[Qemu-devel] [PULL 20/38] s390x/cpumodel: let the CPU model handle feature checks

[Cornelia Huck <cornelia.huck@de.ibm.com>]

From: David Hildenbrand <dahi@linux.vnet.ibm.com>

If we have certain features enabled, we have to migrate additional state
(e.g. vector registers or runtime-instrumentation registers). Let the
CPU model control that unless we have no "host" CPU model in the KVM
case. This will later on be the case for compatibility machines, so
migration from QEMU versions without the CPU model will still work.

Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Message-Id: <20160905085244.99980-12-dahi@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 target-s390x/cpu_models.c | 25 +++++++++++++++++++++++++
 target-s390x/cpu_models.h |  2 ++
 target-s390x/kvm.c        |  4 ++--
 target-s390x/machine.c    | 14 ++------------
 4 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/target-s390x/cpu_models.c b/target-s390x/cpu_models.c
index 1daa208..d44dab2 100644
--- a/target-s390x/cpu_models.c
+++ b/target-s390x/cpu_models.c
@@ -73,6 +73,31 @@ static S390CPUDef s390_cpu_defs[] = {
     CPUDEF_INIT(0x2965, 13, 2, 47, 0x08000000U, "z13s", "IBM z13s GA1"),
 };
 
+bool s390_has_feat(S390Feat feat)
+{
+    static S390CPU *cpu;
+
+    if (!cpu) {
+        cpu = S390_CPU(qemu_get_cpu(0));
+    }
+
+    if (!cpu || !cpu->model) {
+#ifdef CONFIG_KVM
+        if (kvm_enabled()) {
+            if (feat == S390_FEAT_VECTOR) {
+                return kvm_check_extension(kvm_state,
+                                           KVM_CAP_S390_VECTOR_REGISTERS);
+            }
+            if (feat == S390_FEAT_RUNTIME_INSTRUMENTATION) {
+                return kvm_s390_get_ri();
+            }
+        }
+#endif
+        return 0;
+    }
+    return test_bit(feat, cpu->model->features);
+}
+
 struct S390PrintCpuListInfo {
     FILE *f;
     fprintf_function print;
diff --git a/target-s390x/cpu_models.h b/target-s390x/cpu_models.h
index f3f3f3c..cca865d 100644
--- a/target-s390x/cpu_models.h
+++ b/target-s390x/cpu_models.h
@@ -49,4 +49,6 @@ typedef struct S390CPUModel {
     uint8_t cpu_ver;        /* CPU version, usually "ff" for kvm */
 } S390CPUModel;
 
+bool s390_has_feat(S390Feat feat);
+
 #endif /* TARGET_S390X_CPU_MODELS_H */
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 4341d54..4f32a6b 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -1539,7 +1539,7 @@ static void sigp_store_adtl_status(void *arg)
 {
     SigpInfo *si = arg;
 
-    if (!kvm_check_extension(kvm_state, KVM_CAP_S390_VECTOR_REGISTERS)) {
+    if (!s390_has_feat(S390_FEAT_VECTOR)) {
         set_sigp_status(si, SIGP_STAT_INVALID_ORDER);
         return;
     }
@@ -2119,7 +2119,7 @@ static uint64_t build_channel_report_mcic(void)
         MCIC_VB_WP | MCIC_VB_MS | MCIC_VB_PM | MCIC_VB_IA | MCIC_VB_FP |
         MCIC_VB_GR | MCIC_VB_CR | MCIC_VB_ST | MCIC_VB_AR | MCIC_VB_PR |
         MCIC_VB_FC | MCIC_VB_CT | MCIC_VB_CC;
-    if (kvm_check_extension(kvm_state, KVM_CAP_S390_VECTOR_REGISTERS)) {
+    if (s390_has_feat(S390_FEAT_VECTOR)) {
         mcic |= MCIC_VB_VR;
     }
     return mcic;
diff --git a/target-s390x/machine.c b/target-s390x/machine.c
index aa39e5d..edc3a47 100644
--- a/target-s390x/machine.c
+++ b/target-s390x/machine.c
@@ -78,12 +78,7 @@ static const VMStateDescription vmstate_fpu = {
 
 static bool vregs_needed(void *opaque)
 {
-#ifdef CONFIG_KVM
-    if (kvm_enabled()) {
-        return kvm_check_extension(kvm_state, KVM_CAP_S390_VECTOR_REGISTERS);
-    }
-#endif
-    return 0;
+    return s390_has_feat(S390_FEAT_VECTOR);
 }
 
 static const VMStateDescription vmstate_vregs = {
@@ -147,12 +142,7 @@ static const VMStateDescription vmstate_vregs = {
 
 static bool riccb_needed(void *opaque)
 {
-#ifdef CONFIG_KVM
-    if (kvm_enabled()) {
-        return kvm_s390_get_ri();
-    }
-#endif
-    return 0;
+    return s390_has_feat(S390_FEAT_RUNTIME_INSTRUMENTATION);
 }
 
 const VMStateDescription vmstate_riccb = {
-- 
2.9.3