| Date | Thu, 13 Jan 2022 14:51:54 +0100 | From | Borislav Petkov <> | Subject | Re: [PATCH 10/26] x86/tdx: Support TDX guest port I/O at decompression time |
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On Tue, Dec 14, 2021 at 06:02:48PM +0300, Kirill A. Shutemov wrote: > From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > > Port IO triggers a #VE exception in TDX guests. During normal runtime, > the kernel will handle those exceptions for any port IO. > > But for the early code in the decompressor, #VE cannot be used because > the IDT needed for handling the exception is not set up. ... yet.
Well, we're setting up and IDT twice in
arch/x86/boot/compressed/idt_64.c
as early as startup_64 for SEV. And the second stage one do_boot_stage2_vc() handles port IO too.
Can't you hook in your VE handler there too?
> Replace IN/OUT instructions with TDX IO hypercalls by defining helper > macros __in/__out and by re-defining them in the decompressor code. > Also, since TDX IO hypercall requires an IO size parameter, allow > __in/__out macros to accept size as an input parameter.
Please end function/macro names with parentheses. I think in this particular case you wanna say
"__in*()/__out*() macros"
When a function is mentioned in the changelog, either the text body or the subject line, please use the format 'function_name()'. Omitting the brackets after the function name can be ambiguous::
Subject: subsys/component: Make reservation_count static
reservation_count is only used in reservation_stats. Make it static.
The variant with brackets is more precise::
Subject: subsys/component: Make reservation_count() static
reservation_count() is only called from reservation_stats(). Make it static.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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