Messages in this thread | | | Subject | Re: [PATCH v2 5/8] iommu/vt-d: Add first level page table interfaces | From | Lu Baolu <> | Date | Tue, 3 Dec 2019 10:36:48 +0800 |
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Hi,
On 12/3/19 7:27 AM, Jacob Pan wrote: > On Thu, 28 Nov 2019 10:25:47 +0800 > Lu Baolu<baolu.lu@linux.intel.com> wrote: > >> This adds functions to manipulate first level page tables >> which could be used by a scalale mode capable IOMMU unit. >> > FL and SL page tables are very similar, and I presume we are not using > all the flag bits in FL paging structures for DMA mapping. Are there > enough relevant differences to warrant a new set of helper functions > for FL? Or we can merge into one. >
I ever thought about this and I am still open for this suggestion.
We had a quick compare on these two page tables. The only concern is the read/write/present encoding. The present bit in first level implies read permission while second level page table explicitly has a READ bit. (recalled from memory, correct me if it's bad. :-)).
Anyway, let's listen to more opinions.
Best regards, baolu
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