Commit 20e41672 authored by David Dunn's avatar David Dunn Committed by Paolo Bonzini
Browse files

KVM: selftests: Verify disabling PMU virtualization via KVM_CAP_CONFIG_PMU 



On a VM with PMU disabled via KVM_CAP_PMU_CONFIG, the PMU should not be
usable by the guest.

Signed-off-by: default avatarDavid Dunn <daviddunn@google.com>
Message-Id: <20220223225743.2703915-4-daviddunn@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent f49b8138

tools/testing/selftests/kvm/x86_64/pmu_event_filter_test.c

+33 −0
Original line number Diff line number Diff line
@@ -325,6 +325,37 @@ static void test_not_member_allow_list(struct kvm_vm *vm) 
	TEST_ASSERT(!count, "Disallowed PMU Event is counting");

}



/*

 * Verify that setting KVM_PMU_CAP_DISABLE prevents the use of the PMU.

 *

 * Note that KVM_CAP_PMU_CAPABILITY must be invoked prior to creating VCPUs.

 */

static void test_pmu_config_disable(void (*guest_code)(void))

{

	int r;

	struct kvm_vm *vm;

	struct kvm_enable_cap cap = { 0 };



	r = kvm_check_cap(KVM_CAP_PMU_CAPABILITY);

	if (!(r & KVM_PMU_CAP_DISABLE))

		return;



	vm = vm_create_without_vcpus(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES);



	cap.cap = KVM_CAP_PMU_CAPABILITY;

	cap.args[0] = KVM_PMU_CAP_DISABLE;

	TEST_ASSERT(!vm_enable_cap(vm, &cap), "Failed to set KVM_PMU_CAP_DISABLE.");



	vm_vcpu_add_default(vm, VCPU_ID, guest_code);

	vm_init_descriptor_tables(vm);

	vcpu_init_descriptor_tables(vm, VCPU_ID);



	TEST_ASSERT(!sanity_check_pmu(vm),

		    "Guest should not be able to use disabled PMU.");



	kvm_vm_free(vm);

}



/*

 * Check for a non-zero PMU version, at least one general-purpose

 * counter per logical processor, an EBX bit vector of length greater
@@ -430,5 +461,7 @@ int main(int argc, char *argv[]) 


	kvm_vm_free(vm);



	test_pmu_config_disable(guest_code);



	return 0;

}