[PATCH 8/9] KVM: selftests: add svm part to triple_fault_test

From: Maxim Levitsky
Date: Thu Nov 03 2022 - 10:00:02 EST


Add a SVM implementation to triple_fault_test to test that
emulated/injected shutdown works.

Since instead of the VMX, the SVM allows the hypervisor to avoid intercepting
shutdown in guest, don't intercept shutdown to test that
KVM suports this correctly.

Signed-off-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx>
---
.../kvm/x86_64/triple_fault_event_test.c | 71 ++++++++++++++-----
1 file changed, 54 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c b/tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
index 70b44f0b52fef2..78d2941f7c1f0d 100644
--- a/tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
+++ b/tools/testing/selftests/kvm/x86_64/triple_fault_event_test.c
@@ -3,6 +3,7 @@
#include "kvm_util.h"
#include "processor.h"
#include "vmx.h"
+#include "svm_util.h"

#include <string.h>
#include <sys/ioctl.h>
@@ -20,10 +21,11 @@ static void l2_guest_code(void)
: : [port] "d" (ARBITRARY_IO_PORT) : "rax");
}

-void l1_guest_code(struct vmx_pages *vmx)
-{
#define L2_GUEST_STACK_SIZE 64
- unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+unsigned long l2_guest_stack[L2_GUEST_STACK_SIZE];
+
+void l1_guest_code_vmx(struct vmx_pages *vmx)
+{

GUEST_ASSERT(vmx->vmcs_gpa);
GUEST_ASSERT(prepare_for_vmx_operation(vmx));
@@ -38,24 +40,51 @@ void l1_guest_code(struct vmx_pages *vmx)
GUEST_DONE();
}

+void l1_guest_code_svm(struct svm_test_data *svm)
+{
+ struct vmcb *vmcb = svm->vmcb;
+
+ generic_svm_setup(svm, l2_guest_code,
+ &l2_guest_stack[L2_GUEST_STACK_SIZE]);
+
+ /* don't intercept shutdown to test the case of SVM allowing to do so */
+ vmcb->control.intercept &= ~(BIT(INTERCEPT_SHUTDOWN));
+
+ run_guest(vmcb, svm->vmcb_gpa);
+
+ /* should not reach here, L1 should crash */
+ GUEST_ASSERT(0);
+}
+
int main(void)
{
struct kvm_vcpu *vcpu;
struct kvm_run *run;
struct kvm_vcpu_events events;
- vm_vaddr_t vmx_pages_gva;
struct ucall uc;

- TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_VMX));
+ bool has_vmx = kvm_cpu_has(X86_FEATURE_VMX);
+ bool has_svm = kvm_cpu_has(X86_FEATURE_SVM);
+
+ TEST_REQUIRE(has_vmx || has_svm);

TEST_REQUIRE(kvm_has_cap(KVM_CAP_X86_TRIPLE_FAULT_EVENT));

- vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code);
- vm_enable_cap(vm, KVM_CAP_X86_TRIPLE_FAULT_EVENT, 1);

+ if (has_vmx) {
+ vm_vaddr_t vmx_pages_gva;
+ vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code_vmx);
+ vcpu_alloc_vmx(vm, &vmx_pages_gva);
+ vcpu_args_set(vcpu, 1, vmx_pages_gva);
+ } else {
+ vm_vaddr_t svm_gva;
+ vm = vm_create_with_one_vcpu(&vcpu, l1_guest_code_svm);
+ vcpu_alloc_svm(vm, &svm_gva);
+ vcpu_args_set(vcpu, 1, svm_gva);
+ }
+
+ vm_enable_cap(vm, KVM_CAP_X86_TRIPLE_FAULT_EVENT, 1);
run = vcpu->run;
- vcpu_alloc_vmx(vm, &vmx_pages_gva);
- vcpu_args_set(vcpu, 1, vmx_pages_gva);
vcpu_run(vcpu);

TEST_ASSERT(run->exit_reason == KVM_EXIT_IO,
@@ -78,13 +107,21 @@ int main(void)
"No triple fault pending");
vcpu_run(vcpu);

- switch (get_ucall(vcpu, &uc)) {
- case UCALL_DONE:
- break;
- case UCALL_ABORT:
- REPORT_GUEST_ASSERT(uc);
- default:
- TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
- }

+ if (has_svm) {
+ TEST_ASSERT(run->exit_reason == KVM_EXIT_SHUTDOWN,
+ "Got exit_reason other than KVM_EXIT_SHUTDOWN: %u (%s)\n",
+ run->exit_reason,
+ exit_reason_str(run->exit_reason));
+ return 0;
+ } else {
+ switch (get_ucall(vcpu, &uc)) {
+ case UCALL_DONE:
+ break;
+ case UCALL_ABORT:
+ REPORT_GUEST_ASSERT(uc);
+ default:
+ TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+ }
+ }
}
--
2.34.3