Messages in this thread | | | Date | Wed, 6 Oct 2021 20:02:02 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v8 04/11] x86/tdx: Add Intel ARCH support to cc_platform_has() |
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On Tue, Oct 05, 2021 at 02:16:11PM -0700, Josh Poimboeuf wrote: > I assume this needs a rebase on -tip since cc_platform.c already has an > empty version of this function (and it's static so it doesn't need to be > declared in a header).
Yes:
arch/x86/kernel/cc_platform.c:16:28: error: static declaration of ‘intel_cc_platform_has’ follows non-static declaration 16 | static bool __maybe_unused intel_cc_platform_has(enum cc_attr attr) | ^~~~~~~~~~~~~~~~~~~~~ In file included from ./include/linux/mem_encrypt.h:17, from arch/x86/kernel/cc_platform.c:12: ./arch/x86/include/asm/mem_encrypt.h:105:6: note: previous declaration of ‘intel_cc_platform_has’ was here 105 | bool intel_cc_platform_has(enum cc_attr attr); | ^~~~~~~~~~~~~~~~~~~~~ make[2]: *** [scripts/Makefile.build:277: arch/x86/kernel/cc_platform.o] Error 1 make[1]: *** [scripts/Makefile.build:540: arch/x86/kernel] Error 2 make: *** [Makefile:1868: arch/x86] Error 2 make: *** Waiting for unfinished jobs....
I had already started that function there - please add all TDX logic in cc_platform.c.
When you do your next set, you can use tip/master as a base. This should be used for all x86 patchsets anyway.
> > + /** > > + * @CC_ATTR_GUEST_TDX: Trusted Domain Extension Support > > + * > > + * The platform/OS is running as a TDX guest/virtual machine. > > + * > > + * Examples include Intel TDX. > > + */ > > + CC_ATTR_GUEST_TDX, > > Examples of TDX include TDX? :-)
Yeah, so whether we should be naming the actual conf. computing implementation came up during the cc_platform_has() review and looking forward in this patchset:
+ if (cc_platform_has(CC_ATTR_GUEST_TDX)) + return tdx_kvm_hypercall(nr, 0, 0, 0, 0);
you really need to test for TDX because you're doing a TDX-specific hypercall.
Which brings me back to the fastpath use of is_idx_guest(): this looks to me like a fastpath use - dunno how often one needs to do TDX hypercalls so I can imagine that for this, the is_tdx_guest() check should use a static branch.
But only with numbers to show the need for it.
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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