#include <linux/iommu.h>
#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>
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 list_head domain_list;
struct mutex lock;
- struct list_head dma_list;
+ struct rb_root dma_list;
+ bool v2;
+ bool nesting;
+};
+
+struct vfio_domain {
+ struct iommu_domain *domain;
+ struct list_head next;
struct list_head group_list;
- bool cache;
+ int prot; /* IOMMU_CACHE */
+ bool fgsp; /* Fine-grained super pages */
};
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 */
};
* 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_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);
+}
struct vwork {
struct mm_struct *mm;
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;
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];
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;
+ bool rsvd;
+
+ if (!current->mm)
+ return -ENODEV;
- /* 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;
+ ret = vaddr_get_pfn(vaddr, prot, pfn_base);
+ if (ret)
+ return ret;
- iova = start;
+ rsvd = is_invalid_reserved_pfn(*pfn_base);
- if (iommu->cache)
- prot |= IOMMU_CACHE;
+ if (!rsvd && !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;
+ }
- /*
- * 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 (unlikely(disable_hugepages)) {
+ if (!rsvd)
+ 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;
- /*
- * 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++;
+ if (pfn != *pfn_base + i ||
+ rsvd != is_invalid_reserved_pfn(pfn)) {
+ put_pfn(pfn, prot);
+ break;
+ }
- ret = iommu_map(iommu->domain, iova,
- (phys_addr_t)pfn << PAGE_SHIFT,
- PAGE_SIZE, prot);
- if (ret) {
- /* Back out mappings on error */
+ if (!rsvd && !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);
- return 0;
-}
-static inline bool ranges_overlap(dma_addr_t start1, size_t size1,
- dma_addr_t start2, size_t size2)
-{
- if (start1 < start2)
- return (start2 - start1 < size1);
- else if (start2 < start1)
- return (start1 - start2 < size2);
- return (size1 > 0 && size2 > 0);
+ if (!rsvd)
+ vfio_lock_acct(i);
+
+ return i;
}
-static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
- dma_addr_t start, size_t size)
+static long vfio_unpin_pages(unsigned long pfn, long npage,
+ int prot, bool do_accounting)
{
- struct vfio_dma *dma;
+ unsigned long unlocked = 0;
+ long i;
- 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;
+ for (i = 0; i < npage; i++)
+ unlocked += put_pfn(pfn++, prot);
+
+ if (do_accounting)
+ vfio_lock_acct(-unlocked);
+
+ return unlocked;
}
-static long vfio_remove_dma_overlap(struct vfio_iommu *iommu, dma_addr_t start,
- size_t size, struct vfio_dma *dma)
+static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
- struct vfio_dma *split;
- long npage_lo, npage_hi;
+ dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
+ struct vfio_domain *domain, *d;
+ long unlocked = 0;
- /* 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;
- kfree(dma);
- return npage_lo;
+ if (!dma->size)
+ return;
+ /*
+ * 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();
}
- /* Overlap low address of existing range */
- if (start <= dma->iova) {
- size_t overlap;
+ while (iova < end) {
+ size_t unmapped, len;
+ phys_addr_t phys, next;
- overlap = start + size - dma->iova;
- npage_lo = overlap >> PAGE_SHIFT;
+ phys = iommu_iova_to_phys(domain->domain, iova);
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
+ }
- vfio_dma_unmap(iommu, dma->iova, npage_lo, dma->prot);
- dma->iova += overlap;
- dma->vaddr += overlap;
- dma->npage -= npage_lo;
- return npage_lo;
- }
+ /*
+ * 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;
+ }
- /* Overlap high address of existing range */
- if (start + size >= dma->iova + NPAGE_TO_SIZE(dma->npage)) {
- size_t overlap;
+ unmapped = iommu_unmap(domain->domain, iova, len);
+ if (WARN_ON(!unmapped))
+ break;
- overlap = dma->iova + NPAGE_TO_SIZE(dma->npage) - start;
- npage_hi = overlap >> PAGE_SHIFT;
+ unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT,
+ unmapped >> PAGE_SHIFT,
+ dma->prot, false);
+ iova += unmapped;
- vfio_dma_unmap(iommu, start, npage_hi, dma->prot);
- dma->npage -= npage_hi;
- return npage_hi;
+ cond_resched();
}
- /* Split existing */
- npage_lo = (start - dma->iova) >> PAGE_SHIFT;
- npage_hi = dma->npage - (size >> PAGE_SHIFT) - npage_lo;
+ vfio_lock_acct(-unlocked);
+}
- split = kzalloc(sizeof *split, GFP_KERNEL);
- if (!split)
- return -ENOMEM;
+static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
+{
+ vfio_unmap_unpin(iommu, dma);
+ vfio_unlink_dma(iommu, dma);
+ kfree(dma);
+}
- vfio_dma_unmap(iommu, start, size >> PAGE_SHIFT, dma->prot);
+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->ops->pgsize_bitmap;
+ mutex_unlock(&iommu->lock);
- dma->npage = npage_lo;
+ /*
+ * 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;
+ }
- 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;
+ return bitmap;
}
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;
+ int ret = 0;
- mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1;
+ mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 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;
+ /*
+ * 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, 0);
+ 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;
+ unmapped += dma->size;
+ vfio_remove_dma(iommu, dma);
+ }
+
+unlock:
mutex_unlock(&iommu->lock);
- return ret > 0 ? 0 : (int)ret;
+
+ /* 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;
+
+ 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_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;
+ unsigned long vaddr = map->vaddr;
size_t size = map->size;
+ long npage;
int ret = 0, prot = 0;
uint64_t mask;
- long npage;
+ struct vfio_dma *dma;
+ unsigned long pfn;
- mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1;
+ /* 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)
if (map->flags & VFIO_DMA_MAP_FLAG_READ)
prot |= IOMMU_READ;
- if (!prot)
- return -EINVAL; /* No READ/WRITE? */
-
- if (vaddr & mask)
- return -EINVAL;
- if (iova & mask)
- return -EINVAL;
- if (size & mask)
+ if (!prot || !size || (size | iova | vaddr) & 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)
- return -EINVAL;
-
- /* Don't allow virtual address wrap */
- if (vaddr + size && vaddr + size < vaddr)
- return -EINVAL;
-
- npage = size >> PAGE_SHIFT;
- if (!npage)
+ /* 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 = -EBUSY;
- goto out_lock;
+ 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;
+ dma = kzalloc(sizeof(*dma), GFP_KERNEL);
+ if (!dma) {
+ mutex_unlock(&iommu->lock);
+ return -ENOMEM;
}
- ret = __vfio_dma_map(iommu, iova, vaddr, npage, prot);
- if (ret)
- goto out_lock;
+ dma->iova = iova;
+ dma->vaddr = vaddr;
+ dma->prot = prot;
- /* 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) {
+ /* Insert zero-sized and grow as we map chunks of it */
+ vfio_link_dma(iommu, dma);
- dma->npage += npage;
- iova = dma->iova;
- vaddr = dma->vaddr;
- npage = dma->npage;
- size = NPAGE_TO_SIZE(npage);
+ while (size) {
+ /* Pin a contiguous chunk of memory */
+ npage = vfio_pin_pages(vaddr + dma->size,
+ size >> PAGE_SHIFT, prot, &pfn);
+ if (npage <= 0) {
+ WARN_ON(!npage);
+ ret = (int)npage;
+ break;
+ }
- pdma = dma;
+ /* Map it! */
+ ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage, prot);
+ if (ret) {
+ vfio_unpin_pages(pfn, npage, prot, true);
+ break;
}
+
+ size -= npage << PAGE_SHIFT;
+ dma->size += npage << PAGE_SHIFT;
}
- /* 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) {
+ if (ret)
+ vfio_remove_dma(iommu, dma);
- dma->npage += npage;
- dma->iova = iova;
- dma->vaddr = vaddr;
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
- /*
- * If merged above and below, remove previously
- * merged entry. New entry covers it.
- */
- if (pdma) {
- list_del(&pdma->next);
- kfree(pdma);
+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;
+ struct rb_node *n;
+ int ret;
+
+ /* Arbitrarily pick the first domain in the list for lookups */
+ d = list_first_entry(&iommu->domain_list, struct vfio_domain, next);
+ n = rb_first(&iommu->dma_list);
+
+ /* If there's not a domain, there better not be any mappings */
+ if (WARN_ON(n && !d))
+ return -EINVAL;
+
+ 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 = iommu_iova_to_phys(d->domain, iova);
+ size_t size;
+
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
}
- pdma = dma;
+
+ size = PAGE_SIZE;
+
+ while (iova + size < dma->iova + dma->size &&
+ phys + size == iommu_iova_to_phys(d->domain,
+ iova + size))
+ size += PAGE_SIZE;
+
+ ret = iommu_map(domain->domain, iova, phys,
+ size, dma->prot | domain->prot);
+ if (ret)
+ return ret;
+
+ iova += size;
}
}
- /* 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;
- }
+ return 0;
+}
+
+/*
+ * 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);
- dma->npage = npage;
- dma->iova = iova;
- dma->vaddr = vaddr;
- dma->prot = prot;
- list_add(&dma->next, &iommu->dma_list);
+ if (unmapped == PAGE_SIZE)
+ iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
+ else
+ domain->fgsp = true;
}
-out_lock:
- mutex_unlock(&iommu->lock);
- return ret;
+ __free_pages(pages, order);
}
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, *tmp;
+ struct vfio_group *group, *g;
+ struct vfio_domain *domain, *d;
+ struct bus_type *bus = NULL;
int ret;
- group = kzalloc(sizeof(*group), GFP_KERNEL);
- if (!group)
- return -ENOMEM;
-
mutex_lock(&iommu->lock);
- list_for_each_entry(tmp, &iommu->group_list, next) {
- if (tmp->iommu_group == iommu_group) {
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ list_for_each_entry(g, &d->group_list, next) {
+ if (g->iommu_group != iommu_group)
+ continue;
+
mutex_unlock(&iommu->lock);
- kfree(group);
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;
+
+ 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;
+
+ INIT_LIST_HEAD(&domain->group_list);
+ list_add(&group->next, &domain->group_list);
+
+ if (!allow_unsafe_interrupts &&
+ !iommu_capable(bus, IOMMU_CAP_INTR_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;
+
/*
- * TODO: Domain have capabilities that might change as we add
- * groups (see iommu->cache, currently never set). Check for
- * them and potentially disallow groups to be attached when it
- * would change capabilities (ugh).
+ * 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.
*/
- ret = iommu_attach_group(iommu->domain, iommu_group);
- if (ret) {
- mutex_unlock(&iommu->lock);
- kfree(group);
- return ret;
+ 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;
+ }
}
- group->iommu_group = iommu_group;
- list_add(&group->next, &iommu->group_list);
+ vfio_test_domain_fgsp(domain);
+
+ /* replay mappings on new domains */
+ ret = vfio_iommu_replay(iommu, domain);
+ 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_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);
- list_for_each_entry(group, &iommu->group_list, next) {
- if (group->iommu_group == iommu_group) {
- iommu_detach_group(iommu->domain, iommu_group);
+ list_for_each_entry(domain, &iommu->domain_list, next) {
+ list_for_each_entry(group, &domain->group_list, next) {
+ if (group->iommu_group != iommu_group)
+ continue;
+
+ iommu_detach_group(domain->domain, iommu_group);
list_del(&group->next);
kfree(group);
- break;
+ /*
+ * Group ownership provides privilege, if the group
+ * list is empty, the domain goes away. If it's the
+ * last domain, then all the mappings go away too.
+ */
+ if (list_empty(&domain->group_list)) {
+ if (list_is_singular(&iommu->domain_list))
+ vfio_iommu_unmap_unpin_all(iommu);
+ iommu_domain_free(domain->domain);
+ list_del(&domain->next);
+ kfree(domain);
+ }
+ goto done;
}
}
+done:
mutex_unlock(&iommu->lock);
}
{
struct vfio_iommu *iommu;
- if (arg != VFIO_TYPE1_IOMMU)
- return ERR_PTR(-EINVAL);
-
iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
if (!iommu)
return ERR_PTR(-ENOMEM);
- INIT_LIST_HEAD(&iommu->group_list);
- INIT_LIST_HEAD(&iommu->dma_list);
- mutex_init(&iommu->lock);
-
- /*
- * Wish we didn't have to know about bus_type here.
- */
- iommu->domain = iommu_domain_alloc(&pci_bus_type);
- if (!iommu->domain) {
+ switch (arg) {
+ case VFIO_TYPE1_IOMMU:
+ break;
+ case VFIO_TYPE1_NESTING_IOMMU:
+ iommu->nesting = true;
+ case VFIO_TYPE1v2_IOMMU:
+ iommu->v2 = true;
+ break;
+ default:
kfree(iommu);
- return ERR_PTR(-EIO);
+ return ERR_PTR(-EINVAL);
}
- /*
- * Wish we could specify required capabilities rather than create
- * a domain, see what comes out and hope it doesn't change along
- * the way. Fortunately we know interrupt remapping is global for
- * our iommus.
- */
- if (!allow_unsafe_interrupts &&
- !iommu_domain_has_cap(iommu->domain, IOMMU_CAP_INTR_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__);
- iommu_domain_free(iommu->domain);
- kfree(iommu);
- return ERR_PTR(-EPERM);
- }
+ INIT_LIST_HEAD(&iommu->domain_list);
+ iommu->dma_list = RB_ROOT;
+ mutex_init(&iommu->lock);
return iommu;
}
static void vfio_iommu_type1_release(void *iommu_data)
{
struct vfio_iommu *iommu = iommu_data;
+ struct vfio_domain *domain, *domain_tmp;
struct vfio_group *group, *group_tmp;
- struct vfio_dma *dma, *dma_tmp;
- list_for_each_entry_safe(group, group_tmp, &iommu->group_list, next) {
- iommu_detach_group(iommu->domain, group->iommu_group);
- list_del(&group->next);
- kfree(group);
- }
+ vfio_iommu_unmap_unpin_all(iommu);
- 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);
+ list_for_each_entry_safe(domain, domain_tmp,
+ &iommu->domain_list, next) {
+ list_for_each_entry_safe(group, group_tmp,
+ &domain->group_list, next) {
+ iommu_detach_group(domain->domain, group->iommu_group);
+ list_del(&group->next);
+ kfree(group);
+ }
+ iommu_domain_free(domain->domain);
+ list_del(&domain->next);
+ kfree(domain);
}
- iommu_domain_free(iommu->domain);
- iommu->domain = NULL;
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)
{
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;
}
info.flags = 0;
- info.iova_pgsizes = iommu->domain->ops->pgsize_bitmap;
+ info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
- return copy_to_user((void __user *)arg, &info, minsz);
+ 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;
} 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 (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) ?
+ -EFAULT : 0;
}
return -ENOTTY;
static int __init vfio_iommu_type1_init(void)
{
- if (!iommu_present(&pci_bus_type))
- return -ENODEV;
-
return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
}
projects / firefly-linux-kernel-4.4.55.git / blobdiff