Merge tag 'vfio-v3.11' of git://github.com/awilliam/linux-vfio
Pull vfio updates from Alex Williamson:
"Largely hugepage support for vfio/type1 iommu and surrounding cleanups
and fixes"
* tag 'vfio-v3.11' of git://github.com/awilliam/linux-vfio:
vfio/type1: Fix leak on error path
vfio: Limit group opens
vfio/type1: Fix missed frees and zero sized removes
vfio: fix documentation
vfio: Provide module option to disable vfio_iommu_type1 hugepage support
vfio: hugepage support for vfio_iommu_type1
vfio: Convert type1 iommu to use rbtree
diff --git a/Documentation/vfio.txt b/Documentation/vfio.txt
index c55533c..d7993dc 100644
--- a/Documentation/vfio.txt
+++ b/Documentation/vfio.txt
@@ -172,12 +172,12 @@
struct vfio_device_info device_info = { .argsz = sizeof(device_info) };
/* Create a new container */
- container = open("/dev/vfio/vfio, O_RDWR);
+ container = open("/dev/vfio/vfio", O_RDWR);
if (ioctl(container, VFIO_GET_API_VERSION) != VFIO_API_VERSION)
/* Unknown API version */
- if (!ioctl(container, VFIO_CHECK_EXTENSION, VFIO_X86_IOMMU))
+ if (!ioctl(container, VFIO_CHECK_EXTENSION, VFIO_TYPE1_IOMMU))
/* Doesn't support the IOMMU driver we want. */
/* Open the group */
@@ -193,7 +193,7 @@
ioctl(group, VFIO_GROUP_SET_CONTAINER, &container);
/* Enable the IOMMU model we want */
- ioctl(container, VFIO_SET_IOMMU, VFIO_X86_IOMMU)
+ ioctl(container, VFIO_SET_IOMMU, VFIO_TYPE1_IOMMU)
/* Get addition IOMMU info */
ioctl(container, VFIO_IOMMU_GET_INFO, &iommu_info);
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 259ad28..c488da5 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -76,6 +76,7 @@
struct notifier_block nb;
struct list_head vfio_next;
struct list_head container_next;
+ atomic_t opened;
};
struct vfio_device {
@@ -206,6 +207,7 @@
INIT_LIST_HEAD(&group->device_list);
mutex_init(&group->device_lock);
atomic_set(&group->container_users, 0);
+ atomic_set(&group->opened, 0);
group->iommu_group = iommu_group;
group->nb.notifier_call = vfio_iommu_group_notifier;
@@ -1236,12 +1238,22 @@
static int vfio_group_fops_open(struct inode *inode, struct file *filep)
{
struct vfio_group *group;
+ int opened;
group = vfio_group_get_from_minor(iminor(inode));
if (!group)
return -ENODEV;
+ /* Do we need multiple instances of the group open? Seems not. */
+ opened = atomic_cmpxchg(&group->opened, 0, 1);
+ if (opened) {
+ vfio_group_put(group);
+ return -EBUSY;
+ }
+
+ /* Is something still in use from a previous open? */
if (group->container) {
+ atomic_dec(&group->opened);
vfio_group_put(group);
return -EBUSY;
}
@@ -1259,6 +1271,8 @@
vfio_group_try_dissolve_container(group);
+ atomic_dec(&group->opened);
+
vfio_group_put(group);
return 0;
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 6f3fbc4..a9807de 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -31,6 +31,7 @@
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/pci.h> /* pci_bus_type */
+#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
@@ -47,19 +48,25 @@
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.");
+
struct vfio_iommu {
struct iommu_domain *domain;
struct mutex lock;
- struct list_head dma_list;
+ struct rb_root dma_list;
struct list_head group_list;
bool cache;
};
struct vfio_dma {
- struct list_head next;
+ struct rb_node node;
dma_addr_t iova; /* Device address */
unsigned long vaddr; /* Process virtual addr */
- long npage; /* Number of pages */
+ size_t size; /* Map size (bytes) */
int prot; /* IOMMU_READ/WRITE */
};
@@ -73,7 +80,48 @@
* into DMA'ble space using the IOMMU
*/
-#define NPAGE_TO_SIZE(npage) ((size_t)(npage) << PAGE_SHIFT)
+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_insert_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_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
+{
+ rb_erase(&old->node, &iommu->dma_list);
+}
struct vwork {
struct mm_struct *mm;
@@ -100,8 +148,8 @@
struct vwork *vwork;
struct mm_struct *mm;
- if (!current->mm)
- return; /* process exited */
+ if (!current->mm || !npage)
+ return; /* process exited or nothing to do */
if (down_write_trylock(¤t->mm->mmap_sem)) {
current->mm->locked_vm += npage;
@@ -173,33 +221,6 @@
return 0;
}
-/* Unmap DMA region */
-static long __vfio_dma_do_unmap(struct vfio_iommu *iommu, dma_addr_t iova,
- long npage, int prot)
-{
- long i, unlocked = 0;
-
- for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
- unsigned long pfn;
-
- pfn = iommu_iova_to_phys(iommu->domain, iova) >> PAGE_SHIFT;
- if (pfn) {
- iommu_unmap(iommu->domain, iova, PAGE_SIZE);
- unlocked += put_pfn(pfn, prot);
- }
- }
- return unlocked;
-}
-
-static void vfio_dma_unmap(struct vfio_iommu *iommu, dma_addr_t iova,
- long npage, int prot)
-{
- long unlocked;
-
- unlocked = __vfio_dma_do_unmap(iommu, iova, npage, prot);
- vfio_lock_acct(-unlocked);
-}
-
static int vaddr_get_pfn(unsigned long vaddr, int prot, unsigned long *pfn)
{
struct page *page[1];
@@ -226,198 +247,306 @@
return ret;
}
-/* Map DMA region */
-static int __vfio_dma_map(struct vfio_iommu *iommu, dma_addr_t iova,
- unsigned long vaddr, long npage, int prot)
+/*
+ * 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(unsigned long vaddr, long npage,
+ int prot, unsigned long *pfn_base)
{
- dma_addr_t start = iova;
- long i, locked = 0;
- int ret;
+ unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
+ bool lock_cap = capable(CAP_IPC_LOCK);
+ long ret, i;
- /* Verify that pages are not already mapped */
- for (i = 0; i < npage; i++, iova += PAGE_SIZE)
- if (iommu_iova_to_phys(iommu->domain, iova))
- return -EBUSY;
+ if (!current->mm)
+ return -ENODEV;
- iova = start;
+ ret = vaddr_get_pfn(vaddr, prot, pfn_base);
+ if (ret)
+ return ret;
- if (iommu->cache)
- prot |= IOMMU_CACHE;
+ if (is_invalid_reserved_pfn(*pfn_base))
+ return 1;
- /*
- * XXX We break mappings into pages and use get_user_pages_fast to
- * pin the pages in memory. It's been suggested that mlock might
- * provide a more efficient mechanism, but nothing prevents the
- * user from munlocking the pages, which could then allow the user
- * access to random host memory. We also have no guarantee from the
- * IOMMU API that the iommu driver can unmap sub-pages of previous
- * mappings. This means we might lose an entire range if a single
- * page within it is unmapped. Single page mappings are inefficient,
- * but provide the most flexibility for now.
- */
- for (i = 0; i < npage; i++, iova += PAGE_SIZE, vaddr += PAGE_SIZE) {
+ if (!lock_cap && current->mm->locked_vm + 1 > limit) {
+ put_pfn(*pfn_base, prot);
+ pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
+ limit << PAGE_SHIFT);
+ return -ENOMEM;
+ }
+
+ if (unlikely(disable_hugepages)) {
+ vfio_lock_acct(1);
+ return 1;
+ }
+
+ /* Lock all the consecutive pages from pfn_base */
+ for (i = 1, vaddr += PAGE_SIZE; i < npage; i++, vaddr += PAGE_SIZE) {
unsigned long pfn = 0;
ret = vaddr_get_pfn(vaddr, prot, &pfn);
- if (ret) {
- __vfio_dma_do_unmap(iommu, start, i, prot);
- return ret;
+ if (ret)
+ break;
+
+ if (pfn != *pfn_base + i || is_invalid_reserved_pfn(pfn)) {
+ put_pfn(pfn, prot);
+ break;
}
- /*
- * Only add actual locked pages to accounting
- * XXX We're effectively marking a page locked for every
- * IOVA page even though it's possible the user could be
- * backing multiple IOVAs with the same vaddr. This over-
- * penalizes the user process, but we currently have no
- * easy way to do this properly.
- */
- if (!is_invalid_reserved_pfn(pfn))
- locked++;
-
- ret = iommu_map(iommu->domain, iova,
- (phys_addr_t)pfn << PAGE_SHIFT,
- PAGE_SIZE, prot);
- if (ret) {
- /* Back out mappings on error */
+ if (!lock_cap && current->mm->locked_vm + i + 1 > limit) {
put_pfn(pfn, prot);
- __vfio_dma_do_unmap(iommu, start, i, prot);
- return ret;
+ pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
+ __func__, limit << PAGE_SHIFT);
+ break;
}
}
- vfio_lock_acct(locked);
+
+ vfio_lock_acct(i);
+
+ return i;
+}
+
+static long vfio_unpin_pages(unsigned long pfn, long npage,
+ int prot, bool do_accounting)
+{
+ unsigned long unlocked = 0;
+ long i;
+
+ for (i = 0; i < npage; i++)
+ unlocked += put_pfn(pfn++, prot);
+
+ if (do_accounting)
+ vfio_lock_acct(-unlocked);
+
+ return unlocked;
+}
+
+static int vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
+ dma_addr_t iova, size_t *size)
+{
+ dma_addr_t start = iova, end = iova + *size;
+ long unlocked = 0;
+
+ while (iova < end) {
+ size_t unmapped;
+ phys_addr_t phys;
+
+ /*
+ * We use the IOMMU to track the physical address. This
+ * saves us from having a lot more entries in our mapping
+ * tree. The downside is that we don't track the size
+ * used to do the mapping. We request unmap of a single
+ * page, but expect IOMMUs that support large pages to
+ * unmap a larger chunk.
+ */
+ phys = iommu_iova_to_phys(iommu->domain, iova);
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
+ }
+
+ unmapped = iommu_unmap(iommu->domain, iova, PAGE_SIZE);
+ if (!unmapped)
+ break;
+
+ unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT,
+ unmapped >> PAGE_SHIFT,
+ dma->prot, false);
+ iova += unmapped;
+ }
+
+ vfio_lock_acct(-unlocked);
+
+ *size = iova - start;
+
return 0;
}
-static inline bool ranges_overlap(dma_addr_t start1, size_t size1,
- dma_addr_t start2, size_t size2)
+static int vfio_remove_dma_overlap(struct vfio_iommu *iommu, dma_addr_t start,
+ size_t *size, struct vfio_dma *dma)
{
- if (start1 < start2)
- return (start2 - start1 < size1);
- else if (start2 < start1)
- return (start1 - start2 < size2);
- return (size1 > 0 && size2 > 0);
-}
-
-static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
- dma_addr_t start, size_t size)
-{
- struct vfio_dma *dma;
-
- list_for_each_entry(dma, &iommu->dma_list, next) {
- if (ranges_overlap(dma->iova, NPAGE_TO_SIZE(dma->npage),
- start, size))
- return dma;
- }
- return NULL;
-}
-
-static long vfio_remove_dma_overlap(struct vfio_iommu *iommu, dma_addr_t start,
- size_t size, struct vfio_dma *dma)
-{
+ size_t offset, overlap, tmp;
struct vfio_dma *split;
- long npage_lo, npage_hi;
+ int ret;
- /* Existing dma region is completely covered, unmap all */
- if (start <= dma->iova &&
- start + size >= dma->iova + NPAGE_TO_SIZE(dma->npage)) {
- vfio_dma_unmap(iommu, dma->iova, dma->npage, dma->prot);
- list_del(&dma->next);
- npage_lo = dma->npage;
+ if (!*size)
+ return 0;
+
+ /*
+ * Existing dma region is completely covered, unmap all. This is
+ * the likely case since userspace tends to map and unmap buffers
+ * in one shot rather than multiple mappings within a buffer.
+ */
+ if (likely(start <= dma->iova &&
+ start + *size >= dma->iova + dma->size)) {
+ *size = dma->size;
+ ret = vfio_unmap_unpin(iommu, dma, dma->iova, size);
+ if (ret)
+ return ret;
+
+ /*
+ * Did we remove more than we have? Should never happen
+ * since a vfio_dma is contiguous in iova and vaddr.
+ */
+ WARN_ON(*size != dma->size);
+
+ vfio_remove_dma(iommu, dma);
kfree(dma);
- return npage_lo;
+ return 0;
}
/* Overlap low address of existing range */
if (start <= dma->iova) {
- size_t overlap;
+ overlap = start + *size - dma->iova;
+ ret = vfio_unmap_unpin(iommu, dma, dma->iova, &overlap);
+ if (ret)
+ return ret;
- overlap = start + size - dma->iova;
- npage_lo = overlap >> PAGE_SHIFT;
+ vfio_remove_dma(iommu, dma);
- vfio_dma_unmap(iommu, dma->iova, npage_lo, dma->prot);
- dma->iova += overlap;
- dma->vaddr += overlap;
- dma->npage -= npage_lo;
- return npage_lo;
+ /*
+ * Check, we may have removed to whole vfio_dma. If not
+ * fixup and re-insert.
+ */
+ if (overlap < dma->size) {
+ dma->iova += overlap;
+ dma->vaddr += overlap;
+ dma->size -= overlap;
+ vfio_insert_dma(iommu, dma);
+ } else
+ kfree(dma);
+
+ *size = overlap;
+ return 0;
}
/* Overlap high address of existing range */
- if (start + size >= dma->iova + NPAGE_TO_SIZE(dma->npage)) {
- size_t overlap;
+ if (start + *size >= dma->iova + dma->size) {
+ offset = start - dma->iova;
+ overlap = dma->size - offset;
- overlap = dma->iova + NPAGE_TO_SIZE(dma->npage) - start;
- npage_hi = overlap >> PAGE_SHIFT;
+ ret = vfio_unmap_unpin(iommu, dma, start, &overlap);
+ if (ret)
+ return ret;
- vfio_dma_unmap(iommu, start, npage_hi, dma->prot);
- dma->npage -= npage_hi;
- return npage_hi;
+ dma->size -= overlap;
+ *size = overlap;
+ return 0;
}
/* Split existing */
- npage_lo = (start - dma->iova) >> PAGE_SHIFT;
- npage_hi = dma->npage - (size >> PAGE_SHIFT) - npage_lo;
- split = kzalloc(sizeof *split, GFP_KERNEL);
+ /*
+ * Allocate our tracking structure early even though it may not
+ * be used. An Allocation failure later loses track of pages and
+ * is more difficult to unwind.
+ */
+ split = kzalloc(sizeof(*split), GFP_KERNEL);
if (!split)
return -ENOMEM;
- vfio_dma_unmap(iommu, start, size >> PAGE_SHIFT, dma->prot);
+ offset = start - dma->iova;
- dma->npage = npage_lo;
+ ret = vfio_unmap_unpin(iommu, dma, start, size);
+ if (ret || !*size) {
+ kfree(split);
+ return ret;
+ }
- split->npage = npage_hi;
- split->iova = start + size;
- split->vaddr = dma->vaddr + NPAGE_TO_SIZE(npage_lo) + size;
- split->prot = dma->prot;
- list_add(&split->next, &iommu->dma_list);
- return size >> PAGE_SHIFT;
+ tmp = dma->size;
+
+ /* Resize the lower vfio_dma in place, before the below insert */
+ dma->size = offset;
+
+ /* Insert new for remainder, assuming it didn't all get unmapped */
+ if (likely(offset + *size < tmp)) {
+ split->size = tmp - offset - *size;
+ split->iova = dma->iova + offset + *size;
+ split->vaddr = dma->vaddr + offset + *size;
+ split->prot = dma->prot;
+ vfio_insert_dma(iommu, split);
+ } else
+ kfree(split);
+
+ return 0;
}
static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_unmap *unmap)
{
- long ret = 0, npage = unmap->size >> PAGE_SHIFT;
- struct vfio_dma *dma, *tmp;
uint64_t mask;
+ struct vfio_dma *dma;
+ size_t unmapped = 0, size;
+ int ret = 0;
mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1;
if (unmap->iova & mask)
return -EINVAL;
- if (unmap->size & mask)
+ if (!unmap->size || unmap->size & mask)
return -EINVAL;
- /* XXX We still break these down into PAGE_SIZE */
WARN_ON(mask & PAGE_MASK);
mutex_lock(&iommu->lock);
- list_for_each_entry_safe(dma, tmp, &iommu->dma_list, next) {
- if (ranges_overlap(dma->iova, NPAGE_TO_SIZE(dma->npage),
- unmap->iova, unmap->size)) {
- ret = vfio_remove_dma_overlap(iommu, unmap->iova,
- unmap->size, dma);
- if (ret > 0)
- npage -= ret;
- if (ret < 0 || npage == 0)
- break;
- }
+ while ((dma = vfio_find_dma(iommu, unmap->iova, unmap->size))) {
+ size = unmap->size;
+ ret = vfio_remove_dma_overlap(iommu, unmap->iova, &size, dma);
+ if (ret || !size)
+ break;
+ unmapped += size;
}
+
mutex_unlock(&iommu->lock);
- return ret > 0 ? 0 : (int)ret;
+
+ /*
+ * We may unmap more than requested, update the unmap struct so
+ * userspace can know.
+ */
+ 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_iommu *iommu, dma_addr_t iova,
+ unsigned long pfn, long npage, int prot)
+{
+ long i;
+ int ret;
+
+ for (i = 0; i < npage; i++, pfn++, iova += PAGE_SIZE) {
+ ret = iommu_map(iommu->domain, iova,
+ (phys_addr_t)pfn << PAGE_SHIFT,
+ PAGE_SIZE, prot);
+ if (ret)
+ break;
+ }
+
+ for (; i < npage && i > 0; i--, iova -= PAGE_SIZE)
+ iommu_unmap(iommu->domain, iova, PAGE_SIZE);
+
+ return ret;
}
static int vfio_dma_do_map(struct vfio_iommu *iommu,
struct vfio_iommu_type1_dma_map *map)
{
- struct vfio_dma *dma, *pdma = NULL;
- dma_addr_t iova = map->iova;
- unsigned long locked, lock_limit, vaddr = map->vaddr;
+ dma_addr_t end, iova;
+ unsigned long vaddr = map->vaddr;
size_t size = map->size;
+ long npage;
int ret = 0, prot = 0;
uint64_t mask;
- long npage;
+
+ end = map->iova + map->size;
mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1;
@@ -430,104 +559,144 @@
if (!prot)
return -EINVAL; /* No READ/WRITE? */
+ if (iommu->cache)
+ prot |= IOMMU_CACHE;
+
if (vaddr & mask)
return -EINVAL;
- if (iova & mask)
+ if (map->iova & mask)
return -EINVAL;
- if (size & mask)
+ if (!map->size || map->size & mask)
return -EINVAL;
- /* XXX We still break these down into PAGE_SIZE */
WARN_ON(mask & PAGE_MASK);
/* Don't allow IOVA wrap */
- if (iova + size && iova + size < iova)
+ if (end && end < map->iova)
return -EINVAL;
/* Don't allow virtual address wrap */
- if (vaddr + size && vaddr + size < vaddr)
- return -EINVAL;
-
- npage = size >> PAGE_SHIFT;
- if (!npage)
+ if (vaddr + map->size && vaddr + map->size < vaddr)
return -EINVAL;
mutex_lock(&iommu->lock);
- if (vfio_find_dma(iommu, iova, size)) {
- ret = -EBUSY;
- goto out_lock;
+ if (vfio_find_dma(iommu, map->iova, map->size)) {
+ mutex_unlock(&iommu->lock);
+ return -EEXIST;
}
- /* account for locked pages */
- locked = current->mm->locked_vm + npage;
- lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK)) {
- pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
- __func__, rlimit(RLIMIT_MEMLOCK));
- ret = -ENOMEM;
- goto out_lock;
- }
+ for (iova = map->iova; iova < end; iova += size, vaddr += size) {
+ struct vfio_dma *dma = NULL;
+ unsigned long pfn;
+ long i;
- ret = __vfio_dma_map(iommu, iova, vaddr, npage, prot);
- if (ret)
- goto out_lock;
-
- /* Check if we abut a region below - nothing below 0 */
- if (iova) {
- dma = vfio_find_dma(iommu, iova - 1, 1);
- if (dma && dma->prot == prot &&
- dma->vaddr + NPAGE_TO_SIZE(dma->npage) == vaddr) {
-
- dma->npage += npage;
- iova = dma->iova;
- vaddr = dma->vaddr;
- npage = dma->npage;
- size = NPAGE_TO_SIZE(npage);
-
- pdma = dma;
+ /* Pin a contiguous chunk of memory */
+ npage = vfio_pin_pages(vaddr, (end - iova) >> PAGE_SHIFT,
+ prot, &pfn);
+ if (npage <= 0) {
+ WARN_ON(!npage);
+ ret = (int)npage;
+ break;
}
- }
- /* Check if we abut a region above - nothing above ~0 + 1 */
- if (iova + size) {
- dma = vfio_find_dma(iommu, iova + size, 1);
- if (dma && dma->prot == prot &&
- dma->vaddr == vaddr + size) {
+ /* Verify pages are not already mapped */
+ for (i = 0; i < npage; i++) {
+ if (iommu_iova_to_phys(iommu->domain,
+ iova + (i << PAGE_SHIFT))) {
+ vfio_unpin_pages(pfn, npage, prot, true);
+ ret = -EBUSY;
+ break;
+ }
+ }
- dma->npage += npage;
+ ret = iommu_map(iommu->domain, iova,
+ (phys_addr_t)pfn << PAGE_SHIFT,
+ npage << PAGE_SHIFT, prot);
+ if (ret) {
+ if (ret != -EBUSY ||
+ map_try_harder(iommu, iova, pfn, npage, prot)) {
+ vfio_unpin_pages(pfn, npage, prot, true);
+ break;
+ }
+ }
+
+ size = npage << PAGE_SHIFT;
+
+ /*
+ * Check if we abut a region below - nothing below 0.
+ * This is the most likely case when mapping chunks of
+ * physically contiguous regions within a virtual address
+ * range. Update the abutting entry in place since iova
+ * doesn't change.
+ */
+ if (likely(iova)) {
+ struct vfio_dma *tmp;
+ tmp = vfio_find_dma(iommu, iova - 1, 1);
+ if (tmp && tmp->prot == prot &&
+ tmp->vaddr + tmp->size == vaddr) {
+ tmp->size += size;
+ iova = tmp->iova;
+ size = tmp->size;
+ vaddr = tmp->vaddr;
+ dma = tmp;
+ }
+ }
+
+ /*
+ * Check if we abut a region above - nothing above ~0 + 1.
+ * If we abut above and below, remove and free. If only
+ * abut above, remove, modify, reinsert.
+ */
+ if (likely(iova + size)) {
+ struct vfio_dma *tmp;
+ tmp = vfio_find_dma(iommu, iova + size, 1);
+ if (tmp && tmp->prot == prot &&
+ tmp->vaddr == vaddr + size) {
+ vfio_remove_dma(iommu, tmp);
+ if (dma) {
+ dma->size += tmp->size;
+ kfree(tmp);
+ } else {
+ size += tmp->size;
+ tmp->size = size;
+ tmp->iova = iova;
+ tmp->vaddr = vaddr;
+ vfio_insert_dma(iommu, tmp);
+ dma = tmp;
+ }
+ }
+ }
+
+ if (!dma) {
+ dma = kzalloc(sizeof(*dma), GFP_KERNEL);
+ if (!dma) {
+ iommu_unmap(iommu->domain, iova, size);
+ vfio_unpin_pages(pfn, npage, prot, true);
+ ret = -ENOMEM;
+ break;
+ }
+
+ dma->size = size;
dma->iova = iova;
dma->vaddr = vaddr;
-
- /*
- * If merged above and below, remove previously
- * merged entry. New entry covers it.
- */
- if (pdma) {
- list_del(&pdma->next);
- kfree(pdma);
- }
- pdma = dma;
+ dma->prot = prot;
+ vfio_insert_dma(iommu, dma);
}
}
- /* Isolated, new region */
- if (!pdma) {
- dma = kzalloc(sizeof *dma, GFP_KERNEL);
- if (!dma) {
- ret = -ENOMEM;
- vfio_dma_unmap(iommu, iova, npage, prot);
- goto out_lock;
+ if (ret) {
+ struct vfio_dma *tmp;
+ iova = map->iova;
+ size = map->size;
+ while ((tmp = vfio_find_dma(iommu, iova, size))) {
+ int r = vfio_remove_dma_overlap(iommu, iova,
+ &size, tmp);
+ if (WARN_ON(r || !size))
+ break;
}
-
- dma->npage = npage;
- dma->iova = iova;
- dma->vaddr = vaddr;
- dma->prot = prot;
- list_add(&dma->next, &iommu->dma_list);
}
-out_lock:
mutex_unlock(&iommu->lock);
return ret;
}
@@ -606,7 +775,7 @@
return ERR_PTR(-ENOMEM);
INIT_LIST_HEAD(&iommu->group_list);
- INIT_LIST_HEAD(&iommu->dma_list);
+ iommu->dma_list = RB_ROOT;
mutex_init(&iommu->lock);
/*
@@ -640,7 +809,7 @@
{
struct vfio_iommu *iommu = iommu_data;
struct vfio_group *group, *group_tmp;
- struct vfio_dma *dma, *dma_tmp;
+ struct rb_node *node;
list_for_each_entry_safe(group, group_tmp, &iommu->group_list, next) {
iommu_detach_group(iommu->domain, group->iommu_group);
@@ -648,10 +817,12 @@
kfree(group);
}
- list_for_each_entry_safe(dma, dma_tmp, &iommu->dma_list, next) {
- vfio_dma_unmap(iommu, dma->iova, dma->npage, dma->prot);
- list_del(&dma->next);
- kfree(dma);
+ while ((node = rb_first(&iommu->dma_list))) {
+ struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
+ size_t size = dma->size;
+ vfio_remove_dma_overlap(iommu, dma->iova, &size, dma);
+ if (WARN_ON(!size))
+ break;
}
iommu_domain_free(iommu->domain);
@@ -706,6 +877,7 @@
} 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);
@@ -715,7 +887,11 @@
if (unmap.argsz < minsz || unmap.flags)
return -EINVAL;
- return vfio_dma_do_unmap(iommu, &unmap);
+ ret = vfio_dma_do_unmap(iommu, &unmap);
+ if (ret)
+ return ret;
+
+ return copy_to_user((void __user *)arg, &unmap, minsz);
}
return -ENOTTY;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 87ee4f4..916e444 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -362,10 +362,14 @@
#define VFIO_IOMMU_MAP_DMA _IO(VFIO_TYPE, VFIO_BASE + 13)
/**
- * VFIO_IOMMU_UNMAP_DMA - _IOW(VFIO_TYPE, VFIO_BASE + 14, struct vfio_dma_unmap)
+ * VFIO_IOMMU_UNMAP_DMA - _IOWR(VFIO_TYPE, VFIO_BASE + 14,
+ * struct vfio_dma_unmap)
*
* Unmap IO virtual addresses using the provided struct vfio_dma_unmap.
- * Caller sets argsz.
+ * Caller sets argsz. The actual unmapped size is returned in the size
+ * field. No guarantee is made to the user that arbitrary unmaps of iova
+ * or size different from those used in the original mapping call will
+ * succeed.
*/
struct vfio_iommu_type1_dma_unmap {
__u32 argsz;
