diff --git a/documentation/dev-manual/dev-manual-qemu.xml b/documentation/dev-manual/dev-manual-qemu.xml index f4719ebc3c..4e7b5de4e8 100644 --- a/documentation/dev-manual/dev-manual-qemu.xml +++ b/documentation/dev-manual/dev-manual-qemu.xml @@ -343,6 +343,40 @@ +
+ QEMU CPU Compatibility Under KVM + + + By default, the QEMU build compiles for and targets 64-bit and x86 + Intel Core2 + 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. + +
+
QEMU Performance