[kvm-unit-tests PATCH] x86: svm: low CR3 bits are not MBZ

[Nadav Amit <namit@vmware.com>]

The low CR3 bits are reserved but not MBZ according to tha APM. The
tests should therefore not check that they cause failed VM-entry. Tests
on bare-metal show they do not.

Signed-off-by: Nadav Amit <namit@vmware.com>
---
 x86/svm.h       |  4 +---
 x86/svm_tests.c | 26 +-------------------------
 2 files changed, 2 insertions(+), 28 deletions(-)

diff --git a/x86/svm.h b/x86/svm.h
index f8e7429..15e0f18 100644
--- a/x86/svm.h
+++ b/x86/svm.h
@@ -325,9 +325,7 @@ struct __attribute__ ((__packed__)) vmcb {
 #define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)
 
 #define	SVM_CR0_RESERVED_MASK			0xffffffff00000000U
-#define	SVM_CR3_LEGACY_RESERVED_MASK		0xfe7U
-#define	SVM_CR3_LEGACY_PAE_RESERVED_MASK	0x7U
-#define	SVM_CR3_LONG_RESERVED_MASK		0xfff0000000000fe7U
+#define	SVM_CR3_LONG_RESERVED_MASK		0xfff0000000000000U
 #define	SVM_CR4_LEGACY_RESERVED_MASK		0xff88f000U
 #define	SVM_CR4_RESERVED_MASK			0xffffffffff88f000U
 #define	SVM_DR6_RESERVED_MASK			0xffffffffffff1ff0U
diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index 3b0d019..1908c7c 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -2007,38 +2007,14 @@ static void test_cr3(void)
 {
 	/*
 	 * CR3 MBZ bits based on different modes:
-	 *   [2:0]		    - legacy PAE
-	 *   [2:0], [11:5]	    - legacy non-PAE
-	 *   [2:0], [11:5], [63:52] - long mode
+	 *   [63:52] - long mode
 	 */
 	u64 cr3_saved = vmcb->save.cr3;
-	u64 cr4_saved = vmcb->save.cr4;
-	u64 cr4 = cr4_saved;
-	u64 efer_saved = vmcb->save.efer;
-	u64 efer = efer_saved;
 
-	efer &= ~EFER_LME;
-	vmcb->save.efer = efer;
-	cr4 |= X86_CR4_PAE;
-	vmcb->save.cr4 = cr4;
-	SVM_TEST_CR_RESERVED_BITS(0, 2, 1, 3, cr3_saved,
-	    SVM_CR3_LEGACY_PAE_RESERVED_MASK);
-
-	cr4 = cr4_saved & ~X86_CR4_PAE;
-	vmcb->save.cr4 = cr4;
-	SVM_TEST_CR_RESERVED_BITS(0, 11, 1, 3, cr3_saved,
-	    SVM_CR3_LEGACY_RESERVED_MASK);
-
-	cr4 |= X86_CR4_PAE;
-	vmcb->save.cr4 = cr4;
-	efer |= EFER_LME;
-	vmcb->save.efer = efer;
 	SVM_TEST_CR_RESERVED_BITS(0, 63, 1, 3, cr3_saved,
 	    SVM_CR3_LONG_RESERVED_MASK);
 
-	vmcb->save.cr4 = cr4_saved;
 	vmcb->save.cr3 = cr3_saved;
-	vmcb->save.efer = efer_saved;
 }
 
 static void test_cr4(void)
-- 
2.25.1