[PATCH 03/12] KVM: selftests: Extend vmx_close_while_nested_test to cover SVM

Yosry Ahmed
2025-10-01T14:58:45Z

From: Yosry Ahmed <yosryahmed@google.com>

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@linux.dev>
---
tools/testing/selftests/kvm/Makefile.kvm | 2 +-
...ested_test.c => close_while_nested_test.c} | 42 +++++++++++++++----
2 files changed, 35 insertions(+), 9 deletions(-)
rename tools/testing/selftests/kvm/x86/{vmx_close_while_nested_test.c => close_while_nested_test.c} (64%)

diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm
index 6582396518b19..61c6abdc9b36f 100644
--- a/tools/testing/selftests/kvm/Makefile.kvm
+++ b/tools/testing/selftests/kvm/Makefile.kvm
@@ -111,7 +111,7 @@ TEST_GEN_PROGS_x86 += x86/ucna_injection_test
TEST_GEN_PROGS_x86 += x86/userspace_io_test
TEST_GEN_PROGS_x86 += x86/userspace_msr_exit_test
TEST_GEN_PROGS_x86 += x86/vmx_apic_access_test
-TEST_GEN_PROGS_x86 += x86/vmx_close_while_nested_test
+TEST_GEN_PROGS_x86 += x86/close_while_nested_test
TEST_GEN_PROGS_x86 += x86/vmx_dirty_log_test
TEST_GEN_PROGS_x86 += x86/vmx_exception_with_invalid_guest_state
TEST_GEN_PROGS_x86 += x86/vmx_msrs_test
diff --git a/tools/testing/selftests/kvm/x86/vmx_close_while_nested_test.c b/tools/testing/selftests/kvm/x86/close_while_nested_test.c
similarity index 64%
rename from tools/testing/selftests/kvm/x86/vmx_close_while_nested_test.c
rename to tools/testing/selftests/kvm/x86/close_while_nested_test.c
index dad988351493e..cf5f24c83c448 100644
--- a/tools/testing/selftests/kvm/x86/vmx_close_while_nested_test.c
+++ b/tools/testing/selftests/kvm/x86/close_while_nested_test.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * vmx_close_while_nested
+ * close_while_nested_test
*
* Copyright (C) 2019, Red Hat, Inc.
*
@@ -12,6 +12,7 @@
#include "kvm_util.h"
#include "processor.h"
#include "vmx.h"
+#include "svm_util.h"

#include <string.h>
#include <sys/ioctl.h>
@@ -22,6 +23,8 @@ enum {
PORT_L0_EXIT = 0x2000,
};

+#define L2_GUEST_STACK_SIZE 64
+
static void l2_guest_code(void)
{
/* Exit to L0 */
@@ -29,9 +32,8 @@ static void l2_guest_code(void)
: : [port] "d" (PORT_L0_EXIT) : "rax");
}

-static void l1_guest_code(struct vmx_pages *vmx_pages)
+static void l1_vmx_code(struct vmx_pages *vmx_pages)
{
-#define L2_GUEST_STACK_SIZE 64
unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
@@ -45,19 +47,43 @@ static void l1_guest_code(struct vmx_pages *vmx_pages)
GUEST_ASSERT(0);
}

+static void l1_svm_code(struct svm_test_data *svm)
+{
+ unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+
+ /* Prepare the VMCB for L2 execution. */
+ generic_svm_setup(svm, l2_guest_code,
+ &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+ run_guest(svm->vmcb, svm->vmcb_gpa);
+ GUEST_ASSERT(0);
+}
+
+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[])
{
- vm_vaddr_t vmx_pages_gva;
+ vm_vaddr_t guest_gva;
struct kvm_vcpu *vcpu;
struct kvm_vm *vm;

- 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);

- /* Allocate VMX pages and shared descriptors (vmx_pages). */
- vcpu_alloc_vmx(vm, &vmx_pages_gva);
- vcpu_args_set(vcpu, 1, vmx_pages_gva);
+ if (kvm_cpu_has(X86_FEATURE_VMX))
+ vcpu_alloc_vmx(vm, &guest_gva);
+ else
+ vcpu_alloc_svm(vm, &guest_gva);
+
+ vcpu_args_set(vcpu, 1, guest_gva);

for (;;) {
volatile struct kvm_run *run = vcpu->run;
--
2.51.0.618.g983fd99d29-goog