From mboxrd@z Thu Jan 1 00:00:00 1970 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 CA7863AEF49; Tue, 24 Feb 2026 22:34:33 +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=1771972473; cv=none; b=ZOQIrG1zCDocezZMKL0iD3L0KfvaRzqQrv0djE8aliCCfHyQCjiaPF6iCRecbgSaF3NzWIFpDZ9x/oX4GN2q3wkCoearZ5ynWBUIlqXzi15L5sZWGefYgS4OdgawgOC9acOGHn8vqQoguDUZdUI0XBKH+yD6QSd6gWmzp1jdA4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771972473; c=relaxed/simple; bh=Azr0nTsvGAE8w6vk55HoET74YyhG7h/Gv57ZeCxeZk0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=PpCw6sxmv9ggvj+2AmNngF7Jy9hz7gZR6J9MjpE1HamxV5qEIjKheQMMGDRMTRAfCWw0RYAu2iFlHK9DS0t3sKFyLVZ4iS5gAf8LyQOzvmoT3QmfAgGWsNgID4EswHeBFEWro/sgs264NePqM6kUEADS8c10YFL/OboldfCNDXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ZqvtB6eA; 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="ZqvtB6eA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 77025C116D0; Tue, 24 Feb 2026 22:34:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1771972473; bh=Azr0nTsvGAE8w6vk55HoET74YyhG7h/Gv57ZeCxeZk0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZqvtB6eA637PXWxwkxFweBsNrez2K55TAf60zVa1wCU9/koR/pB6bF0an6NMiVuB+ gcyu2A26Cdo16MJZLvTBM/fyqh8a6YjVbgHRrXU6x0OMh3Whue4P4V5dEYg+X8yawt VyNhBZnTkZfmjNUUIUwc0g3MZnCSK7TGYFIkqRjMN5sVwYO6+s1LMd8uFNJLOsVRys VT9svY7iSmf6QK0i8kxx/+k6mQXxtlebJhVi/gWDUElvo6zyMtMTTZcMq5a1xuDEnG 4a86eQ95WmI6UCUNMoCcNrrHXZCZ6pxykVHbCKqNhuepH6FBBusJTwQxGZyoDlR+LJ H3/aFvlujVu5A== From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Subject: [PATCH v6 31/31] KVM: selftest: Add a selftest for VMRUN/#VMEXIT with unmappable vmcb12 Date: Tue, 24 Feb 2026 22:34:05 +0000 Message-ID: <20260224223405.3270433-32-yosry@kernel.org> X-Mailer: git-send-email 2.53.0.414.gf7e9f6c205-goog In-Reply-To: <20260224223405.3270433-1-yosry@kernel.org> References: <20260224223405.3270433-1-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: 8bit 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 | 95 +++++++++++++++++++ 2 files changed, 96 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86/svm_nested_invalid_vmcb12_gpa.c diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/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 += x86/state_test TEST_GEN_PROGS_x86 += x86/vmx_preemption_timer_test TEST_GEN_PROGS_x86 += x86/svm_vmcall_test TEST_GEN_PROGS_x86 += x86/svm_int_ctl_test +TEST_GEN_PROGS_x86 += x86/svm_nested_invalid_vmcb12_gpa TEST_GEN_PROGS_x86 += x86/svm_nested_shutdown_test TEST_GEN_PROGS_x86 += x86/svm_nested_soft_inject_test TEST_GEN_PROGS_x86 += 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..5b0dec4240937 --- /dev/null +++ b/tools/testing/selftests/kvm/x86/svm_nested_invalid_vmcb12_gpa.c @@ -0,0 +1,95 @@ +// 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 + +extern char invalid_vmrun; + +static void guest_gp_handler(struct ex_regs *regs) +{ + GUEST_SYNC(SYNC_GP); + regs->rip = (uintptr_t)&invalid_vmrun; +} + +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_gpa) +{ + unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE]; + + generic_svm_setup(svm, l2_guest_code, + &l2_guest_stack[L2_GUEST_STACK_SIZE]); + + run_guest(svm->vmcb, invalid_vmcb12_gpa); /* #GP */ + + /* GP handler should jump here */ + asm volatile ("invalid_vmrun:"); + run_guest(svm->vmcb, svm->vmcb_gpa); + GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_VMMCALL); + GUEST_DONE(); +} + +int main(int argc, char *argv[]) +{ + struct kvm_x86_state *state; + vm_vaddr_t nested_gva = 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 = 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 = kvm_cpuid_property(vcpu->cpuid, X86_PROPERTY_MAX_PHY_ADDR); + max_legal_gpa = 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 = vcpu_save_state(vcpu); + state->nested.hdr.svm.vmcb_pa = 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; +} -- 2.53.0.414.gf7e9f6c205-goog