[PATCH v3 03/14] x86/svm: Cleanup selective cr0 write intercept test

Yosry Ahmed
2025-11-10T23:27:08Z

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 <yosry.ahmed@linux.dev>
---
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 80d5aeb108650..e911659194b3d 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 },
--
2.51.2.1041.gc1ab5b90ca-goog