public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: Will Deacon <will.deacon@arm.com>
To: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	Robin Murphy <Robin.Murphy@arm.com>,
	Lorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>,
	Marc Zyngier <Marc.Zyngier@arm.com>,
	Punit Agrawal <Punit.Agrawal@arm.com>
Subject: Re: [PATCH v3 kvmtool 00/11] Add PCI passthrough support with VFIO
Date: Wed, 15 Nov 2017 18:01:07 +0000	[thread overview]
Message-ID: <20171115180106.GP19071@arm.com> (raw)
In-Reply-To: <955bf02c-6305-9656-f095-378a8c3a30ff@arm.com>

On Wed, Nov 01, 2017 at 05:16:27PM +0000, Jean-Philippe Brucker wrote:
> On 31/10/17 21:17, Alex Williamson wrote:
> > On Tue, 31 Oct 2017 19:14:38 +0000
> > Jean-Philippe Brucker <jean-philippe.brucker@arm.com> wrote:
> > 
> >> This series implements PCI pass-through using VFIO in kvmtool. We
> >> introduce a new parameter to lkvm run, --vfio-group, that takes an IOMMU
> >> group number as argument, and passes all devices in the group to the
> >> guest.
> > 
> > Is there a discussion somewhere that provides the reasoning behind this
> > whole group choice?  It seems very limiting since there exist plenty of
> > examples of groups where endpoints and interconnects are both included,
> > but only the former is compatible with vfio-pci in the host.  It's
> > currently impossible to open all of these devices.  There's also no
> > opportunity to create different device topologies with this
> > specification (ex. multi-function vs separate devices vs downstream of
> > switches/bridges/root-ports).  It seems like a strange starting point
> > to me, but you probably already guessed that based on the QEMU
> > implementation.
> 
> I don't think it had come up yet. My guess is that it was simpler to do
> whole groups when writing the prototype (by Will) and I didn't think much
> about changing the interface when I took over. I agree that the QEMU
> parameter format is a lot better.
> 
> So maybe we should have "--vfio-pci [<domain>:]<bus>:<dev>.<fn>", and
> later "--vfio-platform <name.address>" etc.

That certainly looks much more expressive to me.

Will

      reply	other threads:[~2017-11-15 18:00 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-10-31 19:14 [PATCH v3 kvmtool 00/11] Add PCI passthrough support with VFIO Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 01/11] pci: add config operations callbacks on the PCI header Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 02/11] pci: allow to specify IRQ type for PCI devices Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 03/11] irq: add irqfd helpers Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 04/11] Extend memory bank API with memory types Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 05/11] pci: add capability helpers Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 06/11] Import VFIO headers Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 07/11] Add PCI device passthrough using VFIO Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 08/11] vfio-pci: add MSI-X support Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 09/11] vfio-pci: add MSI support Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 10/11] Introduce reserved memory regions Jean-Philippe Brucker
2017-10-31 19:14 ` [PATCH v3 kvmtool 11/11] vfio: check reserved regions before mapping DMA Jean-Philippe Brucker
2017-10-31 21:17 ` [PATCH v3 kvmtool 00/11] Add PCI passthrough support with VFIO Alex Williamson
2017-11-01 17:16   ` Jean-Philippe Brucker
2017-11-15 18:01     ` Will Deacon [this message]

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=20171115180106.GP19071@arm.com \
    --to=will.deacon@arm.com \
    --cc=Lorenzo.Pieralisi@arm.com \
    --cc=Marc.Zyngier@arm.com \
    --cc=Punit.Agrawal@arm.com \
    --cc=Robin.Murphy@arm.com \
    --cc=alex.williamson@redhat.com \
    --cc=jean-philippe.brucker@arm.com \
    --cc=kvm@vger.kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox