target/arm: add new property to select pauth-qarma5

Before changing default pauth algorithm, we need to make sure current
default one (QARMA5) can still be selected.

$ qemu-system-aarch64 -cpu max,pauth-qarma5=on ...

Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20241219183211.3493974-2-pierrick.bouvier@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

docs/system/arm/cpu-features.rst

@@ -219,7 +219,10 @@ Below is the list of TCG VCPU features and their descriptions.
 ``pauth-qarma3``
   When ``pauth`` is enabled, select the architected QARMA3 algorithm.
 
-Without either ``pauth-impdef`` or ``pauth-qarma3`` enabled,
+``pauth-qarma5``
+  When ``pauth`` is enabled, select the architected QARMA5 algorithm.
+
+Without ``pauth-impdef``, ``pauth-qarma3`` or ``pauth-qarma5`` enabled,
 the architected QARMA5 algorithm is used.  The architected QARMA5
 and QARMA3 algorithms have good cryptographic properties, but can
 be quite slow to emulate.  The impdef algorithm used by QEMU is

target/arm/arm-qmp-cmds.c

@@ -94,7 +94,7 @@ static const char *cpu_model_advertised_features[] = {
     "sve640", "sve768", "sve896", "sve1024", "sve1152", "sve1280",
     "sve1408", "sve1536", "sve1664", "sve1792", "sve1920", "sve2048",
     "kvm-no-adjvtime", "kvm-steal-time",
-    "pauth", "pauth-impdef", "pauth-qarma3",
+    "pauth", "pauth-impdef", "pauth-qarma3", "pauth-qarma5",
     NULL
 };
 

target/arm/cpu.h

@@ -1062,6 +1062,7 @@ struct ArchCPU {
     bool prop_pauth;
     bool prop_pauth_impdef;
     bool prop_pauth_qarma3;
+    bool prop_pauth_qarma5;
     bool prop_lpa2;
 
     /* DCZ blocksize, in log_2(words), ie low 4 bits of DCZID_EL0 */

target/arm/cpu64.c

@@ -520,9 +520,12 @@ void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp)
         }
 
         if (cpu->prop_pauth) {
-            if (cpu->prop_pauth_impdef && cpu->prop_pauth_qarma3) {
+            if ((cpu->prop_pauth_impdef && cpu->prop_pauth_qarma3) ||
+                (cpu->prop_pauth_impdef && cpu->prop_pauth_qarma5) ||
+                (cpu->prop_pauth_qarma3 && cpu->prop_pauth_qarma5)) {
                 error_setg(errp,
-                           "cannot enable both pauth-impdef and pauth-qarma3");
+                           "cannot enable pauth-impdef, pauth-qarma3 and "
+                           "pauth-qarma5 at the same time");
                 return;
             }
 
@@ -532,13 +535,15 @@ void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp)
             } else if (cpu->prop_pauth_qarma3) {
                 isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, APA3, features);
                 isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, GPA3, 1);
-            } else {
+            } else { /* default is pauth-qarma5 */
                 isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, APA, features);
                 isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPA, 1);
             }
-        } else if (cpu->prop_pauth_impdef || cpu->prop_pauth_qarma3) {
-            error_setg(errp, "cannot enable pauth-impdef or "
-                       "pauth-qarma3 without pauth");
+        } else if (cpu->prop_pauth_impdef ||
+                   cpu->prop_pauth_qarma3 ||
+                   cpu->prop_pauth_qarma5) {
+            error_setg(errp, "cannot enable pauth-impdef, pauth-qarma3 or "
+                       "pauth-qarma5 without pauth");
             error_append_hint(errp, "Add pauth=on to the CPU property list.\n");
         }
     }
@@ -553,6 +558,8 @@ static const Property arm_cpu_pauth_impdef_property =
     DEFINE_PROP_BOOL("pauth-impdef", ARMCPU, prop_pauth_impdef, false);
 static const Property arm_cpu_pauth_qarma3_property =
     DEFINE_PROP_BOOL("pauth-qarma3", ARMCPU, prop_pauth_qarma3, false);
+static Property arm_cpu_pauth_qarma5_property =
+    DEFINE_PROP_BOOL("pauth-qarma5", ARMCPU, prop_pauth_qarma5, false);
 
 void aarch64_add_pauth_properties(Object *obj)
 {
@@ -573,6 +580,7 @@ void aarch64_add_pauth_properties(Object *obj)
     } else {
         qdev_property_add_static(DEVICE(obj), &arm_cpu_pauth_impdef_property);
         qdev_property_add_static(DEVICE(obj), &arm_cpu_pauth_qarma3_property);
+        qdev_property_add_static(DEVICE(obj), &arm_cpu_pauth_qarma5_property);
     }
 }
 

tests/qtest/arm-cpu-features.c

@@ -419,21 +419,28 @@ static void pauth_tests_default(QTestState *qts, const char *cpu_type)
     assert_has_feature_enabled(qts, cpu_type, "pauth");
     assert_has_feature_disabled(qts, cpu_type, "pauth-impdef");
     assert_has_feature_disabled(qts, cpu_type, "pauth-qarma3");
+    assert_has_feature_disabled(qts, cpu_type, "pauth-qarma5");
     assert_set_feature(qts, cpu_type, "pauth", false);
     assert_set_feature(qts, cpu_type, "pauth", true);
     assert_set_feature(qts, cpu_type, "pauth-impdef", true);
     assert_set_feature(qts, cpu_type, "pauth-impdef", false);
     assert_set_feature(qts, cpu_type, "pauth-qarma3", true);
     assert_set_feature(qts, cpu_type, "pauth-qarma3", false);
+    assert_set_feature(qts, cpu_type, "pauth-qarma5", true);
+    assert_set_feature(qts, cpu_type, "pauth-qarma5", false);
     assert_error(qts, cpu_type,
-                 "cannot enable pauth-impdef or pauth-qarma3 without pauth",
+                 "cannot enable pauth-impdef, pauth-qarma3 or pauth-qarma5 without pauth",
                  "{ 'pauth': false, 'pauth-impdef': true }");
     assert_error(qts, cpu_type,
-                 "cannot enable pauth-impdef or pauth-qarma3 without pauth",
+                 "cannot enable pauth-impdef, pauth-qarma3 or pauth-qarma5 without pauth",
                  "{ 'pauth': false, 'pauth-qarma3': true }");
     assert_error(qts, cpu_type,
-                 "cannot enable both pauth-impdef and pauth-qarma3",
-                 "{ 'pauth': true, 'pauth-impdef': true, 'pauth-qarma3': true }");
+                 "cannot enable pauth-impdef, pauth-qarma3 or pauth-qarma5 without pauth",
+                 "{ 'pauth': false, 'pauth-qarma5': true }");
+    assert_error(qts, cpu_type,
+                 "cannot enable pauth-impdef, pauth-qarma3 and pauth-qarma5 at the same time",
+                 "{ 'pauth': true, 'pauth-impdef': true, 'pauth-qarma3': true,"
+                 "  'pauth-qarma5': true }");
 }
 
 static void test_query_cpu_model_expansion(const void *data)