KVM: selftests: Assert success in vmptrst(), kill off vmptrstz()

Assert success in vmptrst() instead of punting to the caller, as literally
every user expects VMPTRST to succeed (and because '0' is a valid physical
address).

Link: https://patch.msgid.link/20260904002423.3154436-7-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

4 files changed, 11 insertions, 22 deletions

diff --git a/tools/testing/selftests/kvm/include/x86/vmx.h b/tools/testing/selftests/kvm/include/x86/vmx.h
index a161dbee7e04..04f638fcd3ba 100644
--- a/tools/testing/selftests/kvm/include/x86/vmx.h
+++ b/tools/testing/selftests/kvm/include/x86/vmx.h
@@ -366,27 +366,16 @@ static inline int __vmptrld(u64 vmcs_pa)
 	return vector ? vector : failed ? -EINVAL : 0;
 }
 
-static inline int vmptrst(u64 *value)
+static inline u64 vmptrst(void)
 {
-	u64 tmp;
+	u64 value = 0;
 	u8 ret;
 
 	__asm__ __volatile__("vmptrst %[value]; setna %[ret]"
-		: [value]"=m"(tmp), [ret]"=rm"(ret)
+		: [value]"=m"(value), [ret]"=rm"(ret)
 		: : "cc", "memory");
 
-	*value = tmp;
-	return ret;
-}
-
-/*
- * A wrapper around vmptrst that ignores errors and returns zero if the
- * vmptrst instruction fails.
- */
-static inline u64 vmptrstz(void)
-{
-	u64 value = 0;
-	vmptrst(&value);
+	__GUEST_ASSERT(!ret, "vmptrst failed");
 	return value;
 }
 
diff --git a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
index 9cb823e20a68..7923229c2dfc 100644
--- a/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
+++ b/tools/testing/selftests/kvm/x86/hyperv_evmcs.c
@@ -97,7 +97,7 @@ void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages,
 	GUEST_SYNC(3);
 	GUEST_ASSERT(load_evmcs(hv_pages));
 	/* VMPTRST returns -1 until VMLAUNCH with eVMCS ptr set */
-	GUEST_ASSERT(vmptrstz() == -1);
+	GUEST_ASSERT(vmptrst() == -1);
 
 	GUEST_SYNC(4);
 
@@ -123,7 +123,7 @@ void guest_code(struct vmx_pages *vmx_pages, struct hyperv_test_pages *hv_pages,
 	GUEST_ASSERT(!vmlaunch());
 	GUEST_ASSERT_EQ(vmreadz(VM_EXIT_REASON), EXIT_REASON_EXCEPTION_NMI);
 	GUEST_ASSERT_EQ((vmreadz(VM_EXIT_INTR_INFO) & 0xff), NMI_VECTOR);
-	GUEST_ASSERT(vmptrstz() == hv_pages->enlightened_vmcs_gpa);
+	GUEST_ASSERT(vmptrst() == hv_pages->enlightened_vmcs_gpa);
 
 	/*
 	 * NMI forces L2->L1 exit, resuming L2 and hope that EVMCS is
diff --git a/tools/testing/selftests/kvm/x86/state_test.c b/tools/testing/selftests/kvm/x86/state_test.c
index e6f521a6e737..354ff3cda597 100644
--- a/tools/testing/selftests/kvm/x86/state_test.c
+++ b/tools/testing/selftests/kvm/x86/state_test.c
@@ -78,17 +78,17 @@ static void vmx_l1_guest_code(struct vmx_pages *vmx_pages)
 	GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
 	GUEST_SYNC(3);
 	GUEST_ASSERT(load_vmcs(vmx_pages));
-	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
+	GUEST_ASSERT(vmptrst() == vmx_pages->vmcs_gpa);
 
 	GUEST_SYNC(4);
-	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
+	GUEST_ASSERT(vmptrst() == vmx_pages->vmcs_gpa);
 
 	prepare_vmcs(vmx_pages, vmx_l2_guest_code);
 
 	GUEST_SYNC(5);
-	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
+	GUEST_ASSERT(vmptrst() == vmx_pages->vmcs_gpa);
 	GUEST_ASSERT(!vmlaunch());
-	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
+	GUEST_ASSERT(vmptrst() == vmx_pages->vmcs_gpa);
 	GUEST_ASSERT(vmreadz(VM_EXIT_REASON) == EXIT_REASON_VMCALL);
 
 	/* Check that the launched state is preserved.  */
diff --git a/tools/testing/selftests/kvm/x86/vmx_preemption_timer_test.c b/tools/testing/selftests/kvm/x86/vmx_preemption_timer_test.c
index 72fbf1b70e9f..3f77afeaad1b 100644
--- a/tools/testing/selftests/kvm/x86/vmx_preemption_timer_test.c
+++ b/tools/testing/selftests/kvm/x86/vmx_preemption_timer_test.c
@@ -73,7 +73,7 @@ void l1_guest_code(struct vmx_pages *vmx_pages)
 	GUEST_ASSERT(vmx_pages->vmcs_gpa);
 	GUEST_ASSERT(prepare_for_vmx_operation(vmx_pages));
 	GUEST_ASSERT(load_vmcs(vmx_pages));
-	GUEST_ASSERT(vmptrstz() == vmx_pages->vmcs_gpa);
+	GUEST_ASSERT(vmptrst() == vmx_pages->vmcs_gpa);
 
 	prepare_vmcs(vmx_pages, l2_guest_code);