linux-kernel - Re: [PATCH v15 06/13] x86/sev: Prevent GUEST_TSC_FREQ MSR interception for Secure TSC enabled guests

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Message-ID: <20241217105739.GBZ2FZI0V8pAIy-kZ8@fat_crate.local>
Date: Tue, 17 Dec 2024 11:57:39 +0100
From: Borislav Petkov <bp@...en8.de>
To: "Nikunj A. Dadhania" <nikunj@....com>
Cc: linux-kernel@...r.kernel.org, thomas.lendacky@....com, x86@...nel.org,
	kvm@...r.kernel.org, mingo@...hat.com, tglx@...utronix.de,
	dave.hansen@...ux.intel.com, pgonda@...gle.com, seanjc@...gle.com,
	pbonzini@...hat.com
Subject: Re: [PATCH v15 06/13] x86/sev: Prevent GUEST_TSC_FREQ MSR
 interception for Secure TSC enabled guests

On Thu, Dec 12, 2024 at 10:23:01AM +0530, Nikunj A. Dadhania wrote:
> @@ -1477,19 +1480,13 @@ static enum es_result vc_handle_msr(struct ghcb *ghcb, struct es_em_ctxt *ctxt)
>  	case MSR_SVSM_CAA:
>  		return __vc_handle_msr_caa(regs, write);
>  	case MSR_IA32_TSC:
> -		return __vc_handle_msr_tsc(regs, write);
> +	case MSR_AMD64_GUEST_TSC_FREQ:
> +		if (sev_status & MSR_AMD64_SNP_SECURE_TSC)
> +			return __vc_handle_msr_tsc(regs, write);

Now push that conditional inside the function too.

-- 
Regards/Gruss,
    Boris.

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