qemu: Manage /dev entry on chardev hotplug

When attaching a device to a domain that's using separate mount
namespace we must maintain /dev entries in order for qemu process
to see them.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_domain.c

@@ -7534,6 +7534,10 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid ATTRIBUTE_UNUSED,
             goto cleanup;
     }   break;
 
+    case VIR_DOMAIN_DEVICE_CHR:
+        /* No labelling. */
+        break;
+
     case VIR_DOMAIN_DEVICE_NONE:
     case VIR_DOMAIN_DEVICE_LEASE:
     case VIR_DOMAIN_DEVICE_FS:
@@ -7547,7 +7551,6 @@ qemuDomainAttachDeviceMknodHelper(pid_t pid ATTRIBUTE_UNUSED,
     case VIR_DOMAIN_DEVICE_HUB:
     case VIR_DOMAIN_DEVICE_REDIRDEV:
     case VIR_DOMAIN_DEVICE_SMARTCARD:
-    case VIR_DOMAIN_DEVICE_CHR:
     case VIR_DOMAIN_DEVICE_MEMBALLOON:
     case VIR_DOMAIN_DEVICE_NVRAM:
     case VIR_DOMAIN_DEVICE_RNG:
@@ -7667,6 +7670,10 @@ qemuDomainDetachDeviceUnlink(virQEMUDriverPtr driver,
             return -1;
     }   break;
 
+    case VIR_DOMAIN_DEVICE_CHR:
+        /* No labelling. */
+        break;
+
     case VIR_DOMAIN_DEVICE_NONE:
     case VIR_DOMAIN_DEVICE_LEASE:
     case VIR_DOMAIN_DEVICE_FS:
@@ -7680,7 +7687,6 @@ qemuDomainDetachDeviceUnlink(virQEMUDriverPtr driver,
     case VIR_DOMAIN_DEVICE_HUB:
     case VIR_DOMAIN_DEVICE_REDIRDEV:
     case VIR_DOMAIN_DEVICE_SMARTCARD:
-    case VIR_DOMAIN_DEVICE_CHR:
     case VIR_DOMAIN_DEVICE_MEMBALLOON:
     case VIR_DOMAIN_DEVICE_NVRAM:
     case VIR_DOMAIN_DEVICE_RNG:
@@ -7829,3 +7835,57 @@ qemuDomainNamespaceTeardownHostdev(virQEMUDriverPtr driver,
     VIR_FREE(path);
     return ret;
 }
+
+
+int
+qemuDomainNamespaceSetupChardev(virQEMUDriverPtr driver,
+                                virDomainObjPtr vm,
+                                virDomainChrDefPtr chr)
+{
+    virDomainDeviceDef dev = {.type = VIR_DOMAIN_DEVICE_CHR, .data.chr = chr};
+    const char *path;
+    int ret = -1;
+
+    if (!qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT))
+        return 0;
+
+    if (chr->source->type != VIR_DOMAIN_CHR_TYPE_DEV)
+        return 0;
+
+    path = chr->source->data.file.path;
+
+    if (qemuDomainAttachDeviceMknod(driver,
+                                    vm,
+                                    &dev,
+                                    path) < 0)
+        goto cleanup;
+    ret = 0;
+ cleanup:
+    return ret;
+}
+
+
+int
+qemuDomainNamespaceTeardownChardev(virQEMUDriverPtr driver,
+                                   virDomainObjPtr vm,
+                                   virDomainChrDefPtr chr)
+{
+    virDomainDeviceDef dev = {.type = VIR_DOMAIN_DEVICE_CHR, .data.chr = chr};
+    int ret = -1;
+    const char *path = NULL;
+
+    if (!qemuDomainNamespaceEnabled(vm, QEMU_DOMAIN_NS_MOUNT))
+        return 0;
+
+    if (chr->source->type != VIR_DOMAIN_CHR_TYPE_DEV)
+        return 0;
+
+    path = chr->source->data.file.path;
+
+    if (qemuDomainDetachDeviceUnlink(driver, vm, &dev, path) < 0)
+        goto cleanup;
+
+    ret = 0;
+ cleanup:
+    return ret;
+}

src/qemu/qemu_domain.h

@@ -821,4 +821,12 @@ int qemuDomainNamespaceSetupHostdev(virQEMUDriverPtr driver,
 int qemuDomainNamespaceTeardownHostdev(virQEMUDriverPtr driver,
                                        virDomainObjPtr vm,
                                        virDomainHostdevDefPtr hostdev);
+
+int qemuDomainNamespaceSetupChardev(virQEMUDriverPtr driver,
+                                    virDomainObjPtr vm,
+                                    virDomainChrDefPtr chr);
+
+int qemuDomainNamespaceTeardownChardev(virQEMUDriverPtr driver,
+                                       virDomainObjPtr vm,
+                                       virDomainChrDefPtr chr);
 #endif /* __QEMU_DOMAIN_H__ */

src/qemu/qemu_hotplug.c

@@ -1851,6 +1851,7 @@ int qemuDomainAttachChrDevice(virConnectPtr conn,
     bool chardevAttached = false;
     bool tlsobjAdded = false;
     bool teardowncgroup = false;
+    bool teardowndevice = false;
     bool secobjAdded = false;
     virJSONValuePtr tlsProps = NULL;
     char *tlsAlias = NULL;
@@ -1872,6 +1873,10 @@ int qemuDomainAttachChrDevice(virConnectPtr conn,
     if (rc == 1)
         need_release = true;
 
+    if (qemuDomainNamespaceSetupChardev(driver, vm, chr) < 0)
+        goto cleanup;
+    teardowndevice = true;
+
     if (qemuSetupChardevCgroup(vm, chr) < 0)
         goto cleanup;
     teardowncgroup = true;
@@ -1935,6 +1940,8 @@ int qemuDomainAttachChrDevice(virConnectPtr conn,
             qemuDomainReleaseDeviceAddress(vm, &chr->info, NULL);
         if (teardowncgroup && qemuTeardownChardevCgroup(vm, chr) < 0)
             VIR_WARN("Unable to remove chr device cgroup ACL on hotplug fail");
+        if (teardowndevice && qemuDomainNamespaceTeardownChardev(driver, vm, chr) < 0)
+            VIR_WARN("Unable to remove chr device from /dev");
     }
     VIR_FREE(tlsAlias);
     virJSONValueFree(tlsProps);
@@ -4021,6 +4028,9 @@ qemuDomainRemoveChrDevice(virQEMUDriverPtr driver,
     if (qemuTeardownChardevCgroup(vm, chr) < 0)
         VIR_WARN("Failed to remove chr device cgroup ACL");
 
+    if (qemuDomainNamespaceTeardownChardev(driver, vm, chr) < 0)
+        VIR_WARN("Unable to remove chr device from /dev");
+
     event = virDomainEventDeviceRemovedNewFromObj(vm, chr->info.alias);
     qemuDomainEventQueue(driver, event);