Re: [PATCH v11 3/5] x86/sgx: Define error codes for use by ENCLS[EUPDATESVN]

["Huang, Kai" <kai.huang@intel.com>]

On Wed, 2025-08-06 at 11:11 +0300, Elena Reshetova wrote:
> Add error codes for ENCLS[EUPDATESVN], then SGX CPUSVN update
> process can know the execution state of EUPDATESVN and notify
> userspace.

I would also add some text to explain why other error codes are not
defined:

EUPDATESVN will be called when no active SGX user is guaranteed.  Only add
the error codes that can legally happen.  E.g., it could also fail due to
"SGX not ready" when there's SGX users but it wouldn't happen in this
implementation.

> 
> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
> ---
>  arch/x86/include/asm/sgx.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/x86/include/asm/sgx.h b/arch/x86/include/asm/sgx.h
> index 6a0069761508..2da5b3b117a1 100644
> --- a/arch/x86/include/asm/sgx.h
> +++ b/arch/x86/include/asm/sgx.h
> @@ -73,6 +73,10 @@ enum sgx_encls_function {
>   *				public key does not match IA32_SGXLEPUBKEYHASH.
>   * %SGX_PAGE_NOT_MODIFIABLE:	The EPC page cannot be modified because it
>   *				is in the PENDING or MODIFIED state.
> + * %SGX_INSUFFICIENT_ENTROPY:	Insufficient entropy in RNG.
> + * %SGX_NO_UPDATE:		EUPDATESVN could not update the CPUSVN because the
> + *				current SVN was not newer than CPUSVN. This is the most
> + *				common error code returned by EUPDATESVN.
>   * %SGX_UNMASKED_EVENT:		An unmasked event, e.g. INTR, was received
>   */
>  enum sgx_return_code {
> @@ -81,6 +85,8 @@ enum sgx_return_code {
>  	SGX_CHILD_PRESENT		= 13,
>  	SGX_INVALID_EINITTOKEN		= 16,
>  	SGX_PAGE_NOT_MODIFIABLE		= 20,
> +	SGX_INSUFFICIENT_ENTROPY	= 29,
> +	SGX_NO_UPDATE				= 31,
>  	SGX_UNMASKED_EVENT		= 128,
>  };
>