Re: [PATCH v6 2/4] vdpa: Allow for printing negotiated features of a device

[Stephen Hemminger <stephen@networkplumber.org>]

On Sun, 13 Mar 2022 14:46:27 +0200
Eli Cohen <elic@nvidia.com> wrote:

> When reading the configuration of a vdpa device, check if the
> VDPA_ATTR_DEV_NEGOTIATED_FEATURES is available. If it is, parse the
> feature bits and print a string representation of each of the feature
> bits.
> 
> We keep the strings in two different arrays. One for net device related
> devices and one for generic feature bits.
> 
> In this patch we parse only net device specific features. Support for
> other devices can be added later. If the device queried is not a net
> device, we print its bit number only.
> 
> Examples:
> 1. Standard presentation
> $ vdpa dev config show vdpa-a
> vdpa-a: mac 00:00:00:00:88:88 link up link_announce false max_vq_pairs 2 mtu 9000
>   negotiated_features CSUM GUEST_CSUM MTU MAC HOST_TSO4 HOST_TSO6 STATUS \
> CTRL_VQ MQ CTRL_MAC_ADDR VERSION_1 ACCESS_PLATFORM
> 
> 2. json output
> $ vdpa -j dev config show vdpa-a
> {"config":{"vdpa-a":{"mac":"00:00:00:00:88:88","link":"up","link_announce":false,\
> "max_vq_pairs":2,"mtu":9000,"negotiated_features":["CSUM","GUEST_CSUM",\
> "MTU","MAC","HOST_TSO4","HOST_TSO6","STATUS","CTRL_VQ","MQ","CTRL_MAC_ADDR",\
> "VERSION_1","ACCESS_PLATFORM"]}}}
> 
> 3. Pretty json
> $ vdpa -jp dev config show vdpa-a
> {
>     "config": {
>         "vdpa-a": {
>             "mac": "00:00:00:00:88:88",
>             "link ": "up",
>             "link_announce ": false,
>             "max_vq_pairs": 2,
>             "mtu": 9000,
>             "negotiated_features": [
> "CSUM","GUEST_CSUM","MTU","MAC","HOST_TSO4","HOST_TSO6","STATUS","CTRL_VQ",\
> "MQ","CTRL_MAC_ADDR","VERSION_1","ACCESS_PLATFORM" ]
>         }
>     }
> }
> 
> Reviewed-by: Si-Wei Liu<si-wei.liu@oracle.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> Signed-off-by: Eli Cohen <elic@nvidia.com>
> ---

checkpatch says:

WARNING: braces {} are not necessary for any arm of this statement
#280: FILE: vdpa/vdpa.c:466:
+			if (feature_strs) {
[...]
+			} else {
[...]