Create some common API's for adding entries to a xa_mmap.
Searching for an entry and freeing one.
The code was copied from the efa driver almost as is, just renamed
function to be generic and not efa specific.
Signed-off-by: Ariel Elior <ariel.elior@xxxxxxxxxxx>
Signed-off-by: Michal Kalderon <michal.kalderon@xxxxxxxxxxx>
---
drivers/infiniband/core/device.c | 1 +
drivers/infiniband/core/rdma_core.c | 1 +
drivers/infiniband/core/uverbs_cmd.c | 1 +
drivers/infiniband/core/uverbs_main.c | 135 ++++++++++++++++++++++++++++++++++
include/rdma/ib_verbs.h | 46 ++++++++++++
5 files changed, 184 insertions(+)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 8a6ccb936dfe..a830c2c5d691 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2521,6 +2521,7 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
SET_DEVICE_OP(dev_ops, map_mr_sg_pi);
SET_DEVICE_OP(dev_ops, map_phys_fmr);
SET_DEVICE_OP(dev_ops, mmap);
+ SET_DEVICE_OP(dev_ops, mmap_free);
SET_DEVICE_OP(dev_ops, modify_ah);
SET_DEVICE_OP(dev_ops, modify_cq);
SET_DEVICE_OP(dev_ops, modify_device);
diff --git a/drivers/infiniband/core/rdma_core.c b/drivers/infiniband/core/rdma_core.c
index ccf4d069c25c..1ed01b02401f 100644
--- a/drivers/infiniband/core/rdma_core.c
+++ b/drivers/infiniband/core/rdma_core.c
@@ -816,6 +816,7 @@ static void ufile_destroy_ucontext(struct ib_uverbs_file *ufile,
rdma_restrack_del(&ucontext->res);
+ rdma_user_mmap_entries_remove_free(ucontext);
ib_dev->ops.dealloc_ucontext(ucontext);
kfree(ucontext);
diff --git a/drivers/infiniband/core/uverbs_cmd.c b/drivers/infiniband/core/uverbs_cmd.c
index 7ddd0e5bc6b3..44c0600245e4 100644
--- a/drivers/infiniband/core/uverbs_cmd.c
+++ b/drivers/infiniband/core/uverbs_cmd.c
@@ -254,6 +254,7 @@ static int ib_uverbs_get_context(struct uverbs_attr_bundle *attrs)
mutex_init(&ucontext->per_mm_list_lock);
INIT_LIST_HEAD(&ucontext->per_mm_list);
+ xa_init(&ucontext->mmap_xa);
ret = get_unused_fd_flags(O_CLOEXEC);
if (ret < 0)
diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/core/uverbs_main.c
index 11c13c1381cf..4b909d7b97de 100644
--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c
@@ -965,6 +965,141 @@ int rdma_user_mmap_io(struct ib_ucontext *ucontext, struct vm_area_struct *vma,
}
EXPORT_SYMBOL(rdma_user_mmap_io);
+static inline u64
+rdma_user_mmap_get_key(const struct rdma_user_mmap_entry *entry)
+{
+ return (u64)entry->mmap_page << PAGE_SHIFT;
+}
+
+/**
+ * rdma_user_mmap_entry_get() - Get an entry from the mmap_xa.
+ *
+ * @ucontext: associated user context.
+ * @key: The key received from rdma_user_mmap_entry_insert which
+ * is provided by user as the address to map.
+ * @len: The length the user wants to map
+ *
+ * This function is called when a user tries to mmap a key it
+ * initially received from the driver. They key was created by
+ * the function rdma_user_mmap_entry_insert.
+ *
+ * Return an entry if exists or NULL if there is no match.
+ */
+struct rdma_user_mmap_entry *
+rdma_user_mmap_entry_get(struct ib_ucontext *ucontext, u64 key, u64 len)
+{
+ struct rdma_user_mmap_entry *entry;
+ u64 mmap_page;
+
+ mmap_page = key >> PAGE_SHIFT;
+ if (mmap_page > U32_MAX)
+ return NULL;
+
+ entry = xa_load(&ucontext->mmap_xa, mmap_page);
+ if (!entry || entry->length != len)
+ return NULL;
+
+ ibdev_dbg(ucontext->device,
+ "mmap: obj[0x%p] key[%#llx] addr[%#llx] len[%#llx] removed\n",
+ entry->obj, key, entry->address, entry->length);
+
+ return entry;
+}
+EXPORT_SYMBOL(rdma_user_mmap_entry_get);
+
+/**
+ * rdma_user_mmap_entry_insert() - Allocate and insert an entry to the mmap_xa.
+ *
+ * @ucontext: associated user context.
+ * @obj: opaque driver object that will be stored in the entry.
+ * @address: The address that will be mmapped to the user
+ * @length: Length of the address that will be mmapped
+ * @mmap_flag: opaque driver flags related to the address (For
+ * example could be used for cachability)
+ *
+ * This function should be called by drivers that use the rdma_user_mmap
+ * interface for handling user mmapped addresses. The database is handled in
+ * the core and helper functions are provided to insert entries into the
+ * database and extract entries when the user call mmap with the given key.
+ * The function returns a unique key that should be provided to user, the user
+ * will use the key to map the given address.
+ *
+ * Note this locking scheme cannot support removal of entries,
+ * except during ucontext destruction when the core code
+ * guarentees no concurrency.
+ *
+ * Return: unique key or RDMA_USER_MMAP_INVALID if entry was not added.
+ */
+u64 rdma_user_mmap_entry_insert(struct ib_ucontext *ucontext, void *obj,
+ u64 address, u64 length, u8 mmap_flag)
+{
+ struct rdma_user_mmap_entry *entry;
+ u32 next_mmap_page;
+ int err;
+
+ entry = kzalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return RDMA_USER_MMAP_INVALID;
+
+ entry->obj = obj;
+ entry->address = address;
+ entry->length = length;
+ entry->mmap_flag = mmap_flag;
+
+ xa_lock(&ucontext->mmap_xa);
+ if (check_add_overflow(ucontext->mmap_xa_page,
+ (u32)(length >> PAGE_SHIFT),
+ &next_mmap_page))
+ goto err_unlock;
+
+ entry->mmap_page = ucontext->mmap_xa_page;
+ ucontext->mmap_xa_page = next_mmap_page;
+ err = __xa_insert(&ucontext->mmap_xa, entry->mmap_page, entry,
+ GFP_KERNEL);
+ if (err)
+ goto err_unlock;
+
+ xa_unlock(&ucontext->mmap_xa);
+
+ ibdev_dbg(ucontext->device,
+ "mmap: obj[0x%p] addr[%#llx], len[%#llx], key[%#llx] inserted\n",
+ entry->obj, entry->address, entry->length,
+ rdma_user_mmap_get_key(entry));
+
+ return rdma_user_mmap_get_key(entry);
+
+err_unlock:
+ xa_unlock(&ucontext->mmap_xa);
+ kfree(entry);
+ return RDMA_USER_MMAP_INVALID;
+}
+EXPORT_SYMBOL(rdma_user_mmap_entry_insert);
+
+/*
+ * This is only called when the ucontext is destroyed and there can be no
+ * concurrent query via mmap or allocate on the xarray, thus we can be sure no
+ * other thread is using the entry pointer. We also know that all the BAR
+ * pages have either been zap'd or munmaped at this point. Normal pages are
+ * refcounted and will be freed at the proper time.
+ */
+void rdma_user_mmap_entries_remove_free(struct ib_ucontext *ucontext)
+{
+ struct rdma_user_mmap_entry *entry;
+ unsigned long mmap_page;
+
+ xa_for_each(&ucontext->mmap_xa, mmap_page, entry) {
+ xa_erase(&ucontext->mmap_xa, mmap_page);
+
+ ibdev_dbg(ucontext->device,
+ "mmap: obj[0x%p] key[%#llx] addr[%#llx] len[%#llx] removed\n",
+ entry->obj, rdma_user_mmap_get_key(entry),
+ entry->address, entry->length);
+ if (ucontext->device->ops.mmap_free)
+ ucontext->device->ops.mmap_free(entry);
+ kfree(entry);
+ }
+}
+
void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
{
struct rdma_umap_priv *priv, *next_priv;
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 26e9c2594913..1ba29a00f584 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -1425,6 +1425,8 @@ struct ib_ucontext {
* Implementation details of the RDMA core, don't use in drivers:
*/
struct rdma_restrack_entry res;
+ struct xarray mmap_xa;
+ u32 mmap_xa_page;
};
struct ib_uobject {
@@ -2199,6 +2201,17 @@ struct iw_cm_conn_param;
#define DECLARE_RDMA_OBJ_SIZE(ib_struct) size_t size_##ib_struct
+#define RDMA_USER_MMAP_FLAG_SHIFT 56
+#define RDMA_USER_MMAP_PAGE_MASK GENMASK(EFA_MMAP_FLAG_SHIFT - 1, 0)
+#define RDMA_USER_MMAP_INVALID U64_MAX
+struct rdma_user_mmap_entry {
+ void *obj;
+ u64 address;
+ u64 length;
+ u32 mmap_page;
+ u8 mmap_flag;
+};
+
/**
* struct ib_device_ops - InfiniBand device operations
* This structure defines all the InfiniBand device operations, providers will
@@ -2311,6 +2324,19 @@ struct ib_device_ops {
struct ib_udata *udata);
void (*dealloc_ucontext)(struct ib_ucontext *context);
int (*mmap)(struct ib_ucontext *context, struct vm_area_struct *vma);
+ /**
+ * Memory that is mapped to the user can only be freed once the
+ * ucontext of the application is destroyed. This is for
+ * security reasons where we don't want an application to have a
+ * mapping to phyiscal memory that is freed and allocated to
+ * another application. For this reason, all the entries are
+ * stored in ucontext and once ucontext is freed mmap_free is
+ * called on each of the entries. They type of the memory that
+ * was mapped may differ between entries and is opaque to the
+ * rdma_user_mmap interface. Therefore needs to be implemented
+ * by the driver in mmap_free.
+ */
+ void (*mmap_free)(struct rdma_user_mmap_entry *entry);
void (*disassociate_ucontext)(struct ib_ucontext *ibcontext);
int (*alloc_pd)(struct ib_pd *pd, struct ib_udata *udata);
void (*dealloc_pd)(struct ib_pd *pd, struct ib_udata *udata);
@@ -2709,6 +2735,11 @@ void ib_set_device_ops(struct ib_device *device,
#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS)
int rdma_user_mmap_io(struct ib_ucontext *ucontext, struct vm_area_struct *vma,
unsigned long pfn, unsigned long size, pgprot_t prot);
+u64 rdma_user_mmap_entry_insert(struct ib_ucontext *ucontext, void *obj,
+ u64 address, u64 length, u8 mmap_flag);
+struct rdma_user_mmap_entry *
+rdma_user_mmap_entry_get(struct ib_ucontext *ucontext, u64 key, u64 len);
+void rdma_user_mmap_entries_remove_free(struct ib_ucontext *ucontext);
#else
static inline int rdma_user_mmap_io(struct ib_ucontext *ucontext,
struct vm_area_struct *vma,
@@ -2717,6 +2748,21 @@ static inline int rdma_user_mmap_io(struct ib_ucontext *ucontext,
{
return -EINVAL;
}
+
+static u64 rdma_user_mmap_entry_insert(struct ib_ucontext *ucontext, void *obj,
+ u64 address, u64 length, u8 mmap_flag)
+{
+ return RDMA_USER_MMAP_INVALID;
+}
+
+static struct rdma_user_mmap_entry *
+rdma_user_mmap_entry_get(struct ib_ucontext *ucontext, u64 key, u64 len)
+{
+ return NULL;
+}
+
+static void rdma_user_mmap_entries_remove_free(struct ib_ucontext *ucontext) {}
+
#endif
static inline int ib_copy_from_udata(void *dest, struct ib_udata *udata, size_t len)
--
2.14.5
