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Date:   Thu, 17 Sep 2020 14:27:33 -0300
From:   Jason Gunthorpe <jgg@nvidia.com>
To:     Dave Jiang <dave.jiang@intel.com>
CC:     <vkoul@kernel.org>, <megha.dey@intel.com>, <maz@kernel.org>,
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Subject: Re: [PATCH v3 00/18] Add VFIO mediated device support and DEV-MSI
 support for the idxd driver
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On Thu, Sep 17, 2020 at 10:15:24AM -0700, Dave Jiang wrote:
> 
> 
> On 9/17/2020 8:06 AM, Jason Gunthorpe wrote:
> > On Tue, Sep 15, 2020 at 04:27:35PM -0700, Dave Jiang wrote:
> > >   drivers/dma/idxd/idxd.h                            |   65 +
> > >   drivers/dma/idxd/init.c                            |  100 ++
> > >   drivers/dma/idxd/irq.c                             |    6
> > >   drivers/dma/idxd/mdev.c                            | 1089 ++++++++++++++++++++
> > >   drivers/dma/idxd/mdev.h                            |  118 ++
> > 
> > It is common that drivers of a subsystem will be under that
> > subsystem's directory tree. This allows the subsystem community to
> > manage pages related to their subsystem and it's drivers.
> > 
> > Should the mdev parts be moved there?
> 
> I personally don't have a preference. I'll defer to Alex or Kirti to provide
> that guidance. It may make certains things like dealing with dma fault
> regions and etc easier using vfio calls from vfio_pci_private.h later on for
> vSVM support. It also may be the better code review and maintenance domain
> and alleviate Vinod having to deal with that portion since it's not
> dmaengine domain.

That is the general reason, yes. Asking the dmaengine maintainer to
review mdev just means it won't be reviewed properly.

This mistake has been made before and I view it as a lesson from the
ARM SOC disaggregation.

Jason