[PATCH v3] vhost/crypto: fix build with GCC 12

[David Marchand <david.marchand@redhat.com>]

GCC 12 raises the following warning:

In file included from ../lib/mempool/rte_mempool.h:46,
                 from ../lib/mbuf/rte_mbuf.h:38,
                 from ../lib/vhost/vhost_crypto.c:7:
../lib/vhost/vhost_crypto.c: In function ‘rte_vhost_crypto_fetch_requests’:
../lib/eal/x86/include/rte_memcpy.h:371:9: warning: array subscript 1 is
     outside array bounds of ‘struct virtio_crypto_op_data_req[1]’
     [-Warray-bounds]
  371 | rte_mov32((uint8_t *)dst + 3 * 32, (const uint8_t *)src + 3 * 32);
      | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../lib/vhost/vhost_crypto.c:1178:42: note: while referencing ‘req’
 1178 |         struct virtio_crypto_op_data_req req;
      |                                          ^~~

Split this function and separate the per descriptor copy.
This makes the code clearer, and the compiler happier.

Note: logs for errors have been moved to callers to avoid duplicates.

Fixes: 3c79609fda7c ("vhost/crypto: handle virtually non-contiguous buffers")
Cc: stable@dpdk.org

Signed-off-by: David Marchand <david.marchand@redhat.com>
---
Changes since v2:
- fixed 32-bits build,

Changes since v1:
- refactored copy function,

---
 lib/vhost/vhost_crypto.c | 123 +++++++++++++++------------------------
 1 file changed, 46 insertions(+), 77 deletions(-)

diff --git a/lib/vhost/vhost_crypto.c b/lib/vhost/vhost_crypto.c
index b1c0eb6a0f..96ffb82a5d 100644
--- a/lib/vhost/vhost_crypto.c
+++ b/lib/vhost/vhost_crypto.c
@@ -565,94 +565,58 @@ get_data_ptr(struct vhost_crypto_data_req *vc_req,
 	return data;
 }
 
-static __rte_always_inline int
-copy_data(void *dst_data, struct vhost_crypto_data_req *vc_req,
-		struct vhost_crypto_desc *head,
-		struct vhost_crypto_desc **cur_desc,
-		uint32_t size, uint32_t max_n_descs)
+static __rte_always_inline uint32_t
+copy_data_from_desc(void *dst, struct vhost_crypto_data_req *vc_req,
+	struct vhost_crypto_desc *desc, uint32_t size)
 {
-	struct vhost_crypto_desc *desc = *cur_desc;
-	uint64_t remain, addr, dlen, len;
-	uint32_t to_copy;
-	uint8_t *data = dst_data;
-	uint8_t *src;
-	int left = size;
-
-	to_copy = RTE_MIN(desc->len, (uint32_t)left);
-	dlen = to_copy;
-	src = IOVA_TO_VVA(uint8_t *, vc_req, desc->addr, &dlen,
-			VHOST_ACCESS_RO);
-	if (unlikely(!src || !dlen))
-		return -1;
+	uint64_t remain;
+	uint64_t addr;
+
+	remain = RTE_MIN(desc->len, size);
+	addr = desc->addr;
+	do {
+		uint64_t len;
+		void *src;
+
+		len = remain;
+		src = IOVA_TO_VVA(void *, vc_req, addr, &len, VHOST_ACCESS_RO);
+		if (unlikely(src == NULL || len == 0))
+			return 0;
 
-	rte_memcpy((uint8_t *)data, src, dlen);
-	data += dlen;
+		rte_memcpy(dst, src, len);
+		remain -= len;
+		/* cast is needed for 32-bit architecture */
+		dst = RTE_PTR_ADD(dst, (size_t)len);
+		addr += len;
+	} while (unlikely(remain != 0));
 
-	if (unlikely(dlen < to_copy)) {
-		remain = to_copy - dlen;
-		addr = desc->addr + dlen;
+	return RTE_MIN(desc->len, size);
+}
 
-		while (remain) {
-			len = remain;
-			src = IOVA_TO_VVA(uint8_t *, vc_req, addr, &len,
-					VHOST_ACCESS_RO);
-			if (unlikely(!src || !len)) {
-				VC_LOG_ERR("Failed to map descriptor");
-				return -1;
-			}
 
-			rte_memcpy(data, src, len);
-			addr += len;
-			remain -= len;
-			data += len;
-		}
-	}
+static __rte_always_inline int
+copy_data(void *data, struct vhost_crypto_data_req *vc_req,
+	struct vhost_crypto_desc *head, struct vhost_crypto_desc **cur_desc,
+	uint32_t size, uint32_t max_n_descs)
+{
+	struct vhost_crypto_desc *desc = *cur_desc;
+	uint32_t left = size;
 
-	left -= to_copy;
+	do {
+		uint32_t copied;
 
-	while (desc >= head && desc - head < (int)max_n_descs && left) {
-		desc++;
-		to_copy = RTE_MIN(desc->len, (uint32_t)left);
-		dlen = to_copy;
-		src = IOVA_TO_VVA(uint8_t *, vc_req, desc->addr, &dlen,
-				VHOST_ACCESS_RO);
-		if (unlikely(!src || !dlen)) {
-			VC_LOG_ERR("Failed to map descriptor");
+		copied = copy_data_from_desc(data, vc_req, desc, left);
+		if (copied == 0)
 			return -1;
-		}
-
-		rte_memcpy(data, src, dlen);
-		data += dlen;
-
-		if (unlikely(dlen < to_copy)) {
-			remain = to_copy - dlen;
-			addr = desc->addr + dlen;
-
-			while (remain) {
-				len = remain;
-				src = IOVA_TO_VVA(uint8_t *, vc_req, addr, &len,
-						VHOST_ACCESS_RO);
-				if (unlikely(!src || !len)) {
-					VC_LOG_ERR("Failed to map descriptor");
-					return -1;
-				}
-
-				rte_memcpy(data, src, len);
-				addr += len;
-				remain -= len;
-				data += len;
-			}
-		}
-
-		left -= to_copy;
-	}
+		left -= copied;
+		data = RTE_PTR_ADD(data, copied);
+		desc++;
+	} while (desc < head + max_n_descs && left != 0);
 
-	if (unlikely(left > 0)) {
-		VC_LOG_ERR("Incorrect virtio descriptor");
+	if (unlikely(left != 0))
 		return -1;
-	}
 
-	if (unlikely(desc - head == (int)max_n_descs))
+	if (unlikely(desc == head + max_n_descs))
 		*cur_desc = NULL;
 	else
 		*cur_desc = desc + 1;
@@ -852,6 +816,7 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op,
 	/* iv */
 	if (unlikely(copy_data(iv_data, vc_req, head, &desc,
 			cipher->para.iv_len, max_n_descs))) {
+		VC_LOG_ERR("Incorrect virtio descriptor");
 		ret = VIRTIO_CRYPTO_BADMSG;
 		goto error_exit;
 	}
@@ -883,6 +848,7 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op,
 		if (unlikely(copy_data(rte_pktmbuf_mtod(m_src, uint8_t *),
 				vc_req, head, &desc, cipher->para.src_data_len,
 				max_n_descs) < 0)) {
+			VC_LOG_ERR("Incorrect virtio descriptor");
 			ret = VIRTIO_CRYPTO_BADMSG;
 			goto error_exit;
 		}
@@ -1006,6 +972,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op,
 	/* iv */
 	if (unlikely(copy_data(iv_data, vc_req, head, &desc,
 			chain->para.iv_len, max_n_descs) < 0)) {
+		VC_LOG_ERR("Incorrect virtio descriptor");
 		ret = VIRTIO_CRYPTO_BADMSG;
 		goto error_exit;
 	}
@@ -1037,6 +1004,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op,
 		if (unlikely(copy_data(rte_pktmbuf_mtod(m_src, uint8_t *),
 				vc_req, head, &desc, chain->para.src_data_len,
 				max_n_descs) < 0)) {
+			VC_LOG_ERR("Incorrect virtio descriptor");
 			ret = VIRTIO_CRYPTO_BADMSG;
 			goto error_exit;
 		}
@@ -1121,6 +1089,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op,
 		if (unlikely(copy_data(digest_addr, vc_req, head, &digest_desc,
 				chain->para.hash_result_len,
 				max_n_descs) < 0)) {
+			VC_LOG_ERR("Incorrect virtio descriptor");
 			ret = VIRTIO_CRYPTO_BADMSG;
 			goto error_exit;
 		}
-- 
2.36.1