On Fri, Jun 14, 2024, Mathias Krause wrote:
> The KVM_SET_BOOT_CPU_ID ioctl missed to reject invalid vCPU IDs. Verify
> this no longer works and gets rejected with an appropriate error code.
>
> Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
> ---
> tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c | 11 +++++++++++
> 1 file changed, 11 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
> index d691d86e5bc3..50a0c3f61baf 100644
> --- a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
> +++ b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
> @@ -33,6 +33,13 @@ static void guest_not_bsp_vcpu(void *arg)
> GUEST_DONE();
> }
>
> +static void test_set_invalid_bsp(struct kvm_vm *vm)
> +{
> + int r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(1L << 32));
> +
I also added a test to verify KVM_CAP_MAX_VCPU_ID+1 also fails, because why not.
unsigned long max_vcpu_id = vm_check_cap(vm, KVM_CAP_MAX_VCPU_ID);
int r;
if (max_vcpu_id) {
r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(max_vcpu_id + 1));
TEST_ASSERT(r == -1 && errno == EINVAL, "BSP with ID > MAX should fail");
}
r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(1L << 32));
TEST_ASSERT(r == -1 && errno == EINVAL, "BSP with ID[63:32]!=0 should fail");
> + TEST_ASSERT(r == -1 && errno == EINVAL, "invalid KVM_SET_BOOT_CPU_ID set");
> +}
> +
> static void test_set_bsp_busy(struct kvm_vcpu *vcpu, const char *msg)
> {
> int r = __vm_ioctl(vcpu->vm, KVM_SET_BOOT_CPU_ID,
> @@ -75,11 +82,15 @@ static void run_vcpu(struct kvm_vcpu *vcpu)
> static struct kvm_vm *create_vm(uint32_t nr_vcpus, uint32_t bsp_vcpu_id,
> struct kvm_vcpu *vcpus[])
> {
> + static int invalid_bsp_tested;
> struct kvm_vm *vm;
> uint32_t i;
>
> vm = vm_create(nr_vcpus);
>
> + if (!invalid_bsp_tested++)
I dropped this and just had every VM run the negative test. There's zero chance
anyone will ever notice an extra failed ioctl() or three, whereas it took me a
second to realize this is just a somewhat lazy way of writing a one-off negative
test.
> + test_set_invalid_bsp(vm);
> +
> vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(unsigned long)bsp_vcpu_id);
>
> for (i = 0; i < nr_vcpus; i++)
> --
> 2.30.2
>
