Messages in this thread | | | Date | Tue, 12 May 2015 14:41:10 +0800 | From | Dave Young <> | Subject | Re: [PATCH v9 0/10] iommu/vt-d: Fix intel vt-d faults in kdump kernel |
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On 05/12/15 at 01:57pm, Dave Young wrote: > On 05/11/15 at 12:11pm, Joerg Roedel wrote: > > On Thu, May 07, 2015 at 09:56:00PM +0800, Dave Young wrote: > > > Joreg, I can not find the last reply from you, so just reply here about > > > my worries here. > > > > > > I said that the patchset will cause more problems, let me explain about > > > it more here: > > > > > > Suppose page table was corrupted, ie. original mapping iova1 -> page 1 > > > it was changed to iova1 -> page 2 accidently while crash happening, > > > thus future dma will read/write page 2 instead page 1, right? > > > > When the page-table is corrupted then it is a left-over from the old > > kernel. When the kdump kernel boots the situation can at least not get > > worse. For the page tables it is also hard to detect wrong mappings (if > > this would be possible the hardware could already do it), so any checks > > we could do there are of limited use anyway. > > Joerg, since both of you guys do not think it is a problem I will object it
s/will object/will not object
> any more though I still do not like reusing the old page tables. So let's > leave it as a future issue. > > Thanks > Dave
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