Messages in this thread | | | Date | Tue, 10 May 2022 00:48:40 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH] x86/Hyper-V: Add SEV negotiate protocol support in Isolation VM |
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On Thu, May 05, 2022 at 09:15:02AM -0400, Tianyu Lan wrote: > From: Tianyu Lan <Tianyu.Lan@microsoft.com> > > Hyper-V Isolation VM code uses sev_es_ghcb_hv_call() to read/write MSR > via GHCB page. The SEV-ES guest should negotiate GHCB version before > reading/writing MSR via GHCB page.
Why is that?
> Expose sev_es_negotiate_protocol() and sev_es_terminate() from AMD SEV > code
Yeah, you keep wanting to expose random SEV-specific code and when we go and change it in the future, you'll come complaining that we broke hyperv.
I think it might be a lot better if you implement your own functions: for example, looking at sev_es_negotiate_protocol() - it uses only primitives which you can use because, well, VMGEXIT() is simply a wrapper around the asm insn and sev_es_wr_ghcb_msr() is simply writing into the MSR.
Ditto for sev_es_terminate().
And sev_es_ghcb_hv_call() too, for that matter. You can define your own.
IOW, you're much better off using those primitives and creating your own functions than picking out random SEV-functions and then us breaking your isolation VM stuff.
Thx.
-- Regards/Gruss, Boris.
https://people.kernel.org/tglx/notes-about-netiquette
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