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Date:   Tue, 15 Jun 2021 12:23:08 +0100
From:   "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To:     Brijesh Singh <brijesh.singh@amd.com>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-coco@lists.linux.dev, linux-mm@kvack.org,
        linux-crypto@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
        Tom Lendacky <thomas.lendacky@amd.com>,
        "H. Peter Anvin" <hpa@zytor.com>, Ard Biesheuvel <ardb@kernel.org>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Andy Lutomirski <luto@kernel.org>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
        Peter Zijlstra <peterz@infradead.org>,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        David Rientjes <rientjes@google.com>, tony.luck@intel.com,
        npmccallum@redhat.com, Borislav Petkov <bp@suse.de>
Subject: Re: [PATCH Part2 RFC v3 14/37] crypto:ccp: Provide APIs to issue
 SEV-SNP commands
Message-ID: <YMiNnN99PuAKbplA@work-vm>
References: <20210602141057.27107-1-brijesh.singh@amd.com>
 <20210602141057.27107-15-brijesh.singh@amd.com>
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* Brijesh Singh (brijesh.singh@amd.com) wrote:
> Provide the APIs for the hypervisor to manage an SEV-SNP guest. The
> commands for SEV-SNP is defined in the SEV-SNP firmware specification.
> 
> Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
> ---
>  drivers/crypto/ccp/sev-dev.c | 24 ++++++++++++
>  include/linux/psp-sev.h      | 74 ++++++++++++++++++++++++++++++++++++
>  2 files changed, 98 insertions(+)
> 
> diff --git a/drivers/crypto/ccp/sev-dev.c b/drivers/crypto/ccp/sev-dev.c
> index b225face37b1..def2996111db 100644
> --- a/drivers/crypto/ccp/sev-dev.c
> +++ b/drivers/crypto/ccp/sev-dev.c
> @@ -1014,6 +1014,30 @@ int sev_guest_df_flush(int *error)
>  }
>  EXPORT_SYMBOL_GPL(sev_guest_df_flush);
>  
> +int snp_guest_decommission(struct sev_data_snp_decommission *data, int *error)
> +{
> +	return sev_do_cmd(SEV_CMD_SNP_DECOMMISSION, data, error);
> +}
> +EXPORT_SYMBOL_GPL(snp_guest_decommission);
> +
> +int snp_guest_df_flush(int *error)
> +{
> +	return sev_do_cmd(SEV_CMD_SNP_DF_FLUSH, NULL, error);
> +}
> +EXPORT_SYMBOL_GPL(snp_guest_df_flush);
> +
> +int snp_guest_page_reclaim(struct sev_data_snp_page_reclaim *data, int *error)
> +{
> +	return sev_do_cmd(SEV_CMD_SNP_PAGE_RECLAIM, data, error);
> +}
> +EXPORT_SYMBOL_GPL(snp_guest_page_reclaim);
> +
> +int snp_guest_dbg_decrypt(struct sev_data_snp_dbg *data, int *error)
> +{
> +	return sev_do_cmd(SEV_CMD_SNP_DBG_DECRYPT, data, error);
> +}
> +EXPORT_SYMBOL_GPL(snp_guest_dbg_decrypt);
> +
>  static void sev_exit(struct kref *ref)
>  {
>  	misc_deregister(&misc_dev->misc);
> diff --git a/include/linux/psp-sev.h b/include/linux/psp-sev.h
> index 1b53e8782250..63ef766cbd7a 100644
> --- a/include/linux/psp-sev.h
> +++ b/include/linux/psp-sev.h
> @@ -860,6 +860,65 @@ int sev_guest_df_flush(int *error);
>   */
>  int sev_guest_decommission(struct sev_data_decommission *data, int *error);
>  
> +/**
> + * snp_guest_df_flush - perform SNP DF_FLUSH command
> + *
> + * @sev_ret: sev command return code
> + *
> + * Returns:
> + * 0 if the sev successfully processed the command
> + * -%ENODEV    if the sev device is not available
> + * -%ENOTSUPP  if the sev does not support SEV

sev not supporting SEV? Is that actually 'sev does not support SNP'?

> + * -%ETIMEDOUT if the sev command timed out
> + * -%EIO       if the sev returned a non-zero return code
> + */
> +int snp_guest_df_flush(int *error);
> +
> +/**
> + * snp_guest_decommission - perform SNP_DECOMMISSION command
> + *
> + * @decommission: sev_data_decommission structure to be processed
> + * @sev_ret: sev command return code
> + *
> + * Returns:
> + * 0 if the sev successfully processed the command
> + * -%ENODEV    if the sev device is not available
> + * -%ENOTSUPP  if the sev does not support SEV
> + * -%ETIMEDOUT if the sev command timed out
> + * -%EIO       if the sev returned a non-zero return code
> + */
> +int snp_guest_decommission(struct sev_data_snp_decommission *data, int *error);
> +
> +/**
> + * snp_guest_page_reclaim - perform SNP_PAGE_RECLAIM command
> + *
> + * @decommission: sev_snp_page_reclaim structure to be processed
> + * @sev_ret: sev command return code
> + *
> + * Returns:
> + * 0 if the sev successfully processed the command
> + * -%ENODEV    if the sev device is not available
> + * -%ENOTSUPP  if the sev does not support SEV
> + * -%ETIMEDOUT if the sev command timed out
> + * -%EIO       if the sev returned a non-zero return code
> + */
> +int snp_guest_page_reclaim(struct sev_data_snp_page_reclaim *data, int *error);
> +
> +/**
> + * snp_guest_dbg_decrypt - perform SEV SNP_DBG_DECRYPT command
> + *
> + * @sev_ret: sev command return code
> + *
> + * Returns:
> + * 0 if the sev successfully processed the command
> + * -%ENODEV    if the sev device is not available
> + * -%ENOTSUPP  if the sev does not support SEV
> + * -%ETIMEDOUT if the sev command timed out
> + * -%EIO       if the sev returned a non-zero return code
> + */
> +int snp_guest_dbg_decrypt(struct sev_data_snp_dbg *data, int *error);
> +
> +
>  void *psp_copy_user_blob(u64 uaddr, u32 len);
>  
>  #else	/* !CONFIG_CRYPTO_DEV_SP_PSP */
> @@ -887,6 +946,21 @@ sev_issue_cmd_external_user(struct file *filep, unsigned int id, void *data, int
>  
>  static inline void *psp_copy_user_blob(u64 __user uaddr, u32 len) { return ERR_PTR(-EINVAL); }
>  
> +static inline int
> +snp_guest_decommission(struct sev_data_snp_decommission *data, int *error) { return -ENODEV; }
> +
> +static inline int snp_guest_df_flush(int *error) { return -ENODEV; }
> +
> +static inline int snp_guest_page_reclaim(struct sev_data_snp_page_reclaim *data, int *error)
> +{
> +	return -ENODEV;
> +}
> +
> +static inline int snp_guest_dbg_decrypt(struct sev_data_snp_dbg *data, int *error)
> +{
> +	return -ENODEV;
> +}
> +
>  #endif	/* CONFIG_CRYPTO_DEV_SP_PSP */
>  
>  #endif	/* __PSP_SEV_H__ */
> -- 
> 2.17.1
> 
> 
-- 
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK