Re: [PATCH v5 7/7] crypto: ccp: Move SEV/SNP Platform initialization to KVM

[Tom Lendacky]

On 2/25/25 15:02, Ashish Kalra wrote:
> From: Ashish Kalra <ashish.kalra@xxxxxxx>
> 
> SNP initialization is forced during PSP driver probe purely because SNP
> can't be initialized if VMs are running.  But the only in-tree user of
> SEV/SNP functionality is KVM, and KVM depends on PSP driver for the same.
> Forcing SEV/SNP initialization because a hypervisor could be running
> legacy non-confidential VMs make no sense.
> 
> This patch removes SEV/SNP initialization from the PSP driver probe
> time and moves the requirement to initialize SEV/SNP functionality
> to KVM if it wants to use SEV/SNP.
> 
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Reviewed-by: Alexey Kardashevskiy <aik@xxxxxxx>
> Signed-off-by: Ashish Kalra <ashish.kalra@xxxxxxx>
> ---
>  drivers/crypto/ccp/sev-dev.c | 16 ----------------
>  1 file changed, 16 deletions(-)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index cde6ebab589d..42988d757665 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1345,10 +1345,6 @@ static int _sev_platform_init_locked(struct sev_platform_init_args *args)
>  	if (sev->state == SEV_STATE_INIT)
>  		return 0;
>  
> -	/*
> -	 * Legacy guests cannot be running while SNP_INIT(_EX) is executing,
> -	 * so perform SEV-SNP initialization at probe time.
> -	 */
>  	rc = __sev_snp_init_locked(&args->error);
>  	if (rc && rc != -ENODEV) {
>  		/*
> @@ -2516,9 +2512,7 @@ EXPORT_SYMBOL_GPL(sev_issue_cmd_external_user);
>  void sev_pci_init(void)
>  {
>  	struct sev_device *sev = psp_master->sev_data;
> -	struct sev_platform_init_args args = {0};
>  	u8 api_major, api_minor, build;
> -	int rc;
>  
>  	if (!sev)
>  		return;
> @@ -2541,16 +2535,6 @@ void sev_pci_init(void)
>  			 api_major, api_minor, build,
>  			 sev->api_major, sev->api_minor, sev->build);
>  
> -	/* Initialize the platform */
> -	args.probe = true;
> -	rc = sev_platform_init(&args);
> -	if (rc)
> -		dev_err(sev->dev, "SEV: failed to INIT error %#x, rc %d\n",
> -			args.error, rc);
> -
> -	dev_info(sev->dev, "SEV%s API:%d.%d build:%d\n", sev->snp_initialized ?
> -		"-SNP" : "", sev->api_major, sev->api_minor, sev->build);

Should this dev_info() have been removed in patch #1? Because it looks
like this would have been a duplicate message after the first patch, right?

Thanks,
Tom

> -
>  	return;
>  
>  err: