1 files changed, 97 insertions, 23 deletions

diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index cc23b90cae02..74fed2c073d4 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>
 
@@ -67,7 +68,7 @@ const struct vmbus_device vmbus_devs[] = {
 	{ .dev_type = HV_PCIE,
 	  HV_PCIE_GUID,
 	  .perf_device = false,
-	  .allowed_in_isolated = false,
+	  .allowed_in_isolated = true,
 	},
 
 	/* Synthetic Frame Buffer */
@@ -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;
@@ -829,11 +839,22 @@ static void vmbus_wait_for_unload(void)
 		if (completion_done(&vmbus_connection.unload_event))
 			goto completed;
 
-		for_each_online_cpu(cpu) {
+		for_each_present_cpu(cpu) {
 			struct hv_per_cpu_context *hv_cpu
 				= per_cpu_ptr(hv_context.cpu_context, cpu);
 
-			page_addr = hv_cpu->synic_message_page;
+			/*
+			 * In a CoCo VM the hyp_synic_message_page is not allocated
+			 * in hv_synic_alloc(). Instead it is set/cleared in
+			 * hv_hyp_synic_enable_regs() and hv_hyp_synic_disable_regs()
+			 * such that it is set only when the CPU is online. If
+			 * not all present CPUs are online, the message page
+			 * might be NULL, so skip such CPUs.
+			 */
+			page_addr = hv_cpu->hyp_synic_message_page;
+			if (!page_addr)
+				continue;
+
 			msg = (struct hv_message *)page_addr
 				+ VMBUS_MESSAGE_SINT;
 
@@ -867,11 +888,14 @@ completed:
 	 * maybe-pending messages on all CPUs to be able to receive new
 	 * messages after we reconnect.
 	 */
-	for_each_online_cpu(cpu) {
+	for_each_present_cpu(cpu) {
 		struct hv_per_cpu_context *hv_cpu
 			= per_cpu_ptr(hv_context.cpu_context, cpu);
 
-		page_addr = hv_cpu->synic_message_page;
+		page_addr = hv_cpu->hyp_synic_message_page;
+		if (!page_addr)
+			continue;
+
 		msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 		msg->header.message_type = HVMSG_NONE;
 	}
@@ -921,16 +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)
 {
@@ -1008,6 +1022,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 	struct vmbus_channel_offer_channel *offer;
 	struct vmbus_channel *oldchannel, *newchannel;
 	size_t offer_sz;
+	bool co_ring_buffer, co_external_memory;
 
 	offer = (struct vmbus_channel_offer_channel *)hdr;
 
@@ -1020,6 +1035,22 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 		return;
 	}
 
+	co_ring_buffer = is_co_ring_buffer(offer);
+	co_external_memory = is_co_external_memory(offer);
+	if (!co_ring_buffer && co_external_memory) {
+		pr_err("Invalid offer relid=%d: the ring buffer isn't encrypted\n",
+			offer->child_relid);
+		return;
+	}
+	if (co_ring_buffer || co_external_memory) {
+		if (vmbus_proto_version < VERSION_WIN10_V6_0 || !vmbus_is_confidential()) {
+			pr_err("Invalid offer relid=%d: no support for confidential VMBus\n",
+				offer->child_relid);
+			atomic_dec(&vmbus_connection.offer_in_progress);
+			return;
+		}
+	}
+
 	oldchannel = find_primary_channel_by_offer(offer);
 
 	if (oldchannel != NULL) {
@@ -1086,8 +1117,6 @@ 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;
 	}
@@ -1100,6 +1129,8 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 		pr_err("Unable to allocate channel object\n");
 		return;
 	}
+	newchannel->co_ring_buffer = co_ring_buffer;
+	newchannel->co_external_memory = co_external_memory;
 
 	vmbus_setup_channel_state(newchannel, offer);
 
@@ -1273,13 +1304,28 @@ 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);
 }
 
 /*
@@ -1555,7 +1601,8 @@ 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)
 {
@@ -1573,6 +1620,10 @@ 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);
 
@@ -1584,6 +1635,29 @@ 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);