On Tue, Jun 30, 2020 at 03:27:45PM +0100, Daniel P. Berrangé wrote:
On Tue, Jun 30, 2020 at 04:00:00PM +0200, Florian Weimer wrote:
> * Jóhann B. Guðmundsson:
>
> > Given Hans proposal [1] introduced systemd/grub2/Gnome upstream
> > changes it beg the question if now would not be the time to stop
> > supporting booting in legacy bios mode and move to uefi only supported
> > boot which has been available on any common intel based x86 platform
> > since atleast 2005.
>
> Even for virtualization? Not sure if that can be done.
KVM virt on aarch64 and x86 can support EFI via AVMF / OVMF firmware
built from the edk2 project from a technical POV.
The first challenge will be that many mgmt tools still default to
using legacy BIOS when deploying guest OS. We've been trying to
make it easier for mgmt apps to "do the right thing" by having
libosinfo record metadata about whether each guest OS supports
legacy BIOS, EFI or both. ie we want the mgmt apps to just pick
EFI if they see the OS doesn't support legacy BIOS, instead of
requiring users to manually tell them to use EFI.
Historically we've tended to discourage use of EFI on virt because,
unless you wanted SecureBoot for your VMs, it hasn't offered much
in the way of compelling benefits to users. The EDK2 project code
is a much higher maint burden for virt than the seabios was, and
there's no sign that situation will improve.
Also it's considerably slower to boot to the kernel, especially if you
enable debug messages on an emulated serial port which makes it almost
comically slow.
So I can't say I'm thrilled about a future that depends on
EFI for
virt, but I'm resigned to the fact this is the direction the world
is taking. So we're not likely to have any choice and will have to
work to mitigate any downsides it brings.
Rich.
--
Richard Jones, Virtualization Group, Red Hat
http://people.redhat.com/~rjones
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