[libvirt] [PATCH 4/5] qemu: Add domain support for VCPU halted state

[Viktor Mihajlovski]

Adding a field to the domain's private vcpu object to hold the halted
state information.
Adding two functions in support of the halted state:
- qemuDomainGetVcpuHalted: retrieve the halted state from a
  private vcpu object
- qemuDomainRefreshVcpuHalted: obtain the per-vcpu halted states
  via qemu monitor and store the results in the private vcpu objects

Signed-off-by: Viktor Mihajlovski <mihajlov at linux.vnet.ibm.com>
Reviewed-by: Bjoern Walk <bwalk at linux.vnet.ibm.com>
Signed-off-by: Boris Fiuczynski <fiuczy at linux.vnet.ibm.com>
---
 src/qemu/qemu_domain.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_domain.h |  4 +++
 2 files changed, 86 insertions(+)

diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index 286f096..945a75d 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -5650,6 +5650,88 @@ qemuDomainDetectVcpuPids(virQEMUDriverPtr driver,
     return ret;
 }
 
+/**
+ * qemuDomainGetVcpuHalted:
+ * @vm: domain object
+ * @vcpu: cpu id
+ *
+ * Returns the vCPU halted state.
+  */
+bool
+qemuDomainGetVcpuHalted(virDomainObjPtr vm,
+                        unsigned int vcpuid)
+{
+    virDomainVcpuDefPtr vcpu = virDomainDefGetVcpu(vm->def, vcpuid);
+    return QEMU_DOMAIN_VCPU_PRIVATE(vcpu)->halted;
+}
+
+/**
+ * qemuDomainRefreshVcpuHalted:
+ * @driver: qemu driver data
+ * @vm: domain object
+ * @asyncJob: current asynchronous job type
+ *
+ * Updates vCPU halted state in the private data of @vm.
+ *
+ * Returns number of detected vCPUs on success, -1 on error and reports
+ * an appropriate error, -2 if the domain doesn't exist any more.
+ */
+int
+qemuDomainRefreshVcpuHalted(virQEMUDriverPtr driver,
+                            virDomainObjPtr vm,
+                            int asyncJob)
+{
+    virDomainVcpuDefPtr vcpu;
+    size_t maxvcpus = virDomainDefGetVcpusMax(vm->def);
+    bool *cpuhalted = NULL;
+    int ncpuhalted;
+    size_t i;
+    int ret = -1;
+
+    /* Not supported currently for TCG, see above
+     */
+    if (vm->def->virtType == VIR_DOMAIN_VIRT_QEMU)
+        return 0;
+
+    if (qemuDomainObjEnterMonitorAsync(driver, vm, asyncJob) < 0)
+        return -1;
+    ncpuhalted = qemuMonitorGetCPUState(qemuDomainGetMonitor(vm), &cpuhalted);
+    if (qemuDomainObjExitMonitor(driver, vm) < 0) {
+        ret = -2;
+        goto cleanup;
+    }
+
+    /* Don't fail for older QEMUs
+     */
+    if (ncpuhalted <= 0) {
+        virResetLastError();
+        ret = 0;
+        goto cleanup;
+    }
+
+    for (i = 0; i < maxvcpus; i++) {
+        vcpu = virDomainDefGetVcpu(vm->def, i);
+
+        if (i < ncpuhalted)
+            QEMU_DOMAIN_VCPU_PRIVATE(vcpu)->halted = cpuhalted[i];
+        else
+            QEMU_DOMAIN_VCPU_PRIVATE(vcpu)->halted = false;
+    }
+
+    if (ncpuhalted != virDomainDefGetVcpus(vm->def)) {
+        virReportError(VIR_ERR_INTERNAL_ERROR,
+                       _("got wrong number of vCPUs from QEMU monitor. "
+                         "got %d, wanted %d"),
+                       ncpuhalted, virDomainDefGetVcpus(vm->def));
+        goto cleanup;
+    }
+
+    ret = ncpuhalted;
+
+ cleanup:
+    VIR_FREE(cpuhalted);
+    return ret;
+}
 
 bool
 qemuDomainSupportsNicdev(virDomainDefPtr def,
diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h
index 114db98..44add02 100644
--- a/src/qemu/qemu_domain.h
+++ b/src/qemu/qemu_domain.h
@@ -316,6 +316,7 @@ struct _qemuDomainVcpuPrivate {
     virObject parent;
 
     pid_t tid; /* vcpu thread id */
+    bool halted; /* vcpu halted state */
 };
 
 # define QEMU_DOMAIN_VCPU_PRIVATE(vcpu)    \
@@ -649,6 +650,9 @@ bool qemuDomainHasVcpuPids(virDomainObjPtr vm);
 pid_t qemuDomainGetVcpuPid(virDomainObjPtr vm, unsigned int vcpuid);
 int qemuDomainDetectVcpuPids(virQEMUDriverPtr driver, virDomainObjPtr vm,
                              int asyncJob);
+bool qemuDomainGetVcpuHalted(virDomainObjPtr vm, unsigned int vcpu);
+int qemuDomainRefreshVcpuHalted(virQEMUDriverPtr driver, virDomainObjPtr vm,
+                                int asyncJob);
 
 bool qemuDomainSupportsNicdev(virDomainDefPtr def,
                               virDomainNetDefPtr net);
-- 
1.9.1