Reply-To: Mingwei Zhang <mizhang@google.com>
Date:   Tue, 21 Feb 2023 16:36:51 +0000
In-Reply-To: <20230221163655.920289-1-mizhang@google.com>
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References: <20230221163655.920289-1-mizhang@google.com>
Message-ID: <20230221163655.920289-10-mizhang@google.com>
Subject: [PATCH v3 09/13] KVM: selftests: x86: Assert that XTILE is XSAVE-enabled
From:   Mingwei Zhang <mizhang@google.com>
To:     Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>
Cc:     "H. Peter Anvin" <hpa@zytor.com>, linux-kernel@vger.kernel.org,
        kvm@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Mingwei Zhang <mizhang@google.com>,
        Jim Mattson <jmattson@google.com>,
        Venkatesh Srinivas <venkateshs@google.com>,
        Aaron Lewis <aaronlewis@google.com>,
        "Chang S. Bae" <chang.seok.bae@intel.com>,
        Chao Gao <chao.gao@intel.com>
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Precedence: bulk

From: Aaron Lewis <aaronlewis@google.com>

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>
---
 tools/testing/selftests/kvm/x86_64/amx_test.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
index 724e991ba814..d1fbf8936192 100644
--- 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);
 
-- 
2.39.2.637.g21b0678d19-goog