[Qemu-devel] [PATCH v2 3/3] arm: implement query-gic-capability

[Peter Xu <peterx@redhat.com>]

For emulated ARM VM, only gicv2 is supported. We need to add gicv3 in
when emulated gicv3 ready. For KVM accelerated ARM VM, we detect the
capability bits using ioctls.

if we want to know GIC kernel capabilities, we need to make sure we have
enabled KVM when querying (like, with "-enable-kvm").

Signed-off-by: Peter Xu <peterx@redhat.com>
---
 target-arm/machine.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/target-arm/machine.c b/target-arm/machine.c
index b3fa64c..98a4094 100644
--- a/target-arm/machine.c
+++ b/target-arm/machine.c
@@ -1,3 +1,4 @@
+#include <linux/kvm.h>
 #include "qemu/osdep.h"
 #include "hw/hw.h"
 #include "hw/boards.h"
@@ -346,9 +347,54 @@ const char *gicv3_class_name(void)
     exit(1);
 }
 
+static GICCapability *gic_cap_new(int version)
+{
+    GICCapability *cap = g_new0(GICCapability, 1);
+    cap->version = version;
+    /* by default, support none */
+    cap->emulated = false;
+    cap->kernel = false;
+    return cap;
+}
+
+static GICCapabilityList *gic_cap_list_add(GICCapabilityList *head,
+                                           GICCapability *cap)
+{
+    GICCapabilityList *item = g_new0(GICCapabilityList, 1);
+    item->value = cap;
+    item->next = head;
+    return item;
+}
+
 GICCapabilityList *qmp_query_gic_capability(Error **errp);
 
 GICCapabilityList *qmp_query_gic_capability(Error **errp)
 {
-    return NULL;
+    GICCapabilityList *head = NULL;
+    GICCapability *v2 = gic_cap_new(2), *v3 = gic_cap_new(3);
+
+    v2->emulated = true;
+    /* FIXME: we'd change to true after we get emulated GICv3 */
+    v3->emulated = false;
+
+#ifdef CONFIG_KVM
+    if (kvm_enabled()) {
+        /* Test KVM GICv2 */
+        if (kvm_create_device(kvm_state, KVM_DEV_TYPE_ARM_VGIC_V2,
+                              true) >= 0) {
+            v2->kernel = true;
+        }
+
+        /* Test KVM GICv3 */
+        if (kvm_create_device(kvm_state, KVM_DEV_TYPE_ARM_VGIC_V3,
+                              true) >= 0) {
+            v3->kernel = true;
+        }
+    }
+#endif
+
+    head = gic_cap_list_add(head, v2);
+    head = gic_cap_list_add(head, v3);
+
+    return head;
 }
-- 
2.4.3