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From: Dave Young <dyoung@redhat.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: "Li, Zhen-Hua" <zhen-hual@hp.com>,
	dwmw2@infradead.org, indou.takao@jp.fujitsu.com, bhe@redhat.com,
	vgoyal@redhat.com, iommu@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
	kexec@lists.infradead.org, alex.williamson@redhat.com,
	ddutile@redhat.com, ishii.hironobu@jp.fujitsu.com,
	bhelgaas@google.com, doug.hatch@hp.com, jerry.hoemann@hp.com,
	tom.vaden@hp.com, li.zhang6@hp.com, lisa.mitchell@hp.com,
	billsumnerlinux@gmail.com, rwright@hp.com
Subject: Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel
Date: Wed, 6 May 2015 09:46:49 +0800	[thread overview]
Message-ID: <20150506014649.GA14065@dhcp-128-4.nay.redhat.com> (raw)
In-Reply-To: <20150505152343.GP15736@8bytes.org>

On 05/05/15 at 05:23pm, Joerg Roedel wrote:
> On Tue, May 05, 2015 at 02:09:31PM +0800, Dave Young wrote:
> > I agree that we can do nothing with the old corrupted data, but I worry
> > about the future corruption after using the old corrupted data. I wonder
> > if we can mark all the oldmem as readonly so that we can lower the risk.
> > Is it resonable?
> 
> Do you mean marking it read-only for the devices? That will very likely
> cause DMAR faults, re-introducing the problem this patch-set tries to
> fix.

I means to block all dma write to oldmem, I believe it will cause DMA error.
But all other DMA reading requests will continue and work. This will avoid
future possible corruption. It will solve half of the problem at least?

For the original problem, the key issue is dmar faults cause kdump kernel
hang so that vmcore can not be saved. I do not know the reason why it hangs
I think it is acceptable if kdump kernel boot ok with some dma errors..

Thanks
Dave

  reply	other threads:[~2015-05-06  1:47 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-03-19  5:36 [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 01/10] iommu/vt-d: New function to attach domain with id Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 02/10] iommu/vt-d: Items required for kdump Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 03/10] iommu/vt-d: Function to get old context entry Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 04/10] iommu/vt-d: functions to copy data from old mem Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 05/10] iommu/vt-d: Add functions to load and save old re Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 06/10] iommu/vt-d: datatypes and functions used for kdump Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 07/10] iommu/vt-d: enable kdump support in iommu module Li, Zhen-Hua
2015-04-02 11:06   ` Joerg Roedel
2015-04-03  7:45     ` Li, ZhenHua
2015-03-19  5:36 ` [PATCH v9 08/10] iommu/vt-d: assign new page table for dma_map Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 09/10] iommu/vt-d: Copy functions for irte Li, Zhen-Hua
2015-03-19  5:36 ` [PATCH v9 10/10] iommu/vt-d: Use old irte in kdump kernel Li, Zhen-Hua
2015-04-02 11:11 ` [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults " Joerg Roedel
2015-04-03  7:54   ` Li, ZhenHua
2015-04-03  8:28 ` Dave Young
2015-04-03  8:31   ` Li, ZhenHua
2015-04-03  8:40 ` Dave Young
2015-04-03  9:01   ` Li, ZhenHua
2015-04-03  9:21     ` Dave Young
2015-04-03 14:05       ` Li, Zhen-Hua
2015-04-07  3:49         ` Dave Young
2015-04-05  1:54       ` Baoquan He
2015-04-07  3:46         ` Dave Young
2015-04-07  9:08           ` Dave Young
2015-04-07  9:55             ` Li, ZhenHua
2015-04-08  3:33               ` Dave Young
2015-04-07 14:12           ` Don Dutile
2015-05-07 14:00             ` Dave Young
2015-05-07 14:25               ` Don Dutile
2015-05-08  1:21                 ` Dave Young
2015-05-10 21:37                   ` Don Dutile
2015-05-10 21:31               ` Don Dutile
2015-05-04 11:05   ` Joerg Roedel
2015-05-04 15:21     ` Don Dutile
2015-05-05  6:09     ` Dave Young
2015-05-05 15:23       ` Joerg Roedel
2015-05-06  1:46         ` Dave Young [this message]
2015-05-06  8:16           ` Joerg Roedel
2015-05-07 13:25             ` Dave Young
2015-05-07 13:56     ` Dave Young
2015-05-11 10:11       ` Joerg Roedel
2015-05-12  5:57         ` Dave Young
2015-05-12  6:41           ` Dave Young

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