Re: [PATCH 2/4] crypto: ccp: Add external API interface for PSP module initialization

Tom Lendacky
2025-01-22T15:53:20Z

On 1/21/25 19:00, Ashish Kalra wrote:
> From: Sean Christopherson <seanjc@google.com>
>
> Add a new external API interface for PSP module initialization which
> allows PSP SEV driver to be initialized explicitly before proceeding
> with SEV/SNP initialization with KVM if KVM is built-in as the
> dependency between modules is not supported/handled by the initcall
> infrastructure and the dependent PSP module is not implicitly loaded
> before KVM module if KVM module is built-in.

This is big run on sentence. Please start off describing the issue and
why this fixes it.

>
> Co-developed-by: Ashish Kalra <ashish.kalra@amd.com>
> Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>

Your SOB should come after Sean's.

> Signed-off-by: Sean Christopherson <seanjc@google.com>
> ---
> drivers/crypto/ccp/sp-dev.c | 12 ++++++++++++
> drivers/crypto/ccp/sp-dev.h | 1 +
> include/linux/psp-sev.h | 11 +++++++++++
> 3 files changed, 24 insertions(+)
>
> diff --git a/drivers/crypto/ccp/sp-dev.c b/drivers/crypto/ccp/sp-dev.c
> index 7eb3e4668286..a0cdc03984cb 100644
> --- a/drivers/crypto/ccp/sp-dev.c
> +++ b/drivers/crypto/ccp/sp-dev.c
> @@ -253,8 +253,12 @@ struct sp_device *sp_get_psp_master_device(void)
> static int __init sp_mod_init(void)
> {
> #ifdef CONFIG_X86
> + static bool initialized;

This definition is within CONFIG_X86, but...

> int ret;
>
> + if (initialized)
> + return 0;
> +
> ret = sp_pci_init();
> if (ret)
> return ret;
> @@ -263,6 +267,7 @@ static int __init sp_mod_init(void)
> psp_pci_init();
> #endif
>
> + initialized = true;

Add a blank line.

> return 0;
> #endif
>
> @@ -279,6 +284,13 @@ static int __init sp_mod_init(void)
> return -ENODEV;
> }
>
> +#if IS_BUILTIN(CONFIG_KVM_AMD) && IS_ENABLED(CONFIG_KVM_AMD_SEV)
> +int __init sev_module_init(void)
> +{
> + return sp_mod_init();
> +}
> +#endif
> +
> static void __exit sp_mod_exit(void)
> {
> #ifdef CONFIG_X86
> diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
> index 6f9d7063257d..3f5f7491bec1 100644
> --- a/drivers/crypto/ccp/sp-dev.h
> +++ b/drivers/crypto/ccp/sp-dev.h
> @@ -148,6 +148,7 @@ int sp_request_psp_irq(struct sp_device *sp, irq_handler_t handler,
> const char *name, void *data);
> void sp_free_psp_irq(struct sp_device *sp, void *data);
> struct sp_device *sp_get_psp_master_device(void);
> +int __init sev_module_init(void);

Why is this declared both here and below? Please just have it one place.

>
> #ifdef CONFIG_CRYPTO_DEV_SP_CCP
>
> diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
> index 903ddfea8585..1cf197fca93d 100644
> --- a/include/linux/psp-sev.h
> +++ b/include/linux/psp-sev.h
> @@ -814,6 +814,15 @@ struct sev_data_snp_commit {
>
> #ifdef CONFIG_CRYPTO_DEV_SP_PSP
>
> +/**
> + * sev_module_init - perform PSP module initialization
> + *
> + * Returns:
> + * 0 if the PSP module is successfully initialized
> + * -%ENODEV if the PSP module initialization fails

There are more possible return values in the sp_mod_init() path than
just ENODEV. So maybe just say that it returns a negative value on error
unless you want to chase them all down.

> + */
> +int __init sev_module_init(void);
> +
> /**
> * sev_platform_init - perform SEV INIT command
> *
> @@ -948,6 +957,8 @@ void snp_free_firmware_page(void *addr);
>
> #else /* !CONFIG_CRYPTO_DEV_SP_PSP */
>
> +static inline int __init sev_module_init(void) { return -ENODEV }

Remove the "__init".

Although I'm not sure this is even needed since it will only be called
by KVM and CONFIG_KVM_AMD_SEV depends on CONFIG_CRYPTO_DEV_SP_PSP. Plus,
the function itself is only defined under a specific config.

Thanks,
Tom

> +
> static inline int
> sev_platform_status(struct sev_user_data_status *status, int *error) { return -ENODEV; }
>