linux-kernel - [PATCH 08/11] KVM: selftests: Drop manual XCR0 configuration from AMX test

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Message-ID: <20241003234337.273364-9-seanjc@google.com>
Date: Thu,  3 Oct 2024 16:43:34 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Sean Christopherson <seanjc@...gle.com>, Paolo Bonzini <pbonzini@...hat.com>
Cc: kvm@...r.kernel.org, linux-kernel@...r.kernel.org, 
	Vitaly Kuznetsov <vkuznets@...hat.com>
Subject: [PATCH 08/11] KVM: selftests: Drop manual XCR0 configuration from AMX test

Now that CR4.OSXSAVE and XCR0 are setup by default, drop the manual
enabling of OXSAVE and XTILE from the AMX test.

Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
 tools/testing/selftests/kvm/x86_64/amx_test.c | 23 ++++---------------
 1 file changed, 4 insertions(+), 19 deletions(-)

diff --git a/tools/testing/selftests/kvm/x86_64/amx_test.c b/tools/testing/selftests/kvm/x86_64/amx_test.c
index 903940c54d2d..f4ce5a185a7d 100644
--- a/tools/testing/selftests/kvm/x86_64/amx_test.c
+++ b/tools/testing/selftests/kvm/x86_64/amx_test.c
@@ -86,6 +86,8 @@ static inline void __xsavec(struct xstate *xstate, uint64_t rfbm)
 
 static void check_xtile_info(void)
 {
+	GUEST_ASSERT((xgetbv(0) & XFEATURE_MASK_XTILE) == XFEATURE_MASK_XTILE);
+
 	GUEST_ASSERT(this_cpu_has_p(X86_PROPERTY_XSTATE_MAX_SIZE_XCR0));
 	GUEST_ASSERT(this_cpu_property(X86_PROPERTY_XSTATE_MAX_SIZE_XCR0) <= XSAVE_SIZE);
 
@@ -122,29 +124,12 @@ static void set_tilecfg(struct tile_config *cfg)
 	}
 }
 
-static void init_regs(void)
-{
-	uint64_t cr4, xcr0;
-
-	GUEST_ASSERT(this_cpu_has(X86_FEATURE_XSAVE));
-
-	/* turn on CR4.OSXSAVE */
-	cr4 = get_cr4();
-	cr4 |= X86_CR4_OSXSAVE;
-	set_cr4(cr4);
-	GUEST_ASSERT(this_cpu_has(X86_FEATURE_OSXSAVE));
-
-	xcr0 = xgetbv(0);
-	xcr0 |= XFEATURE_MASK_XTILE;
-	xsetbv(0x0, xcr0);
-	GUEST_ASSERT((xgetbv(0) & XFEATURE_MASK_XTILE) == XFEATURE_MASK_XTILE);
-}
-
 static void __attribute__((__flatten__)) guest_code(struct tile_config *amx_cfg,
 						    struct tile_data *tiledata,
 						    struct xstate *xstate)
 {
-	init_regs();
+	GUEST_ASSERT(this_cpu_has(X86_FEATURE_XSAVE) &&
+		     this_cpu_has(X86_FEATURE_OSXSAVE));
 	check_xtile_info();
 	GUEST_SYNC(1);
 
-- 
2.47.0.rc0.187.ge670bccf7e-goog