Messages in this thread | | | Date | Fri, 30 Nov 2012 17:16:46 +1100 | From | Alexey Kardashevskiy <> | Subject | Re: [PATCH] vfio powerpc: enabled on powernv platform |
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On 29/11/12 15:20, Alex Williamson wrote:
>> + /* Put tces to the table */ >> + for (i = 0; (i < pages) && !ret; ++i, tce += IOMMU_PAGE_SIZE) { >> + ret = put_tce(tbl, entry + i, tce, direction); >> + /* >> + * As IOMMU page size is always 4K, the system page size >> + * can be 64K and there is no special tracking for IOMMU pages, >> + * we only do rlimit check/update for the very first >> + * 4K IOMMUpage within 64K system page. >> + */ >> + if (!(tce & ~PAGE_MASK)) >> + ++retpages; > > Ah, here's the comment I was looking for, though I'm still not sure > about the read/write bits. > > Isn't there an exploit here that a user can lock pages beyond their > limits if they just skip mapping the first 4k of each page? Thanks,
Heh. True. Posted another patch with 4K pages per system page usage tracking.
-- Alexey
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