Messages in this thread | | | Subject | Re: [PATCH v5 29/32] x86/mm: Add support to encrypt the kernel in-place | From | Tom Lendacky <> | Date | Tue, 30 May 2017 11:39:07 -0500 |
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On 5/26/2017 11:25 AM, Borislav Petkov wrote: > On Thu, May 25, 2017 at 05:24:27PM -0500, Tom Lendacky wrote: >> I guess I could do that, but this will probably only end up clearing a >> single PGD entry anyway since it's highly doubtful the address range >> would cross a 512GB boundary. > > Or you can compute how many 512G-covering, i.e., PGD entries there are > and clear just the right amnount. :^) > >> I can change the name. As for the use of ENTRY... without the >> ENTRY/ENDPROC combination I was receiving a warning about a return >> instruction outside of a callable function. It looks like I can just >> define the "sme_enc_routine:" label with the ENDPROC and the warning >> goes away and the global is avoided. It doesn't like the local labels >> (.L...) so I'll use the new name. > > Is that warning from objtool or where does it come from?
Yes, it's from objtool:
arch/x86/mm/mem_encrypt_boot.o: warning: objtool: .text+0xd2: return instruction outside of a callable function
> > How do I trigger it locally
I think having CONFIG_STACK_VALIDATION=y will trigger it.
> >> The hardware will try to optimize rep movsb into large chunks assuming >> things are aligned, sizes are large enough, etc. so we don't have to >> explicitly specify and setup for a rep movsq. > > I thought the hw does that for movsq too?
It does.
Thanks, Tom
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