Merge tag 'kvm-x86-hyperv-6.8' of https://github.com/kvm-x86/linux into HEAD

KVM x86 Hyper-V changes for 6.8:

 - Guard KVM-on-HyperV's range-based TLB flush hooks with an #ifdef on
   CONFIG_HYPERV as a minor optimization, and to self-document the code.

 - Add CONFIG_KVM_HYPERV to allow disabling KVM support for HyperV "emulation"
   at build time.

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

@@ -211,6 +211,8 @@ int main(void)
 	vm_vaddr_t tsc_page_gva;
 	int stage;
 
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_TIME));
+
 	vm = vm_create_with_one_vcpu(&vcpu, guest_main);
 
 	vcpu_set_hv_cpuid(vcpu);

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

@@ -240,11 +240,12 @@ int main(int argc, char *argv[])
 	struct ucall uc;
 	int stage;
 
-	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
-
 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE));
 	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS));
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_DIRECT_TLBFLUSH));
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 
 	hcall_page = vm_vaddr_alloc_pages(vm, 1);
 	memset(addr_gva2hva(vm, hcall_page), 0x0,  getpagesize());

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

@@ -43,6 +43,8 @@ int main(void)
 	uint64_t *outval;
 	struct ucall uc;
 
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_CPUID));
+
 	/* Verify if extended hypercalls are supported */
 	if (!kvm_cpuid_has(kvm_get_supported_hv_cpuid(),
 			   HV_ENABLE_EXTENDED_HYPERCALLS)) {

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

@@ -690,6 +690,8 @@ static void guest_test_hcalls_access(void)
 
 int main(void)
 {
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_ENFORCE_CPUID));
+
 	pr_info("Testing access to Hyper-V specific MSRs\n");
 	guest_test_msrs_access();
 

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

@@ -248,6 +248,8 @@ int main(int argc, char *argv[])
 	int stage = 1, r;
 	struct ucall uc;
 
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_SEND_IPI));
+
 	vm = vm_create_with_one_vcpu(&vcpu[0], sender_guest_code);
 
 	/* Hypercall input/output */

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

@@ -158,6 +158,7 @@ int main(int argc, char *argv[])
 	int stage;
 
 	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM));
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_DIRECT_TLBFLUSH));
 
 	/* Create VM */
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);

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

@@ -590,6 +590,8 @@ int main(int argc, char *argv[])
 	struct ucall uc;
 	int stage = 1, r, i;
 
+	TEST_REQUIRE(kvm_has_cap(KVM_CAP_HYPERV_TLBFLUSH));
+
 	vm = vm_create_with_one_vcpu(&vcpu[0], sender_guest_code);
 
 	/* Test data page */

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

@@ -125,21 +125,25 @@ void test_vmx_nested_state(struct kvm_vcpu *vcpu)
 
 	/*
 	 * Setting vmxon_pa == -1ull and vmcs_pa == -1ull exits early without
-	 * setting the nested state but flags other than eVMCS must be clear.
-	 * The eVMCS flag can be set if the enlightened VMCS capability has
-	 * been enabled.
+	 * setting the nested state. When the eVMCS flag is not set, the
+	 * expected return value is '0'.
 	 */
 	set_default_vmx_state(state, state_sz);
+	state->flags = 0;
 	state->hdr.vmx.vmxon_pa = -1ull;
 	state->hdr.vmx.vmcs12_pa = -1ull;
-	test_nested_state_expect_einval(vcpu, state);
+	test_nested_state(vcpu, state);
 
-	state->flags &= KVM_STATE_NESTED_EVMCS;
+	/*
+	 * When eVMCS is supported, the eVMCS flag can only be set if the
+	 * enlightened VMCS capability has been enabled.
+	 */
 	if (have_evmcs) {
+		state->flags = KVM_STATE_NESTED_EVMCS;
 		test_nested_state_expect_einval(vcpu, state);
 		vcpu_enable_evmcs(vcpu);
+		test_nested_state(vcpu, state);
 	}
-	test_nested_state(vcpu, state);
 
 	/* It is invalid to have vmxon_pa == -1ull and SMM flags non-zero. */
 	state->hdr.vmx.smm.flags = 1;