[PATCH 9/9] KVM: arm64: selftests: Test with every breakpoint/watchpoint

[Reiji Watanabe]

Currently, the debug-exceptions test always uses only
{break,watch}point#0 and the highest numbered context-aware
breakpoint. Modify the test to use all {break,watch}points and
context-aware breakpoints supported on the system.

Signed-off-by: Reiji Watanabe <reijiw at google.com>
---
 .../selftests/kvm/aarch64/debug-exceptions.c  | 77 +++++++++++++++----
 1 file changed, 61 insertions(+), 16 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index dc94c85bb383..7aeab6ae887a 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -397,14 +397,12 @@ static int debug_version(uint64_t id_aa64dfr0)
 	return cpuid_get_ufield(id_aa64dfr0, ID_AA64DFR0_DEBUGVER_SHIFT);
 }
 
-int main(int argc, char *argv[])
+void run_test(uint8_t bpn, uint8_t wpn, uint8_t ctx_bpn)
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
 	struct ucall uc;
 	int stage;
-	uint64_t aa64dfr0;
-	uint8_t brps;
 
 	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
 	ucall_init(vm, NULL);
@@ -412,10 +410,6 @@ int main(int argc, char *argv[])
 	vm_init_descriptor_tables(vm);
 	vcpu_init_descriptor_tables(vcpu);
 
-	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &aa64dfr0);
-	__TEST_REQUIRE(debug_version(aa64dfr0) >= 6,
-		       "Armv8 debug architecture not supported.");
-
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_BRK_INS, guest_sw_bp_handler);
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
@@ -427,15 +421,9 @@ int main(int argc, char *argv[])
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_SVC64, guest_svc_handler);
 
-	/* Number of breakpoints, minus 1 */
-	brps = cpuid_get_ufield(aa64dfr0, ID_AA64DFR0_BRPS_SHIFT);
-	__TEST_REQUIRE(brps > 0, "At least two breakpoints are required");
-
-	/*
-	 * Run tests with breakpoint#0 and watchpoint#0, and the higiest
-	 * numbered (context-aware) breakpoint.
-	 */
-	vcpu_args_set(vcpu, 3, 0, 0, brps);
+	/* Specify bpn/wpn/ctx_bpn to be tested */
+	vcpu_args_set(vcpu, 3, bpn, wpn, ctx_bpn);
+	pr_debug("Use bpn#%d, wpn#%d and ctx_bpn#%d\n", bpn, wpn, ctx_bpn);
 
 	for (stage = 0; stage < 11; stage++) {
 		vcpu_run(vcpu);
@@ -458,5 +446,62 @@ int main(int argc, char *argv[])
 
 done:
 	kvm_vm_free(vm);
+}
+
+/*
+ * Run debug testing using the various breakpoint#, watchpoint# and
+ * context-aware breakpoint# with the given ID_AA64DFR0_EL1 configuration.
+ */
+void test_debug(uint64_t aa64dfr0)
+{
+	uint8_t brps, wrps, ctx_cmps;
+	uint8_t normal_brp_num, wrp_num, ctx_brp_base, ctx_brp_num;
+	int b, w, c;
+
+	brps = cpuid_get_ufield(aa64dfr0, ID_AA64DFR0_BRPS_SHIFT);
+	__TEST_REQUIRE(brps > 0, "At least two breakpoints are required");
+
+	wrps = cpuid_get_ufield(aa64dfr0, ID_AA64DFR0_WRPS_SHIFT);
+	ctx_cmps = cpuid_get_ufield(aa64dfr0, ID_AA64DFR0_CTX_CMPS_SHIFT);
+
+	pr_debug("%s brps:%d, wrps:%d, ctx_cmps:%d\n", __func__,
+		 brps, wrps, ctx_cmps);
+
+	/* Number of normal (non-context aware) breakpoints */
+	normal_brp_num = brps - ctx_cmps;
+
+	/* Number of watchpoints */
+	wrp_num = wrps + 1;
+
+	/* Number of context aware breakpoints */
+	ctx_brp_num = ctx_cmps + 1;
+
+	/* Lowest context aware breakpoint number */
+	ctx_brp_base = normal_brp_num;
+
+	/* Run tests with all supported breakpoints/watchpoints */
+	for (c = ctx_brp_base; c < ctx_brp_base + ctx_brp_num; c++) {
+		for (b = 0; b < normal_brp_num; b++) {
+			for (w = 0; w < wrp_num; w++)
+				run_test(b, w, c);
+		}
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vm *vm;
+	struct kvm_vcpu *vcpu;
+	uint64_t aa64dfr0;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64DFR0_EL1), &aa64dfr0);
+	kvm_vm_free(vm);
+
+	__TEST_REQUIRE(debug_version(aa64dfr0) >= 6,
+		       "Armv8 debug architecture not supported.");
+
+	/* Run debug tests with the default configuration */
+	test_debug(aa64dfr0);
 	return 0;
 }
-- 
2.37.1.595.g718a3a8f04-goog