Re: [PATCH 2/9] verbs: Add ibv_cmd_query_device_any()

[Gal Pressman <galpress@amazon.com>]

On 16/11/2020 22:23, Jason Gunthorpe wrote:
> This implements all the query_device command flows under a single call.
> 
> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
> ---
>  libibverbs/cmd_device.c      | 155 +++++++++++++++++++++++++++++++++++
>  libibverbs/driver.h          |   5 ++
>  libibverbs/libibverbs.map.in |   1 +
>  3 files changed, 161 insertions(+)
> 
> diff --git a/libibverbs/cmd_device.c b/libibverbs/cmd_device.c
> index 6c8e01ec9866a9..0019784ee779c1 100644
> --- a/libibverbs/cmd_device.c
> +++ b/libibverbs/cmd_device.c
> @@ -35,6 +35,7 @@
>  #include <stdlib.h>
>  #include <dirent.h>
>  #include <infiniband/cmd_write.h>
> +#include <util/util.h>
>  
>  #include <net/if.h>
>  
> @@ -516,3 +517,157 @@ ssize_t _ibv_query_gid_table(struct ibv_context *context,
>  
>  	return num_entries;
>  }
> +
> +int ibv_cmd_query_device_any(struct ibv_context *context,
> +			     const struct ibv_query_device_ex_input *input,
> +			     struct ibv_device_attr_ex *attr, size_t attr_size,
> +			     struct ib_uverbs_ex_query_device_resp *resp,
> +			     size_t *resp_size)
> +{
> +	struct ib_uverbs_ex_query_device_resp internal_resp;
> +	size_t internal_resp_size;
> +	int err;
> +
> +	if (input && input->comp_mask)
> +		return EINVAL;
> +	if (attr_size < sizeof(attr->orig_attr))
> +		return EINVAL;
> +
> +	if (!resp) {
> +		resp = &internal_resp;
> +		internal_resp_size = sizeof(internal_resp);
> +		resp_size = &internal_resp_size;
> +	}
> +	memset(attr, 0, attr_size);
> +	memset(resp, 0, *resp_size);
> +
> +	if (attr_size > sizeof(attr->orig_attr)) {
> +		struct ibv_query_device_ex cmd = {};
> +
> +		err = execute_cmd_write_ex(context,
> +					   IB_USER_VERBS_EX_CMD_QUERY_DEVICE,
> +					   &cmd, sizeof(cmd), resp, *resp_size);
> +		if (err) {
> +			if (err != EOPNOTSUPP)

Are you sure about that?
I think older kernels return ENOSYS.