linux-kernel - Re: [RFC][PATCH] Reset PCIe devices to address DMA problem on kdump with iommu

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]

Date:	Tue, 11 Sep 2012 10:43:23 -0400
From:	Vivek Goyal <vgoyal@...hat.com>
To:	Takao Indoh <indou.takao@...fujitsu.com>
Cc:	kexec@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-pci@...r.kernel.org, bhelgaas@...gle.com, hbabu@...ibm.com,
	ishii.hironobu@...fujitsu.com, martin.wilck@...fujitsu.com
Subject: Re: [RFC][PATCH] Reset PCIe devices to address DMA problem on kdump
 with iommu

On Tue, Sep 11, 2012 at 07:32:35PM +0900, Takao Indoh wrote:

[..]
> I'll post new patch which clears bus master bit and resets devices in
> second kernel.
> 
> As to the boot parameter to enable this function, you suggested using
> reset_devices. I found that on a certain platform resetting devices
> caused PCIe error due to a hardware bug. Therefore I think we need
> new parameter apart from reset_devices to disable this function on
> such a machine.

Can you explain a bit more how the error happens. I still don't think
that because of a bug in a platform somewhere we should be introducing
a separate command line parameter and not reuse the exisiting one. Also
you have not explained what's the bug and how a new parameter will 
avoid the bug.

Thanks
Vivek
--
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/