On Mon, Dec 6, 2021 at 8:54 AM Dave Hansen <dave.hansen@xxxxxxxxx> wrote: > > On 12/6/21 8:39 AM, Dan Williams wrote: > >> But, the trick is that we need a contract. A contract requires a > >> "meeting of the minds" first. > > The WBINVD requirement in sleep states is about getting cache contents > > out to to power preserved domain before the CPU turns off. The bare > > metal host handles that requirement. The conversation that needs to be > > had is with the ACPI specification committee to clarify that virtual > > machines have no responsibility to flush caches. We can do that as a > > Code First proposal to the ACPI Specification Working Group. > > Sounds sane to me. So, we effectively go to the ACPI folks and say that > Linux isn't going to do WBINVD in virtualized environments any more. > That was effectively the approach that the first patch in this thread did: > > > https://lore.kernel.org/all/20211116005027.2929297-1-sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx/ > > Right? Correct, my reviewed-by was based on that observation, and now we can close the loop by proposing the specification change.
