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

Hi Fuad,

On Tue, Jun 15, 2021 at 3:03 AM Fuad Tabba [off-list ref] wrote:

Hi Jing,

quoted

+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 <redacted> #arm64

Cheers,
/fuad

Thanks for the review and testing. Will fix it.

quoted

+
+       /* 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

Thank,
Jing