This patch introduces vfio_group_alloc_map_/unmap_free_reserved_iova
and implements corresponding vfio_iommu_type1 operations.
alloc_map allows to allocate a new reserved iova page and map it
onto the physical page that contains a given PA. It returns the iova
that is mapped onto the provided PA. In case a mapping already exist
between both pages, the IOVA corresponding to the PA is directly returned.
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Signed-off-by: Ankit Jindal <ajindal@xxxxxxx>
Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@xxxxxxxxxx>
Signed-off-by: Bharat Bhushan <Bharat.Bhushan@xxxxxxxxxxxxx>
---
drivers/vfio/vfio.c | 39 ++++++++++
drivers/vfio/vfio_iommu_type1.c | 163 ++++++++++++++++++++++++++++++++++++++--
include/linux/vfio.h | 34 ++++++++-
3 files changed, 228 insertions(+), 8 deletions(-)
diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 82f25cc..3d9de00 100644
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -268,6 +268,45 @@ void vfio_unregister_iommu_driver(const struct vfio_iommu_driver_ops *ops)
}
EXPORT_SYMBOL_GPL(vfio_unregister_iommu_driver);
+int vfio_group_alloc_map_reserved_iova(struct vfio_group *group,
+ phys_addr_t addr, int prot,
+ dma_addr_t *iova)
+{
+ struct vfio_container *container = group->container;
+ const struct vfio_iommu_driver_ops *ops = container->iommu_driver->ops;
+ int ret;
+
+ if (!ops->alloc_map_reserved_iova)
+ return -EINVAL;
+
+ down_read(&container->group_lock);
+ ret = ops->alloc_map_reserved_iova(container->iommu_data,
+ group->iommu_group,
+ addr, prot, iova);
+ up_read(&container->group_lock);
+ return ret;
+
+}
+EXPORT_SYMBOL_GPL(vfio_group_alloc_map_reserved_iova);
+
+int vfio_group_unmap_free_reserved_iova(struct vfio_group *group,
+ dma_addr_t iova)
+{
+ struct vfio_container *container = group->container;
+ const struct vfio_iommu_driver_ops *ops = container->iommu_driver->ops;
+ int ret;
+
+ if (!ops->unmap_free_reserved_iova)
+ return -EINVAL;
+
+ down_read(&container->group_lock);
+ ret = ops->unmap_free_reserved_iova(container->iommu_data,
+ group->iommu_group, iova);
+ up_read(&container->group_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vfio_group_unmap_free_reserved_iova);
+
/**
* Group minor allocation/free - both called with vfio.group_lock held
*/
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 33304c0..a79e2a8 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -156,6 +156,19 @@ static void vfio_unlink_reserved_binding(struct vfio_domain *d,
rb_erase(&old->node, &d->reserved_binding_list);
}
+static void vfio_reserved_binding_release(struct kref *kref)
+{
+ struct vfio_reserved_binding *b =
+ container_of(kref, struct vfio_reserved_binding, kref);
+ struct vfio_domain *d = b->domain;
+ unsigned long order = __ffs(b->size);
+
+ iommu_unmap(d->domain, b->iova, b->size);
+ free_iova(d->reserved_iova_domain, b->iova >> order);
+ vfio_unlink_reserved_binding(d, b);
+ kfree(b);
+}
+
/*
* This code handles mapping and unmapping of user data buffers
* into DMA'ble space using the IOMMU
@@ -1034,6 +1047,138 @@ done:
mutex_unlock(&iommu->lock);
}
+static struct vfio_domain *vfio_find_iommu_domain(void *iommu_data,
+ struct iommu_group *group)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ struct vfio_group *g;
+ struct vfio_domain *d;
+
+ list_for_each_entry(d, &iommu->domain_list, next) {
+ list_for_each_entry(g, &d->group_list, next) {
+ if (g->iommu_group == group)
+ return d;
+ }
+ }
+ return NULL;
+}
+
+static int vfio_iommu_type1_alloc_map_reserved_iova(void *iommu_data,
+ struct iommu_group *group,
+ phys_addr_t addr, int prot,
+ dma_addr_t *iova)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ struct vfio_domain *d;
+ uint64_t mask, iommu_page_size;
+ struct vfio_reserved_binding *b;
+ unsigned long order;
+ struct iova *p_iova;
+ phys_addr_t aligned_addr, offset;
+ int ret = 0;
+
+ order = __ffs(vfio_pgsize_bitmap(iommu));
+ iommu_page_size = (uint64_t)1 << order;
+ mask = iommu_page_size - 1;
+ aligned_addr = addr & ~mask;
+ offset = addr - aligned_addr;
+
+ mutex_lock(&iommu->lock);
+
+ d = vfio_find_iommu_domain(iommu_data, group);
+ if (!d) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ b = vfio_find_reserved_binding(d, aligned_addr, iommu_page_size);
+ if (b) {
+ ret = 0;
+ *iova = b->iova + offset;
+ kref_get(&b->kref);
+ goto unlock;
+ }
+
+ /* allocate a new reserved IOVA page and a new binding node */
+ p_iova = alloc_iova(d->reserved_iova_domain, 1,
+ d->reserved_iova_domain->dma_32bit_pfn, true);
+ if (!p_iova) {
+ ret = -ENOMEM;
+ goto unlock;
+ }
+ *iova = p_iova->pfn_lo << order;
+
+ b = kzalloc(sizeof(*b), GFP_KERNEL);
+ if (!b) {
+ ret = -ENOMEM;
+ goto free_iova_unlock;
+ }
+
+ ret = iommu_map(d->domain, *iova, aligned_addr, iommu_page_size, prot);
+ if (ret)
+ goto free_binding_iova_unlock;
+
+ kref_init(&b->kref);
+ kref_get(&b->kref);
+ b->domain = d;
+ b->addr = aligned_addr;
+ b->iova = *iova;
+ b->size = iommu_page_size;
+ vfio_link_reserved_binding(d, b);
+ *iova += offset;
+
+ goto unlock;
+
+free_binding_iova_unlock:
+ kfree(b);
+free_iova_unlock:
+ free_iova(d->reserved_iova_domain, *iova >> order);
+unlock:
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
+static int vfio_iommu_type1_unmap_free_reserved_iova(void *iommu_data,
+ struct iommu_group *group,
+ dma_addr_t iova)
+{
+ struct vfio_iommu *iommu = iommu_data;
+ struct vfio_reserved_binding *b;
+ struct vfio_domain *d;
+ phys_addr_t aligned_addr;
+ dma_addr_t aligned_iova, iommu_page_size, mask, offset;
+ unsigned long order;
+ int ret = 0;
+
+ order = __ffs(vfio_pgsize_bitmap(iommu));
+ iommu_page_size = (uint64_t)1 << order;
+ mask = iommu_page_size - 1;
+ aligned_iova = iova & ~mask;
+ offset = iova - aligned_iova;
+
+ mutex_lock(&iommu->lock);
+
+ d = vfio_find_iommu_domain(iommu_data, group);
+ if (!d) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ aligned_addr = iommu_iova_to_phys(d->domain, aligned_iova);
+
+ b = vfio_find_reserved_binding(d, aligned_addr, iommu_page_size);
+ if (!b) {
+ ret = -EINVAL;
+ goto unlock;
+ }
+
+ kref_put(&b->kref, vfio_reserved_binding_release);
+
+unlock:
+ mutex_unlock(&iommu->lock);
+ return ret;
+}
+
static void *vfio_iommu_type1_open(unsigned long arg)
{
struct vfio_iommu *iommu;
@@ -1180,13 +1325,17 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
}
static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
- .name = "vfio-iommu-type1",
- .owner = THIS_MODULE,
- .open = vfio_iommu_type1_open,
- .release = vfio_iommu_type1_release,
- .ioctl = vfio_iommu_type1_ioctl,
- .attach_group = vfio_iommu_type1_attach_group,
- .detach_group = vfio_iommu_type1_detach_group,
+ .name = "vfio-iommu-type1",
+ .owner = THIS_MODULE,
+ .open = vfio_iommu_type1_open,
+ .release = vfio_iommu_type1_release,
+ .ioctl = vfio_iommu_type1_ioctl,
+ .attach_group = vfio_iommu_type1_attach_group,
+ .detach_group = vfio_iommu_type1_detach_group,
+ .alloc_map_reserved_iova =
+ vfio_iommu_type1_alloc_map_reserved_iova,
+ .unmap_free_reserved_iova =
+ vfio_iommu_type1_unmap_free_reserved_iova,
};
static int __init vfio_iommu_type1_init(void)
diff --git a/include/linux/vfio.h b/include/linux/vfio.h
index 610a86a..0020f81 100644
--- a/include/linux/vfio.h
+++ b/include/linux/vfio.h
@@ -75,7 +75,13 @@ struct vfio_iommu_driver_ops {
struct iommu_group *group);
void (*detach_group)(void *iommu_data,
struct iommu_group *group);
-
+ int (*alloc_map_reserved_iova)(void *iommu_data,
+ struct iommu_group *group,
+ phys_addr_t addr, int prot,
+ dma_addr_t *iova);
+ int (*unmap_free_reserved_iova)(void *iommu_data,
+ struct iommu_group *group,
+ dma_addr_t iova);
};
extern int vfio_register_iommu_driver(const struct vfio_iommu_driver_ops *ops);
@@ -138,4 +144,30 @@ extern int vfio_virqfd_enable(void *opaque,
void *data, struct virqfd **pvirqfd, int fd);
extern void vfio_virqfd_disable(struct virqfd **pvirqfd);
+/**
+ * vfio_group_alloc_map_reserved_iova: allocates a new iova page and map
+ * it onto the aligned physical page that contains a given physical addr.
+ * page size is the domain iommu page size.
+ *
+ * @group: vfio group handle
+ * @addr: physical address to map
+ * @prot: protection attribute
+ * @iova: returned iova that is mapped onto addr
+ *
+ * returns 0 on success, < 0 on failure
+ */
+extern int vfio_group_alloc_map_reserved_iova(struct vfio_group *group,
+ phys_addr_t addr, int prot,
+ dma_addr_t *iova);
+/**
+ * vfio_group_unmap_free_reserved_iova: unmap and free the reserved iova page
+ *
+ * @group: vfio group handle
+ * @iova: base iova, must be aligned on the IOMMU page size
+ *
+ * returns 0 on success, < 0 on failure
+ */
+extern int vfio_group_unmap_free_reserved_iova(struct vfio_group *group,
+ dma_addr_t iova);
+
#endif /* VFIO_H */
--
1.9.1
--
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