linux-kernel - [PATCH v2 06/23] KVM: selftests: Extend nested_invalid_cr3

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251021074736.1324328-7-yosry.ahmed@linux.dev>
Date: Tue, 21 Oct 2025 07:47:19 +0000
From: Yosry Ahmed <yosry.ahmed@...ux.dev>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>,
	Jim Mattson <jmattson@...gle.com>,
	kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Yosry Ahmed <yosry.ahmed@...ux.dev>
Subject: [PATCH v2 06/23] KVM: selftests: Extend nested_invalid_cr3_test to cover SVM

Add SVM L1 code to run the nested guest, and allow the test to run with
SVM as well as VMX.

Signed-off-by: Yosry Ahmed <yosry.ahmed@...ux.dev>
---
 .../kvm/x86/nested_invalid_cr3_test.c         | 43 +++++++++++++++++--
 1 file changed, 40 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86/nested_invalid_cr3_test.c b/tools/testing/selftests/kvm/x86/nested_invalid_cr3_test.c
index b9853ab532cfe..2a472440cb962 100644
--- a/tools/testing/selftests/kvm/x86/nested_invalid_cr3_test.c
+++ b/tools/testing/selftests/kvm/x86/nested_invalid_cr3_test.c
@@ -9,6 +9,7 @@
  */
 #include "kvm_util.h"
 #include "vmx.h"
+#include "svm_util.h"
 #include "kselftest.h"
 
 
@@ -19,6 +20,28 @@ static void l2_guest_code(void)
 	vmcall();
 }
 
+static void l1_svm_code(struct svm_test_data *svm)
+{
+	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+	uintptr_t save_cr3;
+
+	generic_svm_setup(svm, l2_guest_code,
+			  &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+	/* Try to run L2 with invalid CR3 and make sure it fails */
+	save_cr3 = svm->vmcb->save.cr3;
+	svm->vmcb->save.cr3 = -1ull;
+	run_guest(svm->vmcb, svm->vmcb_gpa);
+	GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_ERR);
+
+	/* Now restore CR3 and make sure L2 runs successfully */
+	svm->vmcb->save.cr3 = save_cr3;
+	run_guest(svm->vmcb, svm->vmcb_gpa);
+	GUEST_ASSERT(svm->vmcb->control.exit_code == SVM_EXIT_VMMCALL);
+
+	GUEST_DONE();
+}
+
 static void l1_vmx_code(struct vmx_pages *vmx_pages)
 {
 	unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
@@ -45,16 +68,30 @@ static void l1_vmx_code(struct vmx_pages *vmx_pages)
 	GUEST_DONE();
 }
 
+static void l1_guest_code(void *data)
+{
+	if (this_cpu_has(X86_FEATURE_VMX))
+		l1_vmx_code(data);
+	else
+		l1_svm_code(data);
+}
+
 int main(int argc, char *argv[])
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	vm_vaddr_t guest_gva = 0;
 
-	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
+	TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX) ||
+		     kvm_cpu_has(X86_FEATURE_SVM));
+
+	vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
+
+	if (kvm_cpu_has(X86_FEATURE_VMX))
+		vcpu_alloc_vmx(vm, &guest_gva);
+	else
+		vcpu_alloc_svm(vm, &guest_gva);
 
-	vm = vm_create_with_one_vcpu(&vcpu, l1_vmx_code);
-	vcpu_alloc_vmx(vm, &guest_gva);
 	vcpu_args_set(vcpu, 1, guest_gva);
 
 	for (;;) {
-- 
2.51.0.869.ge66316f041-goog