blob: 0b4f7c174c7a2b0e15ed9e25762c0de42612cb61 [file] [log] [blame]
// 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 <alex.williamson@redhat.com>
*
* Derived from original vfio:
* Copyright 2010 Cisco Systems, Inc. All rights reserved.
* Author: Tom Lyon, pugs@cisco.com
*
* 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/mdev.h>
#include <linux/notifier.h>
#include <linux/dma-iommu.h>
#include <linux/irqdomain.h>
#define DRIVER_VERSION "0.2"
#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
#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 vfio_domain *external_domain; /* domain for external user */
struct mutex lock;
struct rb_root dma_list;
struct blocking_notifier_head notifier;
unsigned int dma_avail;
unsigned int vaddr_invalid_count;
uint64_t pgsize_bitmap;
uint64_t num_non_pinned_groups;
wait_queue_head_t vaddr_wait;
bool v2;
bool nesting;
bool dirty_page_tracking;
bool container_open;
};
struct vfio_domain {
struct iommu_domain *domain;
struct list_head next;
struct list_head group_list;
int prot; /* IOMMU_CACHE */
bool fgsp; /* Fine-grained super pages */
};
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 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 mdev_group; /* An mdev group */
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 IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \
(!list_empty(&iommu->domain_list))
#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)
#define WAITED 1
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)
{
kfree(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 vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
{
struct mm_struct *mm;
int ret;
if (!npage)
return 0;
mm = async ? get_task_mm(dma->task) : dma->task->mm;
if (!mm)
return -ESRCH; /* process exited */
ret = mmap_write_lock_killable(mm);
if (!ret) {
ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task,
dma->lock_cap);
mmap_write_unlock(mm);
}
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)
{
pte_t *ptep;
spinlock_t *ptl;
int ret;
ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
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_pte(vma->vm_mm, vaddr, &ptep, &ptl);
if (ret)
return ret;
}
if (write_fault && !pte_write(*ptep))
ret = -EFAULT;
else
*pfn = pte_pfn(*ptep);
pte_unmap_unlock(ptep, ptl);
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, NULL);
if (ret > 0) {
*pfn = page_to_pfn(pages[0]);
goto done;
}
vaddr = untagged_addr(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;
}
static int vfio_wait(struct vfio_iommu *iommu)
{
DEFINE_WAIT(wait);
prepare_to_wait(&iommu->vaddr_wait, &wait, TASK_KILLABLE);
mutex_unlock(&iommu->lock);
schedule();
mutex_lock(&iommu->lock);
finish_wait(&iommu->vaddr_wait, &wait);
if (kthread_should_stop() || !iommu->container_open ||
fatal_signal_pending(current)) {
return -EFAULT;
}
return WAITED;
}
/*
* Find dma struct and wait for its vaddr to be valid. iommu lock is dropped
* if the task waits, but is re-locked on return. Return result in *dma_p.
* Return 0 on success with no waiting, WAITED on success if waited, and -errno
* on error.
*/
static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
size_t size, struct vfio_dma **dma_p)
{
int ret;
do {
*dma_p = vfio_find_dma(iommu, start, size);
if (!*dma_p)
ret = -EINVAL;
else if (!(*dma_p)->vaddr_invalid)
ret = 0;
else
ret = vfio_wait(iommu);
} while (ret > 0);
return ret;
}
/*
* Wait for all vaddr in the dma_list to become valid. iommu lock is dropped
* if the task waits, but is re-locked on return. Return 0 on success with no
* waiting, WAITED on success if waited, and -errno on error.
*/
static int vfio_wait_all_valid(struct vfio_iommu *iommu)
{
int ret = 0;
while (iommu->vaddr_invalid_count && ret >= 0)
ret = vfio_wait(iommu);
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 = get_task_mm(dma->task);
if (!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, true);
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,
unsigned long *user_pfn,
int npage, int prot,
unsigned long *phys_pfn)
{
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;
dma_addr_t iova;
if (!iommu || !user_pfn || !phys_pfn)
return -EINVAL;
/* Supported for v2 version only */
if (!iommu->v2)
return -EACCES;
mutex_lock(&iommu->lock);
/*
* Wait for all necessary vaddr's to be valid so they can be used in
* the main loop without dropping the lock, to avoid racing vs unmap.
*/
again:
if (iommu->vaddr_invalid_count) {
for (i = 0; i < npage; i++) {
iova = user_pfn[i] << PAGE_SHIFT;
ret = vfio_find_dma_valid(iommu, iova, PAGE_SIZE, &dma);
if (ret < 0)
goto pin_done;
if (ret == WAITED)
goto again;
}
}
/* Fail if notifier list is empty */
if (!iommu->notifier.head) {
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 = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
for (i = 0; i < npage; i++) {
struct vfio_pfn *vpfn;
iova = user_pfn[i] << PAGE_SHIFT;
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) {
phys_pfn[i] = vpfn->pfn;
continue;
}
remote_vaddr = dma->vaddr + (iova - dma->iova);
ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
do_accounting);
if (ret)
goto pin_unwind;
ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
if (ret) {
if (put_pfn(phys_pfn[i], dma->prot) && do_accounting)
vfio_lock_acct(dma, -1, true);
goto pin_unwind;
}
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:
phys_pfn[i] = 0;
for (j = 0; j < i; j++) {
dma_addr_t iova;
iova = user_pfn[j] << PAGE_SHIFT;
dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
vfio_unpin_page_external(dma, iova, do_accounting);
phys_pfn[j] = 0;
}
pin_done:
mutex_unlock(&iommu->lock);
return ret;
}
static int vfio_iommu_type1_unpin_pages(void *iommu_data,
unsigned long *user_pfn,
int npage)
{
struct vfio_iommu *iommu = iommu_data;
bool do_accounting;
int i;
if (!iommu || !user_pfn || npage <= 0)
return -EINVAL;
/* Supported for v2 version only */
if (!iommu->v2)
return -EACCES;
mutex_lock(&iommu->lock);
do_accounting = !IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu);
for (i = 0; i < npage; i++) {
struct vfio_dma *dma;
dma_addr_t iova;
iova = user_pfn[i] << PAGE_SHIFT;
dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
if (!dma)
break;
vfio_unpin_page_external(dma, iova, do_accounting);
}
mutex_unlock(&iommu->lock);
return i > 0 ? i : -EINVAL;
}
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 (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
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);
vfio_dma_bitmap_free(dma);
if (dma->vaddr_invalid) {
iommu->vaddr_invalid_count--;
wake_up_all(&iommu->vaddr_wait);
}
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;
}
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);
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;
/*
* Task with same address space who mapped this iova range is
* allowed to unmap the iova range.
*/
if (dma->task->mm != current->mm)
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)) {
struct vfio_iommu_type1_dma_unmap nb_unmap;
if (dma_last == dma) {
BUG_ON(++retries > 10);
} else {
dma_last = dma;
retries = 0;
}
nb_unmap.iova = dma->iova;
nb_unmap.size = dma->size;
/*
* Notify anyone (mdev vendor drivers) to invalidate and
* unmap iovas within the range we're about to unmap.
* Vendor drivers MUST unpin pages in response to an
* invalidation.
*/
mutex_unlock(&iommu->lock);
blocking_notifier_call_chain(&iommu->notifier,
VFIO_IOMMU_NOTIFY_DMA_UNMAP,
&nb_unmap);
mutex_lock(&iommu->lock);
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 | d->prot);
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_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 {
dma->vaddr = vaddr;
dma->vaddr_invalid = false;
iommu->vaddr_invalid_count--;
wake_up_all(&iommu->vaddr_wait);
}
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 and VM locked pages requires an mm_struct, however
* holding an indefinite mm reference is not recommended, therefore we
* only hold a reference to a task. We could hold a reference to
* current, however QEMU uses this call path through vCPU threads,
* which can be killed resulting in a NULL mm and failure in the unmap
* path when called via a different thread. Avoid this problem by
* using the group_leader as threads within the same group require
* both CLONE_THREAD and CLONE_VM and will therefore use the same
* mm_struct.
*
* Previously we also used the task for testing CAP_IPC_LOCK at the
* time of pinning and accounting, however has_capability() makes use
* of real_cred, a copy-on-write field, so we can't guarantee that it
* matches group_leader, or in fact that it might not change by the
* time it's evaluated. If a process were to call MAP_DMA with
* CAP_IPC_LOCK but later drop it, it doesn't make sense that they
* possibly see different results for an iommu_mapped vfio_dma vs
* externally mapped. Therefore track CAP_IPC_LOCK in vfio_dma at the
* time of calling MAP_DMA.
*/
get_task_struct(current->group_leader);
dma->task = current->group_leader;
dma->lock_cap = capable(CAP_IPC_LOCK);
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 (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
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_bus_type(struct device *dev, void *data)
{
struct bus_type **bus = data;
if (*bus && *bus != dev->bus)
return -EINVAL;
*bus = dev->bus;
return 0;
}
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;
ret = vfio_wait_all_valid(iommu);
if (ret < 0)
return 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 | domain->prot);
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 page *pages;
int ret, order = get_order(PAGE_SIZE * 2);
pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
if (!pages)
return;
ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
IOMMU_READ | IOMMU_WRITE | domain->prot);
if (!ret) {
size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
if (unmapped == PAGE_SIZE)
iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
else
domain->fgsp = true;
}
__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_domain *domain;
struct vfio_iommu_group *group = NULL;
list_for_each_entry(domain, &iommu->domain_list, next) {
group = find_iommu_group(domain, iommu_group);
if (group)
return group;
}
if (iommu->external_domain)
group = find_iommu_group(iommu->external_domain, iommu_group);
return group;
}
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;
}
static int vfio_mdev_attach_domain(struct device *dev, void *data)
{
struct mdev_device *mdev = to_mdev_device(dev);
struct iommu_domain *domain = data;
struct device *iommu_device;
iommu_device = mdev_get_iommu_device(mdev);
if (iommu_device) {
if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
return iommu_aux_attach_device(domain, iommu_device);
else
return iommu_attach_device(domain, iommu_device);
}
return -EINVAL;
}
static int vfio_mdev_detach_domain(struct device *dev, void *data)
{
struct mdev_device *mdev = to_mdev_device(dev);
struct iommu_domain *domain = data;
struct device *iommu_device;
iommu_device = mdev_get_iommu_device(mdev);
if (iommu_device) {
if (iommu_dev_feature_enabled(iommu_device, IOMMU_DEV_FEAT_AUX))
iommu_aux_detach_device(domain, iommu_device);
else
iommu_detach_device(domain, iommu_device);
}
return 0;
}
static int vfio_iommu_attach_group(struct vfio_domain *domain,
struct vfio_iommu_group *group)
{
if (group->mdev_group)
return iommu_group_for_each_dev(group->iommu_group,
domain->domain,
vfio_mdev_attach_domain);
else
return iommu_attach_group(domain->domain, group->iommu_group);
}
static void vfio_iommu_detach_group(struct vfio_domain *domain,
struct vfio_iommu_group *group)
{
if (group->mdev_group)
iommu_group_for_each_dev(group->iommu_group, domain->domain,
vfio_mdev_detach_domain);
else
iommu_detach_group(domain->domain, group->iommu_group);
}
static bool vfio_bus_is_mdev(struct bus_type *bus)
{
struct bus_type *mdev_bus;
bool ret = false;
mdev_bus = symbol_get(mdev_bus_type);
if (mdev_bus) {
ret = (bus == mdev_bus);
symbol_put(mdev_bus_type);
}
return ret;
}
static int vfio_mdev_iommu_device(struct device *dev, void *data)
{
struct mdev_device *mdev = to_mdev_device(dev);
struct device **old = data, *new;
new = mdev_get_iommu_device(mdev);
if (!new || (*old && *old != new))
return -EINVAL;
*old = new;
return 0;
}
/*
* 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(&region->list);
region->start = start;
region->end = end;
list_add_tail(&region->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_type1_attach_group(void *iommu_data,
struct iommu_group *iommu_group)
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_iommu_group *group;
struct vfio_domain *domain, *d;
struct bus_type *bus = NULL;
int ret;
bool resv_msi, msi_remap;
phys_addr_t resv_msi_base = 0;
struct iommu_domain_geometry *geo;
LIST_HEAD(iova_copy);
LIST_HEAD(group_resv_regions);
mutex_lock(&iommu->lock);
/* Check for duplicates */
if (vfio_iommu_find_iommu_group(iommu, iommu_group)) {
mutex_unlock(&iommu->lock);
return -EINVAL;
}
group = kzalloc(sizeof(*group), GFP_KERNEL);
domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!group || !domain) {
ret = -ENOMEM;
goto out_free;
}
group->iommu_group = iommu_group;
/* Determine bus_type in order to allocate a domain */
ret = iommu_group_for_each_dev(iommu_group, &bus, vfio_bus_type);
if (ret)
goto out_free;
if (vfio_bus_is_mdev(bus)) {
struct device *iommu_device = NULL;
group->mdev_group = true;
/* Determine the isolation type */
ret = iommu_group_for_each_dev(iommu_group, &iommu_device,
vfio_mdev_iommu_device);
if (ret || !iommu_device) {
if (!iommu->external_domain) {
INIT_LIST_HEAD(&domain->group_list);
iommu->external_domain = domain;
vfio_update_pgsize_bitmap(iommu);
} else {
kfree(domain);
}
list_add(&group->next,
&iommu->external_domain->group_list);
/*
* Non-iommu backed 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;
mutex_unlock(&iommu->lock);
return 0;
}
bus = iommu_device->bus;
}
domain->domain = iommu_domain_alloc(bus);
if (!domain->domain) {
ret = -EIO;
goto out_free;
}
if (iommu->nesting) {
ret = iommu_enable_nesting(domain->domain);
if (ret)
goto out_domain;
}
ret = vfio_iommu_attach_group(domain, 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);
msi_remap = irq_domain_check_msi_remap() ||
iommu_capable(bus, IOMMU_CAP_INTR_REMAP);
if (!allow_unsafe_interrupts && !msi_remap) {
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 (iommu_capable(bus, IOMMU_CAP_CACHE_COHERENCY))
domain->prot |= IOMMU_CACHE;
/*
* 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->prot == domain->prot) {
vfio_iommu_detach_group(domain, group);
if (!vfio_iommu_attach_group(d, group)) {
list_add(&group->next, &d->group_list);
iommu_domain_free(domain->domain);
kfree(domain);
goto done;
}
ret = vfio_iommu_attach_group(domain, group);
if (ret)
goto out_domain;
}
}
vfio_test_domain_fgsp(domain);
/* 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:
vfio_iommu_detach_group(domain, group);
out_domain:
iommu_domain_free(domain->domain);
vfio_iommu_iova_free(&iova_copy);
vfio_iommu_resv_free(&group_resv_regions);
out_free:
kfree(domain);
kfree(group);
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);
if (iommu->external_domain) {
group = find_iommu_group(iommu->external_domain, iommu_group);
if (group) {
update_dirty_scope = !group->pinned_page_dirty_scope;
list_del(&group->next);
kfree(group);
if (list_empty(&iommu->external_domain->group_list)) {
if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu)) {
WARN_ON(iommu->notifier.head);
vfio_iommu_unmap_unpin_all(iommu);
}
kfree(iommu->external_domain);
iommu->external_domain = NULL;
}
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;
vfio_iommu_detach_group(domain, 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 (!iommu->external_domain) {
WARN_ON(iommu->notifier.head);
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;
iommu->container_open = true;
mutex_init(&iommu->lock);
BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
init_waitqueue_head(&iommu->vaddr_wait);
return iommu;
}
static void vfio_release_domain(struct vfio_domain *domain, bool external)
{
struct vfio_iommu_group *group, *group_tmp;
list_for_each_entry_safe(group, group_tmp,
&domain->group_list, next) {
if (!external)
vfio_iommu_detach_group(domain, group);
list_del(&group->next);
kfree(group);
}
if (!external)
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;
if (iommu->external_domain) {
vfio_release_domain(iommu->external_domain, true);
kfree(iommu->external_domain);
}
vfio_iommu_unmap_unpin_all(iommu);
list_for_each_entry_safe(domain, domain_tmp,
&iommu->domain_list, next) {
vfio_release_domain(domain, false);
list_del(&domain->next);
kfree(domain);
}
vfio_iommu_iova_free(&iommu->iova_list);
kfree(iommu);
}
static int vfio_domains_have_iommu_cache(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->prot & IOMMU_CACHE)) {
ret = 0;
break;
}
}
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:
case VFIO_UPDATE_VADDR:
return 1;
case VFIO_DMA_CC_IOMMU:
if (!iommu)
return 0;
return vfio_domains_have_iommu_cache(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 =