linux-kernel - Re: [Xen-devel] [PATCH v5 9/9] xen/pciback: Implement PCI reset slot or bus with 'do

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <54818929.5000008@citrix.com>
Date:	Fri, 5 Dec 2014 10:30:01 +0000
From:	David Vrabel <david.vrabel@...rix.com>
To:	Alex Williamson <alex.williamson@...hat.com>,
	Sander Eikelenboom <linux@...elenboom.it>
CC:	<bhelgaas@...gle.com>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	<linux-pci@...r.kernel.org>,
	Boris Ostrovsky <boris.ostrovsky@...cle.com>,
	<linux-kernel@...r.kernel.org>, <xen-devel@...ts.xenproject.org>
Subject: Re: [Xen-devel] [PATCH v5 9/9] xen/pciback: Implement PCI reset slot
 or bus with 'do_flr' SysFS attribute

On 04/12/14 15:39, Alex Williamson wrote:
> 
> I don't know what workaround you're talking about.  As devices are
> released from the user, vfio-pci attempts to reset them.  If
> pci_reset_function() returns success we mark the device clean, otherwise
> it gets marked dirty.  Each time a device is released, if there are
> dirty devices we test whether we can try a bus/slot reset to clean them.
> In the case of assigning a GPU this typically means that the GPU or
> audio function come through first, there's no reset mechanism so it gets
> marked dirty, the next device comes through and we manage to try a bus
> reset.  vfio-pci does not have any device specific resets, all
> functionality is added to the PCI-core, thank-you-very-much.  I even
> posted a generic PCI quirk patch recently that marks AMD VGA PM reset as
> bad so that pci_reset_function() won't claim that worked.  All VGA
> access quirks are done in QEMU, the kernel doesn't have any business in
> remapping config space over MMIO regions or trapping other config space
> backdoors.

Thanks for the info Alex, I hadn't got around to actually looking and
the vfio-pci code and was just going to what Sander said.

We probably do need to have a more in depth look at now PCI devices and
handled by both the toolstack and pciback but in the short term I would
like a simple solution that does not extend the ABI.

David
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/