Re: [PATCH RFC v7 25/64] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP

[Jarkko Sakkinen]

On Thu, Jan 05, 2023 at 04:54:23PM -0600, Kalra, Ashish wrote:
> Hello Jarkko,
> 
> On 1/4/2023 6:12 AM, Jarkko Sakkinen wrote:
> > On Wed, Dec 14, 2022 at 01:40:17PM -0600, Michael Roth wrote:
> > > +	/*
> > > +	 * If boot CPU supports SNP, then first attempt to initialize
> > > +	 * the SNP firmware.
> > > +	 */
> > > +	if (cpu_feature_enabled(X86_FEATURE_SEV_SNP)) {
> > > +		if (!sev_version_greater_or_equal(SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR)) {
> > > +			dev_err(sev->dev, "SEV-SNP support requires firmware version >= %d:%d\n",
> > > +				SNP_MIN_API_MAJOR, SNP_MIN_API_MINOR);
> > > +		} else {
> > > +			rc = sev_snp_init(&error, true);
> > > +			if (rc) {
> > > +				/*
> > > +				 * Don't abort the probe if SNP INIT failed,
> > > +				 * continue to initialize the legacy SEV firmware.
> > > +				 */
> > > +				dev_err(sev->dev, "SEV-SNP: failed to INIT error %#x\n", error);
> > > +			}
> > > +		}
> > > +	}
> > 
> > I think this is not right as there is a dep between sev init and this,
> > and there is about a dozen of call sites already __sev_platform_init_locked().
> > 
> 
> sev_init ?
> 
> As this is invoked during CCP module load/initialization, shouldn't this get
> invoked before any other call sites invoking __sev_platform_init_locked() ?

Then it should not be exported because this the only working call site.

However, the benefit of __sev_platform_init_locked() addressing SNP init is
that psp_init_on_probe can also postpone SNP init without possibility to
any side effects (other call sites than sev_guest_init()).

BR, Jarkko