On Tue, Jul 16, 2024 at 9:14 AM Cindy Lu <l...@redhat.com> wrote:
>
> When using a VDPA device, it is important to ensure that the MAC address
> in the hardware matches the MAC address from the QEMU command line.
>
> There are only two acceptable situations:
> 1. The hardware MAC address is the same as the MAC address specified in the
> QEMU
> command line, and both MAC addresses are not 0.
> 2. The hardware MAC address is not 0, and the MAC address in the QEMU command
> line is 0.
> In this situation, the hardware MAC address will overwrite the QEMU command
> line address.
If this patch tries to do the above two, I'd suggest splitting it into
two patches.
>
> Signed-off-by: Cindy Lu <l...@redhat.com>
> ---
> hw/net/virtio-net.c | 43 +++++++++++++++++++++++++++++++++++++------
> 1 file changed, 37 insertions(+), 6 deletions(-)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 9c7e85caea..8f79785f59 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -178,8 +178,8 @@ static void virtio_net_get_config(VirtIODevice *vdev,
> uint8_t *config)
> * correctly elsewhere - just not reported by the device.
> */
> if (memcmp(&netcfg.mac, &zero, sizeof(zero)) == 0) {
> - info_report("Zero hardware mac address detected. Ignoring.");
> - memcpy(netcfg.mac, n->mac, ETH_ALEN);
> + error_report("Zero hardware mac address detected in vdpa device. "
> + "please check the vdpa device!");
I had two questions:
1) any reason to do this check while the guest is running?
2) I think we need a workaround for this, unless I miss something.
> }
>
> netcfg.status |= virtio_tswap16(vdev,
> @@ -3579,12 +3579,42 @@ static bool
> failover_hide_primary_device(DeviceListener *listener,
> /* failover_primary_hidden is set during feature negotiation */
> return qatomic_read(&n->failover_primary_hidden);
> }
> +static bool virtio_net_check_vdpa_mac(NetClientState *nc, VirtIONet *n,
> + MACAddr *cmdline_mac, Error **errp) {
> + struct virtio_net_config hwcfg = {};
> + static const MACAddr zero = {.a = {0, 0, 0, 0, 0, 0}};
>
> + vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&hwcfg, ETH_ALEN);
> +
> + /* For VDPA device: Only two situations are acceptable:
> + * 1.The hardware MAC address is the same as the QEMU command line MAC
> + * address, and both of them are not 0.
> + * 2.The hardware MAC address is NOT 0, and the QEMU command line MAC
> address
> + * is 0.
Did you mean -device virtio-net-pci,macaddr=0 ? Or you mean mac
address is not specified in the qemu command line?
> In this situation, the hardware MAC address will overwrite the QEMU
> + * command line address.
> + */
> +
> + if (memcmp(&hwcfg.mac, &zero, sizeof(MACAddr)) != 0) {
> + if ((memcmp(&hwcfg.mac, cmdline_mac, sizeof(MACAddr)) == 0) ||
> + (memcmp(cmdline_mac, &zero, sizeof(MACAddr)) == 0)) {
> + /* overwrite the mac address with hardware address*/
> + memcpy(&n->mac[0], &hwcfg.mac, sizeof(n->mac));
> + memcpy(&n->nic_conf.macaddr, &hwcfg.mac, sizeof(n->mac));
> +
> + return true;
> + }
> + }
> + error_setg(errp, "vdpa hardware mac != the mac address from "
> + "qemu cmdline, please check the the vdpa device's
> setting.");
> +
> + return false;
> +}
> static void virtio_net_device_realize(DeviceState *dev, Error **errp)
> {
> VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> VirtIONet *n = VIRTIO_NET(dev);
> NetClientState *nc;
> + MACAddr macaddr_cmdline;
> int i;
>
> if (n->net_conf.mtu) {
> @@ -3692,6 +3722,7 @@ static void virtio_net_device_realize(DeviceState *dev,
> Error **errp)
> virtio_net_add_queue(n, 0);
>
> n->ctrl_vq = virtio_add_queue(vdev, 64, virtio_net_handle_ctrl);
> + memcpy(&macaddr_cmdline, &n->nic_conf.macaddr, sizeof(n->mac));
> qemu_macaddr_default_if_unset(&n->nic_conf.macaddr);
> memcpy(&n->mac[0], &n->nic_conf.macaddr, sizeof(n->mac));
> n->status = VIRTIO_NET_S_LINK_UP;
> @@ -3739,10 +3770,10 @@ static void virtio_net_device_realize(DeviceState
> *dev, Error **errp)
> nc->rxfilter_notify_enabled = 1;
>
> if (nc->peer && nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {
> - struct virtio_net_config netcfg = {};
> - memcpy(&netcfg.mac, &n->nic_conf.macaddr, ETH_ALEN);
> - vhost_net_set_config(get_vhost_net(nc->peer),
> - (uint8_t *)&netcfg, 0, ETH_ALEN, VHOST_SET_CONFIG_TYPE_FRONTEND);
> + if (!virtio_net_check_vdpa_mac(nc, n, &macaddr_cmdline, errp)) {
> + virtio_cleanup(vdev);
> + return;
> + }
> }
> QTAILQ_INIT(&n->rsc_chains);
> n->qdev = dev;
> --
> 2.45.0
>
Thanks
