Re: [PATCH 10/25] x86/sgx: Support enclave page permission changes

[Dave Hansen]

On 12/1/21 11:23 AM, Reinette Chatre wrote:
> Enclave page permission changes need to be approached with care and
> for this reason this initial support is to allow enclave page
> permission changes _only_ if the new permissions are the same or
> more restrictive that the permissions originally vetted at the time the
> pages were added to the enclave. Support for extending enclave page
> permissions beyond what was originally vetted is deferred.

It's probably worth adding a few examples here:

 * RWX => RW => RX => RW => R => RWX
 * RW => R => RW
 * RX => R => RX