Re: [PULL 02/13] hw/rdma/vmw/pvrdma_cmd: Use correct struct in query_port()

[Stefan Hajnoczi]

On Wed, 11 Oct 2023 at 07:23, Michael Tokarev <mjt@tls.msk.ru> wrote:
>
> From: Peter Maydell <peter.maydell@linaro.org>
>
> In query_port() we pass the address of a local pvrdma_port_attr
> struct to the rdma_query_backend_port() function.  Unfortunately,
> rdma_backend_query_port() wants a pointer to a struct ibv_port_attr,
> and the two are not the same length.
>
> Coverity spotted this (CID 1507146): pvrdma_port_attr is 48 bytes
> long, and ibv_port_attr is 52 bytes, because it has a few extra
> fields at the end.
>
> Fortunately, all we do with the attrs struct after the call is to
> read a few specific fields out of it which are all at the same
> offsets in both structs, so we can simply make the local variable the
> correct type.  This also lets us drop the cast (which should have
> been a bit of a warning flag that we were doing something wrong
> here).
>
> Cc: qemu-stable@nongnu.org
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> Reviewed-by: Thomas Huth <thuth@redhat.com>
> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
> ---
>  hw/rdma/vmw/pvrdma_cmd.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)

The following CI failure has occurred:

../hw/rdma/vmw/pvrdma_cmd.c:144:59: error: implicit conversion from
enumeration type 'enum ibv_port_state' to different enumeration type
'enum pvrdma_port_state' [-Werror,-Wenum-conversion]
resp->attrs.state = dev->func0->device_active ? attrs.state :
~ ~~~~~~^~~~~
../hw/rdma/vmw/pvrdma_cmd.c:146:33: error: implicit conversion from
enumeration type 'enum ibv_mtu' to different enumeration type 'enum
pvrdma_mtu' [-Werror,-Wenum-conversion]
resp->attrs.max_mtu = attrs.max_mtu;
~ ~~~~~~^~~~~~~
../hw/rdma/vmw/pvrdma_cmd.c:147:36: error: implicit conversion from
enumeration type 'enum ibv_mtu' to different enumeration type 'enum
pvrdma_mtu' [-Werror,-Wenum-conversion]
resp->attrs.active_mtu = attrs.active_mtu;
~ ~~~~~~^~~~~~~~~~

https://gitlab.com/qemu-project/qemu/-/jobs/5270666420

Please take a look.

Thanks,
Stefan

>
> diff --git a/hw/rdma/vmw/pvrdma_cmd.c b/hw/rdma/vmw/pvrdma_cmd.c
> index c6ed025982..d31c187593 100644
> --- a/hw/rdma/vmw/pvrdma_cmd.c
> +++ b/hw/rdma/vmw/pvrdma_cmd.c
> @@ -129,14 +129,13 @@ static int query_port(PVRDMADev *dev, union 
> pvrdma_cmd_req *req,
>  {
>      struct pvrdma_cmd_query_port *cmd = &req->query_port;
>      struct pvrdma_cmd_query_port_resp *resp = &rsp->query_port_resp;
> -    struct pvrdma_port_attr attrs = {};
> +    struct ibv_port_attr attrs = {};
>
>      if (cmd->port_num > MAX_PORTS) {
>          return -EINVAL;
>      }
>
> -    if (rdma_backend_query_port(&dev->backend_dev,
> -                                (struct ibv_port_attr *)&attrs)) {
> +    if (rdma_backend_query_port(&dev->backend_dev, &attrs)) {
>          return -ENOMEM;
>      }
>
> --
> 2.39.2
>
>