Il 21/02/2013 19:24, Laszlo Ersek ha scritto: >> > (1) The reset capability that OVMF exports via ACPI -- I agree that I >> > should be effecting the 0xCF9 thing in the appropriate table. > On a second thought, this will require a new build -D flag, or a PCD. > > I'm not worried about the ACPI 1.0 --> ACPI 2.0 change in the FADT, the > table struct itself forward compatible. > > However currently we're not saying anything about the reset capabilities > of the platform. A client looking at the FADT for reset info will find > nothing and follow its own logic, which may or may not include writing > to 0xCF9, but we don't have any part in it. > > If now the FADT starts to claim 0xCF9 on a qemu version that doesn't > actually support it, we could mislead the client. Unless we can > interrogate qemu about the support (and I think we can't), we'll have to > depend on a build-time option. (Or should I shoehorn it into -D CSM_ENABLE?) > > Jordan, what do you think?
ACPI tables are hosed enough on some real system that we can assume that all guests will fall back to something else---typically a keyboard controller reset. See the sequence that Windows does: ACPI, kbd, ACPI, kbd. Paolo
