linux-kernel - [kvm-unit-tests 1/7] x86/svm: Cleanup selective cr0 write intercept test

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Message-ID: <20251024194925.3201933-2-yosry.ahmed@linux.dev>
Date: Fri, 24 Oct 2025 19:49:19 +0000
From: Yosry Ahmed <yosry.ahmed@...ux.dev>
To: Sean Christopherson <seanjc@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>,
	Jim Mattson <jmattson@...gle.com>,
	kvm@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	Yosry Ahmed <yosryahmed@...gle.com>
Subject: [kvm-unit-tests 1/7] x86/svm: Cleanup selective cr0 write intercept test

From: Yosry Ahmed <yosryahmed@...gle.com>

Rename the test and functions to more general names describing the test
more accurately. Use X86_CR0_CD instead of hardcoding the bitmask, and
explicitly clear the bit in the prepare() function to make it clearer
that it would only be set by the test.

Signed-off-by: Yosry Ahmed <yosryahmed@...gle.com>
---
 x86/svm_tests.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index 80d5aeb1..e9116591 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -793,23 +793,19 @@ static bool check_asid_zero(struct svm_test *test)
 	return vmcb->control.exit_code == SVM_EXIT_ERR;
 }
 
-static void sel_cr0_bug_prepare(struct svm_test *test)
+static void prepare_sel_cr0_intercept(struct svm_test *test)
 {
+	vmcb->save.cr0 &= ~X86_CR0_CD;
 	vmcb->control.intercept |= (1ULL << INTERCEPT_SELECTIVE_CR0);
 }
 
-static bool sel_cr0_bug_finished(struct svm_test *test)
-{
-	return true;
-}
-
-static void sel_cr0_bug_test(struct svm_test *test)
+static void test_sel_cr0_write_intercept(struct svm_test *test)
 {
 	unsigned long cr0;
 
-	/* read cr0, clear CD, and write back */
+	/* read cr0, set CD, and write back */
 	cr0  = read_cr0();
-	cr0 |= (1UL << 30);
+	cr0 |= X86_CR0_CD;
 	write_cr0(cr0);
 
 	/*
@@ -821,7 +817,7 @@ static void sel_cr0_bug_test(struct svm_test *test)
 	exit(report_summary());
 }
 
-static bool sel_cr0_bug_check(struct svm_test *test)
+static bool check_sel_cr0_intercept(struct svm_test *test)
 {
 	return vmcb->control.exit_code == SVM_EXIT_CR0_SEL_WRITE;
 }
@@ -3486,9 +3482,9 @@ struct svm_test svm_tests[] = {
 	{ "asid_zero", default_supported, prepare_asid_zero,
 	  default_prepare_gif_clear, test_asid_zero,
 	  default_finished, check_asid_zero },
-	{ "sel_cr0_bug", default_supported, sel_cr0_bug_prepare,
-	  default_prepare_gif_clear, sel_cr0_bug_test,
-	  sel_cr0_bug_finished, sel_cr0_bug_check },
+	{ "sel cr0 write intercept", default_supported,
+	  prepare_sel_cr0_intercept, default_prepare_gif_clear,
+	  test_sel_cr0_write_intercept, default_finished, check_sel_cr0_intercept},
 	{ "tsc_adjust", tsc_adjust_supported, tsc_adjust_prepare,
 	  default_prepare_gif_clear, tsc_adjust_test,
 	  default_finished, tsc_adjust_check },
-- 
2.51.1.821.gb6fe4d2222-goog