Kernel KVM virtualization development
 help / color / mirror / Atom feed
From: Jason Gunthorpe <jgg@nvidia.com>
To: "Cao, Yahui" <yahui.cao@intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
	"Liu, Lingyu" <lingyu.liu@intel.com>,
	"intel-wired-lan@lists.osuosl.org"
	<intel-wired-lan@lists.osuosl.org>,
	"Liu, Yi L" <yi.l.liu@intel.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [Intel-wired-lan] [PATCH iwl-next V2 10/15] ice: save and restore TX queue head
Date: Mon, 3 Jul 2023 18:03:51 -0300	[thread overview]
Message-ID: <ZKM3t7FDH09zeJg1@nvidia.com> (raw)
In-Reply-To: <ba8ccf89-6045-4fd7-02b9-308d50226251@intel.com>

On Mon, Jul 03, 2023 at 01:27:51PM +0800, Cao, Yahui wrote:

> > > You can't call VFIO functions from a netdev driver. All this code
> > > needs to be moved into the varient driver.
> 
> Will move vfio_dma_rw() into vfio driver and passing callback function into
> netdev driver

Please make proper layers, you should not need to stitch your driver
together with weird function pointers. 
 
> > > We also don't have any guarentees defined for the VFIO protocol about
> > > what state the vIOMMU will be in prior to reaching RUNNING.
> > This is a good point. Actually it's not just a gap on vIOMMU. it's kind
> > of a dependency on IOMMUFD no matter the IOAS which the migrated
> > device is currently attached to is GPA or GIOVA. The device state can
> > be restored only after IOMMUFD is fully recovered and the device is
> > re-attached to the IOAS.
> > 
> > Need a way for migration driver to advocate such dependency to the user. 
> 
> Since this part is new to me, may need further guidance on how to resolve
> the dependency from you and other community experts.

Personally I'm quite uncomfortable with a driver that tries to work
this way, I'm not sure we should encourage this. Can Intel really be
convincing that this is safe and correct?

Jason

  reply	other threads:[~2023-07-03 21:03 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20230621091112.44945-1-lingyu.liu@intel.com>
     [not found] ` <20230621091112.44945-11-lingyu.liu@intel.com>
     [not found]   ` <ZJMLHSq9rjGIVS4V@nvidia.com>
2023-06-27  6:55     ` [Intel-wired-lan] [PATCH iwl-next V2 10/15] ice: save and restore TX queue head Tian, Kevin
2023-07-03  5:27       ` Cao, Yahui
2023-07-03 21:03         ` Jason Gunthorpe [this message]
2023-07-04  7:35           ` Tian, Kevin

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=ZKM3t7FDH09zeJg1@nvidia.com \
    --to=jgg@nvidia.com \
    --cc=intel-wired-lan@lists.osuosl.org \
    --cc=kevin.tian@intel.com \
    --cc=kvm@vger.kernel.org \
    --cc=lingyu.liu@intel.com \
    --cc=yahui.cao@intel.com \
    --cc=yi.l.liu@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