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

[Thomas Huth <thuth@redhat.com>]

On 11/10/2023 17.38, Stefan Hajnoczi wrote:
> 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.

That pvrdma patch unfortunately does not work with Clang, see also:

 
https://lore.kernel.org/qemu-devel/781330fc-85b3-4ef1-8f07-1cc5fc5e4ad2@redhat.com/T/#t

  Thomas