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Date:   Tue, 17 Oct 2023 20:49:32 +0200
From:   Borislav Petkov <bp@alien8.de>
To:     John Allen <john.allen@amd.com>
Cc:     kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        pbonzini@redhat.com, weijiang.yang@intel.com,
        rick.p.edgecombe@intel.com, seanjc@google.com, x86@kernel.org,
        thomas.lendacky@amd.com
Subject: Re: [PATCH 7/9] x86/sev-es: Include XSS value in GHCB CPUID request
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On Tue, Oct 17, 2023 at 01:12:30PM -0500, John Allen wrote:
> I looked into using __rdmsr in an earlier revision of the patch, but
> found that it causes a build warning:
> 
> ld: warning: orphan section `__ex_table' from `arch/x86/boot/compressed/sev.o' being placed in section `__ex_table'
> 
> This is due to the __ex_table section not being used during
> decompression boot. Do you know of a way around this?

Yeah, arch/x86/boot/msr.h.

We did those a while ago. I guess they could be moved to
asm/shared/msr.h and renamed to something that is not a
"boot_" prefix.

Something like

rdmsr_without_any_exception_handling_and_other_gunk_don_t_you_even_think_of_adding()

...

But srsly:

raw_rdmsr()
raw_wrmsr()

should be good, as tglx suggests offlist.

You can do that in one patch and prepend your set with it.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette