From: Yosry Ahmed Date: Fri, 21 Nov 2025 20:48:03 +0000 (+0000) Subject: KVM: selftests: Extend vmx_set_nested_state_test to cover SVM X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ca2eccb953fd33ef38701e33e660b21f7e84aa14;p=thirdparty%2Flinux.git KVM: selftests: Extend vmx_set_nested_state_test to cover SVM Add test cases for the validation checks in svm_set_nested_state(), and allow the test to run with SVM as well as VMX. The SVM test also makes sure that KVM_SET_NESTED_STATE accepts GIF being set or cleared if EFER.SVME is cleared, verifying a recently fixed bug where GIF was incorrectly expected to always be set when EFER.SVME is cleared. Signed-off-by: Yosry Ahmed Link: https://patch.msgid.link/20251121204803.991707-5-yosry.ahmed@linux.dev Signed-off-by: Sean Christopherson --- diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index ba5c2b643efaa..4ddece4ee3654 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -92,6 +92,7 @@ TEST_GEN_PROGS_x86 += x86/nested_close_kvm_test TEST_GEN_PROGS_x86 += x86/nested_emulation_test TEST_GEN_PROGS_x86 += x86/nested_exceptions_test TEST_GEN_PROGS_x86 += x86/nested_invalid_cr3_test +TEST_GEN_PROGS_x86 += x86/nested_set_state_test TEST_GEN_PROGS_x86 += x86/nested_tsc_adjust_test TEST_GEN_PROGS_x86 += x86/nested_tsc_scaling_test TEST_GEN_PROGS_x86 += x86/platform_info_test @@ -120,7 +121,6 @@ TEST_GEN_PROGS_x86 += x86/vmx_exception_with_invalid_guest_state TEST_GEN_PROGS_x86 += x86/vmx_msrs_test TEST_GEN_PROGS_x86 += x86/vmx_invalid_nested_guest_state TEST_GEN_PROGS_x86 += x86/vmx_nested_la57_state_test -TEST_GEN_PROGS_x86 += x86/vmx_set_nested_state_test TEST_GEN_PROGS_x86 += x86/apic_bus_clock_test TEST_GEN_PROGS_x86 += x86/xapic_ipi_test TEST_GEN_PROGS_x86 += x86/xapic_state_test diff --git a/tools/testing/selftests/kvm/x86/vmx_set_nested_state_test.c b/tools/testing/selftests/kvm/x86/nested_set_state_test.c similarity index 71% rename from tools/testing/selftests/kvm/x86/vmx_set_nested_state_test.c rename to tools/testing/selftests/kvm/x86/nested_set_state_test.c index b59a8a17084d8..0f2102b436291 100644 --- a/tools/testing/selftests/kvm/x86/vmx_set_nested_state_test.c +++ b/tools/testing/selftests/kvm/x86/nested_set_state_test.c @@ -1,7 +1,5 @@ // SPDX-License-Identifier: GPL-2.0-only /* - * vmx_set_nested_state_test - * * Copyright (C) 2019, Google LLC. * * This test verifies the integrity of calling the ioctl KVM_SET_NESTED_STATE. @@ -11,6 +9,7 @@ #include "kvm_util.h" #include "processor.h" #include "vmx.h" +#include "svm_util.h" #include #include @@ -249,6 +248,104 @@ void test_vmx_nested_state(struct kvm_vcpu *vcpu) free(state); } +static void vcpu_efer_enable_svm(struct kvm_vcpu *vcpu) +{ + uint64_t old_efer = vcpu_get_msr(vcpu, MSR_EFER); + + vcpu_set_msr(vcpu, MSR_EFER, old_efer | EFER_SVME); +} + +static void vcpu_efer_disable_svm(struct kvm_vcpu *vcpu) +{ + uint64_t old_efer = vcpu_get_msr(vcpu, MSR_EFER); + + vcpu_set_msr(vcpu, MSR_EFER, old_efer & ~EFER_SVME); +} + +void set_default_svm_state(struct kvm_nested_state *state, int size) +{ + memset(state, 0, size); + state->format = 1; + state->size = size; + state->hdr.svm.vmcb_pa = 0x3000; +} + +void test_svm_nested_state(struct kvm_vcpu *vcpu) +{ + /* Add a page for VMCB. */ + const int state_sz = sizeof(struct kvm_nested_state) + getpagesize(); + struct kvm_nested_state *state = + (struct kvm_nested_state *)malloc(state_sz); + + vcpu_set_cpuid_feature(vcpu, X86_FEATURE_SVM); + + /* The format must be set to 1. 0 for VMX, 1 for SVM. */ + set_default_svm_state(state, state_sz); + state->format = 0; + test_nested_state_expect_einval(vcpu, state); + + /* Invalid flags are rejected, KVM_STATE_NESTED_EVMCS is VMX-only */ + set_default_svm_state(state, state_sz); + state->flags = KVM_STATE_NESTED_EVMCS; + test_nested_state_expect_einval(vcpu, state); + + /* + * If EFER.SVME is clear, guest mode is disallowed and GIF can be set or + * cleared. + */ + vcpu_efer_disable_svm(vcpu); + + set_default_svm_state(state, state_sz); + state->flags = KVM_STATE_NESTED_GUEST_MODE; + test_nested_state_expect_einval(vcpu, state); + + state->flags = 0; + test_nested_state(vcpu, state); + + state->flags = KVM_STATE_NESTED_GIF_SET; + test_nested_state(vcpu, state); + + /* Enable SVM in the guest EFER. */ + vcpu_efer_enable_svm(vcpu); + + /* Setting vmcb_pa to a non-aligned address is only fine when not entering guest mode */ + set_default_svm_state(state, state_sz); + state->hdr.svm.vmcb_pa = -1ull; + state->flags = 0; + test_nested_state(vcpu, state); + state->flags = KVM_STATE_NESTED_GUEST_MODE; + test_nested_state_expect_einval(vcpu, state); + + /* + * Size must be large enough to fit kvm_nested_state and VMCB + * only when entering guest mode. + */ + set_default_svm_state(state, state_sz/2); + state->flags = 0; + test_nested_state(vcpu, state); + state->flags = KVM_STATE_NESTED_GUEST_MODE; + test_nested_state_expect_einval(vcpu, state); + + /* + * Test that if we leave nesting the state reflects that when we get it + * again, except for vmcb_pa, which is always returned as 0 when not in + * guest mode. + */ + set_default_svm_state(state, state_sz); + state->hdr.svm.vmcb_pa = -1ull; + state->flags = KVM_STATE_NESTED_GIF_SET; + test_nested_state(vcpu, state); + vcpu_nested_state_get(vcpu, state); + TEST_ASSERT(state->size >= sizeof(*state) && state->size <= state_sz, + "Size must be between %ld and %d. The size returned was %d.", + sizeof(*state), state_sz, state->size); + + TEST_ASSERT_EQ(state->hdr.svm.vmcb_pa, 0); + TEST_ASSERT_EQ(state->flags, KVM_STATE_NESTED_GIF_SET); + + free(state); +} + int main(int argc, char *argv[]) { struct kvm_vm *vm; @@ -257,20 +354,20 @@ int main(int argc, char *argv[]) have_evmcs = kvm_check_cap(KVM_CAP_HYPERV_ENLIGHTENED_VMCS); + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX) || + kvm_cpu_has(X86_FEATURE_SVM)); TEST_REQUIRE(kvm_has_cap(KVM_CAP_NESTED_STATE)); - /* - * AMD currently does not implement set_nested_state, so for now we - * just early out. - */ - TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX)); - vm = vm_create_with_one_vcpu(&vcpu, NULL); /* - * First run tests with VMX disabled to check error handling. + * First run tests with VMX/SVM disabled to check error handling. + * test_{vmx/svm}_nested_state() will re-enable as needed. */ - vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_VMX); + if (kvm_cpu_has(X86_FEATURE_VMX)) + vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_VMX); + else + vcpu_clear_cpuid_feature(vcpu, X86_FEATURE_SVM); /* Passing a NULL kvm_nested_state causes a EFAULT. */ test_nested_state_expect_efault(vcpu, NULL); @@ -299,7 +396,10 @@ int main(int argc, char *argv[]) state.flags = KVM_STATE_NESTED_RUN_PENDING; test_nested_state_expect_einval(vcpu, &state); - test_vmx_nested_state(vcpu); + if (kvm_cpu_has(X86_FEATURE_VMX)) + test_vmx_nested_state(vcpu); + else + test_svm_nested_state(vcpu); kvm_vm_free(vm); return 0;