From: David Woodhouse <dwmw2@infradead.org>
To: Joerg Roedel <joro@8bytes.org>
Cc: "Li, Zhen-Hua" <zhen-hual@hp.com>,
indou.takao@jp.fujitsu.com, bhe@redhat.com, vgoyal@redhat.com,
dyoung@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 v11 04/10] iommu/vt-d: functions to copy data from old mem
Date: Mon, 08 Jun 2015 16:44:02 +0100 [thread overview]
Message-ID: <1433778242.2952.76.camel@infradead.org> (raw)
In-Reply-To: <20150608152147.GV20384@8bytes.org>
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On Mon, 2015-06-08 at 17:21 +0200, Joerg Roedel wrote:
> Hi David,
>
> On Mon, Jun 08, 2015 at 03:15:35PM +0100, David Woodhouse wrote:
> > Surely this isn't specific to the Intel IOMMU? Shouldn't it live
> > elsewhere — either in generic IOMMU code or perhaps in generic kexec
> > support code?
>
> I put a bigger rework of this on-top of Zhen-Hua's patches, you can find
> the result in my x86/vt-d branch. With my patches I also removed this
> pointer collecting concept and do the iomap_cache and iounmap calls
> before the spin-lock is taken, so this problem is now solved
> differently.
>
> > And I think you're misusing VTD_PAGE_{SHIFT,MASK} when you should be
> > using the normal PAGE_{SHIFT,MASK}.
>
> I think VT_PAGE_* is correct, since the VT-d driver also runs on ia64.
> There the system page-size is different from the VT-d page-size.
That's the problem. In __iommu_load_from_oldmem we start with a
physical address in 'from', convert to a VT-d PFN in 'pfn':
+ pfn = from >> VTD_PAGE_SHIFT;
.. and then proceed to pass that pfn to non-VT-d functions like
page_is_ram() and pfn_to_kaddr() which really need their input pfn
values to be in terms of PAGE_SHIFT not VTD_PAGE_SHIFT.
But it looks like you've completely eliminated that now (including the
page_is_ram check). So although it *was* wrong, it doesn't matter now.
> > And shouldn't physical addresses be phys_addr_t?
>
> This is changed where appropriate, I hope.
OK. In fact once it's purely internal to intel-iommu.c it doesn't
matter as much since we don't put page tables in high memory on 32-bit
machines.
--
David Woodhouse Open Source Technology Centre
David.Woodhouse@intel.com Intel Corporation
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next prev parent reply other threads:[~2015-06-08 15:44 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-11 9:52 [PATCH v11 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel Li, Zhen-Hua
2015-05-11 9:52 ` [PATCH v11 01/10] iommu/vt-d: New function to attach domain with id Li, Zhen-Hua
2015-05-11 9:52 ` [PATCH v11 02/10] iommu/vt-d: Items required for kdump Li, Zhen-Hua
2015-05-12 8:17 ` Dave Young
2015-05-13 1:45 ` Li, ZhenHua
2015-05-13 6:31 ` Alexander Duyck
2015-05-13 8:42 ` Dave Young
2015-05-11 9:52 ` [PATCH v11 03/10] iommu/vt-d: Function to get existing context entry Li, Zhen-Hua
2015-05-11 9:52 ` [PATCH v11 04/10] iommu/vt-d: functions to copy data from old mem Li, Zhen-Hua
2015-05-12 8:29 ` Dave Young
2015-05-13 9:00 ` Baoquan He
2015-05-13 9:13 ` Li, ZhenHua
2015-05-13 9:21 ` Baoquan He
2015-06-08 14:15 ` David Woodhouse
2015-06-08 15:21 ` Joerg Roedel
2015-06-08 15:44 ` David Woodhouse [this message]
2015-05-11 9:52 ` [PATCH v11 05/10] iommu/vt-d: Add functions to load and save old re Li, Zhen-Hua
2015-05-12 8:37 ` Dave Young
2015-05-13 1:47 ` Li, ZhenHua
2015-05-13 8:49 ` Dave Young
2015-05-11 9:52 ` [PATCH v11 06/10] iommu/vt-d: datatypes and functions used for kdump Li, Zhen-Hua
2015-05-12 8:48 ` Dave Young
2015-05-13 8:56 ` Baoquan He
2015-05-13 8:58 ` Li, ZhenHua
2015-05-13 9:10 ` Baoquan He
2015-05-11 9:52 ` [PATCH v11 07/10] iommu/vt-d: enable kdump support in iommu module Li, Zhen-Hua
2015-05-12 8:52 ` Dave Young
2015-05-13 2:10 ` Baoquan He
2015-05-13 2:28 ` Li, ZhenHua
2015-05-13 2:36 ` Baoquan He
2015-05-11 9:52 ` [PATCH v11 08/10] iommu/vt-d: assign new page table for dma_map Li, Zhen-Hua
2015-05-20 23:52 ` Baoquan He
2015-05-21 1:27 ` Li, ZhenHua
2015-05-21 6:54 ` Baoquan He
2015-05-21 8:40 ` Li, ZhenHua
2015-05-21 10:11 ` Baoquan He
2015-05-11 9:52 ` [PATCH v11 09/10] iommu/vt-d: Copy functions for irte Li, Zhen-Hua
2015-05-12 9:00 ` Dave Young
2015-05-11 9:52 ` [PATCH v11 10/10] iommu/vt-d: Use old irte in kdump kernel Li, Zhen-Hua
2015-05-12 6:18 ` [PATCH v11 0/10] iommu/vt-d: Fix intel vt-d faults " Baoquan He
2015-05-12 9:04 ` Dave Young
2015-05-12 9:34 ` Li, Zhen-Hua
2015-05-13 1:54 ` Li, ZhenHua
2015-05-18 10:05 ` Li, ZhenHua
2015-05-19 1:13 ` Dave Young
2015-05-19 7:43 ` Li, ZhenHua
2015-05-29 16:21 ` Joerg Roedel
2015-05-30 11:23 ` Li, Zhen-Hua
2015-06-08 14:26 ` David Woodhouse
2015-06-08 15:29 ` Joerg Roedel
2015-06-08 15:50 ` David Woodhouse
2015-06-08 16:13 ` Joerg Roedel
2015-06-09 12:55 ` David Woodhouse
2015-06-10 9:21 ` Joerg Roedel
2015-06-10 9:32 ` Li, ZhenHua
2015-06-10 14:10 ` David Woodhouse
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