Re: [PATCH v9 4/5] KVM: selftests: Add selftest for KVM statistics data binary interface

[Fuad Tabba <tabba@google.com>]

Hi Jing,

> +int main(int argc, char *argv[])
> +{
> +       int max_vm = DEFAULT_NUM_VM, max_vcpu = DEFAULT_NUM_VCPU, ret, i, j;
> +       struct kvm_vm **vms;
> +
> +       /* Get the number of VMs and VCPUs that would be created for testing. */
> +       if (argc > 1) {
> +               max_vm = strtol(argv[1], NULL, 0);
> +               if (max_vm <= 0)
> +                       max_vm = DEFAULT_NUM_VM;
> +       }
> +       if (argc > 2) {
> +               max_vcpu = strtol(argv[2], NULL, 0);
> +               if (max_vcpu <= 0)
> +                       max_vcpu = DEFAULT_NUM_VCPU;
> +       }
> +
> +       /* Check the extension for binary stats */
> +       ret = kvm_check_cap(KVM_CAP_BINARY_STATS_FD);
> +       TEST_ASSERT(ret >= 0,
> +                       "Binary form statistics interface is not supported");

kvm_check_cap returns the value of KVM_CHECK_EXTENSION, which is 0 if
unsupported (-ERROR on an error). The assertion should be for ret > 0.

Made that change locally, and tested it with various configurations
(vhe, nvhe), as well as kernel versions (with and without
KVM_CAP_BINARY_STATS_FD), and it passes (or fails as expected).
Without that fix and with a kernel that doesn't support
KVM_CAP_BINARY_STATS_FD, it passes that assertion, but fails later at
vcpu_stats_test().

With that fixed:
Tested-by: Fuad Tabba <tabba@google.com> #arm64

Cheers,
/fuad


> +
> +       /* Create VMs and VCPUs */
> +       vms = malloc(sizeof(vms[0]) * max_vm);
> +       TEST_ASSERT(vms, "Allocate memory for storing VM pointers");
> +       for (i = 0; i < max_vm; ++i) {
> +               vms[i] = vm_create(VM_MODE_DEFAULT,
> +                               DEFAULT_GUEST_PHY_PAGES, O_RDWR);
> +               for (j = 0; j < max_vcpu; ++j)
> +                       vm_vcpu_add(vms[i], j);
> +       }
> +
> +       /* Check stats read for every VM and VCPU */
> +       for (i = 0; i < max_vm; ++i) {
> +               vm_stats_test(vms[i]);
> +               for (j = 0; j < max_vcpu; ++j)
> +                       vcpu_stats_test(vms[i], j);
> +       }
> +
> +       for (i = 0; i < max_vm; ++i)
> +               kvm_vm_free(vms[i]);
> +       free(vms);
> +       return 0;
> +}
> diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
> index 5c70596dd1b9..83c02cb0ae1e 100644
> --- a/tools/testing/selftests/kvm/lib/kvm_util.c
> +++ b/tools/testing/selftests/kvm/lib/kvm_util.c
> @@ -2286,3 +2286,15 @@ unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size)
>         n = DIV_ROUND_UP(size, vm_guest_mode_params[mode].page_size);
>         return vm_adjust_num_guest_pages(mode, n);
>  }
> +
> +int vm_get_stats_fd(struct kvm_vm *vm)
> +{
> +       return ioctl(vm->fd, KVM_GET_STATS_FD, NULL);
> +}
> +
> +int vcpu_get_stats_fd(struct kvm_vm *vm, uint32_t vcpuid)
> +{
> +       struct vcpu *vcpu = vcpu_find(vm, vcpuid);
> +
> +       return ioctl(vcpu->fd, KVM_GET_STATS_FD, NULL);
> +}
> --
> 2.32.0.272.g935e593368-goog
>