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-rw-r--r--drivers/hv/channel_mgmt.c61
-rw-r--r--drivers/hv/connection.c4
-rw-r--r--drivers/hv/hyperv_vmbus.h14
-rw-r--r--drivers/hv/vmbus_drv.c16
4 files changed, 51 insertions, 44 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 3c6011a48dab..6e084c207414 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -944,16 +944,6 @@ void vmbus_initiate_unload(bool crash)
vmbus_wait_for_unload();
}
-static void check_ready_for_resume_event(void)
-{
- /*
- * If all the old primary channels have been fixed up, then it's safe
- * to resume.
- */
- if (atomic_dec_and_test(&vmbus_connection.nr_chan_fixup_on_resume))
- complete(&vmbus_connection.ready_for_resume_event);
-}
-
static void vmbus_setup_channel_state(struct vmbus_channel *channel,
struct vmbus_channel_offer_channel *offer)
{
@@ -1109,8 +1099,6 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
/* Add the channel back to the array of channels. */
vmbus_channel_map_relid(oldchannel);
- check_ready_for_resume_event();
-
mutex_unlock(&vmbus_connection.channel_mutex);
return;
}
@@ -1296,13 +1284,28 @@ EXPORT_SYMBOL_GPL(vmbus_hvsock_device_unregister);
/*
* vmbus_onoffers_delivered -
- * This is invoked when all offers have been delivered.
+ * The CHANNELMSG_ALLOFFERS_DELIVERED message arrives after all
+ * boot-time offers are delivered. A boot-time offer is for the primary
+ * channel for any virtual hardware configured in the VM at the time it boots.
+ * Boot-time offers include offers for physical devices assigned to the VM
+ * via Hyper-V's Discrete Device Assignment (DDA) functionality that are
+ * handled as virtual PCI devices in Linux (e.g., NVMe devices and GPUs).
+ * Boot-time offers do not include offers for VMBus sub-channels. Because
+ * devices can be hot-added to the VM after it is booted, additional channel
+ * offers that aren't boot-time offers can be received at any time after the
+ * all-offers-delivered message.
*
- * Nothing to do here.
+ * SR-IOV NIC Virtual Functions (VFs) assigned to a VM are not considered
+ * to be assigned to the VM at boot-time, and offers for VFs may occur after
+ * the all-offers-delivered message. VFs are optional accelerators to the
+ * synthetic VMBus NIC and are effectively hot-added only after the VMBus
+ * NIC channel is opened (once it knows the guest can support it, via the
+ * sriov bit in the netvsc protocol).
*/
static void vmbus_onoffers_delivered(
struct vmbus_channel_message_header *hdr)
{
+ complete(&vmbus_connection.all_offers_delivered_event);
}
/*
@@ -1578,7 +1581,8 @@ void vmbus_onmessage(struct vmbus_channel_message_header *hdr)
}
/*
- * vmbus_request_offers - Send a request to get all our pending offers.
+ * vmbus_request_offers - Send a request to get all our pending offers
+ * and wait for all boot-time offers to arrive.
*/
int vmbus_request_offers(void)
{
@@ -1596,6 +1600,10 @@ int vmbus_request_offers(void)
msg->msgtype = CHANNELMSG_REQUESTOFFERS;
+ /*
+ * This REQUESTOFFERS message will result in the host sending an all
+ * offers delivered message after all the boot-time offers are sent.
+ */
ret = vmbus_post_msg(msg, sizeof(struct vmbus_channel_message_header),
true);
@@ -1607,6 +1615,29 @@ int vmbus_request_offers(void)
goto cleanup;
}
+ /*
+ * Wait for the host to send all boot-time offers.
+ * Keeping it as a best-effort mechanism, where a warning is
+ * printed if a timeout occurs, and execution is resumed.
+ */
+ if (!wait_for_completion_timeout(&vmbus_connection.all_offers_delivered_event,
+ secs_to_jiffies(60))) {
+ pr_warn("timed out waiting for all boot-time offers to be delivered.\n");
+ }
+
+ /*
+ * Flush handling of offer messages (which may initiate work on
+ * other work queues).
+ */
+ flush_workqueue(vmbus_connection.work_queue);
+
+ /*
+ * Flush workqueue for processing the incoming offers. Subchannel
+ * offers and their processing can happen later, so there is no need to
+ * flush that workqueue here.
+ */
+ flush_workqueue(vmbus_connection.handle_primary_chan_wq);
+
cleanup:
kfree(msginfo);
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c
index f001ae880e1d..8351360bba16 100644
--- a/drivers/hv/connection.c
+++ b/drivers/hv/connection.c
@@ -34,8 +34,8 @@ struct vmbus_connection vmbus_connection = {
.ready_for_suspend_event = COMPLETION_INITIALIZER(
vmbus_connection.ready_for_suspend_event),
- .ready_for_resume_event = COMPLETION_INITIALIZER(
- vmbus_connection.ready_for_resume_event),
+ .all_offers_delivered_event = COMPLETION_INITIALIZER(
+ vmbus_connection.all_offers_delivered_event),
};
EXPORT_SYMBOL_GPL(vmbus_connection);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index fad31e30cd53..29780f3a7478 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -287,18 +287,10 @@ struct vmbus_connection {
struct completion ready_for_suspend_event;
/*
- * The number of primary channels that should be "fixed up"
- * upon resume: these channels are re-offered upon resume, and some
- * fields of the channel offers (i.e. child_relid and connection_id)
- * can change, so the old offermsg must be fixed up, before the resume
- * callbacks of the VSC drivers start to further touch the channels.
+ * Completed once the host has offered all boot-time channels.
+ * Note that some channels may still be under process on a workqueue.
*/
- atomic_t nr_chan_fixup_on_resume;
- /*
- * vmbus_bus_resume() waits for "nr_chan_fixup_on_resume" to
- * drop to zero.
- */
- struct completion ready_for_resume_event;
+ struct completion all_offers_delivered_event;
};
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 2892b8da20a5..bf5608a74056 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -2427,11 +2427,6 @@ static int vmbus_bus_suspend(struct device *dev)
if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
wait_for_completion(&vmbus_connection.ready_for_suspend_event);
- if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
- pr_err("Can not suspend due to a previous failed resuming\n");
- return -EBUSY;
- }
-
mutex_lock(&vmbus_connection.channel_mutex);
list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
@@ -2456,17 +2451,12 @@ static int vmbus_bus_suspend(struct device *dev)
pr_err("Sub-channel not deleted!\n");
WARN_ON_ONCE(1);
}
-
- atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
}
mutex_unlock(&vmbus_connection.channel_mutex);
vmbus_initiate_unload(false);
- /* Reset the event for the next resume. */
- reinit_completion(&vmbus_connection.ready_for_resume_event);
-
return 0;
}
@@ -2502,14 +2492,8 @@ static int vmbus_bus_resume(struct device *dev)
if (ret != 0)
return ret;
- WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
-
vmbus_request_offers();
- if (wait_for_completion_timeout(
- &vmbus_connection.ready_for_resume_event, secs_to_jiffies(10)) == 0)
- pr_err("Some vmbus device is missing after suspending?\n");
-
/* Reset the event for the next suspend. */
reinit_completion(&vmbus_connection.ready_for_suspend_event);