On Wed, Jul 21, 2021 at 02:56:46PM +0800, Gary Lin wrote: > BTW, it seems to me that QEMU fwcfg is only used for Xen Direct Kernel > Boot. However, per xl.cfg manpage, it's possible to turn on or off S3 > support by setting "acpi_s3" in xl.cfg, but PcdAcpiS3Enable wasn't set > in the current OvmfXen implementation. Just wonder how xl passes the S3 > support bit to OvmfXen.
It doesn't. "acpi_s3" doesn't have any control over PcdAcpiS3Enable, and doesn't have any control over QEMU, so QEMU would probably always say S3 is available. What happen when "acpi_s3" is set or not is: - the value is stored in xenstore - hvmloader (which runs before OVMF) read the xenstore value and adds the appropriate ACPI SSDT table to allow S3. Cheers, -- Anthony PERARD -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#78209): https://edk2.groups.io/g/devel/message/78209 Mute This Topic: https://groups.io/mt/84061313/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-