1 files changed, 38 insertions, 8 deletions

diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c
index d6303174..01b60ff9 100644
--- a/lib/librte_vhost/socket.c
+++ b/lib/librte_vhost/socket.c
@@ -51,6 +51,8 @@ struct vhost_user_socket {
 	uint64_t supported_features;
 	uint64_t features;
 
+	uint64_t protocol_features;
+
 	/*
 	 * Device id to identify a specific backend device.
 	 * It's set to -1 for the default software implementation.
@@ -94,18 +96,23 @@ static struct vhost_user vhost_user = {
 	.mutex = PTHREAD_MUTEX_INITIALIZER,
 };
 
-/* return bytes# of read on success or negative val on failure. */
+/*
+ * return bytes# of read on success or negative val on failure. Update fdnum
+ * with number of fds read.
+ */
 int
-read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
+read_fd_message(int sockfd, char *buf, int buflen, int *fds, int max_fds,
+		int *fd_num)
 {
 	struct iovec iov;
 	struct msghdr msgh;
-	size_t fdsize = fd_num * sizeof(int);
-	char control[CMSG_SPACE(fdsize)];
+	char control[CMSG_SPACE(max_fds * sizeof(int))];
 	struct cmsghdr *cmsg;
 	int got_fds = 0;
 	int ret;
 
+	*fd_num = 0;
+
 	memset(&msgh, 0, sizeof(msgh));
 	iov.iov_base = buf;
 	iov.iov_len  = buflen;
@@ -131,13 +138,14 @@ read_fd_message(int sockfd, char *buf, int buflen, int *fds, int fd_num)
 		if ((cmsg->cmsg_level == SOL_SOCKET) &&
 			(cmsg->cmsg_type == SCM_RIGHTS)) {
 			got_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
+			*fd_num = got_fds;
 			memcpy(fds, CMSG_DATA(cmsg), got_fds * sizeof(int));
 			break;
 		}
 	}
 
 	/* Clear out unused file descriptors */
-	while (got_fds < fd_num)
+	while (got_fds < max_fds)
 		fds[got_fds++] = -1;
 
 	return ret;
@@ -720,7 +728,7 @@ rte_vhost_driver_get_protocol_features(const char *path,
 	did = vsocket->vdpa_dev_id;
 	vdpa_dev = rte_vdpa_get_device(did);
 	if (!vdpa_dev || !vdpa_dev->ops->get_protocol_features) {
-		*protocol_features = VHOST_USER_PROTOCOL_FEATURES;
+		*protocol_features = vsocket->protocol_features;
 		goto unlock_exit;
 	}
 
@@ -733,7 +741,7 @@ rte_vhost_driver_get_protocol_features(const char *path,
 		goto unlock_exit;
 	}
 
-	*protocol_features = VHOST_USER_PROTOCOL_FEATURES
+	*protocol_features = vsocket->protocol_features
 		& vdpa_protocol_features;
 
 unlock_exit:
@@ -852,11 +860,21 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 	vsocket->use_builtin_virtio_net = true;
 	vsocket->supported_features = VIRTIO_NET_SUPPORTED_FEATURES;
 	vsocket->features           = VIRTIO_NET_SUPPORTED_FEATURES;
+	vsocket->protocol_features  = VHOST_USER_PROTOCOL_FEATURES;
 
-	/* Dequeue zero copy can't assure descriptors returned in order */
+	/*
+	 * Dequeue zero copy can't assure descriptors returned in order.
+	 * Also, it requires that the guest memory is populated, which is
+	 * not compatible with postcopy.
+	 */
 	if (vsocket->dequeue_zero_copy) {
 		vsocket->supported_features &= ~(1ULL << VIRTIO_F_IN_ORDER);
 		vsocket->features &= ~(1ULL << VIRTIO_F_IN_ORDER);
+
+		RTE_LOG(INFO, VHOST_CONFIG,
+			"Dequeue zero copy requested, disabling postcopy support\n");
+		vsocket->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
 	}
 
 	if (!(flags & RTE_VHOST_USER_IOMMU_SUPPORT)) {
@@ -864,6 +882,18 @@ rte_vhost_driver_register(const char *path, uint64_t flags)
 		vsocket->features &= ~(1ULL << VIRTIO_F_IOMMU_PLATFORM);
 	}
 
+	if (!(flags & RTE_VHOST_USER_POSTCOPY_SUPPORT)) {
+		vsocket->protocol_features &=
+			~(1ULL << VHOST_USER_PROTOCOL_F_PAGEFAULT);
+	} else {
+#ifndef RTE_LIBRTE_VHOST_POSTCOPY
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"Postcopy requested but not compiled\n");
+		ret = -1;
+		goto out_mutex;
+#endif
+	}
+
 	if ((flags & RTE_VHOST_USER_CLIENT) != 0) {
 		vsocket->reconnect = !(flags & RTE_VHOST_USER_NO_RECONNECT);
 		if (vsocket->reconnect && reconn_tid == 0) {