All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: Greg Kurz <groug@kaod.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Christoph Hellwig <hch@lst.de>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Alex Williamson <alex.williamson@redhat.com>,
	kvm@vger.kernel.org, David Airlie <airlied@linux.ie>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Paul Mackerras <paulus@samba.org>,
	linux-api@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	qemu-devel@nongnu.org, qemu-ppc@nongnu.org
Subject: Re: remove the nvlink2 pci_vfio subdriver v2
Date: Tue, 4 May 2021 12:53:27 -0300	[thread overview]
Message-ID: <20210504155327.GA94750@nvidia.com> (raw)
In-Reply-To: <YJFY7NjEBtCSlJHw@phenom.ffwll.local>

On Tue, May 04, 2021 at 04:23:40PM +0200, Daniel Vetter wrote:

> Just my 2cents from drm (where we deprecate old gunk uapi quite often):
> Imo it's best to keep the uapi headers as-is, but exchange the
> documentation with a big "this is removed, never use again" warning:

We in RDMA have been doing the opposite, the uapi headers are supposed
to reflect the current kernel. This helps make the kernel
understandable.

When userspace needs backwards compat to ABI that the current kernel
doesn't support then userspace has distinct copies of that information
in some compat location. It has happened a few times over the last 15
years.

We keep full copies of the current kernel headers in the userspace
source tree, when the kernel headers change in a compile incompatible
way we fix everything while updating to the new kernel headers.

> - it's good to know which uapi numbers (like parameter extensions or
>   whatever they are in this case) are defacto reserved, because there are
>   binaries (qemu in this) that have code acting on them out there.

Numbers and things get marked reserved or the like

> Anyway feel free to ignore since this might be different than drivers/gpu.

AFAIK drives/gpu has a lot wider userspace, rdma manages this OK
because we only have one library package that provides the user/kernel
interface.
 
Jason

WARNING: multiple messages have this Message-ID (diff)
From: Jason Gunthorpe <jgg@nvidia.com>
To: Greg Kurz <groug@kaod.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Christoph Hellwig <hch@lst.de>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Alex Williamson <alex.williamson@redhat.com>,
	kvm@vger.kernel.org, David Airlie <airlied@linux.ie>,
	linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
	Paul Mackerras <paulus@samba.org>,
	linux-api@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	qemu-devel@nongnu.org, qemu-ppc@nongnu.org
Subject: Re: remove the nvlink2 pci_vfio subdriver v2
Date: Tue, 4 May 2021 12:53:27 -0300	[thread overview]
Message-ID: <20210504155327.GA94750@nvidia.com> (raw)
In-Reply-To: <YJFY7NjEBtCSlJHw@phenom.ffwll.local>

On Tue, May 04, 2021 at 04:23:40PM +0200, Daniel Vetter wrote:

> Just my 2cents from drm (where we deprecate old gunk uapi quite often):
> Imo it's best to keep the uapi headers as-is, but exchange the
> documentation with a big "this is removed, never use again" warning:

We in RDMA have been doing the opposite, the uapi headers are supposed
to reflect the current kernel. This helps make the kernel
understandable.

When userspace needs backwards compat to ABI that the current kernel
doesn't support then userspace has distinct copies of that information
in some compat location. It has happened a few times over the last 15
years.

We keep full copies of the current kernel headers in the userspace
source tree, when the kernel headers change in a compile incompatible
way we fix everything while updating to the new kernel headers.

> - it's good to know which uapi numbers (like parameter extensions or
>   whatever they are in this case) are defacto reserved, because there are
>   binaries (qemu in this) that have code acting on them out there.

Numbers and things get marked reserved or the like

> Anyway feel free to ignore since this might be different than drivers/gpu.

AFAIK drives/gpu has a lot wider userspace, rdma manages this OK
because we only have one library package that provides the user/kernel
interface.
 
Jason
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel

  reply	other threads:[~2021-05-04 15:53 UTC|newest]

Thread overview: 62+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-26  6:13 remove the nvlink2 pci_vfio subdriver v2 Christoph Hellwig
2021-03-26  6:13 ` Christoph Hellwig
2021-03-26  6:13 ` [PATCH 1/2] vfio/pci: remove vfio_pci_nvlink2 Christoph Hellwig
2021-03-26  6:13   ` Christoph Hellwig
2021-04-06 19:38   ` Alex Williamson
2021-04-06 19:38     ` Alex Williamson
2021-04-06 19:38     ` Alex Williamson
2021-04-12  9:41     ` Michael Ellerman
2021-04-12  9:41       ` Michael Ellerman
2021-04-12  9:41       ` Michael Ellerman
2021-04-12 14:23       ` Alex Williamson
2021-04-12 14:23         ` Alex Williamson
2021-04-12 14:23         ` Alex Williamson
2021-04-22 13:49         ` Michael Ellerman
2021-04-22 13:49           ` Michael Ellerman
2021-04-22 13:49           ` Michael Ellerman
2021-04-22 13:52           ` Jason Gunthorpe
2021-04-22 13:52             ` Jason Gunthorpe
2021-04-22 13:52             ` Jason Gunthorpe
2021-03-26  6:13 ` [PATCH 2/2] powerpc/powernv: remove the nvlink support Christoph Hellwig
2021-03-26  6:13   ` Christoph Hellwig
2021-05-04 12:22 ` remove the nvlink2 pci_vfio subdriver v2 Greg Kurz
2021-05-04 12:22   ` Greg Kurz
2021-05-04 12:22   ` Greg Kurz
2021-05-04 12:22   ` Greg Kurz
2021-05-04 12:59   ` Greg Kroah-Hartman
2021-05-04 12:59     ` Greg Kroah-Hartman
2021-05-04 12:59     ` Greg Kroah-Hartman
2021-05-04 12:59     ` Greg Kroah-Hartman
2021-05-04 13:00     ` Christoph Hellwig
2021-05-04 13:00       ` Christoph Hellwig
2021-05-04 13:00       ` Christoph Hellwig
2021-05-04 13:08       ` Cornelia Huck
2021-05-04 13:08         ` Cornelia Huck
2021-05-04 13:08         ` Cornelia Huck
2021-05-04 13:08         ` Cornelia Huck
2021-05-04 13:20     ` Greg Kurz
2021-05-04 13:20       ` Greg Kurz
2021-05-04 13:20       ` Greg Kurz
2021-05-04 13:20       ` Greg Kurz
2021-05-04 13:30       ` Greg Kroah-Hartman
2021-05-04 13:30         ` Greg Kroah-Hartman
2021-05-04 13:30         ` Greg Kroah-Hartman
2021-05-04 13:30         ` Greg Kroah-Hartman
2021-05-04 14:11         ` Greg Kurz
2021-05-04 14:11           ` Greg Kurz
2021-05-04 14:11           ` Greg Kurz
2021-05-04 14:11           ` Greg Kurz
2021-05-04 15:33           ` Alex Williamson
2021-05-04 15:33             ` Alex Williamson
2021-05-04 15:33             ` Alex Williamson
2021-05-04 15:33             ` Alex Williamson
2021-05-04 14:23       ` Daniel Vetter
2021-05-04 14:23         ` Daniel Vetter
2021-05-04 14:23         ` Daniel Vetter
2021-05-04 14:23         ` Daniel Vetter
2021-05-04 15:53         ` Jason Gunthorpe [this message]
2021-05-04 15:53           ` Jason Gunthorpe
2021-05-04 16:30           ` Daniel Vetter
2021-05-04 16:30             ` Daniel Vetter
2021-05-04 16:30             ` Daniel Vetter
2021-05-04 16:30             ` Daniel Vetter

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=20210504155327.GA94750@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=airlied@linux.ie \
    --cc=alex.williamson@redhat.com \
    --cc=dri-devel@lists.freedesktop.org \
    --cc=gregkh@linuxfoundation.org \
    --cc=groug@kaod.org \
    --cc=hch@lst.de \
    --cc=kvm@vger.kernel.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=mpe@ellerman.id.au \
    --cc=paulus@samba.org \
    --cc=qemu-devel@nongnu.org \
    --cc=qemu-ppc@nongnu.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.