[RFC PATCH 10/12] arm/sdei: check KVM cap and enable SDEI

[Heyi Guo <guoheyi@huawei.com>]

Check KVM hypercall forward capability and enable it, and set global
flag "sdei_enabled" to true if everything works well.

Signed-off-by: Heyi Guo <guoheyi@huawei.com>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
---
 target/arm/sdei.c | 17 +++++++++++++++++
 target/arm/sdei.h |  2 ++
 2 files changed, 19 insertions(+)

diff --git a/target/arm/sdei.c b/target/arm/sdei.c
index efdb681..000545e 100644
--- a/target/arm/sdei.c
+++ b/target/arm/sdei.c
@@ -43,6 +43,7 @@
 #define TYPE_QEMU_SDEI "qemu_sdei"
 #define QEMU_SDEI(obj) OBJECT_CHECK(QemuSDEState, (obj), TYPE_QEMU_SDEI)
 
+bool sdei_enabled;
 static QemuSDEState *sde_state;
 
 typedef struct QemuSDEIBindNotifyEntry {
@@ -1465,6 +1466,7 @@ static const VMStateDescription vmstate_sde_state = {
 static void sdei_initfn(Object *obj)
 {
     QemuSDEState *s = QEMU_SDEI(obj);
+    KVMState *kvm = KVM_STATE(current_machine->accelerator);
 
     if (sde_state) {
         error_report("Only one SDEI dispatcher is allowed!");
@@ -1474,6 +1476,21 @@ static void sdei_initfn(Object *obj)
 
     qemu_sde_init(s);
     qemu_register_reset(qemu_sde_reset, s);
+
+    if (kvm_check_extension(kvm, KVM_CAP_FORWARD_HYPERCALL)) {
+        int ret;
+        ret = kvm_vm_enable_cap(kvm, KVM_CAP_FORWARD_HYPERCALL, 0,
+                                KVM_CAP_FORWARD_HYPERCALL_EXCL_PSCI);
+        if (ret < 0) {
+            error_report("Enable hypercall forwarding failed: %s",
+                         strerror(-ret));
+            abort();
+        }
+        sdei_enabled = true;
+        info_report("qemu sdei enabled");
+    } else {
+        info_report("KVM does not support forwarding hypercall.");
+    }
 }
 
 static void qemu_sde_class_init(ObjectClass *klass, void *data)
diff --git a/target/arm/sdei.h b/target/arm/sdei.h
index feaaf1a..95e7d8d 100644
--- a/target/arm/sdei.h
+++ b/target/arm/sdei.h
@@ -29,6 +29,8 @@
 
 #define SDEI_MAX_REQ        SDEI_1_0_FN(0x12)
 
+extern bool sdei_enabled;
+
 void sdei_handle_request(CPUState *cs, struct kvm_run *run);
 
 /*
-- 
1.8.3.1