Drivers: hv: balloon: Disable balloon and hot-add accordingly

[platform/kernel/linux-rpi.git] / drivers / hv / vmbus_drv.c

diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 392c1ac..aea8125 100644 (file)
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -76,8 +76,8 @@ static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
 
        /*
         * Hyper-V should be notified only once about a panic.  If we will be
-        * doing hyperv_report_panic_msg() later with kmsg data, don't do
-        * the notification here.
+        * doing hv_kmsg_dump() with kmsg data later, don't do the notification
+        * here.
         */
        if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
            && hyperv_report_reg()) {
@@ -99,8 +99,8 @@ static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
 
        /*
         * Hyper-V should be notified only once about a panic.  If we will be
-        * doing hyperv_report_panic_msg() later with kmsg data, don't do
-        * the notification here.
+        * doing hv_kmsg_dump() with kmsg data later, don't do the notification
+        * here.
         */
        if (hyperv_report_reg())
                hyperv_report_panic(regs, val, true);
@@ -1545,14 +1545,20 @@ static int vmbus_bus_init(void)
        if (ret)
                goto err_connect;
 
+       if (hv_is_isolation_supported())
+               sysctl_record_panic_msg = 0;
+
        /*
         * Only register if the crash MSRs are available
         */
        if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
                u64 hyperv_crash_ctl;
                /*
-                * Sysctl registration is not fatal, since by default
-                * reporting is enabled.
+                * Panic message recording (sysctl_record_panic_msg)
+                * is enabled by default in non-isolated guests and
+                * disabled by default in isolated guests; the panic
+                * message recording won't be available in isolated
+                * guests should the following registration fail.
                 */
                hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
                if (!hv_ctl_table_hdr)
@@ -2027,8 +2033,10 @@ int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
        kobj->kset = dev->channels_kset;
        ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
                                   "%u", relid);
-       if (ret)
+       if (ret) {
+               kobject_put(kobj);
                return ret;
+       }
 
        ret = sysfs_create_group(kobj, &vmbus_chan_group);
 
@@ -2037,6 +2045,7 @@ int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
                 * The calling functions' error handling paths will cleanup the
                 * empty channel directory.
                 */
+               kobject_put(kobj);
                dev_err(device, "Unable to set up channel sysfs files\n");
                return ret;
        }
@@ -2773,10 +2782,15 @@ static void __exit vmbus_exit(void)
        if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
                kmsg_dump_unregister(&hv_kmsg_dumper);
                unregister_die_notifier(&hyperv_die_block);
-               atomic_notifier_chain_unregister(&panic_notifier_list,
-                                                &hyperv_panic_block);
        }
 
+       /*
+        * The panic notifier is always registered, hence we should
+        * also unconditionally unregister it here as well.
+        */
+       atomic_notifier_chain_unregister(&panic_notifier_list,
+                                        &hyperv_panic_block);
+
        free_page((unsigned long)hv_panic_page);
        unregister_sysctl_table(hv_ctl_table_hdr);
        hv_ctl_table_hdr = NULL;