On Mon, 2021-09-13 at 07:55 -0700, Dave Hansen wrote: > On 9/13/21 7:24 AM, Paolo Bonzini wrote: > > > How does this end up happening in the first place? > > > > > > All enclave pages should start out on 'sgx_dirty_page_list' and > > > ksgxd sanitizes them with EREMOVE before making them available. That > > > should cover EREMOVE after reboots while SGX pages are initialized, > > > including kexec(). > > > > By "Windows startup" I mean even after guest reboot. Because another > > process could sneak in and steal your EPC pages between a close() and an > > open(), I'd like to have a way to EREMOVE the pages while keeping them > > assigned to the specific vEPC instance, i.e. *without* going through > > sgx_vepc_free_page(). > > Oh, so you want fresh EPC state for the guest, but you're concerned that > the previous guest might have left them in a bad state. The current > method of getting a new vepc instance (which guarantees fresh state) has > some other downsides. > > Can't another process steal pages via sgxd and reclaim at any time? > What's the extra concern here about going through a close()/open() > cycle? Performance? sgxd does not steal anything from vepc regions. They are not part of the reclaiming process. /Jarkko
