xiaoxiang781216 commented on code in PR #20218:
URL: https://github.com/apache/nuttx/pull/20218#discussion_r4062719000
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arch/arm/src/am67/am67_rat.c:
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@@ -53,6 +53,7 @@
#include "arm_internal.h"
#include "am67_rat.h"
+#include <nuttx/vhost/vhost.h>
Review Comment:
move before line 53
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drivers/vhost/Kconfig:
##########
@@ -3,17 +3,47 @@
# see the file kconfig-language.txt in the NuttX tools repository.
#
-config DRIVERS_VHOST
+config ARCH_HAVE_VHOST_IOMAP
bool
+ default n
+
+config DRIVERS_VHOST
+ bool "Virtual Host (device-role virtio) support"
Review Comment:
why add prompt string
##########
drivers/vhost/vhost-net.c:
##########
@@ -0,0 +1,495 @@
+/****************************************************************************
+ * drivers/vhost/vhost-net.c
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership. The
+ * ASF licenses this file to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance with the
+ * License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+ * License for the specific language governing permissions and limitations
+ * under the License.
+ *
+ ****************************************************************************/
+
+/* Device-role virtio network driver ("vhost-net"): implements the DEVICE
+ * end of a virtio-net link, so a peer processor running a stock virtio-net
+ * DRIVER (e.g. Linux via remoteproc/rproc-virtio) sees this side as a
+ * network card. Registers a NuttX netdev lowerhalf (ethN).
+ *
+ * Ring layout is fixed by the peer driver's point of view:
+ * vq[0] = peer driver RX queue: the peer posts empty buffers; the
+ * device side fills them to transmit toward the peer.
+ * vq[1] = peer driver TX queue: the peer posts filled buffers; the
+ * device side harvests them as its receive path.
+ *
+ * No virtio-net features are negotiated (the resource table advertises
+ * none), so every packet is prefixed by the legacy 10-byte
+ * struct virtio_net_hdr with all fields zero (gso_type NONE).
+ */
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <debug.h>
+#include <string.h>
+#include <sys/param.h>
+
+#include <nuttx/kmalloc.h>
+#include <nuttx/net/netdev_lowerhalf.h>
+#include <nuttx/vhost/vhost.h>
+
+#include "vhost-net.h"
+
+/* Peer buffers are referenced by 64-bit guest physical addresses that may
+ * exceed the CPU's direct reach; arches that provide a translation window
+ * implement up_vhost_iomap() (ARCH_HAVE_VHOST_IOMAP), others use the
+ * identity mapping.
+ */
+
+#ifdef CONFIG_ARCH_HAVE_VHOST_IOMAP
+# define vhost_net_map(pa, avl) up_vhost_iomap((pa), (avl))
+#else
+static inline FAR void *vhost_net_map(uint64_t pa, FAR size_t *avail)
+{
+ if (avail != NULL)
+ {
+ *avail = SIZE_MAX;
+ }
+
+ return (FAR void *)(uintptr_t)pa;
+}
+#endif
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/* Queue indices (peer driver's numbering, see file header) */
+
+#define VHOST_NET_PEER_RXQ 0 /* device-side transmit lane */
+#define VHOST_NET_PEER_TXQ 1 /* device-side receive lane */
+#define VHOST_NET_NUM 2
+
+/* Legacy struct virtio_net_hdr (no VIRTIO_NET_F_MRG_RXBUF): flags(1) +
+ * gso_type(1) + hdr_len(2) + gso_size(2) + csum_start(2) + csum_offset(2)
+ */
+
+#define VHOST_NET_HDRSIZE 10
+
+/* netpkt quota per direction and the longest peer descriptor chain we
+ * accept on receive (Linux commonly splits header and payload).
+ */
+
+#define VHOST_NET_NPKTS 8
+#define VHOST_NET_MAXCHAIN 8
+
+/****************************************************************************
+ * Private Types
+ ****************************************************************************/
+
+struct vhost_net_priv_s
+{
+ struct netdev_lowerhalf_s lower; /* Must be first for casts */
+ FAR struct vhost_device *hdev;
+ FAR struct virtqueue *txq; /* peer RX ring (filled here) */
+ FAR struct virtqueue *rxq; /* peer TX ring (drained here) */
+};
+
+/****************************************************************************
+ * Private Function Prototypes
+ ****************************************************************************/
+
+static int vhost_net_ifup(FAR struct netdev_lowerhalf_s *dev);
+static int vhost_net_ifdown(FAR struct netdev_lowerhalf_s *dev);
+static int vhost_net_transmit(FAR struct netdev_lowerhalf_s *dev,
+ FAR netpkt_t *pkt);
+static FAR netpkt_t *vhost_net_receive(FAR struct netdev_lowerhalf_s *dev);
+static int vhost_net_probe(FAR struct vhost_device *hdev);
+static void vhost_net_remove(FAR struct vhost_device *hdev);
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+static const struct netdev_ops_s g_vhost_net_ops =
+{
+ vhost_net_ifup,
+ vhost_net_ifdown,
+ vhost_net_transmit,
+ vhost_net_receive,
+#ifdef CONFIG_NET_MCASTGROUP
+ NULL,
+ NULL,
+#endif
+#ifdef CONFIG_NETDEV_IOCTL
+ NULL,
+#endif
+ NULL
+};
+
+static struct vhost_driver g_vhost_net_driver =
+{
+ LIST_INITIAL_VALUE(g_vhost_net_driver.node), /* node */
+ VIRTIO_ID_NETWORK, /* device id */
+ vhost_net_probe, /* probe */
+ vhost_net_remove, /* remove */
+};
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: vhost_net_rxready / vhost_net_txdone
+ *
+ * Description:
+ * Virtqueue kick callbacks (transport notification context, thread
+ * level). Notify the upper half that ring work is pending; the rings
+ * are processed in transmit()/receive().
+ *
+ ****************************************************************************/
+
+static void vhost_net_rxready(FAR struct virtqueue *vq)
+{
+ FAR struct vhost_net_priv_s *priv = vq->vq_dev->priv;
+
+ netdev_lower_rxready(&priv->lower);
+}
+
+static void vhost_net_txdone(FAR struct virtqueue *vq)
+{
+ FAR struct vhost_net_priv_s *priv = vq->vq_dev->priv;
+
+ netdev_lower_txdone(&priv->lower);
+}
+
+/****************************************************************************
+ * Name: vhost_net_ifup / vhost_net_ifdown
+ ****************************************************************************/
+
+static int vhost_net_ifup(FAR struct netdev_lowerhalf_s *dev)
+{
+ netdev_lower_carrier_on(dev);
+ return OK;
+}
+
+static int vhost_net_ifdown(FAR struct netdev_lowerhalf_s *dev)
+{
+ netdev_lower_carrier_off(dev);
+ return OK;
+}
+
+/****************************************************************************
+ * Name: vhost_net_transmit
+ *
+ * Description:
+ * Fill one peer-posted RX buffer with the frame and complete it.
+ * Completion is synchronous: the netpkt is consumed and freed before
+ * returning.
+ *
+ ****************************************************************************/
+
+static int vhost_net_transmit(FAR struct netdev_lowerhalf_s *dev,
+ FAR netpkt_t *pkt)
+{
+ FAR struct vhost_net_priv_s *priv = (FAR struct vhost_net_priv_s *)dev;
+ struct vhost_buf_s vb[1];
+ unsigned int len;
+ unsigned int pos;
+ size_t cnt;
+ int head;
+
+ head = vhost_get_vq_buffers_pa(priv->txq, vb, nitems(vb), &cnt);
+ if (head < 0)
+ {
+ /* Peer has not posted buffers (yet). Re-enable its notifications;
+ * enable_cb reports buffers that arrived in the race window (their
+ * kick was suppressed), so grab them now if so.
+ */
+
+ if (!virtqueue_enable_cb(priv->txq))
+ {
+ return -ENOBUFS;
+ }
+
+ head = vhost_get_vq_buffers_pa(priv->txq, vb, nitems(vb), &cnt);
+ if (head < 0)
+ {
+ return -ENOBUFS;
+ }
+ }
+
+ len = netpkt_getdatalen(dev, pkt);
+ if (len + VHOST_NET_HDRSIZE > vb[0].len)
+ {
+ /* Frame cannot fit the peer's buffer: complete it empty (drop) */
+
+ vhosterr("frame %u exceeds peer buffer %" PRIu32 ", dropped\n",
+ len, vb[0].len);
+ len = 0;
+ }
+ else
+ {
+ /* Serialize the zero header + frame into the peer buffer through
+ * the translation window, honoring window-boundary splits.
+ */
+
+ for (pos = 0; pos < len + VHOST_NET_HDRSIZE; )
+ {
+ size_t avail;
+ FAR uint8_t *dst = vhost_net_map(vb[0].addr + pos, &avail);
+ unsigned int chunk = MIN(len + VHOST_NET_HDRSIZE - pos, avail);
+ unsigned int hdrlen = 0;
+ int ret = OK;
+
+ if (pos < VHOST_NET_HDRSIZE)
+ {
+ hdrlen = MIN(VHOST_NET_HDRSIZE - pos, chunk);
+ memset(dst, 0, hdrlen);
+ }
+
+ if (chunk > hdrlen)
+ {
+ ret = netpkt_copyout(dev, dst + hdrlen, pkt, chunk - hdrlen,
+ pos + hdrlen - VHOST_NET_HDRSIZE);
+ }
+
+ if (ret < 0)
+ {
+ vhosterr("netpkt_copyout failed, ret=%d, dropped\n", ret);
+ len = 0;
+ break;
+ }
+
+ pos += chunk;
+ }
+ }
+
+ virtqueue_add_consumed_buffer(priv->txq, head,
+ len ? len + VHOST_NET_HDRSIZE : 0);
+ virtqueue_kick(priv->txq);
+
+ netpkt_free(dev, pkt, NETPKT_TX);
+ netdev_lower_txdone(dev);
+ return OK;
+}
+
+/****************************************************************************
+ * Name: vhost_net_receive
+ *
+ * Description:
+ * Harvest one frame (possibly a descriptor chain) from the peer TX
+ * ring, copy it into a fresh netpkt (stripping the virtio-net header)
+ * and return the buffers to the peer.
+ *
+ ****************************************************************************/
+
+static FAR netpkt_t *vhost_net_receive(FAR struct netdev_lowerhalf_s *dev)
+{
+ FAR struct vhost_net_priv_s *priv = (FAR struct vhost_net_priv_s *)dev;
+ struct vhost_buf_s vb[VHOST_NET_MAXCHAIN];
+ FAR netpkt_t *pkt = NULL;
+ unsigned int total = 0;
+ unsigned int skip = VHOST_NET_HDRSIZE;
+ int offset = 0;
+ size_t cnt;
+ size_t i;
+ int head;
+
+ head = vhost_get_vq_buffers_pa(priv->rxq, vb, nitems(vb), &cnt);
+ if (head < 0)
+ {
+ /* See vhost_net_transmit() for the enable_cb recheck rationale */
+
+ if (!virtqueue_enable_cb(priv->rxq))
+ {
+ return NULL;
+ }
+
+ head = vhost_get_vq_buffers_pa(priv->rxq, vb, nitems(vb), &cnt);
+ if (head < 0)
+ {
+ return NULL;
+ }
+ }
+
+ for (i = 0; i < cnt; i++)
+ {
+ total += vb[i].len;
+ }
+
+ if (total > skip)
+ {
+ pkt = netpkt_alloc(dev, NETPKT_RX);
+ }
+
+ if (pkt != NULL &&
+ netpkt_setdatalen(dev, pkt, total - skip) < total - skip)
+ {
+ vhosterr("rx dropped: cannot size netpkt to %u\n", total - skip);
+ netpkt_free(dev, pkt, NETPKT_RX);
+ pkt = NULL;
+ }
+
+ if (pkt != NULL)
+ {
+ for (i = 0; i < cnt; i++)
+ {
+ uint64_t pa = vb[i].addr;
+ uint32_t blen = vb[i].len;
+
+ if (skip > 0)
+ {
+ uint32_t skiplen = MIN(skip, blen);
+
+ pa += skiplen;
+ blen -= skiplen;
+ skip -= skiplen;
+ }
+
+ /* Copy through the translation window, honoring
+ * window-boundary splits.
+ */
+
+ while (blen > 0)
+ {
+ size_t avail;
+ FAR const uint8_t *src = vhost_net_map(pa, &avail);
+ uint32_t chunk = MIN(blen, avail);
+
+ if (netpkt_copyin(dev, pkt, src, chunk, offset) < 0)
+ {
+ vhosterr("netpkt_copyin failed, rx dropped\n");
+ netpkt_free(dev, pkt, NETPKT_RX);
+ pkt = NULL;
+ goto out;
+ }
+
+ offset += chunk;
+ pa += chunk;
+ blen -= chunk;
+ }
+ }
+ }
+ else
+ {
+ vhosterr("rx dropped: total=%u (no netpkt)\n", total);
+ }
+
+out:
+
+ /* Hand the buffers back to the peer either way */
+
+ virtqueue_add_consumed_buffer(priv->rxq, head, total);
+ virtqueue_kick(priv->rxq);
+
+ return pkt;
+}
+
+/****************************************************************************
+ * Name: vhost_net_probe
+ ****************************************************************************/
+
+static int vhost_net_probe(FAR struct vhost_device *hdev)
+{
+ FAR struct vhost_net_priv_s *priv;
+ FAR const char *vqnames[VHOST_NET_NUM];
+ vq_callback callbacks[VHOST_NET_NUM];
+ FAR uint8_t *mac;
+ int ret;
+
+ priv = kmm_zalloc(sizeof(*priv));
+ if (priv == NULL)
+ {
+ return -ENOMEM;
+ }
+
+ priv->hdev = hdev;
+ hdev->priv = priv;
+
+ vqnames[VHOST_NET_PEER_RXQ] = "vhost_net_peer_rx";
+ vqnames[VHOST_NET_PEER_TXQ] = "vhost_net_peer_tx";
+ callbacks[VHOST_NET_PEER_RXQ] = vhost_net_txdone;
+ callbacks[VHOST_NET_PEER_TXQ] = vhost_net_rxready;
+ ret = vhost_create_virtqueues(hdev, 0, VHOST_NET_NUM, vqnames,
+ callbacks, NULL);
+ if (ret < 0)
+ {
+ vhosterr("vhost_create_virtqueues failed, ret=%d\n", ret);
+ goto err_with_priv;
+ }
+
+ priv->txq = hdev->vrings_info[VHOST_NET_PEER_RXQ].vq;
+ priv->rxq = hdev->vrings_info[VHOST_NET_PEER_TXQ].vq;
+
+ priv->lower.quota[NETPKT_RX] = VHOST_NET_NPKTS;
+ priv->lower.quota[NETPKT_TX] = VHOST_NET_NPKTS;
+ priv->lower.ops = &g_vhost_net_ops;
+
+ /* Software-assigned MAC (no MAC config space without negotiated
+ * features); see CONFIG_DRIVERS_VHOST_NET_MACADDR.
+ */
+
+ mac = priv->lower.netdev.d_mac.ether.ether_addr_octet;
+ mac[0] = (CONFIG_DRIVERS_VHOST_NET_MACADDR >> (8 * 5)) & 0xff;
Review Comment:
why not read from virtio_net_config_s
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