From nobody Thu Apr 2 06:31:34 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5B046371CF0; Tue, 3 Mar 2026 00:34:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772498082; cv=none; b=dE/paUQ5Jaw+xYhMSl3oZVTpfEh5hzTJXpHGcVEvdNz4BaumZXMDnUA9KNs8A+wigmv8jMk2zjGpsEg6YZlqOK77OH/vrftRlthqHejUm4cG6HemnwZfqlty7ViJ0B1bkazWLzKShh2a7bEchP2N2e7XF67KilNjV5Zc6VSnOsk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772498082; c=relaxed/simple; bh=xZkALjitzazcpl0Fnsnu/oouWxj8iyjzP/CRxFDvIq4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=op5v0vfg1cZ1znXfk1fbbgebhqXHYOazq3NpwYDJECQLC/AMO2uoq9lFd10LfEO0tgD0KEKV6KVuk67NEjVeR2MwMKENK8O8wF0+9W8JMeKcU1/9gxjFPhy/J6i87hl1jjtcwfMKXNU0Hf7NhSh46etPK8ZvmLyD3Xvx7AmhdM0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jFIySHI9; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jFIySHI9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D2156C2BC86; Tue, 3 Mar 2026 00:34:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772498082; bh=xZkALjitzazcpl0Fnsnu/oouWxj8iyjzP/CRxFDvIq4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jFIySHI9g/hS/LXcSBJEJYAkdQCg5Qior+YCxYMqAO6gKRoN5CKa8ULu17hLl+jKy VGZientHWvmPyVGH8f8/N+MtLRrBBttjh6dbp/ISFi+XuIjEMu957L40vsiASrDARr uAdOSMe5DpYD2TdegumOOyshuXrcKJoDbNWmjwCzh4A7nm3rt1uL2YPKC64p8ecjvX EOL1WzTIMi7KuwpVmCKGSuxljTuTaHEUcT6VFo5kco2rgf37illu6h/XGtaSULDuNK jFVfgFM5+S0+aWPflrZpCoWIvJ7gcCNJVjCo4fRdnWhxLxizLLYmOgF6HUmLtVXZs4 fF4pO0CA3q6SA== From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Subject: [PATCH v7 26/26] KVM: selftest: Add a selftest for VMRUN/#VMEXIT with unmappable vmcb12 Date: Tue, 3 Mar 2026 00:34:20 +0000 Message-ID: <20260303003421.2185681-27-yosry@kernel.org> X-Mailer: git-send-email 2.53.0.473.g4a7958ca14-goog In-Reply-To: <20260303003421.2185681-1-yosry@kernel.org> References: <20260303003421.2185681-1-yosry@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a test that verifies that KVM correctly injects a #GP for nested VMRUN and a shutdown for nested #VMEXIT, if the GPA of vmcb12 cannot be mapped. Signed-off-by: Yosry Ahmed --- tools/testing/selftests/kvm/Makefile.kvm | 1 + .../kvm/x86/svm_nested_invalid_vmcb12_gpa.c | 98 +++++++++++++++++++ 2 files changed, 99 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86/svm_nested_invalid_vmcb= 12_gpa.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selft= ests/kvm/Makefile.kvm index 36b48e766e499..f12e7c17d379d 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -110,6 +110,7 @@ TEST_GEN_PROGS_x86 +=3D x86/state_test TEST_GEN_PROGS_x86 +=3D x86/vmx_preemption_timer_test TEST_GEN_PROGS_x86 +=3D x86/svm_vmcall_test TEST_GEN_PROGS_x86 +=3D x86/svm_int_ctl_test +TEST_GEN_PROGS_x86 +=3D x86/svm_nested_invalid_vmcb12_gpa TEST_GEN_PROGS_x86 +=3D x86/svm_nested_shutdown_test TEST_GEN_PROGS_x86 +=3D x86/svm_nested_soft_inject_test TEST_GEN_PROGS_x86 +=3D x86/svm_lbr_nested_state diff --git a/tools/testing/selftests/kvm/x86/svm_nested_invalid_vmcb12_gpa.= c b/tools/testing/selftests/kvm/x86/svm_nested_invalid_vmcb12_gpa.c new file mode 100644 index 0000000000000..c6d5f712120d1 --- /dev/null +++ b/tools/testing/selftests/kvm/x86/svm_nested_invalid_vmcb12_gpa.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2026, Google LLC. + */ +#include "kvm_util.h" +#include "vmx.h" +#include "svm_util.h" +#include "kselftest.h" + + +#define L2_GUEST_STACK_SIZE 64 + +#define SYNC_GP 101 +#define SYNC_L2_STARTED 102 + +u64 valid_vmcb12_gpa; +int gp_triggered; + +static void guest_gp_handler(struct ex_regs *regs) +{ + GUEST_ASSERT(!gp_triggered); + GUEST_SYNC(SYNC_GP); + gp_triggered =3D 1; + regs->rax =3D valid_vmcb12_gpa; +} + +static void l2_guest_code(void) +{ + GUEST_SYNC(SYNC_L2_STARTED); + vmcall(); +} + +static void l1_guest_code(struct svm_test_data *svm, u64 invalid_vmcb12_gp= a) +{ + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + + generic_svm_setup(svm, l2_guest_code, + &l2_guest_stack[L2_GUEST_STACK_SIZE]); + + valid_vmcb12_gpa =3D svm->vmcb_gpa; + + run_guest(svm->vmcb, invalid_vmcb12_gpa); /* #GP */ + + /* GP handler should jump here */ + GUEST_ASSERT(svm->vmcb->control.exit_code =3D=3D SVM_EXIT_VMMCALL); + GUEST_DONE(); +} + +int main(int argc, char *argv[]) +{ + struct kvm_x86_state *state; + vm_vaddr_t nested_gva =3D 0; + struct kvm_vcpu *vcpu; + uint32_t maxphyaddr; + u64 max_legal_gpa; + struct kvm_vm *vm; + struct ucall uc; + + TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SVM)); + + vm =3D vm_create_with_one_vcpu(&vcpu, l1_guest_code); + vm_install_exception_handler(vcpu->vm, GP_VECTOR, guest_gp_handler); + + /* + * Find the max legal GPA that is not backed by a memslot (i.e. cannot + * be mapped by KVM). + */ + maxphyaddr =3D kvm_cpuid_property(vcpu->cpuid, X86_PROPERTY_MAX_PHY_ADDR); + max_legal_gpa =3D BIT_ULL(maxphyaddr) - PAGE_SIZE; + vcpu_alloc_svm(vm, &nested_gva); + vcpu_args_set(vcpu, 2, nested_gva, max_legal_gpa); + + /* VMRUN with max_legal_gpa, KVM injects a #GP */ + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + TEST_ASSERT_EQ(get_ucall(vcpu, &uc), UCALL_SYNC); + TEST_ASSERT_EQ(uc.args[1], SYNC_GP); + + /* + * Enter L2 (with a legit vmcb12 GPA), then overwrite vmcb12 GPA with + * max_legal_gpa. KVM will fail to map vmcb12 on nested VM-Exit and + * cause a shutdown. + */ + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_IO); + TEST_ASSERT_EQ(get_ucall(vcpu, &uc), UCALL_SYNC); + TEST_ASSERT_EQ(uc.args[1], SYNC_L2_STARTED); + + state =3D vcpu_save_state(vcpu); + state->nested.hdr.svm.vmcb_pa =3D max_legal_gpa; + vcpu_load_state(vcpu, state); + vcpu_run(vcpu); + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_SHUTDOWN); + + kvm_x86_state_cleanup(state); + kvm_vm_free(vm); + return 0; +} --=20 2.53.0.473.g4a7958ca14-goog