virtio-crypto: use private buffer for control request

Originally, all of the control requests share a single buffer(
ctrl & input & ctrl_status fields in struct virtio_crypto), this
allows queue depth 1 only, the performance of control queue gets
limited by this design.

In this patch, each request allocates request buffer dynamically, and
free buffer after request, so the scope protected by ctrl_lock also
get optimized here.
It's possible to optimize control queue depth in the next step.

A necessary comment is already in code, still describe it again:
/*
 * Note: there are padding fields in request, clear them to zero before
 * sending to host to avoid to divulge any information.
 * Ex, virtio_crypto_ctrl_request::ctrl::u::destroy_session::padding[48]
 */
So use kzalloc to allocate buffer of struct virtio_crypto_ctrl_request.

Potentially dereferencing uninitialized variables:
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Gonglei <arei.gonglei@huawei.com>
Reviewed-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20220506131627.180784-3-pizhenwei@bytedance.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 12 insertions, 5 deletions

diff --git a/drivers/crypto/virtio/virtio_crypto_common.h b/drivers/crypto/virtio/virtio_crypto_common.h
index e693d4ee83a6..2422237ec4e6 100644
--- a/drivers/crypto/virtio/virtio_crypto_common.h
+++ b/drivers/crypto/virtio/virtio_crypto_common.h
@@ -13,6 +13,7 @@
 #include <crypto/aead.h>
 #include <crypto/aes.h>
 #include <crypto/engine.h>
+#include <uapi/linux/virtio_crypto.h>
 
 
 /* Internal representation of a data virtqueue */
@@ -65,11 +66,6 @@ struct virtio_crypto {
 	/* Maximum size of per request */
 	u64 max_size;
 
-	/* Control VQ buffers: protected by the ctrl_lock */
-	struct virtio_crypto_op_ctrl_req ctrl;
-	struct virtio_crypto_session_input input;
-	struct virtio_crypto_inhdr ctrl_status;
-
 	unsigned long status;
 	atomic_t ref_count;
 	struct list_head list;
@@ -85,6 +81,17 @@ struct virtio_crypto_sym_session_info {
 	__u64 session_id;
 };
 
+/*
+ * Note: there are padding fields in request, clear them to zero before
+ *       sending to host to avoid to divulge any information.
+ * Ex, virtio_crypto_ctrl_request::ctrl::u::destroy_session::padding[48]
+ */
+struct virtio_crypto_ctrl_request {
+	struct virtio_crypto_op_ctrl_req ctrl;
+	struct virtio_crypto_session_input input;
+	struct virtio_crypto_inhdr ctrl_status;
+};
+
 struct virtio_crypto_request;
 typedef void (*virtio_crypto_data_callback)
 		(struct virtio_crypto_request *vc_req, int len);