summaryrefslogtreecommitdiff
path: root/drivers/hv/channel_mgmt.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/hv/channel_mgmt.c')
-rw-r--r--drivers/hv/channel_mgmt.c77
1 files changed, 59 insertions, 18 deletions
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index 2f4d09ce027a..65dd299e2944 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -20,6 +20,7 @@
#include <linux/delay.h>
#include <linux/cpu.h>
#include <linux/hyperv.h>
+#include <linux/export.h>
#include <asm/mshyperv.h>
#include <linux/sched/isolation.h>
@@ -120,7 +121,9 @@ const struct vmbus_device vmbus_devs[] = {
},
/* File copy */
- { .dev_type = HV_FCOPY,
+ /* fcopy always uses 16KB ring buffer size and is working well for last many years */
+ { .pref_ring_size = 0x4000,
+ .dev_type = HV_FCOPY,
HV_FCOPY_GUID,
.perf_device = false,
.allowed_in_isolated = false,
@@ -140,12 +143,19 @@ const struct vmbus_device vmbus_devs[] = {
.allowed_in_isolated = false,
},
- /* Unknown GUID */
- { .dev_type = HV_UNKNOWN,
+ /*
+ * Unknown GUID
+ * 64 KB ring buffer + 4 KB header should be sufficient size for any Hyper-V device apart
+ * from HV_NIC and HV_SCSI. This case avoid the fallback for unknown devices to allocate
+ * much bigger (2 MB) of ring size.
+ */
+ { .pref_ring_size = 0x11000,
+ .dev_type = HV_UNKNOWN,
.perf_device = false,
.allowed_in_isolated = false,
},
};
+EXPORT_SYMBOL_GPL(vmbus_devs);
static const struct {
guid_t guid;
@@ -935,16 +945,6 @@ 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)
{
@@ -1100,8 +1100,6 @@ 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;
}
@@ -1287,13 +1285,28 @@ 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);
}
/*
@@ -1569,7 +1582,8 @@ 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)
{
@@ -1587,6 +1601,10 @@ 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);
@@ -1598,6 +1616,29 @@ 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);