diff mbox series

[focal:linux-azure,07/21] hv_balloon: Add the support of hibernation

Message ID 20200602020817.236422-8-marcelo.cerri@canonical.com
State New
Headers show
Series LP:#1880032 - [linux-azure] Enable Hibernation on The 18.04 and 20.04 5.4 Kernels | expand

Commit Message

Marcelo Henrique Cerri June 2, 2020, 2:08 a.m. UTC 
From: Dexuan Cui <decui@microsoft.com>

BugLink: http://bugs.launchpad.net/bugs/1880032

When hibernation is enabled, we must ignore the balloon up/down and
hot-add requests from the host, if any.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Acked-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 25bd2b2f1f05347a4cd633138d0e4c2fd5788359)
Signed-off-by: Marcelo Henrique Cerri <marcelo.cerri@canonical.com>
---
 drivers/hv/hv_balloon.c | 87 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 85 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 930674117533..e75419391fa8 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -24,6 +24,8 @@ 
 
 #include <linux/hyperv.h>
 
+#include <asm/mshyperv.h>
+
 #define CREATE_TRACE_POINTS
 #include "hv_trace_balloon.h"
 
@@ -457,6 +459,7 @@  struct hot_add_wrk {
 	struct work_struct wrk;
 };
 
+static bool allow_hibernation;
 static bool hot_add = true;
 static bool do_hot_add;
 /*
@@ -1053,8 +1056,12 @@  static void hot_add_req(struct work_struct *dummy)
 	else
 		resp.result = 0;
 
-	if (!do_hot_add || (resp.page_count == 0))
-		pr_err("Memory hot add failed\n");
+	if (!do_hot_add || resp.page_count == 0) {
+		if (!allow_hibernation)
+			pr_err("Memory hot add failed\n");
+		else
+			pr_info("Ignore hot-add request!\n");
+	}
 
 	dm->state = DM_INITIALIZED;
 	resp.hdr.trans_id = atomic_inc_return(&trans_id);
@@ -1502,6 +1509,11 @@  static void balloon_onchannelcallback(void *context)
 			break;
 
 		case DM_BALLOON_REQUEST:
+			if (allow_hibernation) {
+				pr_info("Ignore balloon-up request!\n");
+				break;
+			}
+
 			if (dm->state == DM_BALLOON_UP)
 				pr_warn("Currently ballooning\n");
 			bal_msg = (struct dm_balloon *)recv_buffer;
@@ -1511,6 +1523,11 @@  static void balloon_onchannelcallback(void *context)
 			break;
 
 		case DM_UNBALLOON_REQUEST:
+			if (allow_hibernation) {
+				pr_info("Ignore balloon-down request!\n");
+				break;
+			}
+
 			dm->state = DM_BALLOON_DOWN;
 			balloon_down(dm,
 				 (struct dm_unballoon_request *)recv_buffer);
@@ -1616,6 +1633,11 @@  static int balloon_connect_vsp(struct hv_device *dev)
 	cap_msg.hdr.size = sizeof(struct dm_capabilities);
 	cap_msg.hdr.trans_id = atomic_inc_return(&trans_id);
 
+	/*
+	 * When hibernation (i.e. virtual ACPI S4 state) is enabled, the host
+	 * currently still requires the bits to be set, so we have to add code
+	 * to fail the host's hot-add and balloon up/down requests, if any.
+	 */
 	cap_msg.caps.cap_bits.balloon = 1;
 	cap_msg.caps.cap_bits.hot_add = 1;
 
@@ -1665,6 +1687,10 @@  static int balloon_probe(struct hv_device *dev,
 {
 	int ret;
 
+	allow_hibernation = hv_is_hibernation_supported();
+	if (allow_hibernation)
+		hot_add = false;
+
 #ifdef CONFIG_MEMORY_HOTPLUG
 	do_hot_add = hot_add;
 #else
@@ -1704,6 +1730,8 @@  static int balloon_probe(struct hv_device *dev,
 	return 0;
 
 probe_error:
+	dm_device.state = DM_INIT_ERROR;
+	dm_device.thread  = NULL;
 	vmbus_close(dev->channel);
 #ifdef CONFIG_MEMORY_HOTPLUG
 	unregister_memory_notifier(&hv_memory_nb);
@@ -1745,6 +1773,59 @@  static int balloon_remove(struct hv_device *dev)
 	return 0;
 }
 
+static int balloon_suspend(struct hv_device *hv_dev)
+{
+	struct hv_dynmem_device *dm = hv_get_drvdata(hv_dev);
+
+	tasklet_disable(&hv_dev->channel->callback_event);
+
+	cancel_work_sync(&dm->balloon_wrk.wrk);
+	cancel_work_sync(&dm->ha_wrk.wrk);
+
+	if (dm->thread) {
+		kthread_stop(dm->thread);
+		dm->thread = NULL;
+		vmbus_close(hv_dev->channel);
+	}
+
+	tasklet_enable(&hv_dev->channel->callback_event);
+
+	return 0;
+
+}
+
+static int balloon_resume(struct hv_device *dev)
+{
+	int ret;
+
+	dm_device.state = DM_INITIALIZING;
+
+	ret = balloon_connect_vsp(dev);
+
+	if (ret != 0)
+		goto out;
+
+	dm_device.thread =
+		 kthread_run(dm_thread_func, &dm_device, "hv_balloon");
+	if (IS_ERR(dm_device.thread)) {
+		ret = PTR_ERR(dm_device.thread);
+		dm_device.thread = NULL;
+		goto close_channel;
+	}
+
+	dm_device.state = DM_INITIALIZED;
+	return 0;
+close_channel:
+	vmbus_close(dev->channel);
+out:
+	dm_device.state = DM_INIT_ERROR;
+#ifdef CONFIG_MEMORY_HOTPLUG
+	unregister_memory_notifier(&hv_memory_nb);
+	restore_online_page_callback(&hv_online_page);
+#endif
+	return ret;
+}
+
 static const struct hv_vmbus_device_id id_table[] = {
 	/* Dynamic Memory Class ID */
 	/* 525074DC-8985-46e2-8057-A307DC18A502 */
@@ -1759,6 +1840,8 @@  static  struct hv_driver balloon_drv = {
 	.id_table = id_table,
 	.probe =  balloon_probe,
 	.remove =  balloon_remove,
+	.suspend = balloon_suspend,
+	.resume = balloon_resume,
 	.driver = {
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},