From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: Alejandro Lucero <alejandro.lucero@netronome.com>,
Ferruh Yigit <ferruh.yigit@intel.com>
Cc: dev <dev@dpdk.org>
Subject: Re: [dpdk-dev] [PATCH] bus/pci: set intr_handle type for secondary processes
Date: Fri, 19 Oct 2018 09:02:43 +0100 [thread overview]
Message-ID: <db49b85a-2d3b-8f12-2977-73d71a6fe774@intel.com> (raw)
In-Reply-To: <CAD+H993Ky5V3uMgYePidu9H8bCzPx-6vM+PC14uhooh5A4WUaw@mail.gmail.com>
On 18-Oct-18 5:41 PM, Alejandro Lucero wrote:
>
>
> On Thu, Oct 18, 2018 at 5:26 PM Burakov, Anatoly
> <anatoly.burakov@intel.com <mailto:anatoly.burakov@intel.com>> wrote:
>
> On 27-Sep-18 1:30 PM, Alejandro Lucero wrote:
> > Invoking rte_pci_read/write_config functions requires device with
> > a intr_handle type for using VFIO or UIO driver related functions.
> >
> > Secondary processes rely on primary processes for device
> initialization
> > so they do not usually require using these functions. However,
> some PMDs,
> > like NFP PMD, require using these functions even for secondary
> processes.
> >
> > Signed-off-by: Alejandro Lucero <alejandro.lucero@netronome.com
> <mailto:alejandro.lucero@netronome.com>>
> > ---
>
> Hi Alejandro,
>
> I’m curious of consequences of setting intr handle to a valid value
> when
> we don’t have an interrupt thread. Something may try to use it
> (although
> I couldn’t find any such usage).
>
>
> The point is secondary processes do not deal with interrupts so I assume
> setting the type does not change anything but it allows to use PCI
> read/write functions by secondary processes.
>
> PCI config read really uses intr handle type to discover userspace
> driver type – this seems ever so slightly wrong, and looks like
> something that should be part of rte_device somewhere, independent of
> interrupt types. Do we have any other alternative to do the same thing
> (i.e. know what userspace driver is used for a particular PCI device)?
>
>
> I agree current way not being specially good.
>
> Your comment has reminded me there is another way: just using the kdrv
> field from the rte_pci_device struct. I have code using that field for
> doing a different thing in the NFP PMD depending on the driver in use,
> UIO or VFIO. So I think a better patch would be just to modify those pci
> functions for using kdrv field instead.
>
> Adding Ferruh in the thread for commenting on this potential change.
>
I definitely think the way you describe would be a better way to fix
this (i.e. use kdrv in PCI config functions rather than intr handle type).
--
Thanks,
Anatoly
next prev parent reply other threads:[~2018-10-19 8:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-27 12:30 Alejandro Lucero
2018-10-18 16:26 ` Burakov, Anatoly
2018-10-18 16:41 ` Alejandro Lucero
2018-10-19 8:02 ` Burakov, Anatoly [this message]
2018-10-19 14:57 ` Alejandro Lucero
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=db49b85a-2d3b-8f12-2977-73d71a6fe774@intel.com \
--to=anatoly.burakov@intel.com \
--cc=alejandro.lucero@netronome.com \
--cc=dev@dpdk.org \
--cc=ferruh.yigit@intel.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).