Print the vcpu_id and errno when the KVM_CREATE_VCPU ioctl fails, for
debug purposes.
This helped in debugging an issue with KVM on PowerVM, where KVM_CREATE_VCPU
only supports max 2048 vcpus, because the PAPR_HCALL H_GUEST_CREATE_VCPU
("Documentation/arch/powerpc/kvm-nested.rst") supports only up to 0-2047
vcpu_id. However KVM_CAP_MAX_VCPUS capability extension always reports max_vcpus
as NR_CPUS of the host.Signed-off-by: Ritesh Harjani (IBM) <[email protected]> --- tools/testing/selftests/kvm/lib/kvm_util.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index e00a25f59416..6319e2037882 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1354,6 +1354,13 @@ struct kvm_vcpu *__vm_vcpu_add(struct kvm_vm *vm, u32 vcpu_id) vcpu->vm = vm; vcpu->id = vcpu_id; vcpu->fd = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)(unsigned long)vcpu_id); + if (vcpu->fd < 0) { + int saved_errno = errno; + + pr_info("Failed KVM_CREATE_VCPU for vcpu_id %u with errno %d\n", + vcpu_id, saved_errno); + errno = saved_errno; + } TEST_ASSERT_VM_VCPU_IOCTL(vcpu->fd >= 0, KVM_CREATE_VCPU, vcpu->fd, vm); TEST_ASSERT(vcpu_mmap_sz() >= sizeof(*vcpu->run), "vcpu mmap size " -- 2.39.5
