kvm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Alex Williamson <alex.williamson@redhat.com>
To: Jason Gunthorpe <jgg@nvidia.com>
Cc: Max Gurtovoy <mgurtovoy@nvidia.com>,
	cohuck@redhat.com, kvm@vger.kernel.org,
	linux-kernel@vger.kernel.org, aviadye@nvidia.com,
	oren@nvidia.com, shahafs@nvidia.com, parav@nvidia.com,
	artemp@nvidia.com, kwankhede@nvidia.com, ACurrid@nvidia.com,
	cjia@nvidia.com, yishaih@nvidia.com, kevin.tian@intel.com,
	hch@infradead.org, targupta@nvidia.com,
	shameerali.kolothum.thodi@huawei.com, liulongfang@huawei.com,
	yan.y.zhao@intel.com
Subject: Re: [PATCH 09/11] PCI: add matching checks for driver_override binding
Date: Tue, 15 Jun 2021 15:59:00 -0600	[thread overview]
Message-ID: <20210615155900.51f09c15.alex.williamson@redhat.com> (raw)
In-Reply-To: <20210615204216.GY1002214@nvidia.com>

On Tue, 15 Jun 2021 17:42:16 -0300
Jason Gunthorpe <jgg@nvidia.com> wrote:

> On Tue, Jun 15, 2021 at 10:20:49AM -0600, Alex Williamson wrote:
> > On Tue, 15 Jun 2021 12:04:58 -0300
> > Jason Gunthorpe <jgg@nvidia.com> wrote:
> >   
> > > On Tue, Jun 15, 2021 at 09:00:29AM -0600, Alex Williamson wrote:
> > >   
> > > > "vfio" override in PCI-core plays out for other override types.  Also I
> > > > don't think dynamic IDs should be handled uniquely, new_id_store()
> > > > should gain support for flags and userspace should be able to add new
> > > > dynamic ID with override-only matches to the table.  Thanks,    
> > > 
> > > Why? Once all the enforcement is stripped out the only purpose of the
> > > new flag is to signal a different prepration of modules.alias - which
> > > won't happen for the new_id path anyhow  
> > 
> > Because new_id allows the admin to insert a new pci_device_id which has
> > been extended to include a flags field and intentionally handling
> > dynamic IDs differently from static IDs seems like generally a bad
> > thing.    
> 
> I'd agree with you if there was a functional difference at runtime,
> but since that was all removed, I don't think we should touch new_id.
> 
> This ends up effectively being only a kbuild related patch that
> changes how modules.alias is built.

But it wasn't all removed.  The proposal had:

 a) Short circuit the dynamic ID match
 b) Fail a driver-override-only match without a driver_override
 c) Fail a non-driver-override-only match with a driver_override

Max is only proposing removing c).

b) alone is a functional, runtime difference.  As per my previous
example, think about using it as effectively an anti-match.  Userspace
can create dynamic entries that will be matched before static entries
that can demote a driver to not be able to bind to a device
automatically.  That's functional and useful, I can't think of any
other way we have to effectively remove a static match entry from a
driver.  Thanks,

Alex


  reply	other threads:[~2021-06-15 21:59 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-03 16:07 [RFC PATCH v4 00/11] Introduce vfio-pci-core subsystem Max Gurtovoy
2021-06-03 16:07 ` [PATCH 01/11] vfio-pci: rename vfio_pci.c to vfio_pci_core.c Max Gurtovoy
2021-06-03 16:08 ` [PATCH 02/11] vfio-pci: rename vfio_pci_private.h to vfio_pci_core.h Max Gurtovoy
2021-06-03 16:08 ` [PATCH 03/11] vfio-pci: rename vfio_pci_device to vfio_pci_core_device Max Gurtovoy
2021-06-03 16:08 ` [PATCH 04/11] vfio-pci: rename ops functions to fit core namings Max Gurtovoy
2021-06-03 16:08 ` [PATCH 05/11] vfio-pci: include vfio header in vfio_pci_core.h Max Gurtovoy
2021-06-03 16:08 ` [PATCH 06/11] vfio-pci: introduce vfio_pci.c Max Gurtovoy
2021-06-03 16:08 ` [PATCH 07/11] vfio-pci: move igd initialization to vfio_pci.c Max Gurtovoy
2021-06-03 16:08 ` [PATCH 08/11] PCI: add flags field to pci_device_id structure Max Gurtovoy
2021-06-03 16:08 ` [PATCH 09/11] PCI: add matching checks for driver_override binding Max Gurtovoy
2021-06-08 21:26   ` Alex Williamson
2021-06-08 22:45     ` Jason Gunthorpe
2021-06-09  1:27       ` Alex Williamson
2021-06-09  9:26         ` Max Gurtovoy
2021-06-13  8:19         ` Max Gurtovoy
2021-06-14  5:40           ` Christoph Hellwig
2021-06-14  8:18             ` Max Gurtovoy
2021-06-14 15:27               ` Christoph Hellwig
2021-06-14 16:01                 ` Jason Gunthorpe
2021-06-14 16:15                   ` Christoph Hellwig
2021-06-14 16:33                     ` Jason Gunthorpe
2021-06-14 18:42           ` Alex Williamson
2021-06-14 23:12             ` Max Gurtovoy
2021-06-15 15:00               ` Alex Williamson
2021-06-15 15:04                 ` Jason Gunthorpe
2021-06-15 16:20                   ` Alex Williamson
2021-06-15 20:42                     ` Jason Gunthorpe
2021-06-15 21:59                       ` Alex Williamson [this message]
2021-06-15 23:00                         ` Jason Gunthorpe
2021-06-15 23:22                           ` Alex Williamson
2021-06-15 23:32                             ` Jason Gunthorpe
2021-06-16  0:22                               ` Alex Williamson
2021-06-16  0:34                                 ` Jason Gunthorpe
2021-06-16 23:28                                   ` Max Gurtovoy
2021-06-16 23:33                                     ` Jason Gunthorpe
2021-06-16 23:42                                       ` Max Gurtovoy
2021-06-16 23:44                                         ` Jason Gunthorpe
2021-06-16 23:51                                           ` Max Gurtovoy
2021-06-16 23:56                                             ` Jason Gunthorpe
2021-06-20 14:46                                               ` Max Gurtovoy
2021-06-03 16:08 ` [PATCH 10/11] vfio-pci: introduce vfio_pci_core subsystem driver Max Gurtovoy
2021-06-08 21:26   ` Alex Williamson
2021-06-09  9:29     ` Max Gurtovoy
2021-06-03 16:08 ` [PATCH 11/11] mlx5-vfio-pci: add new vfio_pci driver for mlx5 devices Max Gurtovoy
2021-07-30  7:53 ` [RFC PATCH v4 00/11] Introduce vfio-pci-core subsystem Shameerali Kolothum Thodi
2021-07-30 11:55   ` Jason Gunthorpe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210615155900.51f09c15.alex.williamson@redhat.com \
    --to=alex.williamson@redhat.com \
    --cc=ACurrid@nvidia.com \
    --cc=artemp@nvidia.com \
    --cc=aviadye@nvidia.com \
    --cc=cjia@nvidia.com \
    --cc=cohuck@redhat.com \
    --cc=hch@infradead.org \
    --cc=jgg@nvidia.com \
    --cc=kevin.tian@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=kwankhede@nvidia.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=liulongfang@huawei.com \
    --cc=mgurtovoy@nvidia.com \
    --cc=oren@nvidia.com \
    --cc=parav@nvidia.com \
    --cc=shahafs@nvidia.com \
    --cc=shameerali.kolothum.thodi@huawei.com \
    --cc=targupta@nvidia.com \
    --cc=yan.y.zhao@intel.com \
    --cc=yishaih@nvidia.com \
    --subject='Re: [PATCH 09/11] PCI: add matching checks for driver_override binding' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
on how to clone and mirror all data and code used for this inbox