On 6/25/19 5:03 AM, Nadav Amit wrote:
CR4.MCE might be set after boot. Remove the assertion that checks that
it is clear. Change the test to toggle the bit instead of setting it.
Cc: Marc Orr <marcorr@xxxxxxxxxx>
Signed-off-by: Nadav Amit <nadav.amit@xxxxxxxxx>
---
x86/vmx_tests.c | 29 +++++++++++++++--------------
1 file changed, 15 insertions(+), 14 deletions(-)
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index b50d858..3731757 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -7096,8 +7096,11 @@ static int write_cr4_checking(unsigned long val)
static void vmx_cr_load_test(void)
{
+ unsigned long cr3, cr4, orig_cr3, orig_cr4;
struct cpuid _cpuid = cpuid(1);
- unsigned long cr4 = read_cr4(), cr3 = read_cr3();
+
+ orig_cr4 = read_cr4();
+ orig_cr3 = read_cr3();
if (!(_cpuid.c & X86_FEATURE_PCID)) {
report_skip("PCID not detected");
@@ -7108,12 +7111,11 @@ static void vmx_cr_load_test(void)
return;
}
- TEST_ASSERT(!(cr4 & (X86_CR4_PCIDE | X86_CR4_MCE)));
- TEST_ASSERT(!(cr3 & X86_CR3_PCID_MASK));
+ TEST_ASSERT(!(orig_cr3 & X86_CR3_PCID_MASK));
/* Enable PCID for L1. */
- cr4 |= X86_CR4_PCIDE;
- cr3 |= 0x1;
+ cr4 = orig_cr4 | X86_CR4_PCIDE;
+ cr3 = orig_cr3 | 0x1;
TEST_ASSERT(!write_cr4_checking(cr4));
write_cr3(cr3);
@@ -7126,17 +7128,16 @@ static void vmx_cr_load_test(void)
* No exception is expected.
*
* NB. KVM loads the last guest write to CR4 into CR4 read
- * shadow. In order to trigger an exit to KVM, we can set a
- * bit that was zero in the above CR4 write and is owned by
- * KVM. We choose to set CR4.MCE, which shall have no side
- * effect because normally no guest MCE (e.g., as the result
- * of bad memory) would happen during this test.
+ * shadow. In order to trigger an exit to KVM, we can toggle a
+ * bit that is owned by KVM. We choose to set CR4.MCE, which shall
+ * have no side effect because normally no guest MCE (e.g., as the
+ * result of bad memory) would happen during this test.
*/
- TEST_ASSERT(!write_cr4_checking(cr4 | X86_CR4_MCE));
+ TEST_ASSERT(!write_cr4_checking(cr4 ^ X86_CR4_MCE));
- /* Cleanup L1 state: disable PCID. */
- write_cr3(cr3 & ~X86_CR3_PCID_MASK);
- TEST_ASSERT(!write_cr4_checking(cr4 & ~X86_CR4_PCIDE));
+ /* Cleanup L1 state. */
+ write_cr3(orig_cr3);
+ TEST_ASSERT(!write_cr4_checking(orig_cr4));
}
static void vmx_nm_test_guest(void)
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
