[libvirt] [PATCH v1 8/8] qemu: Implement chardev hotplug on live level

[Michal Privoznik]

Since previous patches has prepared everything for us, we may now
implement live hotplug of a character device.
---
 src/qemu/qemu_driver.c  | 10 +++++
 src/qemu/qemu_hotplug.c | 97 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/qemu/qemu_hotplug.h |  6 +++
 3 files changed, 113 insertions(+)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 1900c4a..c7481ea 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -5807,6 +5807,13 @@ qemuDomainAttachDeviceLive(virDomainObjPtr vm,
             dev->data.redirdev = NULL;
         break;
 
+    case VIR_DOMAIN_DEVICE_CHR:
+        ret = qemuDomainAttachChrDevice(driver, vm,
+                                        dev->data.chr);
+        if (!ret)
+            dev->data.chr = NULL;
+        break;
+
     default:
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        _("device type '%s' cannot be attached"),
@@ -5894,6 +5901,9 @@ qemuDomainDetachDeviceLive(virDomainObjPtr vm,
     case VIR_DOMAIN_DEVICE_HOSTDEV:
         ret = qemuDomainDetachHostDevice(driver, vm, dev);
         break;
+    case VIR_DOMAIN_DEVICE_CHR:
+        ret = qemuDomainDetachChrDevice(driver, vm, dev->data.chr);
+        break;
     default:
         virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
                        "%s", _("This type of device cannot be hot unplugged"));
diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c
index a4f48b0..0535ef6 100644
--- a/src/qemu/qemu_hotplug.c
+++ b/src/qemu/qemu_hotplug.c
@@ -1132,6 +1132,63 @@ error:
 
 }
 
+int qemuDomainAttachChrDevice(virQEMUDriverPtr driver,
+                              virDomainObjPtr vm,
+                              virDomainChrDefPtr chr)
+{
+    int ret = -1;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virDomainDefPtr vmdef = vm->def;
+    char *devstr = NULL;
+    char *charAlias = NULL;
+
+    if (virDomainChrFind(vmdef, chr)) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("chardev already exists"));
+        return ret;
+    }
+
+    if (!virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DEVICE)) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("qemu does not support -device"));
+        return ret;
+    }
+
+    if (qemuAssignDeviceChrAlias(vmdef, chr, -1) < 0)
+        return ret;
+
+    if (qemuBuildChrDeviceStr(&devstr, vm->def, chr, priv->qemuCaps) < 0)
+        return ret;
+
+    if (virAsprintf(&charAlias, "char%s", chr->info.alias) < 0) {
+        virReportOOMError();
+        goto cleanup;
+    }
+
+    qemuDomainObjEnterMonitor(driver, vm);
+    if (qemuMonitorAttachCharDev(priv->mon, charAlias, &chr->source) < 0) {
+        qemuDomainObjExitMonitor(driver, vm);
+        goto cleanup;
+    }
+
+    if (devstr && qemuMonitorAddDevice(priv->mon, devstr) < 0) {
+        /* detach associated chardev on error */
+        qemuMonitorDetachCharDev(priv->mon, charAlias);
+        qemuDomainObjExitMonitor(driver, vm);
+        goto cleanup;
+    }
+    qemuDomainObjExitMonitor(driver, vm);
+
+    if (virDomainChrInsert(vmdef, chr) < 0)
+        goto cleanup;
+
+    ret = 0;
+cleanup:
+    VIR_FREE(charAlias);
+    VIR_FREE(devstr);
+    return ret;
+}
+
 int qemuDomainAttachHostUsbDevice(virQEMUDriverPtr driver,
                                   virDomainObjPtr vm,
                                   virDomainHostdevDefPtr hostdev)
@@ -2828,3 +2885,43 @@ int qemuDomainDetachLease(virQEMUDriverPtr driver,
     virDomainLeaseDefFree(det_lease);
     return 0;
 }
+
+int qemuDomainDetachChrDevice(virQEMUDriverPtr driver,
+                              virDomainObjPtr vm,
+                              virDomainChrDefPtr chr)
+{
+    int ret = -1;
+    qemuDomainObjPrivatePtr priv = vm->privateData;
+    virDomainDefPtr vmdef = vm->def;
+    virDomainChrDefPtr tmpChr;
+    char *charAlias = NULL;
+
+    if (!(tmpChr = virDomainChrFind(vmdef, chr))) {
+        virReportError(VIR_ERR_OPERATION_INVALID, "%s",
+                       _("device not present in domain configuration"));
+        return ret;
+    }
+
+    if (virAsprintf(&charAlias, "char%s", tmpChr->info.alias) < 0) {
+        virReportOOMError();
+        return ret;
+    }
+
+    qemuDomainObjEnterMonitor(driver, vm);
+    if (qemuMonitorDelDevice(priv->mon, tmpChr->info.alias) < 0) {
+        qemuDomainObjExitMonitor(driver, vm);
+        goto cleanup;
+    }
+
+    if (qemuMonitorDetachCharDev(priv->mon, charAlias) < 0) {
+        qemuDomainObjExitMonitor(driver, vm);
+        goto cleanup;
+    }
+    qemuDomainObjExitMonitor(driver, vm);
+
+    ret = virDomainChrRemove(vmdef, tmpChr);
+
+cleanup:
+    VIR_FREE(charAlias);
+    return ret;
+}
diff --git a/src/qemu/qemu_hotplug.h b/src/qemu/qemu_hotplug.h
index da20eb1..46cd129 100644
--- a/src/qemu/qemu_hotplug.h
+++ b/src/qemu/qemu_hotplug.h
@@ -104,6 +104,12 @@ int qemuDomainAttachLease(virQEMUDriverPtr driver,
 int qemuDomainDetachLease(virQEMUDriverPtr driver,
                           virDomainObjPtr vm,
                           virDomainLeaseDefPtr lease);
+int qemuDomainAttachChrDevice(virQEMUDriverPtr driver,
+                              virDomainObjPtr vm,
+                              virDomainChrDefPtr chr);
+int qemuDomainDetachChrDevice(virQEMUDriverPtr driver,
+                              virDomainObjPtr vm,
+                              virDomainChrDefPtr chr);
 
 
 #endif /* __QEMU_HOTPLUG_H__ */
-- 
1.8.1.5