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Merge tag 'vfio-v4.12-rc1' of git://github.com/awilliam/linux-vfio
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Pull VFIO updates from Alex Williamson:

 - Updates for SPAPR IOMMU backend including compatibility test and
   memory allocation check (Alexey Kardashevskiy)

 - Updates for type1 IOMMU backend to remove asynchronous locked page
   accounting and remove redundancy (Alex Williamson)

* tag 'vfio-v4.12-rc1' of git://github.com/awilliam/linux-vfio:
  vfio/type1: Reduce repetitive calls in vfio_pin_pages_remote()
  vfio/type1: Prune vfio_pin_page_external()
  vfio/type1: Remove locked page accounting workqueue
  vfio/spapr_tce: Check kzalloc() return when preregistering memory
  vfio/powerpc/spapr_tce: Enforce IOMMU type compatibility check
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Linus Torvalds committed May 4, 2017
2 parents a964807 + 7cb671e commit c336bf8
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Showing 2 changed files with 77 additions and 86 deletions.
13 changes: 13 additions & 0 deletions drivers/vfio/vfio_iommu_spapr_tce.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -198,6 +198,11 @@ static long tce_iommu_register_pages(struct tce_container *container,
return ret;

tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
if (!tcemem) {
mm_iommu_put(container->mm, mem);
return -ENOMEM;
}

tcemem->mem = mem;
list_add(&tcemem->next, &container->prereg_list);

Expand Down Expand Up @@ -1335,8 +1340,16 @@ static int tce_iommu_attach_group(void *iommu_data,

if (!table_group->ops || !table_group->ops->take_ownership ||
!table_group->ops->release_ownership) {
if (container->v2) {
ret = -EPERM;
goto unlock_exit;
}
ret = tce_iommu_take_ownership(container, table_group);
} else {
if (!container->v2) {
ret = -EPERM;
goto unlock_exit;
}
ret = tce_iommu_take_ownership_ddw(container, table_group);
if (!tce_groups_attached(container) && !container->tables[0])
container->def_window_pending = true;
Expand Down
150 changes: 64 additions & 86 deletions drivers/vfio/vfio_iommu_type1.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -246,69 +246,46 @@ static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
return ret;
}

struct vwork {
struct mm_struct *mm;
long npage;
struct work_struct work;
};

/* delayed decrement/increment for locked_vm */
static void vfio_lock_acct_bg(struct work_struct *work)
static int vfio_lock_acct(struct task_struct *task, long npage, bool *lock_cap)
{
struct vwork *vwork = container_of(work, struct vwork, work);
struct mm_struct *mm;

mm = vwork->mm;
down_write(&mm->mmap_sem);
mm->locked_vm += vwork->npage;
up_write(&mm->mmap_sem);
mmput(mm);
kfree(vwork);
}

static void vfio_lock_acct(struct task_struct *task, long npage)
{
struct vwork *vwork;
struct mm_struct *mm;
bool is_current;
int ret;

if (!npage)
return;
return 0;

is_current = (task->mm == current->mm);

mm = is_current ? task->mm : get_task_mm(task);
if (!mm)
return; /* process exited */
return -ESRCH; /* process exited */

if (down_write_trylock(&mm->mmap_sem)) {
mm->locked_vm += npage;
up_write(&mm->mmap_sem);
if (!is_current)
mmput(mm);
return;
}
ret = down_write_killable(&mm->mmap_sem);
if (!ret) {
if (npage > 0) {
if (lock_cap ? !*lock_cap :
!has_capability(task, CAP_IPC_LOCK)) {
unsigned long limit;

limit = task_rlimit(task,
RLIMIT_MEMLOCK) >> PAGE_SHIFT;

if (mm->locked_vm + npage > limit)
ret = -ENOMEM;
}
}

if (!ret)
mm->locked_vm += npage;

if (is_current) {
mm = get_task_mm(task);
if (!mm)
return;
up_write(&mm->mmap_sem);
}

/*
* Couldn't get mmap_sem lock, so must setup to update
* mm->locked_vm later. If locked_vm were atomic, we
* wouldn't need this silliness
*/
vwork = kmalloc(sizeof(struct vwork), GFP_KERNEL);
if (WARN_ON(!vwork)) {
if (!is_current)
mmput(mm);
return;
}
INIT_WORK(&vwork->work, vfio_lock_acct_bg);
vwork->mm = mm;
vwork->npage = npage;
schedule_work(&vwork->work);

return ret;
}

/*
Expand Down Expand Up @@ -403,10 +380,10 @@ static int vaddr_get_pfn(struct mm_struct *mm, unsigned long vaddr,
* 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)
long npage, unsigned long *pfn_base,
bool lock_cap, unsigned long limit)
{
unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
bool lock_cap = capable(CAP_IPC_LOCK);
unsigned long pfn = 0;
long ret, pinned = 0, lock_acct = 0;
bool rsvd;
dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
Expand Down Expand Up @@ -442,8 +419,6 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
/* Lock all the consecutive pages from pfn_base */
for (vaddr += PAGE_SIZE, iova += PAGE_SIZE; pinned < npage;
pinned++, vaddr += PAGE_SIZE, iova += PAGE_SIZE) {
unsigned long pfn = 0;

ret = vaddr_get_pfn(current->mm, vaddr, dma->prot, &pfn);
if (ret)
break;
Expand All @@ -460,14 +435,25 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
put_pfn(pfn, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, limit << PAGE_SHIFT);
break;
ret = -ENOMEM;
goto unpin_out;
}
lock_acct++;
}
}

out:
vfio_lock_acct(current, lock_acct);
ret = vfio_lock_acct(current, lock_acct, &lock_cap);

unpin_out:
if (ret) {
if (!rsvd) {
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
}

return ret;
}

return pinned;
}
Expand All @@ -488,45 +474,34 @@ static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
}

if (do_accounting)
vfio_lock_acct(dma->task, locked - unlocked);
vfio_lock_acct(dma->task, locked - unlocked, NULL);

return unlocked;
}

static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
unsigned long *pfn_base, bool do_accounting)
{
unsigned long limit;
bool lock_cap = has_capability(dma->task, CAP_IPC_LOCK);
struct mm_struct *mm;
int ret;
bool rsvd;

mm = get_task_mm(dma->task);
if (!mm)
return -ENODEV;

ret = vaddr_get_pfn(mm, vaddr, dma->prot, pfn_base);
if (ret)
goto pin_page_exit;

rsvd = is_invalid_reserved_pfn(*pfn_base);
limit = task_rlimit(dma->task, RLIMIT_MEMLOCK) >> PAGE_SHIFT;

if (!rsvd && !lock_cap && mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, dma->prot);
pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK (%ld) exceeded\n",
__func__, dma->task->comm, task_pid_nr(dma->task),
limit << PAGE_SHIFT);
ret = -ENOMEM;
goto pin_page_exit;
if (!ret && do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
ret = vfio_lock_acct(dma->task, 1, NULL);
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));
}
}

if (!rsvd && do_accounting)
vfio_lock_acct(dma->task, 1);
ret = 1;

pin_page_exit:
mmput(mm);
return ret;
}
Expand All @@ -543,7 +518,7 @@ static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);

if (do_accounting)
vfio_lock_acct(dma->task, -unlocked);
vfio_lock_acct(dma->task, -unlocked, NULL);

return unlocked;
}
Expand Down Expand Up @@ -606,10 +581,8 @@ static int vfio_iommu_type1_pin_pages(void *iommu_data,
remote_vaddr = dma->vaddr + iova - dma->iova;
ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn[i],
do_accounting);
if (ret <= 0) {
WARN_ON(!ret);
if (ret)
goto pin_unwind;
}

ret = vfio_add_to_pfn_list(dma, iova, phys_pfn[i]);
if (ret) {
Expand Down Expand Up @@ -740,7 +713,7 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,

dma->iommu_mapped = false;
if (do_accounting) {
vfio_lock_acct(dma->task, -unlocked);
vfio_lock_acct(dma->task, -unlocked, NULL);
return 0;
}
return unlocked;
Expand Down Expand Up @@ -951,13 +924,15 @@ static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
unsigned long vaddr = dma->vaddr;
size_t size = map_size;
long npage;
unsigned long pfn;
unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
bool lock_cap = capable(CAP_IPC_LOCK);
int ret = 0;

while (size) {
/* Pin a contiguous chunk of memory */
npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
size >> PAGE_SHIFT, &pfn);
size >> PAGE_SHIFT, &pfn,
lock_cap, limit);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
Expand Down Expand Up @@ -1067,6 +1042,8 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,
{
struct vfio_domain *d;
struct rb_node *n;
unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
bool lock_cap = capable(CAP_IPC_LOCK);
int ret;

/* Arbitrarily pick the first domain in the list for lookups */
Expand Down Expand Up @@ -1113,7 +1090,8 @@ static int vfio_iommu_replay(struct vfio_iommu *iommu,

npage = vfio_pin_pages_remote(dma, vaddr,
n >> PAGE_SHIFT,
&pfn);
&pfn, lock_cap,
limit);
if (npage <= 0) {
WARN_ON(!npage);
ret = (int)npage;
Expand Down Expand Up @@ -1382,7 +1360,7 @@ static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
if (!is_invalid_reserved_pfn(vpfn->pfn))
locked++;
}
vfio_lock_acct(dma->task, locked - unlocked);
vfio_lock_acct(dma->task, locked - unlocked, NULL);
}
}

Expand Down

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