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VFIO updates for v3.15 include:

Browse Source 
- 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).
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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
This commit is contained in:
Linus Torvalds 2014-04-03 14:05:02 -07:00
commit d0cb5f71c5
6 changed files with 400 additions and 318 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/vfio/Kconfig
View File

@ -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.

6
drivers/vfio/vfio.c
View File

@ -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
*/

676
drivers/vfio/vfio_iommu_type1.c
View File

@ -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;
vfio_unmap_unpin(iommu, dma);
vfio_unlink_dma(iommu, dma);
kfree(dma);
}
if (!*size)
return 0;
static unsigned long vfio_pgsize_bitmap(struct vfio_iommu *iommu)
{
struct vfio_domain *domain;
unsigned long bitmap = PAGE_MASK;
/*
* 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;
mutex_lock(&iommu->lock);
list_for_each_entry(domain, &iommu->domain_list, next)
bitmap &= domain->domain->ops->pgsize_bitmap;
mutex_unlock(&iommu->lock);
/*
* 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;
/* 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;
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);
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;
/*
* 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);
/*
* 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;
break;
}
/* 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;
}
}
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;
/*
* 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);
ret = -ENOMEM;
goto out_unpin;
}
dma->size = size;
dma->iova = iova;
dma->vaddr = vaddr;
dma->prot = prot;
vfio_insert_dma(iommu, dma);
}
dma->size += size;
}
WARN_ON(ret);
mutex_unlock(&iommu->lock);
return ret;
out_unpin:
vfio_unpin_pages(pfn, npage, prot, true);
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;
}
if (ret)
vfio_remove_dma(iommu, dma);
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 (WARN_ON(!phys)) {
iova += PAGE_SIZE;
continue;
}
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;
}
}
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;
}
}
/*
* 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).
*/
ret = iommu_attach_group(iommu->domain, iommu_group);
if (ret) {
mutex_unlock(&iommu->lock);
kfree(group);
return ret;
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;
list_add(&group->next, &iommu->group_list);
/* 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;
/*
* Try to match an existing compatible domain. We don't want to
* preclude an IOMMU driver supporting multiple bus_types and being
* able to include different bus_types in the same IOMMU domain, so
* we test whether the domains use the same iommu_ops rather than
* testing if they're on the same bus_type.
*/
list_for_each_entry(d, &iommu->domain_list, next) {
if (d->domain->ops == domain->domain->ops &&
d->prot == domain->prot) {
iommu_detach_group(domain->domain, iommu_group);
if (!iommu_attach_group(d->domain, iommu_group)) {
list_add(&group->next, &d->group_list);
iommu_domain_free(domain->domain);
kfree(domain);
mutex_unlock(&iommu->lock);
return 0;
}
ret = iommu_attach_group(domain->domain, iommu_group);
if (ret)
goto out_domain;
}
}
/* 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;
}
@ -810,28 +846,44 @@ 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))
break;
}
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)
{
@ -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);
}

2
include/linux/vfio.h
View File

@ -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 */

6
include/uapi/linux/vfio.h
View File

@ -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

27
virt/kvm/vfio.c
View File

@ -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) {