When running in a VM, ensure that support for RDPRU is not enumerated
in the guest's CPUID and that the RDPRU instruction raises #UD.
Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
Reviewed-by: Peter Shier <pshier@xxxxxxxxxx>
---
lib/x86/processor.h | 2 ++
x86/Makefile.x86_64 | 1 +
x86/rdpru.c | 27 +++++++++++++++++++++++++++
x86/unittests.cfg | 5 +++++
4 files changed, 35 insertions(+)
create mode 100644 x86/rdpru.c
diff --git a/lib/x86/processor.h b/lib/x86/processor.h
index b1c579b..fe72c13 100644
--- a/lib/x86/processor.h
+++ b/lib/x86/processor.h
@@ -131,6 +131,7 @@ static inline u8 cpuid_maxphyaddr(void)
#define X86_FEATURE_XSAVE (CPUID(0x1, 0, ECX, 26))
#define X86_FEATURE_OSXSAVE (CPUID(0x1, 0, ECX, 27))
#define X86_FEATURE_RDRAND (CPUID(0x1, 0, ECX, 30))
+#define X86_FEATURE_HYPERVISOR (CPUID(0x1, 0, ECX, 31))
#define X86_FEATURE_MCE (CPUID(0x1, 0, EDX, 7))
#define X86_FEATURE_APIC (CPUID(0x1, 0, EDX, 9))
#define X86_FEATURE_CLFLUSH (CPUID(0x1, 0, EDX, 19))
@@ -150,6 +151,7 @@ static inline u8 cpuid_maxphyaddr(void)
#define X86_FEATURE_RDPID (CPUID(0x7, 0, ECX, 22))
#define X86_FEATURE_SPEC_CTRL (CPUID(0x7, 0, EDX, 26))
#define X86_FEATURE_NX (CPUID(0x80000001, 0, EDX, 20))
+#define X86_FEATURE_RDPRU (CPUID(0x80000008, 0, EBX, 4))
/*
* AMD CPUID features
diff --git a/x86/Makefile.x86_64 b/x86/Makefile.x86_64
index 51f9b80..010102b 100644
--- a/x86/Makefile.x86_64
+++ b/x86/Makefile.x86_64
@@ -19,6 +19,7 @@ tests += $(TEST_DIR)/vmx.flat
tests += $(TEST_DIR)/tscdeadline_latency.flat
tests += $(TEST_DIR)/intel-iommu.flat
tests += $(TEST_DIR)/vmware_backdoors.flat
+tests += $(TEST_DIR)/rdpru.flat
include $(SRCDIR)/$(TEST_DIR)/Makefile.common
diff --git a/x86/rdpru.c b/x86/rdpru.c
new file mode 100644
index 0000000..87a517e
--- /dev/null
+++ b/x86/rdpru.c
@@ -0,0 +1,27 @@
+/* RDPRU test */
+
+#include "libcflat.h"
+#include "processor.h"
+#include "desc.h"
+
+static int rdpru_checking(void)
+{
+ asm volatile (ASM_TRY("1f")
+ ".byte 0x0f,0x01,0xfd \n\t" /* rdpru */
+ "1:" : : "c" (0) : "eax", "edx");
+ return exception_vector();
+}
+
+int main(int ac, char **av)
+{
+ setup_idt();
+
+ if (this_cpu_has(X86_FEATURE_HYPERVISOR)) {
+ report("RDPRU not supported", !this_cpu_has(X86_FEATURE_RDPRU));
+ report("RDPRU raises #UD", rdpru_checking() == UD_VECTOR);
+ } else {
+ report_skip("Not in a VM");
+ }
+
+ return report_summary();
+}
diff --git a/x86/unittests.cfg b/x86/unittests.cfg
index 694ee3d..9764e18 100644
--- a/x86/unittests.cfg
+++ b/x86/unittests.cfg
@@ -221,6 +221,11 @@ file = pcid.flat
extra_params = -cpu qemu64,+pcid
arch = x86_64
+[rdpru]
+file = rdpru.flat
+extra_params = -cpu host
+arch = x86_64
+
[umip]
file = umip.flat
extra_params = -cpu qemu64,+umip
--
2.23.0.351.gc4317032e6-goog
