On 19/11/2014 15:03, Juan Quintela wrote: > Paolo Bonzini <pbonz...@redhat.com> wrote: >> On 19/11/2014 14:49, Juan Quintela wrote: >>>>> Real hardware lets users update firmware and so should virtual hardware. >>> But you can hibernate your laptop, update the firmware, and reboot? >>> Where the change can be anyting, like moving from traditional BIOS to >>> UEFI? >> >> Wait wait wait. I totally cannot follow. What would be the equivalent >> in QEMU? > > qemu-2.0 -M pc-2.0 > > migrate to disk/s3/s4 > > upgrade qemu > > qemu-2.2 -M pc-2.0 > > try interesting variation of s3/s4/migration to disk. Migration to disk > should work (we migrate BIOS ROM blocks, enphasis on ROM), s3 perhaps > (machine needs to be saved to disk), s4 ..... depends how it ends being > done.
Ok, got it. S3 + migrate to disk should work. S4 probably would work, but I think it would work on a real system too as long as you update software and not hardware (e.g. changing the motherboard would change the MAC address of the on-board NIC, for example). Consider the similar case on real hardware: boot update microcode RPM s4 turn on CPU microcode is installed early by the kernel, before looking for a hibernation image to resume from, so the CPU microcode after resume from S4 is different from the microcode at the time you suspended to disk. This probably would work. Paolo
