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authorChang S. Bae <chang.seok.bae@intel.com>2025-02-25 17:07:28 -0800
committerIngo Molnar <mingo@kernel.org>2025-02-26 13:05:30 +0100
commitfa826c1f2cc92db44c207d323d2568e3f04c1257 (patch)
treed2fd74f7c7ebc352d1e86dbe92fc0057bde0a9e1
parent10d8a204c5009fb8a6cb2790d17b5611b795c349 (diff)
selftests/x86/xstate: Clarify supported xstates
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> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250226010731.2456-9-chang.seok.bae@intel.com
-rw-r--r--tools/testing/selftests/x86/xstate.c24
1 files changed, 24 insertions, 0 deletions
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);