Re: [PATCH v10 3/9] KVM: Extend the memslot to support fd-based private memory

On Tue, Dec 20, 2022 at 10:55:44AM +0100, Borislav Petkov wrote:

On Tue, Dec 20, 2022 at 03:43:18PM +0800, Chao Peng wrote:

quoted

RESTRICTEDMEM is needed by TDX_HOST, not TDX_GUEST.

Which basically means that RESTRICTEDMEM should simply depend on KVM.
Because you can't know upfront whether KVM will run a TDX guest or a SNP
guest and so on.

Which then means that RESTRICTEDMEM will practically end up always
enabled in KVM HV configs.

That's right, CONFIG_RESTRICTEDMEM is always selected for supported KVM
architectures (currently x86_64).

quoted

The only reason to add another HAVE_KVM_RESTRICTED_MEM is some code only
works for 64bit[*] and CONFIG_RESTRICTEDMEM is not sufficient to enforce
that.

This is what I mean with "we have too many Kconfig items". :-\

Yes I agree. One way to remove this is probably additionally checking
CONFIG_64BIT instead.

Thanks,
Chao

-- 
Regards/Gruss,
    Boris.

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