[PATCH 27/28] selftests: kvm: add a SVM version of state-test

From: Paolo Bonzini
Date: Tue May 26 2020 - 13:24:13 EST


The test is similar to the existing one for VMX, but simpler because we
don't have to test shadow VMCS or vmptrld/vmptrst/vmclear.

Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
---
.../testing/selftests/kvm/x86_64/state_test.c | 69 +++++++++++++++----
1 file changed, 57 insertions(+), 12 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/state_test.c b/tools/testing/selftests/kvm/x86_64/state_test.c
index 5b1a016edf55..af8b6df6a13e 100644
--- a/tools/testing/selftests/kvm/x86_64/state_test.c
+++ b/tools/testing/selftests/kvm/x86_64/state_test.c
@@ -18,14 +18,46 @@
#include "kvm_util.h"
#include "processor.h"
#include "vmx.h"
+#include "svm_util.h"

#define VCPU_ID 5
+#define L2_GUEST_STACK_SIZE 256

-void l2_guest_code(void)
+void svm_l2_guest_code(void)
+{
+ GUEST_SYNC(4);
+ /* Exit to L1 */
+ vmcall();
+ GUEST_SYNC(6);
+ /* Done, exit to L1 and never come back. */
+ vmcall();
+}
+
+static void svm_l1_guest_code(struct svm_test_data *svm)
+{
+ unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+ struct vmcb *vmcb = svm->vmcb;
+
+ GUEST_ASSERT(svm->vmcb_gpa);
+ /* Prepare for L2 execution. */
+ generic_svm_setup(svm, svm_l2_guest_code,
+ &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+ GUEST_SYNC(3);
+ run_guest(vmcb, svm->vmcb_gpa);
+ GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
+ GUEST_SYNC(5);
+ vmcb->save.rip += 3;
+ run_guest(vmcb, svm->vmcb_gpa);
+ GUEST_ASSERT(vmcb->control.exit_code == SVM_EXIT_VMMCALL);
+ GUEST_SYNC(7);
+}
+
+void vmx_l2_guest_code(void)
{
GUEST_SYNC(6);

- /* Exit to L1 */
+ /* Exit to L1 */
vmcall();

/* L1 has now set up a shadow VMCS for us. */
@@ -42,10 +74,9 @@ void l2_guest_code(void)
vmcall();
}

-void l1_guest_code(struct vmx_pages *vmx_pages)
+static void vmx_l1_guest_code(struct vmx_pages *vmx_pages)
{
-#define L2_GUEST_STACK_SIZE 64
- unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+ unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];

GUEST_ASSERT(vmx_pages->vmcs_gpa);
GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
@@ -56,7 +87,7 @@ void l1_guest_code(struct vmx_pages *vmx_pages)
GUEST_SYNC(4);
GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);

- prepare_vmcs(vmx_pages, l2_guest_code,
+ prepare_vmcs(vmx_pages, vmx_l2_guest_code,
&l2_guest_stack[L2_GUEST_STACK_SIZE]);

GUEST_SYNC(5);
@@ -106,20 +137,31 @@ void l1_guest_code(struct vmx_pages *vmx_pages)
GUEST_ASSERT(vmresume());
}

-void guest_code(struct vmx_pages *vmx_pages)
+static u32 cpuid_ecx(u32 eax)
+{
+ u32 ecx;
+ asm volatile("cpuid" : "=a" (eax), "=c" (ecx) : "0" (eax) : "ebx", "edx");
+ return ecx;
+}
+
+static void __attribute__((__flatten__)) guest_code(void *arg)
{
GUEST_SYNC(1);
GUEST_SYNC(2);

- if (vmx_pages)
- l1_guest_code(vmx_pages);
+ if (arg) {
+ if (cpuid_ecx(0x80000001) & CPUID_SVM)
+ svm_l1_guest_code(arg);
+ else
+ vmx_l1_guest_code(arg);
+ }

GUEST_DONE();
}

int main(int argc, char *argv[])
{
- vm_vaddr_t vmx_pages_gva = 0;
+ vm_vaddr_t nested_gva = 0;

struct kvm_regs regs1, regs2;
struct kvm_vm *vm;
@@ -136,8 +178,11 @@ int main(int argc, char *argv[])
vcpu_regs_get(vm, VCPU_ID, &regs1);

if (kvm_check_cap(KVM_CAP_NESTED_STATE)) {
- vcpu_alloc_vmx(vm, &vmx_pages_gva);
- vcpu_args_set(vm, VCPU_ID, 1, vmx_pages_gva);
+ if (kvm_get_supported_cpuid_entry(0x80000001)->ecx & CPUID_SVM)
+ vcpu_alloc_svm(vm, &nested_gva);
+ else
+ vcpu_alloc_vmx(vm, &nested_gva);
+ vcpu_args_set(vm, VCPU_ID, 1, nested_gva);
} else {
pr_info("will skip nested state checks\n");
vcpu_args_set(vm, VCPU_ID, 1, 0);
--
2.26.2