/*
|
* VFIO: IOMMU DMA mapping support for Type1 IOMMU
|
*
|
* Copyright (C) 2012 Red Hat, Inc. All rights reserved.
|
* Author: Alex Williamson <alex.williamson@redhat.com>
|
*
|
* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
|
* published by the Free Software Foundation.
|
*
|
* 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
|
* userpsace 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/iommu.h>
|
#include <linux/module.h>
|
#include <linux/mm.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 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;
|
bool v2;
|
bool nesting;
|
};
|
|
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) */
|
struct task_struct *task;
|
struct rb_root pfn_list; /* Ex-user pinned pfn list */
|
};
|
|
struct vfio_group {
|
struct iommu_group *iommu_group;
|
struct list_head next;
|
};
|
|
/*
|
* 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 */
|
atomic_t 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))
|
|
static int put_pfn(unsigned long pfn, int prot);
|
|
/*
|
* 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 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);
|
}
|
|
/*
|
* 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;
|
atomic_set(&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)
|
atomic_inc(&vpfn->ref_count);
|
return vpfn;
|
}
|
|
static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
|
{
|
int ret = 0;
|
|
if (atomic_dec_and_test(&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 = down_write_killable(&mm->mmap_sem);
|
if (!ret) {
|
if (npage > 0) {
|
if (!dma->lock_cap) {
|
unsigned long limit;
|
|
limit = task_rlimit(dma->task,
|
RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
|
if (mm->locked_vm + npage > limit)
|
ret = -ENOMEM;
|
}
|
}
|
|
if (!ret)
|
mm->locked_vm += npage;
|
|
up_write(&mm->mmap_sem);
|
}
|
|
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.
|
*/
|
static bool is_invalid_reserved_pfn(unsigned long pfn)
|
{
|
if (pfn_valid(pfn)) {
|
bool reserved;
|
struct page *tail = pfn_to_page(pfn);
|
struct page *head = compound_head(tail);
|
reserved = !!(PageReserved(head));
|
if (head != tail) {
|
/*
|
* "head" is not a dangling pointer
|
* (compound_head takes care of that)
|
* but the hugepage may have been split
|
* from under us (and we may not hold a
|
* reference count on the head page so it can
|
* be reused before we run PageReferenced), so
|
* we've to check PageTail before returning
|
* what we just read.
|
*/
|
smp_rmb();
|
if (PageTail(tail))
|
return reserved;
|
}
|
return PageReserved(tail);
|
}
|
|
return true;
|
}
|
|
static int put_pfn(unsigned long pfn, int prot)
|
{
|
if (!is_invalid_reserved_pfn(pfn)) {
|
struct page *page = pfn_to_page(pfn);
|
if (prot & IOMMU_WRITE)
|
SetPageDirty(page);
|
put_page(page);
|
return 1;
|
}
|
return 0;
|
}
|
|
static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
|
unsigned long vaddr, unsigned long *pfn,
|
bool write_fault)
|
{
|
int ret;
|
|
ret = follow_pfn(vma, vaddr, pfn);
|
if (ret) {
|
bool unlocked = false;
|
|
ret = fixup_user_fault(NULL, mm, vaddr,
|
FAULT_FLAG_REMOTE |
|
(write_fault ? FAULT_FLAG_WRITE : 0),
|
&unlocked);
|
if (unlocked)
|
return -EAGAIN;
|
|
if (ret)
|
return ret;
|
|
ret = follow_pfn(vma, vaddr, pfn);
|
}
|
|
return ret;
|
}
|
|
static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
|
int prot, unsigned long *pfn)
|
{
|
struct page *page[1];
|
struct vm_area_struct *vma;
|
struct vm_area_struct *vmas[1];
|
unsigned int flags = 0;
|
int ret;
|
|
if (prot & IOMMU_WRITE)
|
flags |= FOLL_WRITE;
|
|
down_read(&mm->mmap_sem);
|
if (mm == current->mm) {
|
ret = get_user_pages_longterm(vaddr, 1, flags, page, vmas);
|
} else {
|
ret = get_user_pages_remote(NULL, mm, vaddr, 1, flags, page,
|
vmas, NULL);
|
/*
|
* The lifetime of a vaddr_get_pfn() page pin is
|
* userspace-controlled. In the fs-dax case this could
|
* lead to indefinite stalls in filesystem operations.
|
* Disallow attempts to pin fs-dax pages via this
|
* interface.
|
*/
|
if (ret > 0 && vma_is_fsdax(vmas[0])) {
|
ret = -EOPNOTSUPP;
|
put_page(page[0]);
|
}
|
}
|
up_read(&mm->mmap_sem);
|
|
if (ret == 1) {
|
*pfn = page_to_pfn(page[0]);
|
return 0;
|
}
|
|
down_read(&mm->mmap_sem);
|
|
vaddr = untagged_addr(vaddr);
|
|
retry:
|
vma = find_vma_intersection(mm, vaddr, vaddr + 1);
|
|
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 && !is_invalid_reserved_pfn(*pfn))
|
ret = -EFAULT;
|
}
|
|
up_read(&mm->mmap_sem);
|
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)
|
{
|
unsigned long pfn = 0;
|
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 (!current->mm)
|
return -ENODEV;
|
|
ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, pfn_base);
|
if (ret)
|
return ret;
|
|
pinned++;
|
rsvd = is_invalid_reserved_pfn(*pfn_base);
|
|
/*
|
* 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 && current->mm->locked_vm + 1 > limit) {
|
put_pfn(*pfn_base, dma->prot);
|
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
|
limit << PAGE_SHIFT);
|
return -ENOMEM;
|
}
|
lock_acct++;
|
}
|
|
if (unlikely(disable_hugepages))
|
goto out;
|
|
/* Lock all the consecutive pages from pfn_base */
|
for (vaddr += PAGE_SIZE, iova += PAGE_SIZE; pinned < npage;
|
pinned++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
|
ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, &pfn);
|
if (ret)
|
break;
|
|
if (pfn != *pfn_base + pinned ||
|
rsvd != is_invalid_reserved_pfn(pfn)) {
|
put_pfn(pfn, dma->prot);
|
break;
|
}
|
|
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
|
if (!dma->lock_cap &&
|
current->mm->locked_vm + lock_acct + 1 > limit) {
|
put_pfn(pfn, dma->prot);
|
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
|
__func__, limit << PAGE_SHIFT);
|
ret = -ENOMEM;
|
goto unpin_out;
|
}
|
lock_acct++;
|
}
|
}
|
|
out:
|
ret = vfio_lock_acct(dma, lock_acct, false);
|
|
unpin_out:
|
if (ret) {
|
if (!rsvd) {
|
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
|
put_pfn(pfn, dma->prot);
|
}
|
|
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 mm_struct *mm;
|
int ret;
|
|
mm = get_task_mm(dma->task);
|
if (!mm)
|
return -ENODEV;
|
|
ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
|
if (!ret && 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));
|
}
|
}
|
|
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,
|
unsigned long *user_pfn,
|
int npage, int prot,
|
unsigned long *phys_pfn)
|
{
|
struct vfio_iommu *iommu = iommu_data;
|
int i, j, ret;
|
unsigned long remote_vaddr;
|
struct vfio_dma *dma;
|
bool do_accounting;
|
|
if (!iommu || !user_pfn || !phys_pfn)
|
return -EINVAL;
|
|
/* Supported for v2 version only */
|
if (!iommu->v2)
|
return -EACCES;
|
|
mutex_lock(&iommu->lock);
|
|
/* Fail if notifier list is empty */
|
if ((!iommu->external_domain) || (!iommu->notifier.head)) {
|
ret = -EINVAL;
|
goto pin_done;
|
}
|
|
/*
|
* If iommu capable domain exist in the container then all pages are
|
* already pinned and accounted. Accouting 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++) {
|
dma_addr_t iova;
|
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;
|
}
|
}
|
|
ret = i;
|
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)
|
return -EINVAL;
|
|
/* Supported for v2 version only */
|
if (!iommu->v2)
|
return -EACCES;
|
|
mutex_lock(&iommu->lock);
|
|
if (!iommu->external_domain) {
|
mutex_unlock(&iommu->lock);
|
return -EINVAL;
|
}
|
|
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)
|
goto unpin_exit;
|
vfio_unpin_page_external(dma, iova, do_accounting);
|
}
|
|
unpin_exit:
|
mutex_unlock(&iommu->lock);
|
return i > npage ? npage : (i > 0 ? i : -EINVAL);
|
}
|
|
static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
|
struct list_head *regions)
|
{
|
long unlocked = 0;
|
struct vfio_regions *entry, *next;
|
|
iommu_tlb_sync(domain->domain);
|
|
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)
|
{
|
size_t unmapped = 0;
|
struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
|
|
if (entry) {
|
unmapped = iommu_unmap_fast(domain->domain, *iova, len);
|
|
if (!unmapped) {
|
kfree(entry);
|
} else {
|
iommu_tlb_range_add(domain->domain, *iova, unmapped);
|
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);
|
*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);
|
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();
|
}
|
|
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);
|
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);
|
|
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)
|
{
|
vfio_unmap_unpin(iommu, dma, true);
|
vfio_unlink_dma(iommu, dma);
|
put_task_struct(dma->task);
|
kfree(dma);
|
iommu->dma_avail++;
|
}
|
|
static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
|
{
|
struct vfio_domain *domain;
|
unsigned long bitmap = ULONG_MAX;
|
|
mutex_lock(&iommu->lock);
|
list_for_each_entry(domain, &iommu->domain_list, next)
|
bitmap &= domain->domain->pgsize_bitmap;
|
mutex_unlock(&iommu->lock);
|
|
/*
|
* 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 (bitmap & ~PAGE_MASK) {
|
bitmap &= PAGE_MASK;
|
bitmap |= PAGE_SIZE;
|
}
|
|
return bitmap;
|
}
|
|
static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
|
struct vfio_iommu_type1_dma_unmap *unmap)
|
{
|
uint64_t mask;
|
struct vfio_dma *dma, *dma_last = NULL;
|
size_t unmapped = 0;
|
int ret = 0, retries = 0;
|
|
mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
|
|
if (unmap->iova & mask)
|
return -EINVAL;
|
if (!unmap->size || unmap->size & mask)
|
return -EINVAL;
|
if (unmap->iova + unmap->size - 1 < unmap->iova ||
|
unmap->size > SIZE_MAX)
|
return -EINVAL;
|
|
WARN_ON(mask & PAGE_MASK);
|
again:
|
mutex_lock(&iommu->lock);
|
|
/*
|
* 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) {
|
dma = vfio_find_dma(iommu, unmap->iova, 1);
|
if (dma && dma->iova != unmap->iova) {
|
ret = -EINVAL;
|
goto unlock;
|
}
|
dma = vfio_find_dma(iommu, unmap->iova + unmap->size - 1, 0);
|
if (dma && dma->iova + dma->size != unmap->iova + unmap->size) {
|
ret = -EINVAL;
|
goto unlock;
|
}
|
}
|
|
while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
|
if (!iommu->v2 && unmap->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 (!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);
|
goto again;
|
}
|
unmapped += dma->size;
|
vfio_remove_dma(iommu, dma);
|
}
|
|
unlock:
|
mutex_unlock(&iommu->lock);
|
|
/* Report how much was unmapped */
|
unmap->size = unmapped;
|
|
return ret;
|
}
|
|
/*
|
* Turns out AMD IOMMU has a page table bug where it won't map large pages
|
* to a region that previously mapped smaller pages. This should be fixed
|
* soon, so this is just a temporary workaround to break mappings down into
|
* PAGE_SIZE. Better to map smaller pages than nothing.
|
*/
|
static int map_try_harder(struct vfio_domain *domain, dma_addr_t iova,
|
unsigned long pfn, long npage, int prot)
|
{
|
long i;
|
int ret = 0;
|
|
for (i = 0; i < npage; i++, pfn++, iova += PAGE_SIZE) {
|
ret = iommu_map(domain->domain, iova,
|
(phys_addr_t)pfn << PAGE_SHIFT,
|
PAGE_SIZE, prot | domain->prot);
|
if (ret)
|
break;
|
}
|
|
for (; i < npage && i > 0; i--, iova -= PAGE_SIZE)
|
iommu_unmap(domain->domain, iova, PAGE_SIZE);
|
|
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) {
|
if (ret != -EBUSY ||
|
map_try_harder(d, iova, pfn, npage, prot))
|
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);
|
|
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;
|
size_t size = map_size;
|
long npage;
|
unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
|
int ret = 0;
|
|
while (size) {
|
/* Pin a contiguous chunk of memory */
|
npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
|
size >> PAGE_SHIFT, &pfn, limit);
|
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);
|
break;
|
}
|
|
size -= npage << PAGE_SHIFT;
|
dma->size += npage << PAGE_SHIFT;
|
}
|
|
dma->iommu_mapped = true;
|
|
if (ret)
|
vfio_remove_dma(iommu, dma);
|
|
return ret;
|
}
|
|
static int vfio_dma_do_map(struct vfio_iommu *iommu,
|
struct vfio_iommu_type1_dma_map *map)
|
{
|
dma_addr_t iova = map->iova;
|
unsigned long vaddr = map->vaddr;
|
size_t size = map->size;
|
int ret = 0, prot = 0;
|
uint64_t mask;
|
struct vfio_dma *dma;
|
|
/* Verify that none of our __u64 fields overflow */
|
if (map->size != size || map->vaddr != vaddr || map->iova != iova)
|
return -EINVAL;
|
|
mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
|
|
WARN_ON(mask & PAGE_MASK);
|
|
/* 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 || !size || (size | iova | vaddr) & mask)
|
return -EINVAL;
|
|
/* Don't allow IOVA or virtual address wrap */
|
if (iova + size - 1 < iova || vaddr + size - 1 < vaddr)
|
return -EINVAL;
|
|
mutex_lock(&iommu->lock);
|
|
if (vfio_find_dma(iommu, iova, size)) {
|
ret = -EEXIST;
|
goto out_unlock;
|
}
|
|
if (!iommu->dma_avail) {
|
ret = -ENOSPC;
|
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);
|
|
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_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);
|
|
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);
|
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);
|
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;
|
}
|
|
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);
|
}
|
}
|
|
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_group *find_iommu_group(struct vfio_domain *domain,
|
struct iommu_group *iommu_group)
|
{
|
struct vfio_group *g;
|
|
list_for_each_entry(g, &domain->group_list, next) {
|
if (g->iommu_group == iommu_group)
|
return g;
|
}
|
|
return NULL;
|
}
|
|
static bool vfio_iommu_has_sw_msi(struct iommu_group *group, phys_addr_t *base)
|
{
|
struct list_head group_resv_regions;
|
struct iommu_resv_region *region, *next;
|
bool ret = false;
|
|
INIT_LIST_HEAD(&group_resv_regions);
|
iommu_get_group_resv_regions(group, &group_resv_regions);
|
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;
|
}
|
}
|
list_for_each_entry_safe(region, next, &group_resv_regions, list)
|
kfree(region);
|
return ret;
|
}
|
|
static int vfio_iommu_type1_attach_group(void *iommu_data,
|
struct iommu_group *iommu_group)
|
{
|
struct vfio_iommu *iommu = iommu_data;
|
struct vfio_group *group;
|
struct vfio_domain *domain, *d;
|
struct bus_type *bus = NULL, *mdev_bus;
|
int ret;
|
bool resv_msi, msi_remap;
|
phys_addr_t resv_msi_base;
|
|
mutex_lock(&iommu->lock);
|
|
list_for_each_entry(d, &iommu->domain_list, next) {
|
if (find_iommu_group(d, iommu_group)) {
|
mutex_unlock(&iommu->lock);
|
return -EINVAL;
|
}
|
}
|
|
if (iommu->external_domain) {
|
if (find_iommu_group(iommu->external_domain, 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;
|
|
mdev_bus = symbol_get(mdev_bus_type);
|
|
if (mdev_bus) {
|
if ((bus == mdev_bus) && !iommu_present(bus)) {
|
symbol_put(mdev_bus_type);
|
if (!iommu->external_domain) {
|
INIT_LIST_HEAD(&domain->group_list);
|
iommu->external_domain = domain;
|
} else
|
kfree(domain);
|
|
list_add(&group->next,
|
&iommu->external_domain->group_list);
|
mutex_unlock(&iommu->lock);
|
return 0;
|
}
|
symbol_put(mdev_bus_type);
|
}
|
|
domain->domain = iommu_domain_alloc(bus);
|
if (!domain->domain) {
|
ret = -EIO;
|
goto out_free;
|
}
|
|
if (iommu->nesting) {
|
int attr = 1;
|
|
ret = iommu_domain_set_attr(domain->domain, DOMAIN_ATTR_NESTING,
|
&attr);
|
if (ret)
|
goto out_domain;
|
}
|
|
ret = iommu_attach_group(domain->domain, iommu_group);
|
if (ret)
|
goto out_domain;
|
|
resv_msi = vfio_iommu_has_sw_msi(iommu_group, &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) {
|
iommu_detach_group(domain->domain, iommu_group);
|
if (!iommu_attach_group(d->domain, iommu_group)) {
|
list_add(&group->next, &d->group_list);
|
iommu_domain_free(domain->domain);
|
kfree(domain);
|
mutex_unlock(&iommu->lock);
|
return 0;
|
}
|
|
ret = iommu_attach_group(domain->domain, iommu_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)
|
goto out_detach;
|
}
|
|
list_add(&domain->next, &iommu->domain_list);
|
|
mutex_unlock(&iommu->lock);
|
|
return 0;
|
|
out_detach:
|
iommu_detach_group(domain->domain, iommu_group);
|
out_domain:
|
iommu_domain_free(domain->domain);
|
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);
|
}
|
}
|
|
static void vfio_sanity_check_pfn_list(struct vfio_iommu *iommu)
|
{
|
struct rb_node *n;
|
|
n = rb_first(&iommu->dma_list);
|
for (; n; n = rb_next(n)) {
|
struct vfio_dma *dma;
|
|
dma = rb_entry(n, struct vfio_dma, node);
|
|
if (WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list)))
|
break;
|
}
|
/* mdev vendor driver must unregister notifier */
|
WARN_ON(iommu->notifier.head);
|
}
|
|
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_group *group;
|
|
mutex_lock(&iommu->lock);
|
|
if (iommu->external_domain) {
|
group = find_iommu_group(iommu->external_domain, iommu_group);
|
if (group) {
|
list_del(&group->next);
|
kfree(group);
|
|
if (list_empty(&iommu->external_domain->group_list)) {
|
vfio_sanity_check_pfn_list(iommu);
|
|
if (!IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu))
|
vfio_iommu_unmap_unpin_all(iommu);
|
|
kfree(iommu->external_domain);
|
iommu->external_domain = NULL;
|
}
|
goto detach_group_done;
|
}
|
}
|
|
list_for_each_entry(domain, &iommu->domain_list, next) {
|
group = find_iommu_group(domain, iommu_group);
|
if (!group)
|
continue;
|
|
iommu_detach_group(domain->domain, iommu_group);
|
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)
|
vfio_iommu_unmap_unpin_all(iommu);
|
else
|
vfio_iommu_unmap_unpin_reaccount(iommu);
|
}
|
iommu_domain_free(domain->domain);
|
list_del(&domain->next);
|
kfree(domain);
|
}
|
break;
|
}
|
|
detach_group_done:
|
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;
|
/* fall through */
|
case VFIO_TYPE1v2_IOMMU:
|
iommu->v2 = true;
|
break;
|
default:
|
kfree(iommu);
|
return ERR_PTR(-EINVAL);
|
}
|
|
INIT_LIST_HEAD(&iommu->domain_list);
|
iommu->dma_list = RB_ROOT;
|
iommu->dma_avail = dma_entry_limit;
|
mutex_init(&iommu->lock);
|
BLOCKING_INIT_NOTIFIER_HEAD(&iommu->notifier);
|
|
return iommu;
|
}
|
|
static void vfio_release_domain(struct vfio_domain *domain, bool external)
|
{
|
struct vfio_group *group, *group_tmp;
|
|
list_for_each_entry_safe(group, group_tmp,
|
&domain->group_list, next) {
|
if (!external)
|
iommu_detach_group(domain->domain, group->iommu_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);
|
vfio_sanity_check_pfn_list(iommu);
|
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);
|
}
|
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 long vfio_iommu_type1_ioctl(void *iommu_data,
|
unsigned int cmd, unsigned long arg)
|
{
|
struct vfio_iommu *iommu = iommu_data;
|
unsigned long minsz;
|
|
if (cmd == VFIO_CHECK_EXTENSION) {
|
switch (arg) {
|
case VFIO_TYPE1_IOMMU:
|
case VFIO_TYPE1v2_IOMMU:
|
case VFIO_TYPE1_NESTING_IOMMU:
|
return 1;
|
case VFIO_DMA_CC_IOMMU:
|
if (!iommu)
|
return 0;
|
return vfio_domains_have_iommu_cache(iommu);
|
default:
|
return 0;
|
}
|
} else if (cmd == VFIO_IOMMU_GET_INFO) {
|
struct vfio_iommu_type1_info info;
|
|
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;
|
|
info.flags = VFIO_IOMMU_INFO_PGSIZES;
|
|
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
|
|
return copy_to_user((void __user *)arg, &info, minsz) ?
|
-EFAULT : 0;
|
|
} else if (cmd == VFIO_IOMMU_MAP_DMA) {
|
struct vfio_iommu_type1_dma_map map;
|
uint32_t mask = VFIO_DMA_MAP_FLAG_READ |
|
VFIO_DMA_MAP_FLAG_WRITE;
|
|
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);
|
|
} else if (cmd == VFIO_IOMMU_UNMAP_DMA) {
|
struct vfio_iommu_type1_dma_unmap unmap;
|
long 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)
|
return -EINVAL;
|
|
ret = vfio_dma_do_unmap(iommu, &unmap);
|
if (ret)
|
return ret;
|
|
return copy_to_user((void __user *)arg, &unmap, minsz) ?
|
-EFAULT : 0;
|
}
|
|
return -ENOTTY;
|
}
|
|
static int vfio_iommu_type1_register_notifier(void *iommu_data,
|
unsigned long *events,
|
struct notifier_block *nb)
|
{
|
struct vfio_iommu *iommu = iommu_data;
|
|
/* clear known events */
|
*events &= ~VFIO_IOMMU_NOTIFY_DMA_UNMAP;
|
|
/* refuse to register if still events remaining */
|
if (*events)
|
return -EINVAL;
|
|
return blocking_notifier_chain_register(&iommu->notifier, nb);
|
}
|
|
static int vfio_iommu_type1_unregister_notifier(void *iommu_data,
|
struct notifier_block *nb)
|
{
|
struct vfio_iommu *iommu = iommu_data;
|
|
return blocking_notifier_chain_unregister(&iommu->notifier, nb);
|
}
|
|
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_notifier = vfio_iommu_type1_register_notifier,
|
.unregister_notifier = vfio_iommu_type1_unregister_notifier,
|
};
|
|
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);
|
