Auch wenn z.B. einige CPU-Flags gesetzt wurden?
Ich kenn das z.B. von Proxmox, AMD und INTEL mixen bei Intel-spezifischen Flags funktioniert nicht.
Auszug aus der Proxmox-Help:
CPU Type
QEMU can emulate a number different of
CPU types from 486 to the latest Xeonprocessors. Each new processor generation adds new features, like hardware assisted 3d rendering, random number generation, memory protection, etc.. Also, a current generation can be upgraded through microcode update with bug orsecurity fixes.
Usually you should select for your VM a processor type which closely matches the CPU of the host system, as it means that the host CPU features (also called
CPUflags ) will be available in your VMs. If you want an exact match, you can set the CPU type to
host in which case the VM will have exactly the same CPU flagsas your host system.
This has a downside though. If you want to do a live migration of VMs between different hosts, your VM might end up on a new system with a different CPU type or a different microcode version. If the CPU flags passed to the guest are missing, the QEMU process will stop. To remedy this QEMU has also its own virtual CPU types, that Proxmox VE uses by default.
The backend default is
kvm64 which works on essentially all x86_64 host CPUs and the UI default when creating a new VM is
x86-64-v2-AES, which requires a host CPU starting from Westmere for Intel or at least a fourth generationOpteron for AMD.
In short:
If you don’t care about live migration or have a homogeneous cluster where all nodes have the same CPU and same microcode version, set the CPU type to host, as in theory this will give your guests maximum performance.
If you care about live migration and security, and you have only Intel CPUs or only AMD CPUs, choose the lowest generation CPU model of your cluster.
If you care about live migration without security, or have mixed Intel/AMD cluster, choose the lowest compatible virtual QEMU CPU type.
| Live migrations between Intel and AMD host CPUs have no guarantee to work. |
Gruß!
