On Mon, Sep 13, 2021 at 9:06 AM Xu, Min M <min.m...@intel.com> wrote: > > > > +TdxApWait: > > > + cmp byte[TDX_WORK_AREA_PGTBL_READY], 0 > > > + je TdxApWait > > Don't we need memory fence before je TdxApWait. I did not check > > what the compiler generates for this loop. > Below is the code compiler generated for this loop. (VS2017/release) > 106 <1> TdxApWait: > 107 0000070B 803D04B0800000 <1> cmp > byte[TDX_WORK_AREA_PGTBL_READY], 0 > 108 00000712 74F7 <1> je TdxApWait > 109 00000714 EB17 <1> jmp > ExitInitTdxWorkarea > > This is the code lfence is added. > 106 <1> TdxApWait: > 107 0000070B 803D04B0800000 <1> cmp > byte[TDX_WORK_AREA_PGTBL_READY], 0 > 108 00000712 0FAEE8 <1> lfence > 109 00000715 74F4 <1> je TdxApWait > 110 00000717 EB17 <1> jmp > ExitInitTdxWorkarea > > I am not sure if lfence is needed.
Thanks Min! You are right, I also checked it with GCC5 and saw the same output. Thanks for checking it. -Erdem -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#80631): https://edk2.groups.io/g/devel/message/80631 Mute This Topic: https://groups.io/mt/84837891/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
