On Mon, Jul 19, 2021, Sean Christopherson wrote: > On Mon, Jul 19, 2021, Brijesh Singh wrote: > > > > On 7/19/21 12:18 PM, Sean Christopherson wrote: > > > > > > > > Okay, I will add helper to make things easier. One case where we will > > > > need to directly call the rmpupdate() is during the LAUNCH_UPDATE > > > > command. In that case the page is private and its immutable bit is also > > > > set. This is because the firmware makes change to the page, and we are > > > > required to set the immutable bit before the call. > > > > > > Or do "int rmp_make_firmware(u64 pfn, bool immutable)"? > > > > That's not what we need. > > > > We need 'rmp_make_private() + immutable' all in one RMPUPDATE. Here is the > > snippet from SNP_LAUNCH_UPDATE. > > Ah, not firmwrare, gotcha. But we can still use a helper, e.g. an inner > double-underscore helper, __rmp_make_private(). Hmm, looking at it again, I think I also got confused by the comment for the VMSA page: /* Transition the VMSA page to a firmware state. */ e.assigned = 1; e.immutable = 1; e.asid = sev->asid; e.gpa = -1; e.pagesize = RMP_PG_SIZE_4K; Unlike __snp_alloc_firmware_pages() in the CCP code, the VMSA is associated with the guest's ASID, just not a GPA. I.e. the VMSA is more of a specialized guest private page, as opposed to a dedicated firmware page. I.e. a __rmp_make_private() and/or rmp_make_private_immutable() definitely seems like a good idea.
