diff --git a/test/vmapi/primary_with_secondaries/debug_el1.c b/test/vmapi/primary_with_secondaries/debug_el1.c
index d7d3df1..a6d07a3 100644
--- a/test/vmapi/primary_with_secondaries/debug_el1.c
+++ b/test/vmapi/primary_with_secondaries/debug_el1.c
@@ -91,6 +91,6 @@
 {
 	EXPECT_EQ(hf_vm_get_id(), HF_PRIMARY_VM_ID);
 
-	TRY_WRITE_READ(DBGBCR0_EL1, 0x2);
-	TRY_WRITE_READ(DBGBVR0_EL1, 0xf0);
+	CHECK_UPDATE(DBGBCR0_EL1, 0x0, 0x2);
+	CHECK_UPDATE(DBGBVR0_EL1, 0x7, 0xf0);
 }
diff --git a/test/vmapi/primary_with_secondaries/perfmon.c b/test/vmapi/primary_with_secondaries/perfmon.c
index 4b5ff53..5d62250 100644
--- a/test/vmapi/primary_with_secondaries/perfmon.c
+++ b/test/vmapi/primary_with_secondaries/perfmon.c
@@ -63,7 +63,7 @@
 	 */
 	EXPECT_GE(perf_mon_count, 4);
 
-	TRY_WRITE_READ(PMCCNTR_EL0, 0xaaaa);
+	CHECK_UPDATE(PMCCNTR_EL0, 0x5555, 0xaaaa);
 
 	write_msr(PMINTENCLR_EL1, 0xffff);
 	CHECK_READ(PMINTENSET_EL1, 0);
@@ -104,127 +104,127 @@
 		FAIL("More performance monitor registers than supported.");
 	case 30:
 		TRY_READ(PMEVCNTR30_EL0);
-		TRY_WRITE_READ(PMEVTYPER30_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER30_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 29:
 		TRY_READ(PMEVCNTR29_EL0);
-		TRY_WRITE_READ(PMEVTYPER29_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER29_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 28:
 		TRY_READ(PMEVCNTR28_EL0);
-		TRY_WRITE_READ(PMEVTYPER28_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER28_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 27:
 		TRY_READ(PMEVCNTR27_EL0);
-		TRY_WRITE_READ(PMEVTYPER27_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER27_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 26:
 		TRY_READ(PMEVCNTR26_EL0);
-		TRY_WRITE_READ(PMEVTYPER26_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER26_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 25:
 		TRY_READ(PMEVCNTR25_EL0);
-		TRY_WRITE_READ(PMEVTYPER25_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER25_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 24:
 		TRY_READ(PMEVCNTR24_EL0);
-		TRY_WRITE_READ(PMEVTYPER24_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER24_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 23:
 		TRY_READ(PMEVCNTR23_EL0);
-		TRY_WRITE_READ(PMEVTYPER23_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER23_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 22:
 		TRY_READ(PMEVCNTR22_EL0);
-		TRY_WRITE_READ(PMEVTYPER22_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER22_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 21:
 		TRY_READ(PMEVCNTR21_EL0);
-		TRY_WRITE_READ(PMEVTYPER21_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER21_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 20:
 		TRY_READ(PMEVCNTR20_EL0);
-		TRY_WRITE_READ(PMEVTYPER20_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER20_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 19:
 		TRY_READ(PMEVCNTR19_EL0);
-		TRY_WRITE_READ(PMEVTYPER19_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER19_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 18:
 		TRY_READ(PMEVCNTR18_EL0);
-		TRY_WRITE_READ(PMEVTYPER18_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER18_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 17:
 		TRY_READ(PMEVCNTR17_EL0);
-		TRY_WRITE_READ(PMEVTYPER17_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER17_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 16:
 		TRY_READ(PMEVCNTR16_EL0);
-		TRY_WRITE_READ(PMEVTYPER16_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER16_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 15:
 		TRY_READ(PMEVCNTR15_EL0);
-		TRY_WRITE_READ(PMEVTYPER15_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER15_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 14:
 		TRY_READ(PMEVCNTR14_EL0);
-		TRY_WRITE_READ(PMEVTYPER14_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER14_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 13:
 		TRY_READ(PMEVCNTR13_EL0);
-		TRY_WRITE_READ(PMEVTYPER13_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER13_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 12:
 		TRY_READ(PMEVCNTR12_EL0);
-		TRY_WRITE_READ(PMEVTYPER12_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER12_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 11:
 		TRY_READ(PMEVCNTR11_EL0);
-		TRY_WRITE_READ(PMEVTYPER11_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER11_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 10:
 		TRY_READ(PMEVCNTR10_EL0);
-		TRY_WRITE_READ(PMEVTYPER10_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER10_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 9:
 		TRY_READ(PMEVCNTR9_EL0);
-		TRY_WRITE_READ(PMEVTYPER9_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER9_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 8:
 		TRY_READ(PMEVCNTR8_EL0);
-		TRY_WRITE_READ(PMEVTYPER8_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER8_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 7:
 		TRY_READ(PMEVCNTR7_EL0);
-		TRY_WRITE_READ(PMEVTYPER7_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER7_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 6:
 		TRY_READ(PMEVCNTR6_EL0);
-		TRY_WRITE_READ(PMEVTYPER6_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER6_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 5:
 		TRY_READ(PMEVCNTR5_EL0);
-		TRY_WRITE_READ(PMEVTYPER5_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER5_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 4:
 		TRY_READ(PMEVCNTR4_EL0);
-		TRY_WRITE_READ(PMEVTYPER4_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER4_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 3:
 		TRY_READ(PMEVCNTR3_EL0);
-		TRY_WRITE_READ(PMEVTYPER3_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER3_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 2:
 		TRY_READ(PMEVCNTR2_EL0);
-		TRY_WRITE_READ(PMEVTYPER2_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER2_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 1:
 		TRY_READ(PMEVCNTR1_EL0);
-		TRY_WRITE_READ(PMEVTYPER1_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER1_EL0, 0x0, 0x1);
 		/* fallthrough */
 	case 0:
 		TRY_READ(PMEVCNTR0_EL0);
-		TRY_WRITE_READ(PMEVTYPER0_EL0, 0x1);
+		CHECK_UPDATE(PMEVTYPER0_EL0, 0x0, 0x1);
 		break;
 	}
 }
diff --git a/test/vmapi/primary_with_secondaries/sysregs.h b/test/vmapi/primary_with_secondaries/sysregs.h
index 50faab4..920da01 100644
--- a/test/vmapi/primary_with_secondaries/sysregs.h
+++ b/test/vmapi/primary_with_secondaries/sysregs.h
@@ -30,12 +30,20 @@
 		EXPECT_EQ(x, VALUE); \
 	} while (0)
 
-#define TRY_WRITE_READ(REG, VALUE)     \
-	do {                           \
-		uintreg_t x;           \
-		x = read_msr(REG);     \
-		EXPECT_NE(x, VALUE);   \
-		write_msr(REG, VALUE); \
-		x = read_msr(REG);     \
-		EXPECT_EQ(x, VALUE);   \
+/*
+ * Checks that the register can be updated. The first value is written and read
+ * back and then the second value is written and read back. The values must be
+ * different so that success means the register value has been changed and
+ * updated as expected without relying on the initial value of the register.
+ */
+#define CHECK_UPDATE(REG, FROM, TO)   \
+	do {                          \
+		uintreg_t x;          \
+		EXPECT_NE(FROM, TO);  \
+		write_msr(REG, FROM); \
+		x = read_msr(REG);    \
+		EXPECT_EQ(x, FROM);   \
+		write_msr(REG, TO);   \
+		x = read_msr(REG);    \
+		EXPECT_EQ(x, TO);     \
 	} while (0)