Re: [v4] virtio-gpu: use consistent error checking style for virtio_gpu_create_mapping_iov

[Markus Armbruster <armbru@redhat.com>]

Honglei Huang <honghuan@amd.com> writes:

> Fix error handling logic in virgl_cmd_resource_create_blob and improve
> consistency across the codebase.
>
> virtio_gpu_create_mapping_iov() returns 0 on success and negative values
> on error, but the original code was inconsistently checking for error
> conditions using different patterns.
>
> Change all virtio_gpu_create_mapping_iov() error checks to use consistent
> 'ret < 0' or 'ret >= 0' patterns, following the preferred QEMU coding
> convention for functions that return 0 on success and negative on error.
> This makes the return value convention immediately clear to code readers
> without needing to look up the function definition.
>
> Updated locations:
> - hw/display/virtio-gpu-virgl.c: virgl_cmd_resource_create_blob()
> - hw/display/virtio-gpu-virgl.c: virgl_cmd_resource_attach_backing()
> - hw/display/virtio-gpu.c: virtio_gpu_resource_create_blob()
> - hw/display/virtio-gpu.c: virtio_gpu_resource_attach_backing()
> - hw/display/virtio-gpu-rutabaga.c: rutabaga_cmd_attach_backing()
> - hw/display/virtio-gpu-rutabaga.c: rutabaga_cmd_resource_create_blob()
>
> Changes since v3:
> - Extended consistency improvements to virtio-gpu-rutabaga.c
> - Changed CHECK(!ret) to CHECK(ret >= 0) and CHECK(!result) to
>   CHECK(result >= 0) in rutabaga functions for consistency
> - Now covers all virtio-gpu files that use virtio_gpu_create_mapping_iov()
>
> Changes since v2:
> - Use 'if (ret < 0)' instead of 'if (ret != 0)' following maintainer's
>   feedback on preferred QEMU coding style for error checking functions
>   that return 0 on success and negative on error
> - Updated all similar usages across virtio-gpu files for consistency
> - Expanded scope from single function fix to codebase-wide style consistency
>
> Fixes: 7c092f17ccee ("virtio-gpu: Handle resource blob commands")
> Signed-off-by: Honglei Huang <honghuan@amd.com>
> Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>

Reviewed-by: Markus Armbruster <armbru@redhat.com>