On Wed, 2023-11-29 at 13:13 -0800, Teres Alexis, Alan Previn wrote: > On Mon, 2023-11-27 at 15:24 -0500, Vivi, Rodrigo wrote: > > On Wed, Nov 22, 2023 at 12:30:03PM -0800, Alan Previn wrote: > alan:snip > alan: thanks for reviewing and apologize for replying to this late. > > > > /* > > > - * On MTL and newer platforms, protected contexts require setting > > > - * the LRC run-alone bit or else the encryption will not happen. > > > + * Wa_14019159160 - Case 2: mtl > > > + * On some platforms, protected contexts require setting > > > + * the LRC run-alone bit or else the encryption/decryption will not happen. > > > + * NOTE: Case 2 only applies to PXP use-case of said workaround. > > > */ > > > > hmm, interesting enough, on the wa description I read that it is incomplete for MTL/ARL > > and something about a fuse bit. We should probably chase for some clarification in the > > HSD?! > alan: yes, i went through the HSD description with the architect and we both had agreed that > that from the KMD's perspective. At that time, the checking of the fuse from KMD's > could be optimized out for Case-2-PXP: if the fuses was set a certain way, KMD can skip setting > the bit in lrc because hw will enforce runalone in pxp mode irrespective of what KMD does but > if fuse was was not set that way KMD needed to set the runalone in lrc. So for case2, its simpler > to just turn it on always when the context is protected. However, that said, i realized the > wording of the HSDs have changed since the original patch was implemented so i will reclarify > offline and reply back. NOTE: i believe John Harrison is working on case-3 through a > separate series. alan: based on conversations with the architect, a different WA number, 14019725520, has the details of case-2 that explains the relationship the new fuse. However, as before it can be optimized as explained above where PXP context need to always set this bit to ensure encryption/decryption engages.
