[PATCH 4/4] Enable to use kvm emulated watchdog

[PATCH 4/4] Enable to use kvm emulated watchdog

[Bharat Bhushan]

This patch adds the support to enable KVM emulated watchdog
if KVM supports (use the capability enablement in watchdog handler).

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
---
 linux-headers/linux/kvm.h |    1 +
 target-ppc/kvm.c          |   28 +++++++++++++++++++++++++++-
 2 files changed, 28 insertions(+), 1 deletions(-)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index c1169ff..8a149db 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -619,6 +619,7 @@ struct kvm_ppc_smmu_info {
 #define KVM_CAP_PPC_GET_SMMU_INFO 78
 #define KVM_CAP_S390_COW 79
 #define KVM_CAP_PPC_ALLOC_HTAB 80
+#define KVM_CAP_PPC_WDT 81
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index 6a37e94..52f00b5 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -61,6 +61,7 @@ static int cap_booke_sregs;
 static int cap_ppc_smt;
 static int cap_ppc_rma;
 static int cap_spapr_tce;
+static int cap_ppc_wdt;
 
 /* XXX We have a race condition where we actually have a level triggered
  *     interrupt, but the infrastructure can't expose that yet, so the guest
@@ -87,6 +88,7 @@ int kvm_arch_init(KVMState *s)
     cap_ppc_smt = kvm_check_extension(s, KVM_CAP_PPC_SMT);
     cap_ppc_rma = kvm_check_extension(s, KVM_CAP_PPC_RMA);
     cap_spapr_tce = kvm_check_extension(s, KVM_CAP_SPAPR_TCE);
+    cap_ppc_wdt = kvm_check_extension(s, KVM_CAP_PPC_WDT);
 
     if (!cap_interrupt_level) {
         fprintf(stderr, "KVM: Couldn't find level irq capability. Expect the "
@@ -169,6 +171,25 @@ static int kvm_booke206_tlb_init(CPUPPCState *env)
     return 0;
 }
 
+static int kvm_wdt_enable(CPUPPCState *env)
+{
+    int ret;
+    struct kvm_enable_cap encap = {};
+
+    if (!kvm_enabled() || !cap_ppc_wdt) {
+        return 0;
+    }
+
+    encap.cap = KVM_CAP_PPC_WDT;
+    ret = kvm_vcpu_ioctl(env, KVM_ENABLE_CAP, &encap);
+    if (ret < 0) {
+        fprintf(stderr, "%s: couldn't enable KVM_CAP_PPC_WDT: %s\n",
+                __func__, strerror(-ret));
+        return ret;
+    }
+
+    return ret;
+}
 
 #if defined(TARGET_PPC64)
 static void kvm_get_fallback_smmu_info(CPUPPCState *env,
@@ -385,6 +406,11 @@ int kvm_arch_init_vcpu(CPUPPCState *cenv)
         return ret;
     }
 
+    ret = kvm_wdt_enable(cenv);
+    if (ret) {
+        return ret;
+    }
+
     idle_timer = qemu_new_timer_ns(vm_clock, kvm_kick_env, cenv);
 
     /* Some targets support access to KVM's guest TLB. */
@@ -755,7 +781,7 @@ static int kvm_arch_handle_watchdog(CPUPPCState *env)
      * Clear watchdog interrupt condition by clearing TSR.
      * Similar logic needed to be implemented for watchdog emulation in qemu
      */
-    if (cap_booke_sregs) {
+    if (cap_booke_sregs && cap_ppc_wdt) {
         ret = kvm_vcpu_ioctl(env, KVM_GET_SREGS, &sregs);
         if (ret < 0) {
             return ret;
-- 
1.7.0.4