qemu: Add hotpluging support for PCI devices on S390 guests

This commit adds hotplug support for PCI devices on S390 guests.
There's no need to implement hot unplug for zPCI as QEMU implements
an unplug callback which will unplug both PCI and zPCI device in a
cascaded way.
Currently, the following PCI devices are supported:
  virtio-blk-pci
  virtio-net-pci
  virtio-rng-pci
  virtio-input-host-pci
  virtio-keyboard-pci
  virtio-mouse-pci
  virtio-tablet-pci
  vfio-pci
  SCSIVhost device
Signed-off-by: NYi Min Zhao <zyimin@linux.ibm.com>
Reviewed-by: NBoris Fiuczynski <fiuczy@linux.ibm.com>
Reviewed-by: NStefan Zimmermann <stzi@linux.ibm.com>
Reviewed-by: NBjoern Walk <bwalk@linux.ibm.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>
Reviewed-by: NAndrea Bolognani <abologna@redhat.com>

src/qemu/qemu_hotplug.c

@@ -154,6 +154,80 @@ qemuHotplugPrepareDiskAccess(virQEMUDriverPtr driver,
 }
 
 
+static int
+qemuDomainAttachZPCIDevice(qemuMonitorPtr mon,
+                           virDomainDeviceInfoPtr info)
+{
+    char *devstr_zpci = NULL;
+    int ret = -1;
+
+    if (!(devstr_zpci = qemuBuildZPCIDevStr(info)))
+        goto cleanup;
+
+    if (qemuMonitorAddDevice(mon, devstr_zpci) < 0)
+        goto cleanup;
+
+    ret = 0;
+
+ cleanup:
+    VIR_FREE(devstr_zpci);
+    return ret;
+}
+
+
+static int
+qemuDomainDetachZPCIDevice(qemuMonitorPtr mon,
+                           virDomainDeviceInfoPtr info)
+{
+    char *zpciAlias = NULL;
+    int ret = -1;
+
+    if (virAsprintf(&zpciAlias, "zpci%d", info->addr.pci.zpci.uid) < 0)
+        goto cleanup;
+
+    if (qemuMonitorDelDevice(mon, zpciAlias) < 0)
+        goto cleanup;
+
+    ret = 0;
+
+ cleanup:
+    VIR_FREE(zpciAlias);
+    return ret;
+}
+
+
+static int
+qemuDomainAttachExtensionDevice(qemuMonitorPtr mon,
+                                virDomainDeviceInfoPtr info)
+{
+    if (info->type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI ||
+        info->addr.pci.extFlags == VIR_PCI_ADDRESS_EXTENSION_NONE) {
+        return 0;
+    }
+
+    if (info->addr.pci.extFlags & VIR_PCI_ADDRESS_EXTENSION_ZPCI)
+        return qemuDomainAttachZPCIDevice(mon, info);
+
+    return 0;
+}
+
+
+static int
+qemuDomainDetachExtensionDevice(qemuMonitorPtr mon,
+                                virDomainDeviceInfoPtr info)
+{
+    if (info->type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI ||
+        info->addr.pci.extFlags == VIR_PCI_ADDRESS_EXTENSION_NONE) {
+        return 0;
+    }
+
+    if (info->addr.pci.extFlags & VIR_PCI_ADDRESS_EXTENSION_ZPCI)
+        return qemuDomainDetachZPCIDevice(mon, info);
+
+    return 0;
+}
+
+
 static int
 qemuHotplugWaitForTrayEject(virDomainObjPtr vm,
                             virDomainDiskDefPtr disk)
@@ -845,8 +919,13 @@ qemuDomainAttachDiskGeneric(virQEMUDriverPtr driver,
     if (qemuHotplugDiskSourceAttach(priv->mon, diskdata) < 0)
         goto exit_monitor;
 
-    if (qemuMonitorAddDevice(priv->mon, devstr) < 0)
+    if (qemuDomainAttachExtensionDevice(priv->mon, &disk->info) < 0)
+        goto exit_monitor;
+
+    if (qemuMonitorAddDevice(priv->mon, devstr) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &disk->info));
         goto exit_monitor;
+    }
 
     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         ret = -2;
@@ -954,7 +1033,16 @@ int qemuDomainAttachControllerDevice(virQEMUDriverPtr driver,
         goto cleanup;
 
     qemuDomainObjEnterMonitor(driver, vm);
-    ret = qemuMonitorAddDevice(priv->mon, devstr);
+
+    if ((ret = qemuDomainAttachExtensionDevice(priv->mon,
+                                               &controller->info)) < 0) {
+        goto exit_monitor;
+    }
+
+    if ((ret = qemuMonitorAddDevice(priv->mon, devstr)) < 0)
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &controller->info));
+
+ exit_monitor:
     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         releaseaddr = false;
         ret = -1;
@@ -1417,6 +1505,7 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver,
     }
 
     if (qemuDomainIsS390CCW(vm->def) &&
+        net->info.type != VIR_DOMAIN_DEVICE_ADDRESS_TYPE_PCI &&
         virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_CCW)) {
         net->info.type = VIR_DOMAIN_DEVICE_ADDRESS_TYPE_CCW;
         if (!(ccwaddrs = virDomainCCWAddressSetCreateFromDomain(vm->def)))
@@ -1486,7 +1575,15 @@ qemuDomainAttachNetDevice(virQEMUDriverPtr driver,
         goto try_remove;
 
     qemuDomainObjEnterMonitor(driver, vm);
+
+    if (qemuDomainAttachExtensionDevice(priv->mon, &net->info) < 0) {
+        ignore_value(qemuDomainObjExitMonitor(driver, vm));
+        virDomainAuditNet(vm, NULL, net, "attach", false);
+        goto try_remove;
+    }
+
     if (qemuMonitorAddDevice(priv->mon, nicstr) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &net->info));
         ignore_value(qemuDomainObjExitMonitor(driver, vm));
         virDomainAuditNet(vm, NULL, net, "attach", false);
         goto try_remove;
@@ -1703,8 +1800,16 @@ qemuDomainAttachHostPCIDevice(virQEMUDriverPtr driver,
         goto error;
 
     qemuDomainObjEnterMonitor(driver, vm);
-    ret = qemuMonitorAddDeviceWithFd(priv->mon, devstr,
-                                     configfd, configfd_name);
+
+    if ((ret = qemuDomainAttachExtensionDevice(priv->mon, hostdev->info)) < 0)
+        goto exit_monitor;
+
+    if ((ret = qemuMonitorAddDeviceWithFd(priv->mon, devstr,
+                                          configfd, configfd_name)) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, hostdev->info));
+    }
+
+ exit_monitor:
     if (qemuDomainObjExitMonitor(driver, vm) < 0)
         goto error;
 
@@ -2360,9 +2465,14 @@ qemuDomainAttachRNGDevice(virQEMUDriverPtr driver,
     if (qemuMonitorAddObject(priv->mon, &props, &objAlias) < 0)
         goto exit_monitor;
 
-    if (qemuMonitorAddDevice(priv->mon, devstr) < 0)
+    if (qemuDomainAttachExtensionDevice(priv->mon, &rng->info) < 0)
         goto exit_monitor;
 
+    if (qemuMonitorAddDevice(priv->mon, devstr) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &rng->info));
+        goto exit_monitor;
+    }
+
     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         releaseaddr = false;
         goto cleanup;
@@ -2842,8 +2952,16 @@ qemuDomainAttachSCSIVHostDevice(virQEMUDriverPtr driver,
 
     qemuDomainObjEnterMonitor(driver, vm);
 
-    ret = qemuMonitorAddDeviceWithFd(priv->mon, devstr, vhostfd, vhostfdName);
+    if ((ret = qemuDomainAttachExtensionDevice(priv->mon, hostdev->info)) < 0)
+        goto exit_monitor;
+
+    if ((ret = qemuMonitorAddDeviceWithFd(priv->mon, devstr, vhostfd,
+                                          vhostfdName)) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, hostdev->info));
+        goto exit_monitor;
+    }
 
+ exit_monitor:
     if (qemuDomainObjExitMonitor(driver, vm) < 0 || ret < 0)
         goto audit;
 
@@ -3088,8 +3206,13 @@ qemuDomainAttachShmemDevice(virQEMUDriverPtr driver,
 
     release_backing = true;
 
-    if (qemuMonitorAddDevice(priv->mon, shmstr) < 0)
+    if (qemuDomainAttachExtensionDevice(priv->mon, &shmem->info) < 0)
+        goto exit_monitor;
+
+    if (qemuMonitorAddDevice(priv->mon, shmstr) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &shmem->info));
         goto exit_monitor;
+    }
 
     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         release_address = false;
@@ -3262,9 +3385,15 @@ qemuDomainAttachInputDevice(virQEMUDriverPtr driver,
         goto cleanup;
 
     qemuDomainObjEnterMonitor(driver, vm);
-    if (qemuMonitorAddDevice(priv->mon, devstr) < 0)
+
+    if (qemuDomainAttachExtensionDevice(priv->mon, &input->info) < 0)
         goto exit_monitor;
 
+    if (qemuMonitorAddDevice(priv->mon, devstr) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &input->info));
+        goto exit_monitor;
+    }
+
     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         releaseaddr = false;
         goto cleanup;
@@ -3341,8 +3470,14 @@ qemuDomainAttachVsockDevice(virQEMUDriverPtr driver,
         goto cleanup;
 
     qemuDomainObjEnterMonitor(driver, vm);
-    if (qemuMonitorAddDeviceWithFd(priv->mon, devstr, vsockPriv->vhostfd, fdname) < 0)
+
+    if (qemuDomainAttachExtensionDevice(priv->mon, &vsock->info) < 0)
+        goto exit_monitor;
+
+    if (qemuMonitorAddDeviceWithFd(priv->mon, devstr, vsockPriv->vhostfd, fdname) < 0) {
+        ignore_value(qemuDomainDetachExtensionDevice(priv->mon, &vsock->info));
         goto exit_monitor;
+    }
 
     if (qemuDomainObjExitMonitor(driver, vm) < 0) {
         releaseaddr = false;
@@ -5328,10 +5463,17 @@ int qemuDomainDetachControllerDevice(virQEMUDriverPtr driver,
         qemuDomainMarkDeviceForRemoval(vm, &detach->info);
 
     qemuDomainObjEnterMonitor(driver, vm);
+    if (detach->type == VIR_DOMAIN_CONTROLLER_TYPE_PCI &&
+        qemuDomainDetachExtensionDevice(priv->mon, &detach->info)) {
+        goto exit_monitor;
+    }
+
     if (qemuMonitorDelDevice(priv->mon, detach->info.alias)) {
         ignore_value(qemuDomainObjExitMonitor(driver, vm));
         goto cleanup;
     }
+
+ exit_monitor:
     if (qemuDomainObjExitMonitor(driver, vm) < 0)
         goto cleanup;