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KVM is the Kernel-based Virtual Machine [1], a hypervisor system in the Linux Kernel. The firmware in question is, as I (minimally) understand it, like a PC BIO
by sjagoe 7y ago
KVM is the Kernel-based Virtual Machine [1], a hypervisor system in the Linux Kernel. The firmware in question is, as I (minimally) understand it, like a PC BIOS, that does the initial system bootstrapping. So it's not firmware on the physical host, but acts as firmware in the virtualized host.
I don't know enough about KVM to know why this firmware is significant, but I have seen some of QEMU (which can use KVM for its hypervisor) requiring a kernel image separate from the virtual host disk image. This firmware loads a kernel from the disk image itself, like a kernel is loaded from disk on a physical host.
[1] https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine https://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine
- bonzini 7y agoQEMU runs a full-blown firmware (SeaBIOS or UEFI) so it does not need this. You can, if you want, pass the kernel on a command line but it's not the default. However, Firecracker can only boot from a manually-provided kernel so you need this in order to boot from a partition. It is still not a complete replacement for e.g. Grub, which supports boot from various filesystems and from LVM, including encrypted logical volumes.