From: David Marchand <david.marchand@redhat.com>
To: Tiwei Bie <tiwei.bie@intel.com>
Cc: dev <dev@dpdk.org>, "Burakov, Anatoly" <anatoly.burakov@intel.com>
Subject: Re: [dpdk-dev] [RFC PATCH] bus/pci: avoid depending on private value in kernel source
Date: Wed, 3 Jul 2019 10:01:44 +0200 [thread overview]
Message-ID: <CAJFAV8ySVzimaOVWHH7APhG2Vx=8BYkofZqw5oVhExsmj069JA@mail.gmail.com> (raw)
In-Reply-To: <20190703075657.GA20458@___>
On Wed, Jul 3, 2019 at 9:58 AM Tiwei Bie <tiwei.bie@intel.com> wrote:
> On Wed, Jul 03, 2019 at 09:36:26AM +0200, David Marchand wrote:
> > On Wed, Jul 3, 2019 at 9:35 AM Tiwei Bie <tiwei.bie@intel.com> wrote:
> >
> > Hi David,
> >
> > On Wed, Jul 03, 2019 at 09:02:59AM +0200, David Marchand wrote:
> > > Hello,
> > >
> > > On Wed, Jul 3, 2019 at 7:47 AM Tiwei Bie <tiwei.bie@intel.com>
> wrote:
> > >
> > > The value 40 used in VFIO_GET_REGION_ADDR() is a private value
> > > (VFIO_PCI_OFFSET_SHIFT) defined in Linux kernel source [1]. It
> > > is not part of VFIO API, and we should not depend on it.
> > >
> > > [1]
> https://github.com/torvalds/linux/blob/6fbc7275c7a9/drivers/vfio/
> > pci/
> > > vfio_pci_private.h#L19
> > >
> > >
> > >
> > > I did not follow linux kernel changes, is there something that
> would
> > change
> > > this offset?
> > > It looks like a cleanup (did not look into the details yet), do we
> need
> > this
> > > now?
> >
> > In VFIO/mdev [1], the offset can be something different. It depends
> > on the parent device. It's not just a cleanup. It's a preparation
> > for the mdev support in DPDK.
> >
> > [1] https://github.com/torvalds/linux/blob/master/Documentation/
> > vfio-mediated-device.txt
> >
> >
> >
> > Ok, thanks.
> > So we can wait for mdev to be ready before working on this.
>
> What do you mean by "mdev to be ready"? RFC ready? I don't see
> anything blocking the discussion on this now.
>
> PS. I already sent a RFC series of the mdev support in DPDK
> to the mailing list 3 month ago.
>
If you need it and the mdev support has been posted already, why not send a
n+1 patchset with this patch in it?
This patch alone looked odd to me.
I want to understand if this is a fix we need now or something that can
wait.
We have a really large backlog.
--
David Marchand
next prev parent reply other threads:[~2019-07-03 8:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-03 5:45 Tiwei Bie
2019-07-03 7:02 ` David Marchand
2019-07-03 7:33 ` Tiwei Bie
2019-07-03 7:36 ` David Marchand
2019-07-03 7:56 ` Tiwei Bie
2019-07-03 8:01 ` David Marchand [this message]
2019-07-03 8:15 ` Tiwei Bie
2019-07-03 8:26 ` David Marchand
2019-07-03 8:59 ` Tiwei Bie
2019-07-03 9:10 ` David Marchand
2019-07-03 9:25 ` Tiwei Bie
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