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path: root/drivers/vfio
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-rw-r--r--drivers/vfio/vfio_iommu_spapr_tce.c61
1 files changed, 60 insertions, 1 deletions
diff --git a/drivers/vfio/vfio_iommu_spapr_tce.c b/drivers/vfio/vfio_iommu_spapr_tce.c
index 4c03c8525c26..c8823578a1b2 100644
--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -89,6 +89,15 @@ struct tce_iommu_group {
};
/*
+ * A container needs to remember which preregistered region it has
+ * referenced to do proper cleanup at the userspace process exit.
+ */
+struct tce_iommu_prereg {
+ struct list_head next;
+ struct mm_iommu_table_group_mem_t *mem;
+};
+
+/*
* The container descriptor supports only a single group per container.
* Required by the API as the container is not supplied with the IOMMU group
* at the moment of initialization.
@@ -102,6 +111,7 @@ struct tce_container {
struct mm_struct *mm;
struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
struct list_head group_list;
+ struct list_head prereg_list;
};
static long tce_iommu_mm_set(struct tce_container *container)
@@ -118,10 +128,27 @@ static long tce_iommu_mm_set(struct tce_container *container)
return 0;
}
+static long tce_iommu_prereg_free(struct tce_container *container,
+ struct tce_iommu_prereg *tcemem)
+{
+ long ret;
+
+ ret = mm_iommu_put(container->mm, tcemem->mem);
+ if (ret)
+ return ret;
+
+ list_del(&tcemem->next);
+ kfree(tcemem);
+
+ return 0;
+}
+
static long tce_iommu_unregister_pages(struct tce_container *container,
__u64 vaddr, __u64 size)
{
struct mm_iommu_table_group_mem_t *mem;
+ struct tce_iommu_prereg *tcemem;
+ bool found = false;
if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
return -EINVAL;
@@ -130,7 +157,17 @@ static long tce_iommu_unregister_pages(struct tce_container *container,
if (!mem)
return -ENOENT;
- return mm_iommu_put(container->mm, mem);
+ list_for_each_entry(tcemem, &container->prereg_list, next) {
+ if (tcemem->mem == mem) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return -ENOENT;
+
+ return tce_iommu_prereg_free(container, tcemem);
}
static long tce_iommu_register_pages(struct tce_container *container,
@@ -138,16 +175,29 @@ static long tce_iommu_register_pages(struct tce_container *container,
{
long ret = 0;
struct mm_iommu_table_group_mem_t *mem = NULL;
+ struct tce_iommu_prereg *tcemem;
unsigned long entries = size >> PAGE_SHIFT;
if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
((vaddr + size) < vaddr))
return -EINVAL;
+ mem = mm_iommu_find(container->mm, vaddr, entries);
+ if (mem) {
+ list_for_each_entry(tcemem, &container->prereg_list, next) {
+ if (tcemem->mem == mem)
+ return -EBUSY;
+ }
+ }
+
ret = mm_iommu_get(container->mm, vaddr, entries, &mem);
if (ret)
return ret;
+ tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
+ tcemem->mem = mem;
+ list_add(&tcemem->next, &container->prereg_list);
+
container->enabled = true;
return 0;
@@ -334,6 +384,7 @@ static void *tce_iommu_open(unsigned long arg)
mutex_init(&container->lock);
INIT_LIST_HEAD_RCU(&container->group_list);
+ INIT_LIST_HEAD_RCU(&container->prereg_list);
container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
@@ -372,6 +423,14 @@ static void tce_iommu_release(void *iommu_data)
tce_iommu_free_table(container, tbl);
}
+ while (!list_empty(&container->prereg_list)) {
+ struct tce_iommu_prereg *tcemem;
+
+ tcemem = list_first_entry(&container->prereg_list,
+ struct tce_iommu_prereg, next);
+ WARN_ON_ONCE(tce_iommu_prereg_free(container, tcemem));
+ }
+
tce_iommu_disable(container);
if (container->mm)
mmdrop(container->mm);