherwise we'd
* need a much more complicated tracking system. Unfortunately that
* means we need to use one of the iommu domains to figure out the
* pfns to unpin. The rest need to be unmapped in advance so we have
* no iommu translations remaining when the pages are unpinned.
*/
domain = d = list_first_entry(&iommu->domain_list,
struct vfio_domain, next);
list_for_each_entry_continue(d, &iommu->domain_list, next) {
iommu_unmap(d->domain, dma->iova, dma->size);
cond_resched();
}
iommu_iotlb_gather_init(&iotlb_gather);
while (iova < end) {
size_t unmapped, len;
phys_addr_t phys, next;
phys = iommu_iova_to_phys(domain->domain, iova);
if (WARN_ON(!phys)) {
iova += PAGE_SIZE;
continue;
}
/*
* To optimize for fewer iommu_unmap() calls, each of which
* may require hardware cache flushing, try to find the
* largest contiguous physical memory chunk to unmap.
*/
for (len = PAGE_SIZE;
!domain->fgsp && iova + len < end; len += PAGE_SIZE) {
next = iommu_iova_to_phys(domain->domain, iova + len);
if (next != phys + len)
break;
}
/*
* First, try to use fast unmap/unpin. In case of failure,
* switch to slow unmap/unpin path.
*/
unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys,
&unlocked, &unmapped_region_list,
&unmapped_region_cnt,
&iotlb_gather);
if (!unmapped) {
unmapped = unmap_unpin_slow(domain, dma, &iova, len,
phys, &unlocked);
if (WARN_ON(!unmapped))
break;
}
}
dma->iommu_mapped = false;
if (unmapped_region_cnt) {
unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list,
&iotlb_gather);
}
if (do_accounting) {
vfio_lock_acct(dma, -unlocked, true);
return 0;
}
return unlocked;
}
static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
vfio_unmap_unpin(iommu, dma, true);
vfio_unlink_dma(iommu, dma);
put_task_struct(dma->task);
mmdrop(dma->mm);
vfio_dma_bitmap_free(dma);
if (dma->vaddr_invalid)
iommu->vaddr_invalid_count--;
kfree(dma);
iommu->dma_avail++;
}
static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu)
{
struct vfio_domain *domain;
iommu->pgsize_bitmap = ULONG_MAX;
list_for_each_entry(domain, &iommu->domain_list, next)
iommu->pgsize_bitmap &= domain->domain->pgsize_bitmap;
/*
* In case the IOMMU supports page sizes smaller than PAGE_SIZE
* we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
* That way the user will be able to map/unmap buffers whose size/
* start address is aligned with PAGE_SIZE. Pinning code uses that
* granularity while iommu driver can use the sub-PAGE_SIZE size
* to map the buffer.
*/
if (iommu->pgsize_bitmap & ~PAGE_MASK) {
iommu->pgsize_bitmap &= PAGE_MASK;
iommu->pgsize_bitmap |= PAGE_SIZE;
}
}
static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
struct vfio_dma *dma, dma_addr_t base_iova,
size_t pgsize)
{
unsigned long pgshift = __ffs(pgsize);
unsigned long nbits = dma->size >> pgshift;
unsigned long bit_offset = (dma->iova - base_iova) >> pgshift;
unsigned long copy_offset = bit_offset / BITS_PER_LONG;
unsigned long shift = bit_offset % BITS_PER_LONG;
unsigned long leftover;
/*
* mark all pages dirty if any IOMMU capable device is not able
* to report dirty pages and all pages are pinned and mapped.
*/
if (iommu->num_non_pinned_groups && dma->iommu_mapped)
bitmap_set(dma->bitmap, 0, nbits);
if (shift) {
bitmap_shift_left(dma->bitmap, dma->bitmap, shift,
nbits + shift);
if (copy_from_user(&leftover,
(void __user *)(bitmap + copy_offset),
sizeof(leftover)))
return -EFAULT;
bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift);
}
if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap,
DIRTY_BITMAP_BYTES(nbits + shift)))
return -EFAULT;
return 0;
}
static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
dma_addr_t iova, size_t size, size_t pgsize)
{
struct vfio_dma *dma;
struct rb_node *n;
unsigned long pgshift = __ffs(pgsize);
int ret;
/*
* GET_BITMAP request must fully cover vfio_dma mappings. Multiple
* vfio_dma mappings may be clubbed by specifying large ranges, but
* there must not be any previous mappings bisected by the range.
* An error will be returned if these conditions are not met.
*/
dma = vfio_find_dma(iommu, iova, 1);
if (dma && dma->iova != iova)
return -EINVAL;
dma = vfio_find_dma(iommu, iova + size - 1, 0);
if (dma && dma->iova + dma->size != iova + size)
return -EINVAL;
for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
if (dma->iova < iova)
continue;
if (dma->iova > iova + size - 1)
break;
ret = update_user_bitmap(bitmap, iommu, dma, iova, pgsize);
if (ret)
return ret;
/*
* Re-populate bitmap to include all pinned pages which are
* considered as dirty but exclude pages which are unpinned and
* pages which are marked dirty by vfio_dma_rw()
*/
bitmap_clear(dma->bitmap, 0, dma->size >> pgshift);
vfio_dma_populate_bitmap(dma, pgsize);
}
return 0;
}
static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size)
{
if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) ||
(bitmap_size < DIRTY_BITMAP_BYTES(npages)))
return -EINVAL;
return 0;
}
/*
* Notify VFIO drivers using vfio_register_emulated_iommu_dev() to invalidate
* and unmap iovas within the range we're about to unmap. Drivers MUST unpin
* pages in response to an invalidation.
*/
static void vfio_notify_dma_unmap(struct vfio_iommu *iommu,
struct vfio_dma *dma)
{
struct vfio_device *device;
if (list_empty(&iommu->device_list))
return;
/*
* The device is expected to call vfio_unpin_pages() for any IOVA it has
* pinned within the range. Since vfio_unpin_pages() will eventually
* call back down to this code and try to obtain the iommu->lock we must
* drop it.
*/
mutex_lock(&iommu->device_list_lock);
mutex_unlock(&iommu->lock);
list_for_each_entry(device, &iommu->device_list, iommu_entry)
device->ops->dma_unmap(device, dma->iova, dma->size);
mutex_unlock(&iommu->device_list_lock);
mutex_lock(&iommu->lock);
}
static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_unmap *unmap,
struct vfio_bitmap *bitmap)
{
struct vfio_dma *dma, *dma_last = NULL;
size_t unmapped = 0, pgsize;
int ret = -EINVAL, retries = 0;
unsigned long pgshift;
dma_addr_t iova = unmap->iova;
u64 size = unmap->size;
bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL;
bool invalidate_vaddr = unmap->flags & VFIO_DMA_UNMAP_FLAG_VADDR;
struct rb_node *n, *first_n;
mutex_lock(&iommu->lock);
/* Cannot update vaddr if mdev is present. */
if (invalidate_vaddr && !list_empty(&iommu->emulated_iommu_groups)) {
ret = -EBUSY;
goto unlock;
}
pgshift = __ffs(iommu->pgsize_bitmap);
pgsize = (size_t)1 << pgshift;
if (iova & (pgsize - 1))
goto unlock;
if (unmap_all) {
if (iova || size)
goto unlock;
size = U64_MAX;
} else if (!size || size & (pgsize - 1) ||
iova + size - 1 < iova || size > SIZE_MAX) {
goto unlock;
}
/* When dirty tracking is enabled, allow only min supported pgsize */
if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
(!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) {
goto unlock;
}
WARN_ON((pgsize - 1) & PAGE_MASK);
again:
/*
* vfio-iommu-type1 (v1) - User mappings were coalesced together to
* avoid tracking individual mappings. This means that the granularity
* of the original mapping was lost and the user was allowed to attempt
* to unmap any range. Depending on the contiguousness of physical
* memory and page sizes supported by the IOMMU, arbitrary unmaps may
* or may not have worked. We only guaranteed unmap granularity
* matching the original mapping; even though it was untracked here,
* the original mappings are reflected in IOMMU mappings. This
* resulted in a couple unusual behaviors. First, if a range is not
* able to be unmapped, ex. a set of 4k pages that was mapped as a
* 2M hugepage into the IOMMU, the unmap ioctl returns success but with
* a zero sized unmap. Also, if an unmap request overlaps the first
* address of a hugepage, the IOMMU will unmap the entire hugepage.
* This also returns success and the returned unmap size reflects the
* actual size unmapped.
*
* We attempt to maintain compatibility with this "v1" interface, but
* we take control out of the hands of the IOMMU. Therefore, an unmap
* request offset from the beginning of the original mapping will
* return success with zero sized unmap. And an unmap request covering
* the first iova of mapping will unmap the entire range.
*
* The v2 version of this interface intends to be more deterministic.
* Unmap requests must fully cover previous mappings. Multiple
* mappings may still be unmaped by specifying large ranges, but there
* must not be any previous mappings bisected by the range. An error
* will be returned if these conditions are not met. The v2 interface
* will only return success and a size of zero if there were no
* mappings within the range.
*/
if (iommu->v2 && !unmap_all) {
dma = vfio_find_dma(iommu, iova, 1);
if (dma && dma->iova != iova)
goto unlock;
dma = vfio_find_dma(iommu, iova + size - 1, 0);
if (dma && dma->iova + dma->size != iova + size)
goto unlock;
}
ret = 0;
n = first_n = vfio_find_dma_first_node(iommu, iova, size);
while (n) {
dma = rb_entry(n, struct vfio_dma, node);
if (dma->iova >= iova + size)
break;
if (!iommu->v2 && iova > dma->iova)
break;
if (invalidate_vaddr) {
if (dma->vaddr_invalid) {
struct rb_node *last_n = n;
for (n = first_n; n != last_n; n = rb_next(n)) {
dma = rb_entry(n,
struct vfio_dma, node);
dma->vaddr_invalid = false;
iommu->vaddr_invalid_count--;
}
ret = -EINVAL;
unmapped = 0;
break;
}
dma->vaddr_invalid = true;
iommu->vaddr_invalid_count++;
unmapped += dma->size;
n = rb_next(n);
continue;
}
if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
if (dma_last == dma) {
BUG_ON(++retries > 10);
} else {
dma_last = dma;
retries = 0;
}
vfio_notify_dma_unmap(iommu, dma);
goto again;
}
if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
ret = update_user_bitmap(bitmap->data, iommu, dma,
iova, pgsize);
if (ret)
break;
}
unmapped += dma->size;
n = rb_next(n);
vfio_remove_dma(iommu, dma);
}
unlock:
mutex_unlock(&iommu->lock);
/* Report how much was unmapped */
unmap->size = unmapped;
return ret;
}
static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
unsigned long pfn, long npage, int prot)
{
struct vfio_domain *d;
int ret;
list_for_each_entry(d, &iommu->domain_list, next) {
ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
npage << PAGE_SHIFT, prot | IOMMU_CACHE,
GFP_KERNEL_ACCOUNT);
if (ret)
goto unwind;
cond_resched();
}
return 0;
unwind:
list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
cond_resched();
}
return ret;
}
static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
size_t map_size)
{
dma_addr_t iova = dma->iova;
unsigned long vaddr = dma->vaddr;
struct vfio_batch batch;
size_t size = map_size;
long npage;
unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
int ret = 0;
vfio_batch_init(&batch);
while (size) {
/* Pin a contiguous chunk of memory */
npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
size >> PAGE_SHIFT, &pfn, limit,
&batch);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
break;
}
/* Map it! */
ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
dma->prot);
if (ret) {
vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
npage, true);
vfio_batch_unpin(&batch, dma);
break;
}
size -= npage << PAGE_SHIFT;
dma->size += npage << PAGE_SHIFT;
}
vfio_batch_fini(&batch);
dma->iommu_mapped = true;
if (ret)
vfio_remove_dma(iommu, dma);
return ret;
}
/*
* Check dma map request is within a valid iova range
*/
static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu,
dma_addr_t start, dma_addr_t end)
{
struct list_head *iova = &iommu->iova_list;
struct vfio_iova *node;
list_for_each_entry(node, iova, list) {
if (start >= node->start && end <= node->end)
return true;
}
/*
* Check for list_empty() as well since a container with
* a single mdev device will have an empty list.
*/
return list_empty(iova);
}
static int vfio_change_dma_owner(struct vfio_dma *dma)
{
struct task_struct *task = current->group_leader;
struct mm_struct *mm = current->mm;
long npage = dma->locked_vm;
bool lock_cap;
int ret;
if (mm == dma->mm)
return 0;
lock_cap = capable(CAP_IPC_LOCK);
ret = mm_lock_acct(task, mm, lock_cap, npage);
if (ret)
return ret;
if (mmget_not_zero(dma->mm)) {
mm_lock_acct(dma->task, dma->mm, dma->lock_cap, -npage);
mmput(dma->mm);
}
if (dma->task != task) {
put_task_struct(dma->task);
dma->task = get_task_struct(task);
}
mmdrop(dma->mm);
dma->mm = mm;
mmgrab(dma->mm);
dma->lock_cap = lock_cap;
return 0;
}
static int vfio_dma_do_map(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_map *map)
{
bool set_vaddr = map->flags & VFIO_DMA_MAP_FLAG_VADDR;
dma_addr_t iova = map->iova;
unsigned long vaddr = map->vaddr;
size_t size = map->size;
int ret = 0, prot = 0;
size_t pgsize;
struct vfio_dma *dma;
/* Verify that none of our __u64 fields overflow */
if (map->size != size || map->vaddr != vaddr || map->iova != iova)
return -EINVAL;
/* READ/WRITE from device perspective */
if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
prot |= IOMMU_WRITE;
if (map->flags & VFIO_DMA_MAP_FLAG_READ)
prot |= IOMMU_READ;
if ((prot && set_vaddr) || (!prot && !set_vaddr))
return -EINVAL;
mutex_lock(&iommu->lock);
pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
WARN_ON((pgsize - 1) & PAGE_MASK);
if (!size || (size | iova | vaddr) & (pgsize - 1)) {
ret = -EINVAL;
goto out_unlock;
}
/* Don't allow IOVA or virtual address wrap */
if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) {
ret = -EINVAL;
goto out_unlock;
}
dma = vfio_find_dma(iommu, iova, size);
if (set_vaddr) {
if (!dma) {
ret = -ENOENT;
} else if (!dma->vaddr_invalid || dma->iova != iova ||
dma->size != size) {
ret = -EINVAL;
} else {
ret = vfio_change_dma_owner(dma);
if (ret)
goto out_unlock;
dma->vaddr = vaddr;
dma->vaddr_invalid = false;
iommu->vaddr_invalid_count--;
}
goto out_unlock;
} else if (dma) {
ret = -EEXIST;
goto out_unlock;
}
if (!iommu->dma_avail) {
ret = -ENOSPC;
goto out_unlock;
}
if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) {
ret = -EINVAL;
goto out_unlock;
}
dma = kzalloc(sizeof(*dma), GFP_KERNEL);
if (!dma) {
ret = -ENOMEM;
goto out_unlock;
}
iommu->dma_avail--;
dma->iova = iova;
dma->vaddr = vaddr;
dma->prot = prot;
/*
* We need to be able to both add to a task's locked memory and test
* against the locked memory limit and we need to be able to do both
* outside of this call path as pinning can be asynchronous via the
* external interfaces for mdev devices. RLIMIT_MEMLOCK requires a
* task_struct. Save the group_leader so that all DMA tracking uses
* the same task, to make debugging easier. VM locked pages requires
* an mm_struct, so grab the mm in case the task dies.
*/
get_task_struct(current->group_leader);
dma->task = current->group_leader;
dma->lock_cap = capable(CAP_IPC_LOCK);
dma->mm = current->mm;
mmgrab(dma->mm);
dma->pfn_list = RB_ROOT;
/* Insert zero-sized and grow as we map chunks of it */
vfio_link_dma(iommu, dma);
/* Don't pin and map if container doesn't contain IOMMU capable domain*/
if (list_empty(&iommu->domain_list))
dma->size = size;
else
ret = vfio_pin_map_dma(iommu, dma, size);
if (!ret && iommu->dirty_page_tracking) {
ret = vfio_dma_bitmap_alloc(dma, pgsize);
if (ret)
vfio_remove_dma(iommu, dma);
}
out_unlock:
mutex_unlock(&iommu->lock);
return ret;
}
static int vfio_iommu_replay(struct vfio_iommu *iommu,
struct vfio_domain *domain)
{
struct vfio_batch batch;
struct vfio_domain *d = NULL;
struct rb_node *n;
unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
int ret;
/* Arbitrarily pick the first domain in the list for lookups */
if (!list_empty(&iommu->domain_list))
d = list_first_entry(&iommu->domain_list,
struct vfio_domain, next);
vfio_batch_init(&batch);
n = rb_first(&iommu->dma_list);
for (; n; n = rb_next(n)) {
struct vfio_dma *dma;
dma_addr_t iova;
dma = rb_entry(n, struct vfio_dma, node);
iova = dma->iova;
while (iova < dma->iova + dma->size) {
phys_addr_t phys;
size_t size;
if (dma->iommu_mapped) {
phys_addr_t p;
dma_addr_t i;
if (WARN_ON(!d)) { /* mapped w/o a domain?! */
ret = -EINVAL;
goto unwind;
}
phys = iommu_iova_to_phys(d->domain, iova);
if (WARN_ON(!phys)) {
iova += PAGE_SIZE;
continue;
}
size = PAGE_SIZE;
p = phys + size;
i = iova + size;
while (i < dma->iova + dma->size &&
p == iommu_iova_to_phys(d->domain, i)) {
size += PAGE_SIZE;
p += PAGE_SIZE;
i += PAGE_SIZE;
}
} else {
unsigned long pfn;
unsigned long vaddr = dma->vaddr +
(iova - dma->iova);
size_t n = dma->iova + dma->size - iova;
long npage;
npage = vfio_pin_pages_remote(dma, vaddr,
n >> PAGE_SHIFT,
&pfn, limit,
&batch);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
goto unwind;
}
phys = pfn << PAGE_SHIFT;
size = npage << PAGE_SHIFT;
}
ret = iommu_map(domain->domain, iova, phys, size,
dma->prot | IOMMU_CACHE,
GFP_KERNEL_ACCOUNT);
if (ret) {
if (!dma->iommu_mapped) {
vfio_unpin_pages_remote(dma, iova,
phys >> PAGE_SHIFT,
size >> PAGE_SHIFT,
true);
vfio_batch_unpin(&batch, dma);
}
goto unwind;
}
iova += size;
}
}
/* All dmas are now mapped, defer to second tree walk for unwind */
for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
dma->iommu_mapped = true;
}
vfio_batch_fini(&batch);
return 0;
unwind:
for (; n; n = rb_prev(n)) {
struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
dma_addr_t iova;
if (dma->iommu_mapped) {
iommu_unmap(domain->domain, dma->iova, dma->size);
continue;
}
iova = dma->iova;
while (iova < dma->iova + dma->size) {
phys_addr_t phys, p;
size_t size;
dma_addr_t i;
phys = iommu_iova_to_phys(domain->domain, iova);
if (!phys) {
iova += PAGE_SIZE;
continue;
}
size = PAGE_SIZE;
p = phys + size;
i = iova + size;
while (i < dma->iova + dma->size &&
p == iommu_iova_to_phys(domain->domain, i)) {
size += PAGE_SIZE;
p += PAGE_SIZE;
i += PAGE_SIZE;
}
iommu_unmap(domain->domain, iova, size);
vfio_unpin_pages_remote(dma, iova, phys >> PAGE_SHIFT,
size >> PAGE_SHIFT, true);
}
}
vfio_batch_fini(&batch);
return ret;
}
/*
* We change our unmap behavior slightly depending on whether the IOMMU
* supports fine-grained superpages. IOMMUs like AMD-Vi will use a superpage
* for practically any contiguous power-of-two mapping we give it. This means
* we don't need to look for contiguous chunks ourselves to make unmapping
* more efficient. On IOMMUs with coarse-grained super pages, like Intel VT-d
* with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
* significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
* hugetlbfs is in use.
*/
static void vfio_test_domain_fgsp(struct vfio_domain *domain, struct list_head *regions)
{
int ret, order = get_order(PAGE_SIZE * 2);
struct vfio_iova *region;
struct page *pages;
dma_addr_t start;
pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!pages)
return;
list_for_each_entry(region, regions, list) {
start = ALIGN(region->start, PAGE_SIZE * 2);
if (start >= region->end || (region->end - start < PAGE_SIZE * 2))
continue;
ret = iommu_map(domain->domain, start, page_to_phys(pages), PAGE_SIZE * 2,
IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE,
GFP_KERNEL_ACCOUNT);
if (!ret) {
size_t unmapped = iommu_unmap(domain->domain, start, PAGE_SIZE);
if (unmapped == PAGE_SIZE)
iommu_unmap(domain->domain, start + PAGE_SIZE, PAGE_SIZE);
else
domain->fgsp = true;
}
break;
}
__free_pages(pages, order);
}
static struct vfio_iommu_group *find_iommu_group(struct vfio_domain *domain,
struct iommu_group *iommu_group)
{
struct vfio_iommu_group *g;
list_for_each_entry(g, &domain->group_list, next) {
if (g->iommu_group == iommu_group)
return g;
}
return NULL;
}
static struct vfio_iommu_group*
vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
struct iommu_group *iommu_group)
{
struct vfio_iommu_group *group;
struct vfio_domain *domain;
list_for_each_entry(domain, &iommu->domain_list, next) {
group = find_iommu_group(domain, iommu_group);
if (group)
return group;
}
list_for_each_entry(group, &iommu->emulated_iommu_groups, next)
if (group->iommu_group == iommu_group)
return group;
return NULL;
}
static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
phys_addr_t *base)
{
struct iommu_resv_region *region;
bool ret = false;
list_for_each_entry(region, group_resv_regions, list) {
/*
* The presence of any 'real' MSI regions should take
* precedence over the software-managed one if the
* IOMMU driver happens to advertise both types.
*/
if (region->type == IOMMU_RESV_MSI) {
ret = false;
break;
}
if (region->type == IOMMU_RESV_SW_MSI) {
*base = region->start;
ret = true;
}
}
return ret;
}
/*
* This is a helper function to insert an address range to iova list.
* The list is initially created with a single entry corresponding to
* the IOMMU domain geometry to which the device group is attached.
* The list aperture gets modified when a new domain is added to the
* container if the new aperture doesn't conflict with the current one
* or with any existing dma mappings. The list is also modified to
* exclude any reserved regions associated with the device group.
*/
static int vfio_iommu_iova_insert(struct list_head *head,
dma_addr_t start, dma_addr_t end)
{
struct vfio_iova *region;
region = kmalloc(sizeof(*region), GFP_KERNEL);
if (!region)
return -ENOMEM;
INIT_LIST_HEAD(®ion->list);
region->start = start;
region->end = end;
list_add_tail(®ion->list, head);
return 0;
}
/*
* Check the new iommu aperture conflicts with existing aper or with any
* existing dma mappings.
*/
static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu,
dma_addr_t start, dma_addr_t end)
{
struct vfio_iova *first, *last;
struct list_head *iova = &iommu->iova_list;
if (list_empty(iova))
return false;
/* Disjoint sets, return conflict */
first = list_first_entry(iova, struct vfio_iova, list);
last = list_last_entry(iova, struct vfio_iova, list);
if (start > last->end || end < first->start)
return true;
/* Check for any existing dma mappings below the new start */
if (start > first->start) {
if (vfio_find_dma(iommu, first->start, start - first->start))
return true;
}
/* Check for any existing dma mappings beyond the new end */
if (end < last->end) {
if (vfio_find_dma(iommu, end + 1, last->end - end))
return true;
}
return false;
}
/*
* Resize iommu iova aperture window. This is called only if the new
* aperture has no conflict with existing aperture and dma mappings.
*/
static int vfio_iommu_aper_resize(struct list_head *iova,
dma_addr_t start, dma_addr_t end)
{
struct vfio_iova *node, *next;
if (list_empty(iova))
return vfio_iommu_iova_insert(iova, start, end);
/* Adjust iova list start */
list_for_each_entry_safe(node, next, iova, list) {
if (start < node->start)
break;
if (start >= node->start && start < node->end) {
node->start = start;
break;
}
/* Delete nodes before new start */
list_del(&node->list);
kfree(node);
}
/* Adjust iova list end */
list_for_each_entry_safe(node, next, iova, list) {
if (end > node->end)
continue;
if (end > node->start && end <= node->end) {
node->end = end;
continue;
}
/* Delete nodes after new end */
list_del(&node->list);
kfree(node);
}
return 0;
}
/*
* Check reserved region conflicts with existing dma mappings
*/
static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
struct list_head *resv_regions)
{
struct iommu_resv_region *region;
/* Check for conflict with existing dma mappings */
list_for_each_entry(region, resv_regions, list) {
if (region->type == IOMMU_RESV_DIRECT_RELAXABLE)
continue;
if (vfio_find_dma(iommu, region->start, region->length))
return true;
}
return false;
}
/*
* Check iova region overlap with reserved regions and
* exclude them from the iommu iova range
*/
static int vfio_iommu_resv_exclude(struct list_head *iova,
struct list_head *resv_regions)
{
struct iommu_resv_region *resv;
struct vfio_iova *n, *next;
list_for_each_entry(resv, resv_regions, list) {
phys_addr_t start, end;
if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE)
continue;
start = resv->start;
end = resv->start + resv->length - 1;
list_for_each_entry_safe(n, next, iova, list) {
int ret = 0;
/* No overlap */
if (start > n->end || end < n->start)
continue;
/*
* Insert a new node if current node overlaps with the
* reserve region to exclude that from valid iova range.
* Note that, new node is inserted before the current
* node and finally the current node is deleted keeping
* the list updated and sorted.
*/
if (start > n->start)
ret = vfio_iommu_iova_insert(&n->list, n->start,
start - 1);
if (!ret && end < n->end)
ret = vfio_iommu_iova_insert(&n->list, end + 1,
n->end);
if (ret)
return ret;
list_del(&n->list);
kfree(n);
}
}
if (list_empty(iova))
return -EINVAL;
return 0;
}
static void vfio_iommu_resv_free(struct list_head *resv_regions)
{
struct iommu_resv_region *n, *next;
list_for_each_entry_safe(n, next, resv_regions, list) {
list_del(&n->list);
kfree(n);
}
}
static void vfio_iommu_iova_free(struct list_head *iova)
{
struct vfio_iova *n, *next;
list_for_each_entry_safe(n, next, iova, list) {
list_del(&n->list);
kfree(n);
}
}
static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu,
struct list_head *iova_copy)
{
struct list_head *iova = &iommu->iova_list;
struct vfio_iova *n;
int ret;
list_for_each_entry(n, iova, list) {
ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end);
if (ret)
goto out_free;
}
return 0;
out_free:
vfio_iommu_iova_free(iova_copy);
return ret;
}
static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu,
struct list_head *iova_copy)
{
struct list_head *iova = &iommu->iova_list;
vfio_iommu_iova_free(iova);
list_splice_tail(iova_copy, iova);
}
static int vfio_iommu_domain_alloc(struct device *dev, void *data)
{
struct iommu_domain **domain = data;
*domain = iommu_paging_domain_alloc(dev);
return 1; /* Don't iterate */
}
static int vfio_iommu_type1_attach_group(void *iommu_data,
struct iommu_group *iommu_group, enum vfio_group_type type)
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_iommu_group *group;
struct vfio_domain *domain, *d;
bool resv_msi;
phys_addr_t resv_msi_base = 0;
struct iommu_domain_geometry *geo;
LIST_HEAD(iova_copy);
LIST_HEAD(group_resv_regions);
int ret = -EBUSY;
mutex_lock(&iommu->lock);
/* Attach could require pinning, so disallow while vaddr is invalid. */
if (iommu->vaddr_invalid_count)
goto out_unlock;
/* Check for duplicates */
ret = -EINVAL;
if (vfio_iommu_find_iommu_group(iommu, iommu_group))
goto out_unlock;
ret = -ENOMEM;
group = kzalloc(sizeof(*group), GFP_KERNEL);
if (!group)
goto out_unlock;
group->iommu_group = iommu_group;
if (type == VFIO_EMULATED_IOMMU) {
list_add(&group->next, &iommu->emulated_iommu_groups);
/*
* An emulated IOMMU group cannot dirty memory directly, it can
* only use interfaces that provide dirty tracking.
* The iommu scope can only be promoted with the addition of a
* dirty tracking group.
*/
group->pinned_page_dirty_scope = true;
ret = 0;
goto out_unlock;
}
ret = -ENOMEM;
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!domain)
goto out_free_group;
/*
* Going via the iommu_group iterator avoids races, and trivially gives
* us a representative device for the IOMMU API call. We don't actually
* want to iterate beyond the first device (if any).
*/
iommu_group_for_each_dev(iommu_group, &domain->domain,
vfio_iommu_domain_alloc);
if (IS_ERR(domain->domain)) {
ret = PTR_ERR(domain->domain);
goto out_free_domain;
}
if (iommu->nesting) {
ret = iommu_enable_nesting(domain->domain);
if (ret)
goto out_domain;
}
ret = iommu_attach_group(domain->domain, group->iommu_group);
if (ret)
goto out_domain;
/* Get aperture info */
geo = &domain->domain->geometry;
if (vfio_iommu_aper_conflict(iommu, geo->aperture_start,
geo->aperture_end)) {
ret = -EINVAL;
goto out_detach;
}
ret = iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
if (ret)
goto out_detach;
if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
ret = -EINVAL;
goto out_detach;
}
/*
* We don't want to work on the original iova list as the list
* gets modified and in case of failure we have to retain the
* original list. Get a copy here.
*/
ret = vfio_iommu_iova_get_copy(iommu, &iova_copy);
if (ret)
goto out_detach;
ret = vfio_iommu_aper_resize(&iova_copy, geo->aperture_start,
geo->aperture_end);
if (ret)
goto out_detach;
ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
if (ret)
goto out_detach;
resv_msi = vfio_iommu_has_sw_msi(&group_resv_regions, &resv_msi_base);
INIT_LIST_HEAD(&domain->group_list);
list_add(&group->next, &domain->group_list);
if (!allow_unsafe_interrupts &&
!iommu_group_has_isolated_msi(iommu_group)) {
pr_warn("%s: No interrupt remapping support. Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
__func__);
ret = -EPERM;
goto out_detach;
}
/*
* If the IOMMU can block non-coherent operations (ie PCIe TLPs with
* no-snoop set) then VFIO always turns this feature on because on Intel
* platforms it optimizes KVM to disable wbinvd emulation.
*/
if (domain->domain->ops->enforce_cache_coherency)
domain->enforce_cache_coherency =
domain->domain->ops->enforce_cache_coherency(
domain->domain);
/*
* Try to match an existing compatible domain. We don't want to
* preclude an IOMMU driver supporting multiple bus_types and being
* able to include different bus_types in the same IOMMU domain, so
* we test whether the domains use the same iommu_ops rather than
* testing if they're on the same bus_type.
*/
list_for_each_entry(d, &iommu->domain_list, next) {
if (d->domain->ops == domain->domain->ops &&
d->enforce_cache_coherency ==
domain->enforce_cache_coherency) {
iommu_detach_group(domain->domain, group->iommu_group);
if (!iommu_attach_group(d->domain,
group->iommu_group)) {
list_add(&group->next, &d->group_list);
iommu_domain_free(domain->domain);
kfree(domain);
goto done;
}
ret = iommu_attach_group(domain->domain,
group->iommu_group);
if (ret)
goto out_domain;
}
}
vfio_test_domain_fgsp(domain, &iova_copy);
/* replay mappings on new domains */
ret = vfio_iommu_replay(iommu, domain);
if (ret)
goto out_detach;
if (resv_msi) {
ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
if (ret && ret != -ENODEV)
goto out_detach;
}
list_add(&domain->next, &iommu->domain_list);
vfio_update_pgsize_bitmap(iommu);
done:
/* Delete the old one and insert new iova list */
vfio_iommu_iova_insert_copy(iommu, &iova_copy);
/*
* An iommu backed group can dirty memory directly and therefore
* demotes the iommu scope until it declares itself dirty tracking
* capable via the page pinning interface.
*/
iommu->num_non_pinned_groups++;
mutex_unlock(&iommu->lock);
vfio_iommu_resv_free(&group_resv_regions);
return 0;
out_detach:
iommu_detach_group(domain->domain, group->iommu_group);
out_domain:
iommu_domain_free(domain->domain);
vfio_iommu_iova_free(&iova_copy);
vfio_iommu_resv_free(&group_resv_regions);
out_free_domain:
kfree(domain);
out_free_group:
kfree(group);
out_unlock:
mutex_unlock(&iommu->lock);
return ret;
}
static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
{
struct rb_node *node;
while ((node = rb_first(&iommu->dma_list)))
vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
}
static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
{
struct rb_node *n, *p;
n = rb_first(&iommu->dma_list);
for (; n; n = rb_next(n)) {
struct vfio_dma *dma;
long locked = 0, unlocked = 0;
dma = rb_entry(n, struct vfio_dma, node);
unlocked += vfio_unmap_unpin(iommu, dma, false);
p = rb_first(&dma->pfn_list);
for (; p; p = rb_next(p)) {
struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
node);
if (!is_invalid_reserved_pfn(vpfn->pfn))
locked++;
}
vfio_lock_acct(dma, locked - unlocked, true);
}
}
/*
* Called when a domain is removed in detach. It is possible that
* the removed domain decided the iova aperture window. Modify the
* iova aperture with the smallest window among existing domains.
*/
static void vfio_iommu_aper_expand(struct vfio_iommu *iommu,
struct list_head *iova_copy)
{
struct vfio_domain *domain;
struct vfio_iova *node;
dma_addr_t start = 0;
dma_addr_t end = (dma_addr_t)~0;
if (list_empty(iova_copy))
return;
list_for_each_entry(domain, &iommu->domain_list, next) {
struct iommu_domain_geometry *geo = &domain->domain->geometry;
if (geo->aperture_start > start)
start = geo->aperture_start;
if (geo->aperture_end < end)
end = geo->aperture_end;
}
/* Modify aperture limits. The new aper is either same or bigger */
node = list_first_entry(iova_copy, struct vfio_iova, list);
node->start = start;
node = list_last_entry(iova_copy, struct vfio_iova, list);
node->end = end;
}
/*
* Called when a group is detached. The reserved regions for that
* group can be part of valid iova now. But since reserved regions
* may be duplicated among groups, populate the iova valid regions
* list again.
*/
static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu,
struct list_head *iova_copy)
{
struct vfio_domain *d;
struct vfio_iommu_group *g;
struct vfio_iova *node;
dma_addr_t start, end;
LIST_HEAD(resv_regions);
int ret;
if (list_empty(iova_copy))
return -EINVAL;
list_for_each_entry(d, &iommu->domain_list, next) {
list_for_each_entry(g, &d->group_list, next) {
ret = iommu_get_group_resv_regions(g->iommu_group,
&resv_regions);
if (ret)
goto done;
}
}
node = list_first_entry(iova_copy, struct vfio_iova, list);
start = node->start;
node = list_last_entry(iova_copy, struct vfio_iova, list);
end = node->end;
/* purge the iova list and create new one */
vfio_iommu_iova_free(iova_copy);
ret = vfio_iommu_aper_resize(iova_copy, start, end);
if (ret)
goto done;
/* Exclude current reserved regions from iova ranges */
ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions);
done:
vfio_iommu_resv_free(&resv_regions);
return ret;
}
static void vfio_iommu_type1_detach_group(void *iommu_data,
struct iommu_group *iommu_group)
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_domain *domain;
struct vfio_iommu_group *group;
bool update_dirty_scope = false;
LIST_HEAD(iova_copy);
mutex_lock(&iommu->lock);
list_for_each_entry(group, &iommu->emulated_iommu_groups, next) {
if (group->iommu_group != iommu_group)
continue;
update_dirty_scope = !group->pinned_page_dirty_scope;
list_del(&group->next);
kfree(group);
if (list_empty(&iommu->emulated_iommu_groups) &&
list_empty(&iommu->domain_list)) {
WARN_ON(!list_empty(&iommu->device_list));
vfio_iommu_unmap_unpin_all(iommu);
}
goto detach_group_done;
}
/*
* Get a copy of iova list. This will be used to update
* and to replace the current one later. Please note that
* we will leave the original list as it is if update fails.
*/
vfio_iommu_iova_get_copy(iommu, &iova_copy);
list_for_each_entry(domain, &iommu->domain_list, next) {
group = find_iommu_group(domain, iommu_group);
if (!group)
continue;
iommu_detach_group(domain->domain, group->iommu_group);
update_dirty_scope = !group->pinned_page_dirty_scope;
list_del(&group->next);
kfree(group);
/*
* Group ownership provides privilege, if the group list is
* empty, the domain goes away. If it's the last domain with
* iommu and external domain doesn't exist, then all the
* mappings go away too. If it's the last domain with iommu and
* external domain exist, update accounting
*/
if (list_empty(&domain->group_list)) {
if (list_is_singular(&iommu->domain_list)) {
if (list_empty(&iommu->emulated_iommu_groups)) {
WARN_ON(!list_empty(
&iommu->device_list));
vfio_iommu_unmap_unpin_all(iommu);
} else {
vfio_iommu_unmap_unpin_reaccount(iommu);
}
}
iommu_domain_free(domain->domain);
list_del(&domain->next);
kfree(domain);
vfio_iommu_aper_expand(iommu, &iova_copy);
vfio_update_pgsize_bitmap(iommu);
}
break;
}
if (!vfio_iommu_resv_refresh(iommu, &iova_copy))
vfio_iommu_iova_insert_copy(iommu, &iova_copy);
else
vfio_iommu_iova_free(&iova_copy);
detach_group_done:
/*
* Removal of a group without dirty tracking may allow the iommu scope
* to be promoted.
*/
if (update_dirty_scope) {
iommu->num_non_pinned_groups--;
if (iommu->dirty_page_tracking)
vfio_iommu_populate_bitmap_full(iommu);
}
mutex_unlock(&iommu->lock);
}
static void *vfio_iommu_type1_open(unsigned long arg)
{
struct vfio_iommu *iommu;
iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
if (!iommu)
return ERR_PTR(-ENOMEM);
switch (arg) {
case VFIO_TYPE1_IOMMU:
break;
case VFIO_TYPE1_NESTING_IOMMU:
iommu->nesting = true;
fallthrough;
case VFIO_TYPE1v2_IOMMU:
iommu->v2 = true;
break;
default:
kfree(iommu);
return ERR_PTR(-EINVAL);
}
INIT_LIST_HEAD(&iommu->domain_list);
INIT_LIST_HEAD(&iommu->iova_list);
iommu->dma_list = RB_ROOT;
iommu->dma_avail = dma_entry_limit;
mutex_init(&iommu->lock);
mutex_init(&iommu->device_list_lock);
INIT_LIST_HEAD(&iommu->device_list);
iommu->pgsize_bitmap = PAGE_MASK;
INIT_LIST_HEAD(&iommu->emulated_iommu_groups);
return iommu;
}
static void vfio_release_domain(struct vfio_domain *domain)
{
struct vfio_iommu_group *group, *group_tmp;
list_for_each_entry_safe(group, group_tmp,
&domain->group_list, next) {
iommu_detach_group(domain->domain, group->iommu_group);
list_del(&group->next);
kfree(group);
}
iommu_domain_free(domain->domain);
}
static void vfio_iommu_type1_release(void *iommu_data)
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_domain *domain, *domain_tmp;
struct vfio_iommu_group *group, *next_group;
list_for_each_entry_safe(group, next_group,
&iommu->emulated_iommu_groups, next) {
list_del(&group->next);
kfree(group);
}
vfio_iommu_unmap_unpin_all(iommu);
list_for_each_entry_safe(domain, domain_tmp,
&iommu->domain_list, next) {
vfio_release_domain(domain);
list_del(&domain->next);
kfree(domain);
}
vfio_iommu_iova_free(&iommu->iova_list);
kfree(iommu);
}
static int vfio_domains_have_enforce_cache_coherency(struct vfio_iommu *iommu)
{
struct vfio_domain *domain;
int ret = 1;
mutex_lock(&iommu->lock);
list_for_each_entry(domain, &iommu->domain_list, next) {
if (!(domain->enforce_cache_coherency)) {
ret = 0;
break;
}
}
mutex_unlock(&iommu->lock);
return ret;
}
static bool vfio_iommu_has_emulated(struct vfio_iommu *iommu)
{
bool ret;
mutex_lock(&iommu->lock);
ret = !list_empty(&iommu->emulated_iommu_groups);
mutex_unlock(&iommu->lock);
return ret;
}
static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
unsigned long arg)
{
switch (arg) {
case VFIO_TYPE1_IOMMU:
case VFIO_TYPE1v2_IOMMU:
case VFIO_TYPE1_NESTING_IOMMU:
case VFIO_UNMAP_ALL:
return 1;
case VFIO_UPDATE_VADDR:
/*
* Disable this feature if mdevs are present. They cannot
* safely pin/unpin/rw while vaddrs are being updated.
*/
return iommu && !vfio_iommu_has_emulated(iommu);
case VFIO_DMA_CC_IOMMU:
if (!iommu)
return 0;
return vfio_domains_have_enforce_cache_coherency(iommu);
default:
return 0;
}
}
static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
size_t size)
{
struct vfio_info_cap_header *header;
struct vfio_iommu_type1_info_cap_iova_range *iova_cap;
header = vfio_info_cap_add(caps, size,
VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);
if (IS_ERR(header))
return PTR_ERR(header);
iova_cap = container_of(header,
struct vfio_iommu_type1_info_cap_iova_range,
header);
iova_cap->nr_iovas = cap_iovas->nr_iovas;
memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges,
cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges));
return 0;
}
static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,
struct vfio_info_cap *caps)
{
struct vfio_iommu_type1_info_cap_iova_range *cap_iovas;
struct vfio_iova *iova;
size_t size;
int iovas = 0, i = 0, ret;
list_for_each_entry(iova, &iommu->iova_list, list)
iovas++;
if (!iovas) {
/*
* Return 0 as a container with a single mdev device
* will have an empty list
*/
return 0;
}
size = struct_size(cap_iovas, iova_ranges, iovas);
cap_iovas = kzalloc(size, GFP_KERNEL);
if (!cap_iovas)
return -ENOMEM;
cap_iovas->nr_iovas = iovas;
list_for_each_entry(iova, &iommu->iova_list, list) {
cap_iovas->iova_ranges[i].start = iova->start;
cap_iovas->iova_ranges[i].end = iova->end;
i++;
}
ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size);
kfree(cap_iovas);
return ret;
}
static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
struct vfio_info_cap *caps)
{
struct vfio_iommu_type1_info_cap_migration cap_mig = {};
cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
cap_mig.header.version = 1;
cap_mig.flags = 0;
/* support minimum pgsize */
cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap);
cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX;
return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
}
static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu,
struct vfio_info_cap *caps)
{
struct vfio_iommu_type1_info_dma_avail cap_dma_avail;
cap_dma_avail.header.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL;
cap_dma_avail.header.version = 1;
cap_dma_avail.avail = iommu->dma_avail;
return vfio_info_add_capability(caps, &cap_dma_avail.header,
sizeof(cap_dma_avail));
}
static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
unsigned long arg)
{
struct vfio_iommu_type1_info info = {};
unsigned long minsz;
struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
int ret;
minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
if (copy_from_user(&info, (void __user *)arg, minsz))
return -EFAULT;
if (info.argsz < minsz)
return -EINVAL;
minsz = min_t(size_t, info.argsz, sizeof(info));
mutex_lock(&iommu->lock);
info.flags = VFIO_IOMMU_INFO_PGSIZES;
info.iova_pgsizes = iommu->pgsize_bitmap;
ret = vfio_iommu_migration_build_caps(iommu, &caps);
if (!ret)
ret = vfio_iommu_dma_avail_build_caps(iommu, &caps);
if (!ret)
ret = vfio_iommu_iova_build_caps(iommu, &caps);
mutex_unlock(&iommu->lock);
if (ret)
return ret;
if (caps.size) {
info.flags |= VFIO_IOMMU_INFO_CAPS;
if (info.argsz < sizeof(info) + caps.size) {
info.argsz = sizeof(info) + caps.size;
} else {
vfio_info_cap_shift(&caps, sizeof(info));
if (copy_to_user((void __user *)arg +
sizeof(info), caps.buf,
caps.size)) {
kfree(caps.buf);
return -EFAULT;
}
info.cap_offset = sizeof(info);
}
kfree(caps.buf);
}
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
}
static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu,
unsigned long arg)
{
struct vfio_iommu_type1_dma_map map;
unsigned long minsz;
uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE |
VFIO_DMA_MAP_FLAG_VADDR;
minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
if (copy_from_user(&map, (void __user *)arg, minsz))
return -EFAULT;
if (map.argsz < minsz || map.flags & ~mask)
return -EINVAL;
return vfio_dma_do_map(iommu, &map);
}
static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
unsigned long arg)
{
struct vfio_iommu_type1_dma_unmap unmap;
struct vfio_bitmap bitmap = { 0 };
uint32_t mask = VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP |
VFIO_DMA_UNMAP_FLAG_VADDR |
VFIO_DMA_UNMAP_FLAG_ALL;
unsigned long minsz;
int ret;
minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
if (copy_from_user(&unmap, (void __user *)arg, minsz))
return -EFAULT;
if (unmap.argsz < minsz || unmap.flags & ~mask)
return -EINVAL;
if ((unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
(unmap.flags & (VFIO_DMA_UNMAP_FLAG_ALL |
VFIO_DMA_UNMAP_FLAG_VADDR)))
return -EINVAL;
if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
unsigned long pgshift;
if (unmap.argsz < (minsz + sizeof(bitmap)))
return -EINVAL;
if (copy_from_user(&bitmap,
(void __user *)(arg + minsz),
sizeof(bitmap)))
return -EFAULT;
if (!access_ok((void __user *)bitmap.data, bitmap.size))
return -EINVAL;
pgshift = __ffs(bitmap.pgsize);
ret = verify_bitmap_size(unmap.size >> pgshift,
bitmap.size);
if (ret)
return ret;
}
ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
if (ret)
return ret;
return copy_to_user((void __user *)arg, &unmap, minsz) ?
-EFAULT : 0;
}
static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
unsigned long arg)
{
struct vfio_iommu_type1_dirty_bitmap dirty;
uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
unsigned long minsz;
int ret = 0;
if (!iommu->v2)
return -EACCES;
minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags);
if (copy_from_user(&dirty, (void __user *)arg, minsz))
return -EFAULT;
if (dirty.argsz < minsz || dirty.flags & ~mask)
return -EINVAL;
/* only one flag should be set at a time */
if (__ffs(dirty.flags) != __fls(dirty.flags))
return -EINVAL;
if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) {
size_t pgsize;
mutex_lock(&iommu->lock);
pgsize = 1 << __ffs(iommu->pgsize_bitmap);
if (!iommu->dirty_page_tracking) {
ret = vfio_dma_bitmap_alloc_all(iommu, pgsize);
if (!ret)
iommu->dirty_page_tracking = true;
}
mutex_unlock(&iommu->lock);
return ret;
} else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) {
mutex_lock(&iommu->lock);
if (iommu->dirty_page_tracking) {
iommu->dirty_page_tracking = false;
vfio_dma_bitmap_free_all(iommu);
}
mutex_unlock(&iommu->lock);
return 0;
} else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
struct vfio_iommu_type1_dirty_bitmap_get range;
unsigned long pgshift;
size_t data_size = dirty.argsz - minsz;
size_t iommu_pgsize;
if (!data_size || data_size < sizeof(range))
return -EINVAL;
if (copy_from_user(&range, (void __user *)(arg + minsz),
sizeof(range)))
return -EFAULT;
if (range.iova + range.size < range.iova)
return -EINVAL;
if (!access_ok((void __user *)range.bitmap.data,
range.bitmap.size))
return -EINVAL;
pgshift = __ffs(range.bitmap.pgsize);
ret = verify_bitmap_size(range.size >> pgshift,
range.bitmap.size);
if (ret)
return ret;
mutex_lock(&iommu->lock);
iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
/* allow only smallest supported pgsize */
if (range.bitmap.pgsize != iommu_pgsize) {
ret = -EINVAL;
goto out_unlock;
}
if (range.iova & (iommu_pgsize - 1)) {
ret = -EINVAL;
goto out_unlock;
}
if (!range.size || range.size & (iommu_pgsize - 1)) {
ret = -EINVAL;
goto out_unlock;
}
if (iommu->dirty_page_tracking)
ret = vfio_iova_dirty_bitmap(range.bitmap.data,
iommu, range.iova,
range.size,
range.bitmap.pgsize);
else
ret = -EINVAL;
out_unlock:
mutex_unlock(&iommu->lock);
return ret;
}
return -EINVAL;
}
static long vfio_iommu_type1_ioctl(void *iommu_data,
unsigned int cmd, unsigned long arg)
{
struct vfio_iommu *iommu = iommu_data;
switch (cmd) {
case VFIO_CHECK_EXTENSION:
return vfio_iommu_type1_check_extension(iommu, arg);
case VFIO_IOMMU_GET_INFO:
return vfio_iommu_type1_get_info(iommu, arg);
case VFIO_IOMMU_MAP_DMA:
return vfio_iommu_type1_map_dma(iommu, arg);
case VFIO_IOMMU_UNMAP_DMA:
return vfio_iommu_type1_unmap_dma(iommu, arg);
case VFIO_IOMMU_DIRTY_PAGES:
return vfio_iommu_type1_dirty_pages(iommu, arg);
default:
return -ENOTTY;
}
}
static void vfio_iommu_type1_register_device(void *iommu_data,
struct vfio_device *vdev)
{
struct vfio_iommu *iommu = iommu_data;
if (!vdev->ops->dma_unmap)
return;
/*
* list_empty(&iommu->device_list) is tested under the iommu->lock while
* iteration for dma_unmap must be done under the device_list_lock.
* Holding both locks here allows avoiding the device_list_lock in
* several fast paths. See vfio_notify_dma_unmap()
*/
mutex_lock(&iommu->lock);
mutex_lock(&iommu->device_list_lock);
list_add(&vdev->iommu_entry, &iommu->device_list);
mutex_unlock(&iommu->device_list_lock);
mutex_unlock(&iommu->lock);
}
static void vfio_iommu_type1_unregister_device(void *iommu_data,
struct vfio_device *vdev)
{
struct vfio_iommu *iommu = iommu_data;
if (!vdev->ops->dma_unmap)
return;
mutex_lock(&iommu->lock);
mutex_lock(&iommu->device_list_lock);
list_del(&vdev->iommu_entry);
mutex_unlock(&iommu->device_list_lock);
mutex_unlock(&iommu->lock);
}
static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
dma_addr_t user_iova, void *data,
size_t count, bool write,
size_t *copied)
{
struct mm_struct *mm;
unsigned long vaddr;
struct vfio_dma *dma;
bool kthread = current->mm == NULL;
size_t offset;
*copied = 0;
dma = vfio_find_dma(iommu, user_iova, 1);
if (!dma)
return -EINVAL;
if ((write && !(dma->prot & IOMMU_WRITE)) ||
!(dma->prot & IOMMU_READ))
return -EPERM;
mm = dma->mm;
if (!mmget_not_zero(mm))
return -EPERM;
if (kthread)
kthread_use_mm(mm);
else if (current->mm != mm)
goto out;
offset = user_iova - dma->iova;
if (count > dma->size - offset)
count = dma->size - offset;
vaddr = dma->vaddr + offset;
if (write) {
*copied = copy_to_user((void __user *)vaddr, data,
count) ? 0 : count;
if (*copied && iommu->dirty_page_tracking) {
unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
/*
* Bitmap populated with the smallest supported page
* size
*/
bitmap_set(dma->bitmap, offset >> pgshift,
((offset + *copied - 1) >> pgshift) -
(offset >> pgshift) + 1);
}
} else
*copied = copy_from_user(data, (void __user *)vaddr,
count) ? 0 : count;
if (kthread)
kthread_unuse_mm(mm);
out:
mmput(mm);
return *copied ? 0 : -EFAULT;
}
static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova,
void *data, size_t count, bool write)
{
struct vfio_iommu *iommu = iommu_data;
int ret = 0;
size_t done;
mutex_lock(&iommu->lock);
if (WARN_ONCE(iommu->vaddr_invalid_count,
"vfio_dma_rw not allowed with VFIO_UPDATE_VADDR\n")) {
ret = -EBUSY;
goto out;
}
while (count > 0) {
ret = vfio_iommu_type1_dma_rw_chunk(iommu, user_iova, data,
count, write, &done);
if (ret)
break;
count -= done;
data += done;
user_iova += done;
}
out:
mutex_unlock(&iommu->lock);
return ret;
}
static struct iommu_domain *
vfio_iommu_type1_group_iommu_domain(void *iommu_data,
struct iommu_group *iommu_group)
{
struct iommu_domain *domain = ERR_PTR(-ENODEV);
struct vfio_iommu *iommu = iommu_data;
struct vfio_domain *d;
if (!iommu || !iommu_group)
return ERR_PTR(-EINVAL);
mutex_lock(&iommu->lock);
list_for_each_entry(d, &iommu->domain_list, next) {
if (find_iommu_group(d, iommu_group)) {
domain = d->domain;
break;
}
}
mutex_unlock(&iommu->lock);
return domain;
}
static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
.name = "vfio-iommu-type1",
.owner = THIS_MODULE,
.open = vfio_iommu_type1_open,
.release = vfio_iommu_type1_release,
.ioctl = vfio_iommu_type1_ioctl,
.attach_group = vfio_iommu_type1_attach_group,
.detach_group = vfio_iommu_type1_detach_group,
.pin_pages = vfio_iommu_type1_pin_pages,
.unpin_pages = vfio_iommu_type1_unpin_pages,
.register_device = vfio_iommu_type1_register_device,
.unregister_device = vfio_iommu_type1_unregister_device,
.dma_rw = vfio_iommu_type1_dma_rw,
.group_iommu_domain = vfio_iommu_type1_group_iommu_domain,
};
static int __init vfio_iommu_type1_init(void)
{
return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
}
static void __exit vfio_iommu_type1_cleanup(void)
{
vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1);
}
module_init(vfio_iommu_type1_init);
module_exit(vfio_iommu_type1_cleanup);
MODULE_VERSION(DRIVER_VERSION);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_DESCRIPTION(DRIVER_DESC);
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