Messages in this thread | | | Date | Sat, 3 Sep 2022 06:25:36 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH Part2 v6 09/49] x86/fault: Add support to handle the RMP fault for user address |
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On Fri, Sep 02, 2022 at 03:33:20PM +0000, Kalra, Ashish wrote: > Yes we want to map the faulting address to a RMP entry, but hugepage > entries in RMP table are basically subpage 4K entries. So it is a 4K > entry when the page is a 2M one and also a 4K entry when the page is a > 1G one.
Wait, what?!
APM v2 section "15.36.11 Large Page Management" and PSMASH are then for what exactly?
> That's why the computation to get a 4K page index within a 2M/1G > hugepage mapping is required.
What if a guest RMP-faults on a 2M page and there's a corresponding 2M RMP entry? What do you need the 4K entry then for?
Hell, __snp_lookup_rmpentry() even tries to return the proper page level...
/me looks in disbelief in your direction...
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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