qemu: fail before running hostagent when QEMU is too old

[afbjorklund]

Description

Need a reasonable QEMU, something like qemu-system 4+

See https://repology.org/project/qemu/badges for a summary

The hostagent fails when running on RHEL 7, without a clear reason.

Better to state up front, that it needs something newer than 1.5.3

[afbjorklund]

Could run some more experiments, but qemu 1.5.3 is too old and qemu 4.2.1 is new enough

So maybe a reasonable cut-off point could be 4.0.0, but could experiment with 2.0.0 or 3.0.0

Related to:

• docs: find out the oldest QEMU version that is compatible with Lima #320

[afbjorklund]

Example too old:

QEMU emulator version 1.5.3 (qemu-kvm-1.5.3-175.el7_9.6), Copyright (c) 2003-2008 Fabrice Bellard

QEMU emulator version 2.0.0 (Debian 2.0.0+dfsg-2ubuntu1.46), Copyright (c) 2003-2008 Fabrice Bellard

QEMU emulator version 2.5.0 (Debian 1:2.5+dfsg-5ubuntu10.51), Copyright (c) 2003-2008 Fabrice Bellard

QEMU emulator version 2.11.1(Debian 1:2.11+dfsg-1ubuntu7.42)
Copyright (c) 2003-2017 Fabrice Bellard and the QEMU Project developers

Example new enough:

QEMU emulator version 4.2.1 (Debian 1:4.2-3ubuntu6.26)
Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers

QEMU emulator version 6.2.0 (Debian 1:6.2+dfsg-2ubuntu6.8)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

QEMU emulator version 6.2.0 (qemu-kvm-6.2.0-22.module_el8.7.0+3493+5ed0bd1c.2)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers

QEMU emulator version 7.2.0 (qemu-kvm-7.2.0-14.el9_2)
Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers

Custom upstream build:

QEMU emulator version 8.0.0 (v8.0.0)
Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers

[afbjorklund]

There are still failures, due to qemu-img also being too old - and not supporting all flags

failed to run [qemu-img info --output=json --force-share /home/user/.lima/default/basedisk]
stderr="info: unrecognized option '--force-share'\n": exit status 1

failed to run [/usr/bin/qemu-system-x86_64 -M none -accel help]
stderr=\"qemu-system-x86_64: -accel: invalid option\\n\"

So there need to be some similar checks, also for the invocations of qemu on the host side

---

only -help

-machine [type=]name[,prop[=value][,...]]
                selects emulated machine ('-machine help' for list)
                property accel=accel1[:accel2[:...]] selects accelerator
                supported accelerators are kvm, xen, tcg (default: tcg)
                kernel_irqchip=on|off controls accelerated irqchip support
                kvm_shadow_mem=size of KVM shadow MMU
                dump-guest-core=on|off include guest memory in a core dump (default=on)
                mem-merge=on|off controls memory merge support (default: on)

-netdev [user|tap|bridge|socket|hubport],id=str[,option][,option][,...]