Add a flag to indicate that the vmbus is suspended so we should ignore the
rescind offer message. Add a new work_queue for rescind msg, so we could
drain it in vmbus_suspend processing. This should help avoid any rescind
offer msg processing if ignore_offer_rescind_msg flag is set to true.
It was observed in some hibernation related scenario testing that after
KVP_vmbus suspend, we get another rescind offer message for the vmbus. This
led to rescind message processing after vm_suspend and we would end up with
a warning and stack dumps
Signed-off-by: Shradha Gupta <shradhagupta@xxxxxxxxxxxxxxxxxxx>
---
drivers/hv/connection.c | 11 +++++++++++
drivers/hv/hyperv_vmbus.h | 7 +++++++
drivers/hv/vmbus_drv.c | 24 +++++++++++++++++++++++-
3 files changed, 41 insertions(+), 1 deletion(-)
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index 6218bbf6863a..88a0fd8e80c0 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -171,6 +171,14 @@ int vmbus_connect(void)
goto cleanup;
}
+ vmbus_connection.rescind_work_queue =
+ create_workqueue("hv_vmbus_rescind");
+ if (!vmbus_connection.rescind_work_queue) {
+ ret = -ENOMEM;
+ goto cleanup;
+ }
+ vmbus_connection.ignore_offer_rescind_msg = false;
+
vmbus_connection.handle_primary_chan_wq =
create_workqueue("hv_pri_chan");
if (!vmbus_connection.handle_primary_chan_wq) {
@@ -357,6 +365,9 @@ void vmbus_disconnect(void)
if (vmbus_connection.handle_primary_chan_wq)
destroy_workqueue(vmbus_connection.handle_primary_chan_wq);
+ if (vmbus_connection.rescind_work_queue)
+ destroy_workqueue(vmbus_connection.rescind_work_queue);
+
if (vmbus_connection.work_queue)
destroy_workqueue(vmbus_connection.work_queue);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 4f5b824b16cf..ff8707284554 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -262,6 +262,13 @@ struct vmbus_connection {
struct workqueue_struct *handle_primary_chan_wq;
struct workqueue_struct *handle_sub_chan_wq;
+ /*
+ * On suspension of the vmbus, the accumulated rescind message
+ * must be dropped.
+ */
+ bool ignore_offer_rescind_msg;
+ struct workqueue_struct *rescind_work_queue;
+
/*
* The number of sub-channels and hv_sock channels that should be
* cleaned up upon suspend: sub-channels will be re-created upon
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 547ae334e5cd..46bd867f11ba 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -1160,7 +1160,9 @@ void vmbus_on_msg_dpc(unsigned long data)
* work queue: the RESCIND handler can not start to
* run before the OFFER handler finishes.
*/
- schedule_work(&ctx->work);
+ if (vmbus_connection.ignore_offer_rescind_msg)
+ break;
+ queue_work(vmbus_connection.rescind_work_queue, &ctx->work);
break;
case CHANNELMSG_OFFERCHANNEL:
@@ -1186,6 +1188,8 @@ void vmbus_on_msg_dpc(unsigned long data)
* to the CPUs which will execute the offer & rescind
* works by the time these works will start execution.
*/
+ if (vmbus_connection.ignore_offer_rescind_msg)
+ break;
atomic_inc(&vmbus_connection.offer_in_progress);
fallthrough;
@@ -2446,8 +2450,20 @@ static int vmbus_acpi_add(struct acpi_device *device)
#ifdef CONFIG_PM_SLEEP
static int vmbus_bus_suspend(struct device *dev)
{
+ struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(
+ hv_context.cpu_context, VMBUS_CONNECT_CPU);
struct vmbus_channel *channel, *sc;
+ tasklet_disable(&hv_cpu->msg_dpc);
+ vmbus_connection.ignore_offer_rescind_msg = true;
+ tasklet_enable(&hv_cpu->msg_dpc);
+
+ /* Drain all the workqueues as we are in suspend */
+ drain_workqueue(vmbus_connection.rescind_work_queue);
+ drain_workqueue(vmbus_connection.work_queue);
+ drain_workqueue(vmbus_connection.handle_primary_chan_wq);
+ drain_workqueue(vmbus_connection.handle_sub_chan_wq);
+
while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
/*
* We wait here until the completion of any channel
@@ -2527,10 +2543,16 @@ static int vmbus_bus_suspend(struct device *dev)
static int vmbus_bus_resume(struct device *dev)
{
+ struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(
+ hv_context.cpu_context, VMBUS_CONNECT_CPU);
struct vmbus_channel_msginfo *msginfo;
size_t msgsize;
int ret;
+ tasklet_disable(&hv_cpu->msg_dpc);
+ vmbus_connection.ignore_offer_rescind_msg = false;
+ tasklet_enable(&hv_cpu->msg_dpc);
+
/*
* We only use the 'vmbus_proto_version', which was in use before
* hibernation, to re-negotiate with the host.
--
2.17.1
