On Wed, 17 May 2023 at 03:23, Jiatong Shen <yshxxsjt...@gmail.com> wrote: > > Hello community Experts! > > I am doing some experiments with arm64 host machine. The host machine is > kunpeng 920 5251k. I try to boot a virtual machine with the following command: > > qemu-system-aarch64 -cpu cortex-a53 -enable-kvm -smp 1 -m 4096 -M > virt,gic-version=3 > > Here I have modified the code, and change kvm_target from > QEMU_KVM_ARM_TARGET_CORTEX_A53 to 5(generic arm v8).
This is part of what is confusing you: this is not a correct change. > when the vm boots, I try to use lscpu, but I still saw some feature flags > like atomics exist. In a KVM VM you will always see in the guest the exact same CPU type as the host. There is no support in the kernel for showing the guest a different CPU type to what the hardware has. At the QEMU level, that means you should always use '-cpu host' when using KVM. (Or you can use '-cpu max' if you want the same command line to work without KVM. For KVM max and host do the same thing.) thanks -- PMM
