4.7. QEMU CPU Compatibility Under KVM

By default, the QEMU build compiles for and targets 64-bit and x86 Intel® Core™2 Duo processors and 32-bit x86 Intel® Pentium® II processors. QEMU builds for and targets these CPU types because they display a broad range of CPU feature compatibility with many commonly used CPUs.

Despite this broad range of compatibility, the CPUs could support a feature that your host CPU does not support. Although this situation is not a problem when QEMU uses software emulation of the feature, it can be a problem when QEMU is running with KVM enabled. Specifically, software compiled with a certain CPU feature crashes when run on a CPU under KVM that does not support that feature. To work around this problem, you can override QEMU's runtime CPU setting by changing the QB_CPU_KVM variable in qemuboot.conf in the Build Directory's deploy/image directory. This setting specifies a -cpu option passed into QEMU in the runqemu script. Running qemu -cpu help returns a list of available supported CPU types.