Il 01/09/2014 09:20, Gal Hammer ha scritto: >> >> We are still in the process of defining which devices/methods go in the >> DSDT and which go in the SSDT. We had bad experiences with ACPI table >> migration in 2.1, and one plan to fix them is the following: >> >> * the DSDT should always be the same size no matter what command line >> options are there >> >> * the SSDT should have the exact same content (byte-for-byte) for >> different versions of QEMU, with the same command line options >> (including the machine type). >> >> Right now your code obeys the first rule, not the second rule, so it >> should add the device to the DSDT. > > Are you sure about selecting the DSDT? I don't see anyone else is using > the ACPI_EXTRACT_NAME_* macros in the DSDT table (and I keep crashing my > guest, but ignore it for now ;-)).
There is one user: acpi-dsdt-isa.dsl: ACPI_EXTRACT_NAME_BYTE_CONST DSDT_APPLESMC_STA >> BTW, which events would cause the ID to change? How should live cloning >> (or revert to a disk+RAM snapshot) be implemented by layers above QEMU >> for the VM gen ID to be patched? Can you add something to docs/ about >> it? > > The VGID is expected to change when executing a VM with the -snapshot > option, when a VM is restored from a backup or when it is imported, > copied or cloned. So I would say it is a management's call. Ok, got it. So to support migration (which includes reverting to an earlier disk+RAM snapshot) you just need to ensure the VGID is patched accordingly. Whether VGID _will_ be different or not, that's management's call. > I think that the Microsoft's document describes the requirements better > than me :-). > >> Also, how does this ID compare to the UUID in the DMI info (-uuid)? > > The -uuid is not expected to change after the VM was created. Unlike the > -vmgenid that is designed to give the guest OS a notification that a > change has occurred. Microsoft, as an example, writes that is can be use > for a safer cryptographic software. I would say that cloning should change the UUID (and the VMGID). Paolo
