Commit e3645446 authored by Sean Christopherson's avatar Sean Christopherson
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KVM: selftests: Add CPUID tests for Hyper-V features that need in-kernel APIC 



Add testcases to x86's Hyper-V CPUID test to verify that KVM advertises
support for features that require an in-kernel local APIC appropriately,
i.e. that KVM hides support from the vCPU-scoped ioctl if the VM doesn't
have an in-kernel local APIC.

Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250118003454.2619573-5-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent cd5a0c2f

tools/testing/selftests/kvm/x86/hyperv_cpuid.c

+14 −1
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ static bool smt_possible(void) 


static void test_hv_cpuid(struct kvm_vcpu *vcpu, bool evmcs_expected)

{

	const bool has_irqchip = !vcpu || vcpu->vm->has_irqchip;

	const struct kvm_cpuid2 *hv_cpuid_entries;

	int i;

	int nent_expected = 10;
@@ -85,12 +86,19 @@ static void test_hv_cpuid(struct kvm_vcpu *vcpu, bool evmcs_expected) 
				    entry->eax, evmcs_expected

				);

			break;

		case 0x40000003:

			TEST_ASSERT(has_irqchip || !(entry->edx & BIT(19)),

				    "\"Direct\" Synthetic Timers should require in-kernel APIC");

			break;

		case 0x40000004:

			test_val = entry->eax & (1UL << 18);



			TEST_ASSERT(!!test_val == !smt_possible(),

				    "NoNonArchitecturalCoreSharing bit"

				    " doesn't reflect SMT setting");



			TEST_ASSERT(has_irqchip || !(entry->eax & BIT(10)),

				    "Cluster IPI (i.e. SEND_IPI) should require in-kernel APIC");

			break;

		case 0x4000000A:

			TEST_ASSERT(entry->eax & (1UL << 19),
@@ -145,9 +153,14 @@ int main(int argc, char *argv[]) 


	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));



	vm = vm_create_with_one_vcpu(&vcpu, guest_code);

	/* Test the vCPU ioctl without an in-kernel local APIC. */

	vm = vm_create_barebones();

	vcpu = __vm_vcpu_add(vm, 0);

	test_hv_cpuid(vcpu, false);

	kvm_vm_free(vm);



	/* Test vCPU ioctl version */

	vm = vm_create_with_one_vcpu(&vcpu, guest_code);

	test_hv_cpuid_e2big(vm, vcpu);

	test_hv_cpuid(vcpu, false);