RE: [net-next v2 1/1] virtual-bus: Implementation of Virtual Bus

["Ertman, David M" <david.m.ertman@intel.com>]

> -----Original Message-----
> From: Jason Wang <jasowang@redhat.com>
> Sent: Tuesday, November 19, 2019 12:05 AM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; Ertman, David M
> <david.m.ertman@intel.com>
> Cc: Greg KH <gregkh@linuxfoundation.org>; davem@davemloft.net;
> netdev@vger.kernel.org; linux-rdma@vger.kernel.org;
> nhorman@redhat.com; sassmann@redhat.com; jgg@ziepe.ca;
> parav@mellanox.com; Patil, Kiran <kiran.patil@intel.com>
> Subject: Re: [net-next v2 1/1] virtual-bus: Implementation of Virtual Bus
> 
> 
> On 2019/11/18 下午3:48, Greg KH wrote:
> > +Virtbus drivers
> > +~~~~~~~~~~~~~~~
> > +Virtbus drivers register with the virtual bus to be matched with
> > +virtbus devices.  They expect to be registered with a probe and
> > +remove callback, and also support shutdown, suspend, and resume
> > +callbacks.  They otherwise follow the standard driver behavior of
> > +having discovery and enumeration handled in the bus infrastructure.
> > +
> > +Virtbus drivers register themselves with the API entry point
> > +virtbus_drv_reg and unregister with virtbus_drv_unreg.
> > +
> > +Device Enumeration
> > +~~~~~~~~~~~~~~~~~~
> > +Enumeration is handled automatically by the bus infrastructure via
> > +the ida_simple methods.
> > +
> > +Device naming and driver binding
> > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > +The virtbus_device.dev.name is the canonical name for the device. It
> > +is built from two other parts:
> > +
> > +        - virtbus_device.name (also used for matching).
> > +        - virtbus_device.id (generated automatically from ida_simple
> > + calls)
> > +
> > +This allows for multiple virtbus_devices with the same name, which
> > +will all be matched to the same virtbus_driver. Driver binding is
> > +performed by the driver core, invoking driver probe() after finding a
> match between device and driver.
> > +
> > +Virtual Bus API entry points
> > +~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > +struct virtbus_device *virtbus_dev_alloc(const char *name, void
> > +*data)
> 
> 
> Hi:
> 
> Several questions about the name parameter here:
> 
> - If we want to have multiple types of device to be attached, some
> convention is needed to avoid confusion during the match. But if we had
> such one (e.g prefix or suffix), it basically another bus?
> - Who decides the name of this virtbus dev, is it under the control of
> userspace? If yes, a management interface is required.
> 
> Thanks
> 
This function has been removed from the API.  New patch set inbound
implementing changes that Parav suggested.

> 
> > +int virtbus_dev_register(struct virtbus_device *vdev) void
> > +virtbus_dev_unregister(struct virtbus_device *vdev) int
> > +virtbus_drv_register(struct virtbus_driver *vdrv, struct module
> > +*owner) void virtbus_drv_unregister(struct virtbus_driver *vdrv)