From: Alex Williamson <alex.williamson@redhat.com>
To: Jan Glauber <jan.glauber@caviumnetworks.com>
Cc: kvm@vger.kernel.org, david.daney@cavium.com,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
Robert Richter <robert.richter@cavium.com>,
Jon Masters <jcm@redhat.com>, Bjorn Helgaas <bhelgaas@google.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v2 3/3] vfio/pci: Don't probe devices that can't be reset
Date: Fri, 18 Aug 2017 08:12:51 -0600 [thread overview]
Message-ID: <20170818081251.2bbffe56@w520.home> (raw)
In-Reply-To: <20170818134231.GA3464@hc>
On Fri, 18 Aug 2017 15:42:31 +0200
Jan Glauber <jan.glauber@caviumnetworks.com> wrote:
> On Thu, Aug 17, 2017 at 07:00:17AM -0600, Alex Williamson wrote:
> > On Thu, 17 Aug 2017 10:14:23 +0200
> > Jan Glauber <jglauber@cavium.com> wrote:
> >
> > > If a PCI device supports neither function-level reset, nor slot
> > > or bus reset then refuse to probe it. A line is printed to inform
> > > the user.
> >
> > But that's not what this does, this requires that the device is on a
> > reset-able bus. This is a massive regression. With this we could no
> > longer assign devices on the root complex or any device which doesn't
> > return from bus reset and currently makes use of the NO_BUS_RESET flag
> > and works happily otherwise. Full NAK. Thanks,
>
> Looks like I missed the slot reset check. So how about this:
>
> if (pci_probe_reset_slot(pdev->slot) && pci_probe_reset_bus(pdev->bus)) {
> dev_warn(...);
> return -ENODEV;
> }
>
> Or am I still missing something here?
We don't require that a device is on a reset-able bus/slot, so any
attempt to impose that requirement means that there are devices that
might work perfectly fine that are now excluded from assignment. The
entire premise is unacceptable. Thanks,
Alex
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next prev parent reply other threads:[~2017-08-18 14:12 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-08-17 8:14 [PATCH v2 0/3] Workaround for bus reset on Cavium cn8xxx root ports Jan Glauber
2017-08-17 8:14 ` [PATCH v2 1/3] PCI: Allow PCI_DEV_FLAGS_NO_BUS_RESET to be used on bus device Jan Glauber
2017-08-17 8:14 ` [PATCH v2 2/3] PCI: Avoid bus reset for Cavium cn8xxx root ports Jan Glauber
2017-08-17 8:14 ` [PATCH v2 3/3] vfio/pci: Don't probe devices that can't be reset Jan Glauber
2017-08-17 13:00 ` Alex Williamson
2017-08-18 13:42 ` Jan Glauber
2017-08-18 14:12 ` Alex Williamson [this message]
2017-08-18 15:57 ` David Daney
2017-08-19 3:55 ` Alex Williamson
2017-08-23 8:06 ` Jan Glauber
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