KVM: selftests: Assert that XTILE is XSAVE-enabled

Assert that XTILE is XSAVE-enabled. check_xsave_supports_xtile() doesn't
actually check anything since its return value is not used. Add the
intended assert.

Opportunistically, move the assert to a more appropriate location:
immediately after XSETBV and remove check_xsave_supports_xtile().

Fixes: 5dc19f1c7dd3 ("KVM: selftests: Convert AMX test to use X86_PROPRETY_XXX")
Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20230221163655.920289-10-mizhang@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
index e6bc6cd108dc0912514daba5e898d8779a61bbf6..6f788e6d8a8da108d5a9f0f6bef02a7c7cfd6e3a 100644 (file)
--- a/tools/testing/selftests/kvm/x86_64/amx_test.c
+++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
@@ -115,11 +115,6 @@ static inline void check_cpuid_xsave(void)
        GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE));
 }
 
-static bool check_xsave_supports_xtile(void)
-{
-       return __xgetbv(0) & XFEATURE_MASK_XTILE;
-}
-
 static void check_xtile_info(void)
 {
        GUEST_ASSERT(this_cpu_has_p(X86_PROPERTY_XSTATE_MAX_SIZE_XCR0));
@@ -166,6 +161,7 @@ static void init_regs(void)
        xcr0 = __xgetbv(0);
        xcr0 |= XFEATURE_MASK_XTILE;
        __xsetbv(0x0, xcr0);
+       GUEST_ASSERT(__xgetbv(0) & XFEATURE_MASK_XTILE);
 }
 
 static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg,
@@ -174,7 +170,6 @@ static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg,
 {
        init_regs();
        check_cpuid_xsave();
-       check_xsave_supports_xtile();
        check_xtile_info();
        GUEST_SYNC(1);