linux-kernel - Re: [PATCH v4 3/7] crypto: ccp: Reset TMR size at SNP Shutdown

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Message-ID: <2d15480e-2782-89bf-4eec-681de812fa5e@amd.com>
Date: Thu, 20 Feb 2025 12:55:44 -0600
From: Tom Lendacky <thomas.lendacky@....com>
To: Ashish Kalra <Ashish.Kalra@....com>, seanjc@...gle.com,
 pbonzini@...hat.com, tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
 dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
 john.allen@....com, herbert@...dor.apana.org.au
Cc: michael.roth@....com, dionnaglaze@...gle.com, nikunj@....com,
 ardb@...nel.org, kevinloughlin@...gle.com, Neeraj.Upadhyay@....com,
 aik@....com, kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
 linux-crypto@...r.kernel.org, linux-coco@...ts.linux.dev
Subject: Re: [PATCH v4 3/7] crypto: ccp: Reset TMR size at SNP Shutdown

On 2/19/25 14:53, Ashish Kalra wrote:
> From: Ashish Kalra <ashish.kalra@....com>
> 
> When SEV-SNP is enabled the TMR needs to be 2MB aligned and 2MB sized,
> ensure that TMR size is reset back to default when SNP is shutdown as
> SNP initialization and shutdown as part of some SNP ioctls may leave
> TMR size modified and cause subsequent SEV only initialization to fail.

This is a long run-on sentence, please re-work this to make it more
informative and clear as to what the issue is.

Other than that,

Reviewed-by: Tom Lendacky <thomas.lendacky@....com>

> 
> Signed-off-by: Ashish Kalra <ashish.kalra@....com>
> ---
>  drivers/crypto/ccp/sev-dev.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index b06f43eb18f7..be8a84ce24c7 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1751,6 +1751,9 @@ static int __sev_snp_shutdown_locked(int *error, bool panic)
>  	sev->snp_initialized = false;
>  	dev_dbg(sev->dev, "SEV-SNP firmware shutdown\n");
>  
> +	/* Reset TMR size back to default */
> +	sev_es_tmr_size = SEV_TMR_SIZE;
> +
>  	return ret;
>  }
>