RE: [EXTERNAL] Re: [PATCH v2 1/5] uio: Add hv_vmbus_client driver

[Saurabh Singh Sengar <ssengar@microsoft.com>]

> -----Original Message-----
> From: Greg KH <gregkh@linuxfoundation.org>
> Sent: Tuesday, June 20, 2023 12:37 PM
> To: Saurabh Singh Sengar <ssengar@microsoft.com>
> Cc: Saurabh Sengar <ssengar@linux.microsoft.com>; KY Srinivasan
> <kys@microsoft.com>; Haiyang Zhang <haiyangz@microsoft.com>;
> wei.liu@kernel.org; Dexuan Cui <decui@microsoft.com>; Michael Kelley
> (LINUX) <mikelley@microsoft.com>; corbet@lwn.net; linux-
> kernel@vger.kernel.org; linux-hyperv@vger.kernel.org; linux-
> doc@vger.kernel.org
> Subject: Re: [EXTERNAL] Re: [PATCH v2 1/5] uio: Add hv_vmbus_client driver
> 
> On Tue, Jun 20, 2023 at 05:19:14AM +0000, Saurabh Singh Sengar wrote:
> > > And you are defining a "global" variable that can be modified by an
> > > individual sysfs file for ANY device bound to this driver, messing
> > > with the other device's ring buffer size, right?  This needs to be
> > > per-device, or explain in huge detail here why not.
> >
> > The global variable is expected to be set by userspace per device
> > before opening, the particular uio device. For a particular Hyper-v
> > device this value be same, and once device is open the ring buffer is
> > allocated and there won't be any impact afterwards changing it. I can
> elaborate more of this in sysfs documentation.
> 
> That's totally confusing, please make this per-device properly, as you will find
> out when you try to document it, what you are describing is unlike any other
> per-device interface we have.

Ok, will make this per device. Thanks.

- Saurabh

> 
> greg k-h