On 3/16/23 11:56, Jim Fehlig wrote:
On 3/15/23 08:40, Ján Tomko wrote:
On a Monday in 2023, Jim Fehlig wrote:
If an explicit machine type is not specified in the VM config, the qemu
driver will select the first machine type in the list of machine types for
the specified accelerator. See virQEMUCapsGetPreferredMachine
https://gitlab.com/libvirt/libvirt/-/blob/master/src/qemu/qemu_capabilities.c#L6133
On my test machines, this works reasonably well for x86_64 where the first
machine type is pc-i440fx-7.1. But for aarch64, the first machine is
integratorcp, which is not very useful with maxCpus=1 and other limitations.
Is it possible to run such machine with libvirt?
I just did a quick check with libvirt 9.1.0 (qemu is a bit older, at 7.1.0):
# cat test.xml
<domain type='kvm'>
<name>test</name>
<memory unit='KiB'>2097152</memory>
<vcpu placement='static'>1</vcpu>
<os>
<type>hvm</type>
<loader readonly='yes'
type='pflash'>/usr/share/qemu/aavmf-aarch64-code.bin</loader>
<nvram template='/usr/share/qemu/aavmf-aarch64-vars.bin'/>
<boot dev='hd'/>
</os>
<clock offset='utc'/>
<on_poweroff>destroy</on_poweroff>
<on_reboot>restart</on_reboot>
<on_crash>destroy</on_crash>
<devices>
<emulator>/usr/bin/qemu-system-aarch64</emulator>
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2' discard='unmap'/>
<source file='/var/lib/libvirt/images/test.qcow2'/>
<target dev='vda' bus='virtio'/>
</disk>
</devices>
</domain>
To be fair, this config does not work when specifying machine='virt'
# virsh create test.xml
error: Failed to create domain from test.xml
error: internal error: process exited while connecting to monitor:
2023-03-16T21:37:30.895916Z qemu-system-aarch64: KVM is not supported for this
guest CPU type
2023-03-16T21:37:30.895989Z qemu-system-aarch64: kvm_init_vcpu:
kvm_arch_init_vcpu failed (0): Invalid argument
It worked after adding
<cpu mode='host-passthrough'/>
# virsh create test.xml
error: Failed to create domain from test.xml
error: internal error: Unexpected enum value 0 for virDomainDeviceAddressType
The same error occurs with host-passthrough CPU and default machine type.
Regards,
Jim
