Re: [PATCH v4 3/3] vhost-user: Fix the virtio features negotiation flaw

[Hyman Huang]

Thanks xiangdong for the testing and reporting, indeed, vhost-user 
negotiaion features saving only apply on dpdk interface, vhost-net and 
vdpa interface can be ingored. I'll apply it next version.

Yong

在 2022/12/14 16:15, Liuxiangdong 写道:
> QEMU will coredump when vm starts.
>
> Using command line:
>
> ./build/qemu-system-x86_64 \
>      -nodefaults \
>      -m 4G \
>      -machine pc-i440fx-4.1 \
>      -accel kvm \
>      -cpu host \
>      -smp 4 \
>      -device qemu-xhci -device usb-kbd -device usb-tablet \
>      -drive if=none,id=linux,file=test.img,format=raw \
>      -device virtio-blk-pci,drive=linux,disable-legacy=on \
>      -vnc :0 \
>      -d all \
>      -D %dlog \
>      -netdev tap,id=hostnet0,ifname=tap0,vhost=on,script=no,downscript=no \
>      -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:6b:0d:a1 \
>      -device cirrus-vga \
>      -msg timestamp=on
>
>
> And then:
> qemu-system-x86_64: ../hw/net/vhost_net.c:149: 
> vhost_net_save_acked_features: Assertion `nc->info->type == 
> NET_CLIENT_DRIVER_VHOST_USER' failed.
> Aborted (core dumped)
>
> Because it may be a tap or vdpa besides vhost user when function 
> "get_vhost_net(nc->peer)" returns ture.
>
>
>
>
>
> From: liuxiangdong <liuxiangdong5@huawei.com>
> Date: Mon, 5 Dec 2022 07:11:28 +0800
> Subject: [PATCH] vhost_net: keep acked_feature only for
>   NET_CLIENT_DRIVER_VHOST_USER
>
> Keep acked_features in NetVhostUserState up-to-date by function 
> vhost_net_save_acked_features
> in function virtio_net_set_features. But nc->peer->info->type maybe 
> NET_CLIENT_DRIVER_TAP or
> NET_CLIENT_DRIVER_VHOST_VDPA besides NET_CLIENT_DRIVER_VHOST_USER.
>
> Don't keep acked_features in other type now except 
> NET_CLIENT_DRIVER_VHOST_USER
>
> Fix:  vhost-user: Fix the virtio features negotiation flaw
>
> Signed-off-by: liuxiangdong <liuxiangdong5@huawei.com>
> ---
>   hw/net/vhost_net.c | 5 +++--
>   1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index a98575ffbc..bea053a742 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -143,8 +143,9 @@ uint64_t vhost_net_get_acked_features(VHostNetState 
> *net)
>
>   void vhost_net_save_acked_features(NetClientState *nc)
>   {
> -    assert(nc->info->type == NET_CLIENT_DRIVER_VHOST_USER);
> -    vhost_user_save_acked_features(nc);
> +    if (nc->info->type == NET_CLIENT_DRIVER_VHOST_USER) {
> +        vhost_user_save_acked_features(nc);
> +    }
>   }
>
>   static int vhost_net_get_fd(NetClientState *backend)

--
Best regard

Hyman Huang(黄勇)