linux-kernel - Re: [PATCH 1/2] x86/sev/vc: fix efi runtime instruction emulation

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Message-ID: <20250527162151.GAaDXmn8O3f_HYgRju@fat_crate.local>
Date: Tue, 27 May 2025 18:21:51 +0200
From: Borislav Petkov <bp@...en8.de>
To: Gerd Hoffmann <kraxel@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>, Ingo Molnar <mingo@...hat.com>,
	Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
	"H. Peter Anvin" <hpa@...or.com>, kvm@...r.kernel.org,
	linux-coco@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 1/2] x86/sev/vc: fix efi runtime instruction emulation

On Tue, May 27, 2025 at 04:45:44PM +0200, Gerd Hoffmann wrote:
> In case efi_mm is active go use the userspace instruction decoder which
> supports fetching instructions from active_mm.  This is needed to make
> instruction emulation work for EFI runtime code, so it can use cpuid
> and rdmsr.
> 
> Signed-off-by: Gerd Hoffmann <kraxel@...hat.com>
> ---
>  arch/x86/coco/sev/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Can you pls explain what the use cases for this and your next patch are?

We'd like to add them to our test pile.

Thx.

-- 
Regards/Gruss,
    Boris.

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