On 9/22/21 3:21 AM, Gerd Hoffmann wrote: > On Mon, Sep 20, 2021 at 01:45:49PM -0500, Brijesh Singh wrote: >> BZ: >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Fbugzilla.tianocore.org%2Fshow_bug.cgi%3Fid%3D3275&data=04%7C01%7Cbrijesh.singh%40amd.com%7Cdb7ae27f87684e0252d008d97da1f85f%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637678956888503398%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&sdata=Cm1E%2BJSrQ%2B%2BCjv5ZqC%2BXNqVGbzwZ32PFGDTZtoL8e84%3D&reserved=0 >> >> The initial page built during the SEC phase is used by the >> MemEncryptSevSnpValidateSystemRam() for the system RAM validation. The >> page validation process requires using the PVALIDATE instruction; the >> instruction accepts a virtual address of the memory region that needs >> to be validated. If hardware encounters a page table walk failure (due >> to page-not-present) then it raises #GP. >> >> The initial page table built in SEC phase address up to 4GB. Add an >> internal function to extend the page table to cover > 4GB. The function >> builds 1GB entries in the page table for access > 4GB. This will provide >> the support to call PVALIDATE instruction for the virtual address > >> 4GB in PEI phase. > Hmm, well, playing with page tables like that in sev-specific code > instead of having memory core handle this properly is quite hackish. > > What is the long-term plan with this? I assume once support for lazy > acceptance/validation is merged we can simply delete this?
Yes, this is just an interim problem. Once we move to lazy validation then this will be removed. > > Assuming this is only a temporary solution I think we can tolerate the > hacks. > > take care, > Gerd > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#81085): https://edk2.groups.io/g/devel/message/81085 Mute This Topic: https://groups.io/mt/85749032/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
