Re: [PATCH for-next] RDMA/efa: Add EFA query MR support

[Gal Pressman <gal.pressman@linux.dev>]

Hi Michael,

On 06/12/2023 0:16, Michael Margolin wrote:
> @@ -432,6 +435,9 @@ static int efa_ib_device_add(struct efa_dev *dev)
>  
>  	ib_set_device_ops(&dev->ibdev, &efa_dev_ops);
>  
> +	if (IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS))

EFA depends on CONFIG_INFINIBAND_USER_ACCESS:

      7 config INFINIBAND_EFA
      8         tristate "Amazon Elastic Fabric Adapter (EFA) support"
      9         depends on PCI_MSI && 64BIT && !CPU_BIG_ENDIAN
     10         depends on INFINIBAND_USER_ACCESS

> +		dev->ibdev.driver_def = efa_uapi_defs;
> +
>  	err = ib_register_device(&dev->ibdev, "efa_%d", &pdev->dev);
>  	if (err)
>  		goto err_destroy_eqs;
> diff --git a/drivers/infiniband/hw/efa/efa_verbs.c b/drivers/infiniband/hw/efa/efa_verbs.c
> index 0f8ca99d0827..d81904f4b876 100644
> --- a/drivers/infiniband/hw/efa/efa_verbs.c
> +++ b/drivers/infiniband/hw/efa/efa_verbs.c
> @@ -13,6 +13,9 @@
>  #include <rdma/ib_user_verbs.h>
>  #include <rdma/ib_verbs.h>
>  #include <rdma/uverbs_ioctl.h>
> +#define UVERBS_MODULE_NAME efa_ib
> +#include <rdma/uverbs_named_ioctl.h>
> +#include <rdma/ib_user_ioctl_cmds.h>
>  
>  #include "efa.h"
>  #include "efa_io_defs.h"
> @@ -1653,6 +1656,9 @@ static int efa_register_mr(struct ib_pd *ibpd, struct efa_mr *mr, u64 start,
>  	mr->ibmr.lkey = result.l_key;
>  	mr->ibmr.rkey = result.r_key;
>  	mr->ibmr.length = length;
> +	mr->recv_pci_bus_id = result.recv_pci_bus_id;
> +	mr->rdma_read_pci_bus_id = result.rdma_read_pci_bus_id;
> +	mr->rdma_recv_pci_bus_id = result.rdma_recv_pci_bus_id;

Why is a query_mr ioctl better than returning this data through udata on
MR creation?