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[8/9] selftests/x86/xstate: Clarify supported xstates

Message ID 20250226010731.2456-9-chang.seok.bae@intel.com (mailing list archive)
State New
Headers show
Series selftests/x86/xstate: Introduce common code for testing extended states | expand

Commit Message

Chang S. Bae Feb. 26, 2025, 1:07 a.m. UTC 
The established xstate test code is designed to be generic, but certain
xstates require special handling and cannot be tested without additional
adjustments.

Clarify which xstates are currently supported, and enforce testing only
for them.

Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
---
 tools/testing/selftests/x86/xstate.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)
diff mbox series

Patch

diff --git a/tools/testing/selftests/x86/xstate.c b/tools/testing/selftests/x86/xstate.c
index fd8451e55f3f..875777911d82 100644
--- a/tools/testing/selftests/x86/xstate.c
+++ b/tools/testing/selftests/x86/xstate.c
@@ -15,6 +15,24 @@ 
 #include "helpers.h"
 #include "xstate.h"
 
+/*
+ * The userspace xstate test suite is designed to be generic and operates
+ * with randomized xstate data. However, some states require special handling:
+ *
+ * - PKRU and XTILECFG need specific adjustments, such as modifying
+ *   randomization behavior or using fixed values.
+ * - But, PKRU already has a dedicated test suite in /tools/selftests/mm.
+ * - Legacy states (FP and SSE) are excluded, as they are not considered
+ *   part of extended states (xstates) and their usage is already deeply
+ *   integrated into user-space libraries.
+ */
+#define XFEATURE_MASK_TEST_SUPPORTED	\
+	((1 << XFEATURE_YMM) |		\
+	 (1 << XFEATURE_OPMASK)	|	\
+	 (1 << XFEATURE_ZMM_Hi256) |	\
+	 (1 << XFEATURE_Hi16_ZMM) |	\
+	 (1 << XFEATURE_XTILEDATA))
+
 static inline uint64_t xgetbv(uint32_t index)
 {
 	uint32_t eax, edx;
@@ -435,6 +453,12 @@  void test_xstate(uint32_t feature_num)
 	unsigned long features;
 	long rc;
 
+	if (!(XFEATURE_MASK_TEST_SUPPORTED & (1 << feature_num))) {
+		ksft_print_msg("The xstate test does not fully support the component %u, yet.\n",
+			       feature_num);
+		return;
+	}
+
 	rc = syscall(SYS_arch_prctl, ARCH_GET_XCOMP_SUPP, &features);
 	if (rc || !(features & (1 << feature_num))) {
 		ksft_print_msg("The kernel does not support feature number: %u\n", feature_num);