Add an i386-only test to check that setting CR4.LA57 fails when 5-level
paging is not exposed to the guest. Old versions of KVM don't intercept
LA57 by default on VMX, which means a clever guest could set LA57
without it being detected by KVM.
This test is i386-only because toggling CR4.LA57 in long mode is
illegal, i.e. won't verify the desired KVM behavior.
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
x86/Makefile.i386 | 2 +-
x86/la57.c | 13 +++++++++++++
x86/unittests.cfg | 4 ++++
3 files changed, 18 insertions(+), 1 deletion(-)
create mode 100644 x86/la57.c
diff --git a/x86/Makefile.i386 b/x86/Makefile.i386
index be9d6bc..c04e5aa 100644
--- a/x86/Makefile.i386
+++ b/x86/Makefile.i386
@@ -6,6 +6,6 @@ COMMON_CFLAGS += -mno-sse -mno-sse2
cflatobjs += lib/x86/setjmp32.o
tests = $(TEST_DIR)/taskswitch.flat $(TEST_DIR)/taskswitch2.flat \
- $(TEST_DIR)/cmpxchg8b.flat
+ $(TEST_DIR)/cmpxchg8b.flat $(TEST_DIR)/la57.flat
include $(SRCDIR)/$(TEST_DIR)/Makefile.common
diff --git a/x86/la57.c b/x86/la57.c
new file mode 100644
index 0000000..b537bb2
--- /dev/null
+++ b/x86/la57.c
@@ -0,0 +1,13 @@
+#include "libcflat.h"
+#include "processor.h"
+#include "desc.h"
+
+int main(int ac, char **av)
+{
+ int vector = write_cr4_checking(read_cr4() | X86_CR4_LA57);
+ int expected = this_cpu_has(X86_FEATURE_LA57) ? 0 : 13;
+
+ report(vector == expected, "%s when CR4.LA57 %ssupported",
+ expected ? "#GP" : "No fault", expected ? "un" : "");
+ return report_summary();
+}
diff --git a/x86/unittests.cfg b/x86/unittests.cfg
index 3a79151..6eb8e19 100644
--- a/x86/unittests.cfg
+++ b/x86/unittests.cfg
@@ -245,6 +245,10 @@ arch = x86_64
file = umip.flat
extra_params = -cpu qemu64,+umip
+[la57]
+file = la57.flat
+arch = i386
+
[vmx]
file = vmx.flat
extra_params = -cpu host,+vmx -append "-exit_monitor_from_l2_test -ept_access* -vmx_smp* -vmx_vmcs_shadow_test -atomic_switch_overflow_msrs_test -vmx_init_signal_test -vmx_apic_passthrough_tpr_threshold_test"
--
2.28.0
