On 9 December 2014 at 10:50, Kashyap Chamarthy <kcham...@redhat.com> wrote: > Booting a minimal KVM guest throws the below error on Cubietruck: > > "kvm_init_vcpu failed: Invalid argument" > > More context and an easy reproducer in this QEMU bug[1] for Fedora. > > Context quoting Rich Jones from comment #2: > > "For some reason I thought this had been fixed upstream, but > now that I've finally got my CT working again, I see that I > am still carrying that patch in my custom qemu. > > diff --git a/target-arm/cpu.c b/target-arm/cpu.c > index 5ce7350..04d69d1 100644 > --- a/target-arm/cpu.c > +++ b/target-arm/cpu.c > @@ -858,7 +858,7 @@ static void cortex_a15_initfn(Object *obj) > set_feature(&cpu->env, ARM_FEATURE_DUMMY_C15_REGS); > set_feature(&cpu->env, ARM_FEATURE_CBAR_RO); > set_feature(&cpu->env, ARM_FEATURE_LPAE); > - cpu->kvm_target = QEMU_KVM_ARM_TARGET_CORTEX_A15; > + cpu->kvm_target = QEMU_KVM_ARM_TARGET_CORTEX_A7; > cpu->midr = 0x412fc0f1; > cpu->reset_fpsid = 0x410430f0; > cpu->mvfr0 = 0x10110222;
This is obviously a bogus patch -- this is the initfn for Cortex-A15 so telling it to be a Cortex-A7 is wrong (and would break working setups on A15 hosts). > So that's the answer really, it's a qemu bug. Actually it looks as > if qemu contains some code to try to get the host CPU type, but it > doesn't work, or maybe we need to pass a -cpu option ..." Yes, you need to pass a -cpu option. For KVM on ARM, you always need to either: * pass a -cpu option matching the host CPU * pass "-cpu host" The CubieTruck is a Cortex-A7, which we don't have specific support for in QEMU, so you will need "-cpu host". thanks -- PMM
