On Tue, 10 May 2022 at 10:31, Thomas Huth <th...@redhat.com> wrote: > On 10/05/2022 11.22, Dr. David Alan Gilbert wrote: > > To my mind, qemu-system-arm makes a lot of sense, and I'd rather see the > > 32 bit guests disappear from qemu-system-aarch64. > > It's difficult to justify to someone running their aarch virt stack why > > their binary has the security footprint that includes a camera or PDA.
There's a lot of stuff you would want to chop out if you want a stripped-down "just for KVM" binary, though, and not all of it is 32-bit-related. And unless you're chopping non-KVM machine types and devices out of qemu-system-aarch64 anyway, you need the 32-bit CPU support in there: we have a machine type which has both 64-bit and 32-bit CPUs in it. > I'm not very familiar with KVM on ARM - but is it possible to use KVM there > with an arbitrary machine? If that's the case, a user might want to use KVM > on their 64-bit host to run a 32-bit guest machine, and then you need to > keep the 32-bit machines in the -aarch64 binary. No, Arm KVM is pretty restrictive -- effectively you can only really use it with the 'virt' board. You can do a 32-bit guest, but you do that with qemu-system-aarch64 and telling the 64-bit vcpu "actually start with EL1 (guest kernel) in 32-bit mode". thanks -- PMM
