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authorLinus Torvalds <torvalds@linux-foundation.org>2014-04-03 14:05:02 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2014-04-03 14:05:02 -0700
commitd0cb5f71c5cde8e1ef6d03983641366800ceabdb (patch)
tree893fcbb069bb255cf320b4e4c61a0515d02c4bed
parenta372c967a38a789caf52d4b1d2a78781e1b25d91 (diff)
parent4379d2ae152860e023b42257fd60b5e235047f63 (diff)
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Merge tag 'vfio-v3.15-rc1' of git://github.com/awilliam/linux-vfio
Pull VFIO updates from Alex Williamson: "VFIO updates for v3.15 include: - Allow the vfio-type1 IOMMU to support multiple domains within a container - Plumb path to query whether all domains are cache-coherent - Wire query into kvm-vfio device to avoid KVM x86 WBINVD emulation - Always select CONFIG_ANON_INODES, vfio depends on it (Arnd) The first patch also makes the vfio-type1 IOMMU driver completely independent of the bus_type of the devices it's handling, which enables it to be used for both vfio-pci and a future vfio-platform (and hopefully combinations involving both simultaneously)" * tag 'vfio-v3.15-rc1' of git://github.com/awilliam/linux-vfio: vfio: always select ANON_INODES kvm/vfio: Support for DMA coherent IOMMUs vfio: Add external user check extension interface vfio/type1: Add extension to test DMA cache coherence of IOMMU vfio/iommu_type1: Multi-IOMMU domain support
-rw-r--r--drivers/vfio/Kconfig1
-rw-r--r--drivers/vfio/vfio.c6
-rw-r--r--drivers/vfio/vfio_iommu_type1.c656
-rw-r--r--include/linux/vfio.h2
-rw-r--r--include/uapi/linux/vfio.h6
-rw-r--r--virt/kvm/vfio.c27
6 files changed, 390 insertions, 308 deletions
diff --git a/drivers/vfio/Kconfig b/drivers/vfio/Kconfig
index 26b3d9d1409f..af7b204b9215 100644
--- a/drivers/vfio/Kconfig
+++ b/drivers/vfio/Kconfig
@@ -13,6 +13,7 @@ menuconfig VFIO
depends on IOMMU_API
select VFIO_IOMMU_TYPE1 if X86
select VFIO_IOMMU_SPAPR_TCE if (PPC_POWERNV || PPC_PSERIES)
+ select ANON_INODES
help
VFIO provides a framework for secure userspace device drivers.
See Documentation/vfio.txt for more details.
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 21271d8df023..512f479d8a50 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -1413,6 +1413,12 @@ int vfio_external_user_iommu_id(struct vfio_group *group)
}
EXPORT_SYMBOL_GPL(vfio_external_user_iommu_id);
+long vfio_external_check_extension(struct vfio_group *group, unsigned long arg)
+{
+ return vfio_ioctl_check_extension(group->container, arg);
+}
+EXPORT_SYMBOL_GPL(vfio_external_check_extension);
+
/**
* Module/class support
*/
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 54af4e933695..6673e7be507f 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -30,7 +30,6 @@
#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>
@@ -55,11 +54,17 @@ 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 rb_root dma_list;
+ bool v2;
+};
+
+struct vfio_domain {
+ struct iommu_domain *domain;
+ struct list_head next;
struct list_head group_list;
- bool cache;
+ int prot; /* IOMMU_CACHE */
};
struct vfio_dma {
@@ -99,7 +104,7 @@ static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
return NULL;
}
-static void vfio_insert_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
+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;
@@ -118,7 +123,7 @@ static void vfio_insert_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
rb_insert_color(&new->node, &iommu->dma_list);
}
-static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
+static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
{
rb_erase(&old->node, &iommu->dma_list);
}
@@ -322,32 +327,39 @@ static long vfio_unpin_pages(unsigned long pfn, long npage,
return unlocked;
}
-static int vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
- dma_addr_t iova, size_t *size)
+static void vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
- dma_addr_t start = iova, end = iova + *size;
+ dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
+ struct vfio_domain *domain, *d;
long unlocked = 0;
+ 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);
+
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);
+ phys = iommu_iova_to_phys(domain->domain, iova);
if (WARN_ON(!phys)) {
iova += PAGE_SIZE;
continue;
}
- unmapped = iommu_unmap(iommu->domain, iova, PAGE_SIZE);
- if (!unmapped)
+ unmapped = iommu_unmap(domain->domain, iova, PAGE_SIZE);
+ if (WARN_ON(!unmapped))
break;
unlocked += vfio_unpin_pages(phys >> PAGE_SHIFT,
@@ -357,119 +369,26 @@ static int vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
}
vfio_lock_acct(-unlocked);
-
- *size = iova - start;
-
- return 0;
}
-static int vfio_remove_dma_overlap(struct vfio_iommu *iommu, dma_addr_t start,
- size_t *size, struct vfio_dma *dma)
+static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
{
- size_t offset, overlap, tmp;
- struct vfio_dma *split;
- int ret;
-
- 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 0;
- }
-
- /* Overlap low address of existing range */
- if (start <= dma->iova) {
- overlap = start + *size - dma->iova;
- ret = vfio_unmap_unpin(iommu, dma, dma->iova, &overlap);
- if (ret)
- return ret;
-
- vfio_remove_dma(iommu, dma);
-
- /*
- * 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 + dma->size) {
- offset = start - dma->iova;
- overlap = dma->size - offset;
-
- ret = vfio_unmap_unpin(iommu, dma, start, &overlap);
- if (ret)
- return ret;
-
- dma->size -= overlap;
- *size = overlap;
- return 0;
- }
-
- /* Split existing */
-
- /*
- * 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;
-
- offset = start - dma->iova;
-
- ret = vfio_unmap_unpin(iommu, dma, start, size);
- if (ret || !*size) {
- kfree(split);
- return ret;
- }
-
- tmp = dma->size;
+ vfio_unmap_unpin(iommu, dma);
+ vfio_unlink_dma(iommu, dma);
+ kfree(dma);
+}
- /* Resize the lower vfio_dma in place, before the below insert */
- dma->size = offset;
+static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
+{
+ struct vfio_domain *domain;
+ unsigned long bitmap = PAGE_MASK;
- /* 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);
+ mutex_lock(&iommu->lock);
+ list_for_each_entry(domain, &iommu->domain_list, next)
+ bitmap &= domain->domain->ops->pgsize_bitmap;
+ mutex_unlock(&iommu->lock);
- return 0;
+ return bitmap;
}
static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
@@ -477,10 +396,10 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
{
uint64_t mask;
struct vfio_dma *dma;
- size_t unmapped = 0, size;
+ 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;
@@ -491,20 +410,61 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
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, 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))) {
- size = unmap->size;
- ret = vfio_remove_dma_overlap(iommu, unmap->iova, &size, dma);
- if (ret || !size)
+ if (!iommu->v2 && unmap->iova > dma->iova)
break;
- unmapped += size;
+ unmapped += dma->size;
+ vfio_remove_dma(iommu, dma);
}
+unlock:
mutex_unlock(&iommu->lock);
- /*
- * We may unmap more than requested, update the unmap struct so
- * userspace can know.
- */
+ /* Report how much was unmapped */
unmap->size = unmapped;
return ret;
@@ -516,22 +476,47 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
* 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,
+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(iommu->domain, iova,
+ ret = iommu_map(domain->domain, iova,
(phys_addr_t)pfn << PAGE_SHIFT,
- PAGE_SIZE, prot);
+ PAGE_SIZE, prot | domain->prot);
if (ret)
break;
}
for (; i < npage && i > 0; i--, iova -= PAGE_SIZE)
- iommu_unmap(iommu->domain, 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;
+ }
+ }
+
+ return 0;
+
+unwind:
+ list_for_each_entry_continue_reverse(d, &iommu->domain_list, next)
+ iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
return ret;
}
@@ -545,12 +530,12 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
long npage;
int ret = 0, prot = 0;
uint64_t mask;
- struct vfio_dma *dma = NULL;
+ struct vfio_dma *dma;
unsigned long pfn;
end = map->iova + map->size;
- mask = ((uint64_t)1 << __ffs(iommu->domain->ops->pgsize_bitmap)) - 1;
+ mask = ((uint64_t)1 << __ffs(vfio_pgsize_bitmap(iommu))) - 1;
/* READ/WRITE from device perspective */
if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
@@ -561,9 +546,6 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
if (!prot)
return -EINVAL; /* No READ/WRITE? */
- if (iommu->cache)
- prot |= IOMMU_CACHE;
-
if (vaddr & mask)
return -EINVAL;
if (map->iova & mask)
@@ -588,180 +570,257 @@ static int vfio_dma_do_map(struct vfio_iommu *iommu,
return -EEXIST;
}
- for (iova = map->iova; iova < end; iova += size, vaddr += size) {
- long i;
+ dma = kzalloc(sizeof(*dma), GFP_KERNEL);
+ if (!dma) {
+ mutex_unlock(&iommu->lock);
+ return -ENOMEM;
+ }
+
+ dma->iova = map->iova;
+ dma->vaddr = map->vaddr;
+ dma->prot = prot;
+
+ /* Insert zero-sized and grow as we map chunks of it */
+ vfio_link_dma(iommu, dma);
+ for (iova = map->iova; iova < end; iova += size, vaddr += size) {
/* 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;
- goto out;
- }
-
- /* Verify pages are not already mapped */
- for (i = 0; i < npage; i++) {
- if (iommu_iova_to_phys(iommu->domain,
- iova + (i << PAGE_SHIFT))) {
- ret = -EBUSY;
- goto out_unpin;
- }
+ break;
}
- ret = iommu_map(iommu->domain, iova,
- (phys_addr_t)pfn << PAGE_SHIFT,
- npage << PAGE_SHIFT, prot);
+ /* Map it! */
+ ret = vfio_iommu_map(iommu, iova, pfn, npage, prot);
if (ret) {
- if (ret != -EBUSY ||
- map_try_harder(iommu, iova, pfn, npage, prot)) {
- goto out_unpin;
- }
+ vfio_unpin_pages(pfn, npage, prot, true);
+ break;
}
size = npage << PAGE_SHIFT;
+ dma->size += size;
+ }
- /*
- * 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;
- }
- }
+ if (ret)
+ vfio_remove_dma(iommu, dma);
- /*
- * 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;
- }
- }
- }
+ 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;
+ 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 (!dma) {
- dma = kzalloc(sizeof(*dma), GFP_KERNEL);
- if (!dma) {
- iommu_unmap(iommu->domain, iova, size);
- ret = -ENOMEM;
- goto out_unpin;
+ if (WARN_ON(!phys)) {
+ iova += PAGE_SIZE;
+ continue;
}
- dma->size = size;
- dma->iova = iova;
- dma->vaddr = vaddr;
- dma->prot = prot;
- vfio_insert_dma(iommu, dma);
- }
- }
+ size = PAGE_SIZE;
- WARN_ON(ret);
- mutex_unlock(&iommu->lock);
- return ret;
+ while (iova + size < dma->iova + dma->size &&
+ phys + size == iommu_iova_to_phys(d->domain,
+ iova + size))
+ size += PAGE_SIZE;
-out_unpin:
- vfio_unpin_pages(pfn, npage, prot, true);
+ ret = iommu_map(domain->domain, iova, phys,
+ size, dma->prot | domain->prot);
+ if (ret)
+ return ret;
-out:
- iova = map->iova;
- size = map->size;
- while ((dma = vfio_find_dma(iommu, iova, size))) {
- int r = vfio_remove_dma_overlap(iommu, iova,
- &size, dma);
- if (WARN_ON(r || !size))
- break;
+ iova += size;
+ }
}
- mutex_unlock(&iommu->lock);
- return ret;
+ return 0;
}
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;
+ }
+
+ 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_domain_has_cap(domain->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__);
+ ret = -EPERM;
+ goto out_detach;
+ }
+
+ if (iommu_domain_has_cap(domain->domain, 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);
+ /* 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);
}
@@ -769,40 +828,17 @@ static void *vfio_iommu_type1_open(unsigned long arg)
{
struct vfio_iommu *iommu;
- if (arg != VFIO_TYPE1_IOMMU)
+ if (arg != VFIO_TYPE1_IOMMU && arg != VFIO_TYPE1v2_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->domain_list);
iommu->dma_list = RB_ROOT;
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) {
- kfree(iommu);
- return ERR_PTR(-EIO);
- }
-
- /*
- * 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);
- }
+ iommu->v2 = (arg == VFIO_TYPE1v2_IOMMU);
return iommu;
}
@@ -810,26 +846,42 @@ static void *vfio_iommu_type1_open(unsigned long arg)
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 rb_node *node;
- 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(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);
}
- 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))
+ 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);
- iommu_domain_free(iommu->domain);
- iommu->domain = NULL;
- kfree(iommu);
+ return ret;
}
static long vfio_iommu_type1_ioctl(void *iommu_data,
@@ -841,7 +893,12 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
if (cmd == VFIO_CHECK_EXTENSION) {
switch (arg) {
case VFIO_TYPE1_IOMMU:
+ case VFIO_TYPE1v2_IOMMU:
return 1;
+ case VFIO_DMA_CC_IOMMU:
+ if (!iommu)
+ return 0;
+ return vfio_domains_have_iommu_cache(iommu);
default:
return 0;
}
@@ -858,7 +915,7 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
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);
@@ -911,9 +968,6 @@ static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
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);
}
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 24579a0312a0..81022a52bc34 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -96,5 +96,7 @@ extern void vfio_unregister_iommu_driver(
extern struct vfio_group *vfio_group_get_external_user(struct file *filep);
extern void vfio_group_put_external_user(struct vfio_group *group);
extern int vfio_external_user_iommu_id(struct vfio_group *group);
+extern long vfio_external_check_extension(struct vfio_group *group,
+ unsigned long arg);
#endif /* VFIO_H */
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 0fd47f5bc146..cb9023d4f063 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -23,6 +23,12 @@
#define VFIO_TYPE1_IOMMU 1
#define VFIO_SPAPR_TCE_IOMMU 2
+#define VFIO_TYPE1v2_IOMMU 3
+/*
+ * IOMMU enforces DMA cache coherence (ex. PCIe NoSnoop stripping). This
+ * capability is subject to change as groups are added or removed.
+ */
+#define VFIO_DMA_CC_IOMMU 4
/*
* The IOCTL interface is designed for extensibility by embedding the
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index b4f9507ae650..ba1a93f935c7 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -59,6 +59,22 @@ static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group)
symbol_put(vfio_group_put_external_user);
}
+static bool kvm_vfio_group_is_coherent(struct vfio_group *vfio_group)
+{
+ long (*fn)(struct vfio_group *, unsigned long);
+ long ret;
+
+ fn = symbol_get(vfio_external_check_extension);
+ if (!fn)
+ return false;
+
+ ret = fn(vfio_group, VFIO_DMA_CC_IOMMU);
+
+ symbol_put(vfio_external_check_extension);
+
+ return ret > 0;
+}
+
/*
* Groups can use the same or different IOMMU domains. If the same then
* adding a new group may change the coherency of groups we've previously
@@ -75,13 +91,10 @@ static void kvm_vfio_update_coherency(struct kvm_device *dev)
mutex_lock(&kv->lock);
list_for_each_entry(kvg, &kv->group_list, node) {
- /*
- * TODO: We need an interface to check the coherency of
- * the IOMMU domain this group is using. For now, assume
- * it's always noncoherent.
- */
- noncoherent = true;
- break;
+ if (!kvm_vfio_group_is_coherent(kvg->vfio_group)) {
+ noncoherent = true;
+ break;
+ }
}
if (noncoherent != kv->noncoherent) {