[PATCH 3/4] kvm-unit-tests: nSVM: Test that DR6[63:32], DR7[63:32] and EFER reserved bits are not set on vmrun of nested guests

[Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>]

According to section "Canonicalization and Consistency Checks" in APM vol. 2
the following guest state is illegal:

    "DR6[63:32] are not zero."
    "DR7[63:32] are not zero."
    "Any MBZ bit of EFER is set."

Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
---
 x86/svm.h       |  3 +++
 x86/svm_tests.c | 59 ++++++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 42 insertions(+), 20 deletions(-)

diff --git a/x86/svm.h b/x86/svm.h
index 3d5b79c..14418ef 100644
--- a/x86/svm.h
+++ b/x86/svm.h
@@ -329,6 +329,9 @@ struct __attribute__ ((__packed__)) vmcb {
 #define	SVM_CR3_LONG_RESERVED_MASK		0xfff0000000000fe7U
 #define	SVM_CR4_LEGACY_RESERVED_MASK		0xffbaf000U
 #define	SVM_CR4_RESERVED_MASK			0xffffffffffbaf000U
+#define	SVM_DR6_RESERVED_MASK			0xffffffffffff1ff0U
+#define	SVM_DR7_RESERVED_MASK			0xffffffff0000cc00U
+#define	SVM_EFER_RESERVED_MASK			0xffffffffffff0200U
 
 #define MSR_BITMAP_SIZE 8192
 
diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index 99cfe4a..d96f3ee 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -1799,7 +1799,8 @@ static void basic_guest_main(struct svm_test *test)
 {
 }
 
-#define SVM_TEST_CR_RESERVED_BITS(start, end, inc, cr, val, resv_mask)	\
+#define SVM_TEST_REG_RESERVED_BITS(start, end, inc, str_name, reg, val,	\
+				   resv_mask)				\
 {									\
         u64 tmp, mask;							\
         int i;								\
@@ -1809,18 +1810,9 @@ static void basic_guest_main(struct svm_test *test)
                 if (!(mask & resv_mask))				\
                         continue;					\
                 tmp = val | mask;					\
-                switch (cr) {						\
-                        case 0:						\
-                                vmcb->save.cr0 = tmp;			\
-                                break;					\
-                        case 3:						\
-                                vmcb->save.cr3 = tmp;			\
-                                break;					\
-                        case 4:						\
-                                vmcb->save.cr4 = tmp;			\
-                }							\
-                report(svm_vmrun() == SVM_EXIT_ERR, "Test CR%d %d:%d: %lx",\
-		    cr, end, start, tmp);				\
+		reg = tmp;						\
+		report(svm_vmrun() == SVM_EXIT_ERR, "Test %s %d:%d: %lx",\
+		    str_name, end, start, tmp);				\
         }								\
 }
 
@@ -1871,7 +1863,7 @@ static void svm_guest_state_test(void)
 	 */
 	cr0 = cr0_saved;
 
-	SVM_TEST_CR_RESERVED_BITS(32, 63, 4, 0, cr0_saved,
+	SVM_TEST_REG_RESERVED_BITS(32, 63, 4, "CR0", vmcb->save.cr0, cr0_saved,
 	    SVM_CR0_RESERVED_MASK);
 	vmcb->save.cr0 = cr0_saved;
 
@@ -1891,19 +1883,19 @@ static void svm_guest_state_test(void)
 	vmcb->save.efer = efer;
 	cr4 |= X86_CR4_PAE;
 	vmcb->save.cr4 = cr4;
-	SVM_TEST_CR_RESERVED_BITS(0, 2, 1, 3, cr3_saved,
+	SVM_TEST_REG_RESERVED_BITS(0, 2, 1, "CR3", vmcb->save.cr3, 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, 2, 3, cr3_saved,
+	SVM_TEST_REG_RESERVED_BITS(0, 11, 2, "CR3", vmcb->save.cr3, cr3_saved,
 	    SVM_CR3_LEGACY_RESERVED_MASK);
 
 	cr4 |= X86_CR4_PAE;
 	vmcb->save.cr4 = cr4;
 	efer |= EFER_LMA;
 	vmcb->save.efer = efer;
-	SVM_TEST_CR_RESERVED_BITS(0, 63, 2, 3, cr3_saved,
+	SVM_TEST_REG_RESERVED_BITS(0, 63, 2, "CR3", vmcb->save.cr3, cr3_saved,
 	    SVM_CR3_LONG_RESERVED_MASK);
 
 	vmcb->save.cr4 = cr4_saved;
@@ -1919,18 +1911,45 @@ static void svm_guest_state_test(void)
 	efer_saved = vmcb->save.efer;
 	efer &= ~EFER_LMA;
 	vmcb->save.efer = efer;
-	SVM_TEST_CR_RESERVED_BITS(12, 31, 2, 4, cr4_saved,
+	SVM_TEST_REG_RESERVED_BITS(12, 31, 2, "CR4", vmcb->save.cr4, cr4_saved,
 	    SVM_CR4_LEGACY_RESERVED_MASK);
 
 	efer |= EFER_LMA;
 	vmcb->save.efer = efer;
-	SVM_TEST_CR_RESERVED_BITS(12, 31, 2, 4, cr4_saved,
+	SVM_TEST_REG_RESERVED_BITS(12, 31, 2, "CR4", vmcb->save.cr4, cr4_saved,
 	    SVM_CR4_RESERVED_MASK);
-	SVM_TEST_CR_RESERVED_BITS(32, 63, 4, 4, cr4_saved,
+	SVM_TEST_REG_RESERVED_BITS(32, 63, 4, "CR4", vmcb->save.cr4, cr4_saved,
 	    SVM_CR4_RESERVED_MASK);
 
 	vmcb->save.cr4 = cr4_saved;
 	vmcb->save.efer = efer_saved;
+
+	/*
+	 * DR6[63:32] and DR7[63:32] are MBZ
+	 */
+	u64 dr_saved = vmcb->save.dr6;
+
+	SVM_TEST_REG_RESERVED_BITS(32, 63, 4, "DR6", vmcb->save.dr6, dr_saved,
+	    SVM_DR6_RESERVED_MASK);
+	vmcb->save.dr6 = dr_saved;
+
+	dr_saved = vmcb->save.dr7;
+	SVM_TEST_REG_RESERVED_BITS(32, 63, 4, "DR7", vmcb->save.dr7, dr_saved,
+	    SVM_DR7_RESERVED_MASK);
+
+	vmcb->save.dr7 = dr_saved;
+
+	/*
+	 * EFER MBZ bits: 63:16, 9
+	 */
+	efer_saved = vmcb->save.efer;
+
+	SVM_TEST_REG_RESERVED_BITS(8, 9, 1, "EFER", vmcb->save.efer,
+	    efer_saved, SVM_EFER_RESERVED_MASK);
+	SVM_TEST_REG_RESERVED_BITS(16, 63, 4, "EFER", vmcb->save.efer,
+	    efer_saved, SVM_EFER_RESERVED_MASK);
+
+	vmcb->save.efer = efer_saved;
 }
 
 struct svm_test svm_tests[] = {
-- 
1.8.3.1