* Paolo Bonzini (pbonz...@redhat.com) wrote: > > > 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.
You mean, unless for example, someone had disabled a CPU feature in the new microcode? Dave > > Paolo -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
