Subject: Re: [PATCH V1 vhost-next] vdpa/mlx5: Make vdpa core driver a distinct module

From: "Michael S. Tsirkin" <[email-masked]>
Date: Tue, 29 Sep 2020 02:26:44 -0400

On Tue, Sep 29, 2020 at 09:20:26AM +0300, Eli Cohen wrote:
> On Mon, Sep 28, 2020 at 03:55:09PM -0400, Michael S. Tsirkin wrote:
> > On Thu, Sep 24, 2020 at 05:32:31PM +0300, Eli Cohen wrote:
> > > Change core vdpa functionality into a loadbale module such that upcoming
> > > block implementation will be able to use it.
> > > 
> > > Signed-off-by: Eli Cohen <[email-masked]>
> > 
> > Why don't we merge this patch together with the block module?
> > 
> 
> Since there are still not too many users of this driver, I would prefer
> to merge this as early as possible so pepole get used to the involved
> modules.
> 
> Anyways, I will send another version of the patch which makes use of
> 'select' instead of 'depends'.
> 
> Hope you agree to merge this.

Are you quite sure there will be a block driver though?
I'd like to avoid a situation in which we have infrastructure
in place but no users.

> > > ---
> > > V0 --> V1:
> > > Removed "default n" for configu options as 'n' is the default
> > > 
> > >  drivers/vdpa/Kconfig               |  8 +++-----
> > >  drivers/vdpa/Makefile              |  2 +-
> > >  drivers/vdpa/mlx5/Makefile         |  7 +++++--
> > >  drivers/vdpa/mlx5/core/core_main.c | 20 ++++++++++++++++++++
> > >  drivers/vdpa/mlx5/core/mr.c        |  3 +++
> > >  drivers/vdpa/mlx5/core/resources.c | 10 ++++++++++
> > >  6 files changed, 42 insertions(+), 8 deletions(-)
> > >  create mode 100644 drivers/vdpa/mlx5/core/core_main.c
> > > 
> > > diff --git a/drivers/vdpa/Kconfig b/drivers/vdpa/Kconfig
> > > index 4271c408103e..57ff6a7f7401 100644
> > > --- a/drivers/vdpa/Kconfig
> > > +++ b/drivers/vdpa/Kconfig
> > > @@ -29,10 +29,9 @@ config IFCVF
> > >  	  To compile this driver as a module, choose M here: the module will
> > >  	  be called ifcvf.
> > >  
> > > -config MLX5_VDPA
> > > -	bool "MLX5 VDPA support library for ConnectX devices"
> > > +config MLX5_VDPA_CORE
> > > +	tristate "MLX5 VDPA support library for ConnectX devices"
> > >  	depends on MLX5_CORE
> > > -	default n
> > >  	help
> > >  	  Support library for Mellanox VDPA drivers. Provides code that is
> > >  	  common for all types of VDPA drivers. The following drivers are planned:
> > > @@ -40,8 +39,7 @@ config MLX5_VDPA
> > >  
> > >  config MLX5_VDPA_NET
> > >  	tristate "vDPA driver for ConnectX devices"
> > > -	depends on MLX5_VDPA
> > > -	default n
> > > +	depends on MLX5_VDPA_CORE
> > >  	help
> > >  	  VDPA network driver for ConnectX6 and newer. Provides offloading
> > >  	  of virtio net datapath such that descriptors put on the ring will
> > > diff --git a/drivers/vdpa/Makefile b/drivers/vdpa/Makefile
> > > index d160e9b63a66..07353bbb9f8b 100644
> > > --- a/drivers/vdpa/Makefile
> > > +++ b/drivers/vdpa/Makefile
> > > @@ -2,4 +2,4 @@
> > >  obj-$(CONFIG_VDPA) += vdpa.o
> > >  obj-$(CONFIG_VDPA_SIM) += vdpa_sim/
> > >  obj-$(CONFIG_IFCVF)    += ifcvf/
> > > -obj-$(CONFIG_MLX5_VDPA) += mlx5/
> > > +obj-$(CONFIG_MLX5_VDPA_CORE) += mlx5/
> > > diff --git a/drivers/vdpa/mlx5/Makefile b/drivers/vdpa/mlx5/Makefile
> > > index 89a5bededc9f..9f50f7e8d889 100644
> > > --- a/drivers/vdpa/mlx5/Makefile
> > > +++ b/drivers/vdpa/mlx5/Makefile
> > > @@ -1,4 +1,7 @@
> > >  subdir-ccflags-y += -I$(srctree)/drivers/vdpa/mlx5/core
> > >  
> > > -obj-$(CONFIG_MLX5_VDPA_NET) += mlx5_vdpa.o
> > > -mlx5_vdpa-$(CONFIG_MLX5_VDPA_NET) += net/main.o net/mlx5_vnet.o core/resources.o core/mr.o
> > > +obj-$(CONFIG_MLX5_VDPA_CORE) += mlx5_vdpa_core.o
> > > +mlx5_vdpa_core-$(CONFIG_MLX5_VDPA_CORE) += core/resources.o core/mr.o core/core_main.o
> > > +
> > > +obj-$(CONFIG_MLX5_VDPA_NET) += mlx5_vdpa_net.o
> > > +mlx5_vdpa_net-$(CONFIG_MLX5_VDPA_NET) += net/main.o net/mlx5_vnet.o
> > > diff --git a/drivers/vdpa/mlx5/core/core_main.c b/drivers/vdpa/mlx5/core/core_main.c
> > > new file mode 100644
> > > index 000000000000..4b39b55f57ab
> > > --- /dev/null
> > > +++ b/drivers/vdpa/mlx5/core/core_main.c
> > > @@ -0,0 +1,20 @@
> > > +// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
> > > +/* Copyright (c) 2020 Mellanox Technologies Ltd. */
> > > +
> > > +#include <linux/module.h>
> > > +
> > > +MODULE_AUTHOR("Eli Cohen <[email-masked]>");
> > > +MODULE_DESCRIPTION("Mellanox VDPA core driver");
> > > +MODULE_LICENSE("Dual BSD/GPL");
> > > +
> > > +static int __init mlx5_vdpa_core_init(void)
> > > +{
> > > +	return 0;
> > > +}
> > > +
> > > +static void __exit mlx5_vdpa_core_exit(void)
> > > +{
> > > +}
> > > +
> > > +module_init(mlx5_vdpa_core_init);
> > > +module_exit(mlx5_vdpa_core_exit);
> > > diff --git a/drivers/vdpa/mlx5/core/mr.c b/drivers/vdpa/mlx5/core/mr.c
> > > index ef1c550f8266..c093eab6c714 100644
> > > --- a/drivers/vdpa/mlx5/core/mr.c
> > > +++ b/drivers/vdpa/mlx5/core/mr.c
> > > @@ -434,6 +434,7 @@ int mlx5_vdpa_create_mr(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *iotlb)
> > >  	mutex_unlock(&mr->mkey_mtx);
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_create_mr);
> > >  
> > >  void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev)
> > >  {
> > > @@ -456,6 +457,7 @@ void mlx5_vdpa_destroy_mr(struct mlx5_vdpa_dev *mvdev)
> > >  out:
> > >  	mutex_unlock(&mr->mkey_mtx);
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_destroy_mr);
> > >  
> > >  static bool map_empty(struct vhost_iotlb *iotlb)
> > >  {
> > > @@ -484,3 +486,4 @@ int mlx5_vdpa_handle_set_map(struct mlx5_vdpa_dev *mvdev, struct vhost_iotlb *io
> > >  
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_handle_set_map);
> > > diff --git a/drivers/vdpa/mlx5/core/resources.c b/drivers/vdpa/mlx5/core/resources.c
> > > index 96e6421c5d1c..89606a18e286 100644
> > > --- a/drivers/vdpa/mlx5/core/resources.c
> > > +++ b/drivers/vdpa/mlx5/core/resources.c
> > > @@ -98,6 +98,7 @@ int mlx5_vdpa_create_tis(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tisn)
> > >  
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_create_tis);
> > >  
> > >  void mlx5_vdpa_destroy_tis(struct mlx5_vdpa_dev *mvdev, u32 tisn)
> > >  {
> > > @@ -108,6 +109,7 @@ void mlx5_vdpa_destroy_tis(struct mlx5_vdpa_dev *mvdev, u32 tisn)
> > >  	MLX5_SET(destroy_tis_in, in, tisn, tisn);
> > >  	mlx5_cmd_exec_in(mvdev->mdev, destroy_tis, in);
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_destroy_tis);
> > >  
> > >  int mlx5_vdpa_create_rqt(struct mlx5_vdpa_dev *mvdev, void *in, int inlen, u32 *rqtn)
> > >  {
> > > @@ -121,6 +123,7 @@ int mlx5_vdpa_create_rqt(struct mlx5_vdpa_dev *mvdev, void *in, int inlen, u32 *
> > >  
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_create_rqt);
> > >  
> > >  void mlx5_vdpa_destroy_rqt(struct mlx5_vdpa_dev *mvdev, u32 rqtn)
> > >  {
> > > @@ -131,6 +134,7 @@ void mlx5_vdpa_destroy_rqt(struct mlx5_vdpa_dev *mvdev, u32 rqtn)
> > >  	MLX5_SET(destroy_rqt_in, in, rqtn, rqtn);
> > >  	mlx5_cmd_exec_in(mvdev->mdev, destroy_rqt, in);
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_destroy_rqt);
> > >  
> > >  int mlx5_vdpa_create_tir(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tirn)
> > >  {
> > > @@ -144,6 +148,7 @@ int mlx5_vdpa_create_tir(struct mlx5_vdpa_dev *mvdev, void *in, u32 *tirn)
> > >  
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_create_tir);
> > >  
> > >  void mlx5_vdpa_destroy_tir(struct mlx5_vdpa_dev *mvdev, u32 tirn)
> > >  {
> > > @@ -154,6 +159,7 @@ void mlx5_vdpa_destroy_tir(struct mlx5_vdpa_dev *mvdev, u32 tirn)
> > >  	MLX5_SET(destroy_tir_in, in, tirn, tirn);
> > >  	mlx5_cmd_exec_in(mvdev->mdev, destroy_tir, in);
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_destroy_tir);
> > >  
> > >  int mlx5_vdpa_alloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 *tdn)
> > >  {
> > > @@ -170,6 +176,7 @@ int mlx5_vdpa_alloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 *tdn)
> > >  
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_alloc_transport_domain);
> > >  
> > >  void mlx5_vdpa_dealloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 tdn)
> > >  {
> > > @@ -180,6 +187,7 @@ void mlx5_vdpa_dealloc_transport_domain(struct mlx5_vdpa_dev *mvdev, u32 tdn)
> > >  	MLX5_SET(dealloc_transport_domain_in, in, transport_domain, tdn);
> > >  	mlx5_cmd_exec_in(mvdev->mdev, dealloc_transport_domain, in);
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_dealloc_transport_domain);
> > >  
> > >  int mlx5_vdpa_create_mkey(struct mlx5_vdpa_dev *mvdev, struct mlx5_core_mkey *mkey, u32 *in,
> > >  			  int inlen)
> > > @@ -266,6 +274,7 @@ int mlx5_vdpa_alloc_resources(struct mlx5_vdpa_dev *mvdev)
> > >  	mutex_destroy(&mvdev->mr.mkey_mtx);
> > >  	return err;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_alloc_resources);
> > >  
> > >  void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev)
> > >  {
> > > @@ -282,3 +291,4 @@ void mlx5_vdpa_free_resources(struct mlx5_vdpa_dev *mvdev)
> > >  	mutex_destroy(&mvdev->mr.mkey_mtx);
> > >  	res->valid = false;
> > >  }
> > > +EXPORT_SYMBOL(mlx5_vdpa_free_resources);
> > > -- 
> > > 2.27.0
> >