Merge tag 'hyperv-next-signed-20220528' of...

Merge tag 'hyperv-next-signed-20220528' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv updates from Wei Liu:

 - Harden hv_sock driver (Andrea Parri)

 - Harden Hyper-V PCI driver (Andrea Parri)

 - Fix multi-MSI for Hyper-V PCI driver (Jeffrey Hugo)

 - Fix Hyper-V PCI to reduce boot time (Dexuan Cui)

 - Remove code for long EOL'ed Hyper-V versions (Michael Kelley, Saurabh
   Sengar)

 - Fix balloon driver error handling (Shradha Gupta)

 - Fix a typo in vmbus driver (Julia Lawall)

 - Ignore vmbus IMC device (Michael Kelley)

 - Add a new error message to Hyper-V DRM driver (Saurabh Sengar)

* tag 'hyperv-next-signed-20220528' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (28 commits)
  hv_balloon: Fix balloon_probe() and balloon_remove() error handling
  scsi: storvsc: Removing Pre Win8 related logic
  Drivers: hv: vmbus: fix typo in comment
  PCI: hv: Fix synchronization between channel callback and hv_pci_bus_exit()
  PCI: hv: Add validation for untrusted Hyper-V values
  PCI: hv: Fix interrupt mapping for multi-MSI
  PCI: hv: Reuse existing IRTE allocation in compose_msi_msg()
  drm/hyperv: Remove support for Hyper-V 2008 and 2008R2/Win7
  video: hyperv_fb: Remove support for Hyper-V 2008 and 2008R2/Win7
  scsi: storvsc: Remove support for Hyper-V 2008 and 2008R2/Win7
  Drivers: hv: vmbus: Remove support for Hyper-V 2008 and Hyper-V 2008R2/Win7
  x86/hyperv: Disable hardlockup detector by default in Hyper-V guests
  drm/hyperv: Add error message for fb size greater than allocated
  PCI: hv: Do not set PCI_COMMAND_MEMORY to reduce VM boot time
  PCI: hv: Fix hv_arch_irq_unmask() for multi-MSI
  Drivers: hv: vmbus: Refactor the ring-buffer iterator functions
  Drivers: hv: vmbus: Accept hv_sock offers in isolated guests
  hv_sock: Add validation for untrusted Hyper-V values
  hv_sock: Copy packets sent by Hyper-V out of the ring buffer
  hv_sock: Check hv_pkt_iter_first_raw()'s return value
  ...

arch/x86/kernel/cpu/mshyperv.c

@@ -457,6 +457,8 @@ static void __init ms_hyperv_init_platform(void)
 	 */
 	if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
 		mark_tsc_unstable("running on Hyper-V");
+
+	hardlockup_detector_disable();
 }
 
 static bool __init ms_hyperv_x2apic_available(void)

drivers/gpu/drm/hyperv/hyperv_drm_modeset.c

@@ -123,8 +123,11 @@ static int hyperv_pipe_check(struct drm_simple_display_pipe *pipe,
 	if (fb->format->format != DRM_FORMAT_XRGB8888)
 		return -EINVAL;
 
-	if (fb->pitches[0] * fb->height > hv->fb_size)
+	if (fb->pitches[0] * fb->height > hv->fb_size) {
+		drm_err(&hv->dev, "fb size requested by %s for %dX%d (pitch %d) greater than %ld\n",
+			current->comm, fb->width, fb->height, fb->pitches[0], hv->fb_size);
 		return -EINVAL;
+	}
 
 	return 0;
 }

drivers/gpu/drm/hyperv/hyperv_drm_proto.c

@@ -18,16 +18,16 @@
 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
+
+/* Support for VERSION_WIN7 is removed. #define is retained for reference. */
 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
 
-#define SYNTHVID_DEPTH_WIN7 16
 #define SYNTHVID_DEPTH_WIN8 32
-#define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
+#define SYNTHVID_WIDTH_WIN8 1600
+#define SYNTHVID_HEIGHT_WIN8 1200
 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
-#define SYNTHVID_WIDTH_MAX_WIN7 1600
-#define SYNTHVID_HEIGHT_MAX_WIN7 1200
 
 enum pipe_msg_type {
 	PIPE_MSG_INVALID,
@@ -496,12 +496,6 @@ int hyperv_connect_vsp(struct hv_device *hdev)
 	case VERSION_WIN8:
 	case VERSION_WIN8_1:
 		ret = hyperv_negotiate_version(hdev, SYNTHVID_VERSION_WIN8);
-		if (!ret)
-			break;
-		fallthrough;
-	case VERSION_WS2008:
-	case VERSION_WIN7:
-		ret = hyperv_negotiate_version(hdev, SYNTHVID_VERSION_WIN7);
 		break;
 	default:
 		ret = hyperv_negotiate_version(hdev, SYNTHVID_VERSION_WIN10);
@@ -513,18 +507,15 @@ int hyperv_connect_vsp(struct hv_device *hdev)
 		goto error;
 	}
 
-	if (hv->synthvid_version == SYNTHVID_VERSION_WIN7)
-		hv->screen_depth = SYNTHVID_DEPTH_WIN7;
-	else
-		hv->screen_depth = SYNTHVID_DEPTH_WIN8;
+	hv->screen_depth = SYNTHVID_DEPTH_WIN8;
 
 	if (hyperv_version_ge(hv->synthvid_version, SYNTHVID_VERSION_WIN10)) {
 		ret = hyperv_get_supported_resolution(hdev);
 		if (ret)
 			drm_err(dev, "Failed to get supported resolution from host, use default\n");
 	} else {
-		hv->screen_width_max = SYNTHVID_WIDTH_MAX_WIN7;
-		hv->screen_height_max = SYNTHVID_HEIGHT_MAX_WIN7;
+		hv->screen_width_max = SYNTHVID_WIDTH_WIN8;
+		hv->screen_height_max = SYNTHVID_HEIGHT_WIN8;
 	}
 
 	hv->mmio_megabytes = hdev->channel->offermsg.offer.mmio_megabytes;

drivers/hv/channel.c

@@ -1022,11 +1022,13 @@ void vmbus_close(struct vmbus_channel *channel)
 EXPORT_SYMBOL_GPL(vmbus_close);
 
 /**
- * vmbus_sendpacket() - Send the specified buffer on the given channel
+ * vmbus_sendpacket_getid() - Send the specified buffer on the given channel
  * @channel: Pointer to vmbus_channel structure
  * @buffer: Pointer to the buffer you want to send the data from.
  * @bufferlen: Maximum size of what the buffer holds.
  * @requestid: Identifier of the request
+ * @trans_id: Identifier of the transaction associated to this request, if
+ *            the send is successful; undefined, otherwise.
  * @type: Type of packet that is being sent e.g. negotiate, time
  *	  packet etc.
  * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
@@ -1036,8 +1038,8 @@ EXPORT_SYMBOL_GPL(vmbus_close);
  *
  * Mainly used by Hyper-V drivers.
  */
-int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
-			   u32 bufferlen, u64 requestid,
+int vmbus_sendpacket_getid(struct vmbus_channel *channel, void *buffer,
+			   u32 bufferlen, u64 requestid, u64 *trans_id,
 			   enum vmbus_packet_type type, u32 flags)
 {
 	struct vmpacket_descriptor desc;
@@ -1063,7 +1065,31 @@ int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid);
+	return hv_ringbuffer_write(channel, bufferlist, num_vecs, requestid, trans_id);
+}
+EXPORT_SYMBOL(vmbus_sendpacket_getid);
+
+/**
+ * vmbus_sendpacket() - Send the specified buffer on the given channel
+ * @channel: Pointer to vmbus_channel structure
+ * @buffer: Pointer to the buffer you want to send the data from.
+ * @bufferlen: Maximum size of what the buffer holds.
+ * @requestid: Identifier of the request
+ * @type: Type of packet that is being sent e.g. negotiate, time
+ *	  packet etc.
+ * @flags: 0 or VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED
+ *
+ * Sends data in @buffer directly to Hyper-V via the vmbus.
+ * This will send the data unparsed to Hyper-V.
+ *
+ * Mainly used by Hyper-V drivers.
+ */
+int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer,
+		     u32 bufferlen, u64 requestid,
+		     enum vmbus_packet_type type, u32 flags)
+{
+	return vmbus_sendpacket_getid(channel, buffer, bufferlen,
+				      requestid, NULL, type, flags);
 }
 EXPORT_SYMBOL(vmbus_sendpacket);
 
@@ -1122,7 +1148,7 @@ int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
+	return hv_ringbuffer_write(channel, bufferlist, 3, requestid, NULL);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_pagebuffer);
 
@@ -1160,7 +1186,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
 	bufferlist[2].iov_base = &aligned_data;
 	bufferlist[2].iov_len = (packetlen_aligned - packetlen);
 
-	return hv_ringbuffer_write(channel, bufferlist, 3, requestid);
+	return hv_ringbuffer_write(channel, bufferlist, 3, requestid, NULL);
 }
 EXPORT_SYMBOL_GPL(vmbus_sendpacket_mpb_desc);
 
@@ -1226,12 +1252,12 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 	if (!channel->rqstor_size)
 		return VMBUS_NO_RQSTOR;
 
-	spin_lock_irqsave(&rqstor->req_lock, flags);
+	lock_requestor(channel, flags);
 	current_id = rqstor->next_request_id;
 
 	/* Requestor array is full */
 	if (current_id >= rqstor->size) {
-		spin_unlock_irqrestore(&rqstor->req_lock, flags);
+		unlock_requestor(channel, flags);
 		return VMBUS_RQST_ERROR;
 	}
 
@@ -1241,27 +1267,23 @@ u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 	/* The already held spin lock provides atomicity */
 	bitmap_set(rqstor->req_bitmap, current_id, 1);
 
-	spin_unlock_irqrestore(&rqstor->req_lock, flags);
+	unlock_requestor(channel, flags);
 
 	/*
 	 * Cannot return an ID of 0, which is reserved for an unsolicited
-	 * message from Hyper-V.
+	 * message from Hyper-V; Hyper-V does not acknowledge (respond to)
+	 * VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED requests with ID of
+	 * 0 sent by the guest.
 	 */
 	return current_id + 1;
 }
 EXPORT_SYMBOL_GPL(vmbus_next_request_id);
 
-/*
- * vmbus_request_addr - Returns the memory address stored at @trans_id
- * in @rqstor. Uses a spin lock to avoid race conditions.
- * @channel: Pointer to the VMbus channel struct
- * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
- * next request id.
- */
-u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
+/* As in vmbus_request_addr_match() but without the requestor lock */
+u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			       u64 rqst_addr)
 {
 	struct vmbus_requestor *rqstor = &channel->requestor;
-	unsigned long flags;
 	u64 req_addr;
 
 	/* Check rqstor has been initialized */
@@ -1270,27 +1292,61 @@ u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
 
 	/* Hyper-V can send an unsolicited message with ID of 0 */
 	if (!trans_id)
-		return trans_id;
-
-	spin_lock_irqsave(&rqstor->req_lock, flags);
+		return VMBUS_RQST_ERROR;
 
 	/* Data corresponding to trans_id is stored at trans_id - 1 */
 	trans_id--;
 
 	/* Invalid trans_id */
-	if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap)) {
-		spin_unlock_irqrestore(&rqstor->req_lock, flags);
+	if (trans_id >= rqstor->size || !test_bit(trans_id, rqstor->req_bitmap))
 		return VMBUS_RQST_ERROR;
-	}
 
 	req_addr = rqstor->req_arr[trans_id];
-	rqstor->req_arr[trans_id] = rqstor->next_request_id;
-	rqstor->next_request_id = trans_id;
+	if (rqst_addr == VMBUS_RQST_ADDR_ANY || req_addr == rqst_addr) {
+		rqstor->req_arr[trans_id] = rqstor->next_request_id;
+		rqstor->next_request_id = trans_id;
 
-	/* The already held spin lock provides atomicity */
-	bitmap_clear(rqstor->req_bitmap, trans_id, 1);
+		/* The already held spin lock provides atomicity */
+		bitmap_clear(rqstor->req_bitmap, trans_id, 1);
+	}
 
-	spin_unlock_irqrestore(&rqstor->req_lock, flags);
 	return req_addr;
 }
+EXPORT_SYMBOL_GPL(__vmbus_request_addr_match);
+
+/*
+ * vmbus_request_addr_match - Clears/removes @trans_id from the @channel's
+ * requestor, provided the memory address stored at @trans_id equals @rqst_addr
+ * (or provided @rqst_addr matches the sentinel value VMBUS_RQST_ADDR_ANY).
+ *
+ * Returns the memory address stored at @trans_id, or VMBUS_RQST_ERROR if
+ * @trans_id is not contained in the requestor.
+ *
+ * Acquires and releases the requestor spin lock.
+ */
+u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			     u64 rqst_addr)
+{
+	unsigned long flags;
+	u64 req_addr;
+
+	lock_requestor(channel, flags);
+	req_addr = __vmbus_request_addr_match(channel, trans_id, rqst_addr);
+	unlock_requestor(channel, flags);
+
+	return req_addr;
+}
+EXPORT_SYMBOL_GPL(vmbus_request_addr_match);
+
+/*
+ * vmbus_request_addr - Returns the memory address stored at @trans_id
+ * in @rqstor. Uses a spin lock to avoid race conditions.
+ * @channel: Pointer to the VMbus channel struct
+ * @trans_id: Request id sent back from Hyper-V. Becomes the requestor's
+ * next request id.
+ */
+u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id)
+{
+	return vmbus_request_addr_match(channel, trans_id, VMBUS_RQST_ADDR_ANY);
+}
 EXPORT_SYMBOL_GPL(vmbus_request_addr);

drivers/hv/channel_mgmt.c

@@ -152,6 +152,7 @@ static const struct {
 	{ HV_AVMA1_GUID },
 	{ HV_AVMA2_GUID },
 	{ HV_RDV_GUID	},
+	{ HV_IMC_GUID	},
 };
 
 /*
@@ -442,7 +443,7 @@ void hv_process_channel_removal(struct vmbus_channel *channel)
 	/*
 	 * Upon suspend, an in-use hv_sock channel is removed from the array of
 	 * channels and the relid is invalidated.  After hibernation, when the
-	 * user-space appplication destroys the channel, it's unnecessary and
+	 * user-space application destroys the channel, it's unnecessary and
 	 * unsafe to remove the channel from the array of channels.  See also
 	 * the inline comments before the call of vmbus_release_relid() below.
 	 */
@@ -713,15 +714,13 @@ static bool hv_cpuself_used(u32 cpu, struct vmbus_channel *chn)
 static int next_numa_node_id;
 
 /*
- * Starting with Win8, we can statically distribute the incoming
- * channel interrupt load by binding a channel to VCPU.
+ * We can statically distribute the incoming channel interrupt load
+ * by binding a channel to VCPU.
  *
- * For pre-win8 hosts or non-performance critical channels we assign the
- * VMBUS_CONNECT_CPU.
- *
- * Starting with win8, performance critical channels will be distributed
- * evenly among all the available NUMA nodes.  Once the node is assigned,
- * we will assign the CPU based on a simple round robin scheme.
+ * For non-performance critical channels we assign the VMBUS_CONNECT_CPU.
+ * Performance critical channels will be distributed evenly among all
+ * the available NUMA nodes.  Once the node is assigned, we will assign
+ * the CPU based on a simple round robin scheme.
  */
 static void init_vp_index(struct vmbus_channel *channel)
 {
@@ -732,13 +731,10 @@ static void init_vp_index(struct vmbus_channel *channel)
 	u32 target_cpu;
 	int numa_node;
 
-	if ((vmbus_proto_version == VERSION_WS2008) ||
-	    (vmbus_proto_version == VERSION_WIN7) || (!perf_chn) ||
+	if (!perf_chn ||
 	    !alloc_cpumask_var(&available_mask, GFP_KERNEL)) {
 		/*
-		 * Prior to win8, all channel interrupts are
-		 * delivered on VMBUS_CONNECT_CPU.
-		 * Also if the channel is not a performance critical
+		 * If the channel is not a performance critical
 		 * channel, bind it to VMBUS_CONNECT_CPU.
 		 * In case alloc_cpumask_var() fails, bind it to
 		 * VMBUS_CONNECT_CPU.
@@ -931,11 +927,9 @@ static void vmbus_setup_channel_state(struct vmbus_channel *channel,
 	 */
 	channel->sig_event = VMBUS_EVENT_CONNECTION_ID;
 
-	if (vmbus_proto_version != VERSION_WS2008) {
-		channel->is_dedicated_interrupt =
-				(offer->is_dedicated_interrupt != 0);
-		channel->sig_event = offer->connection_id;
-	}
+	channel->is_dedicated_interrupt =
+			(offer->is_dedicated_interrupt != 0);
+	channel->sig_event = offer->connection_id;
 
 	memcpy(&channel->offermsg, offer,
 	       sizeof(struct vmbus_channel_offer_channel));
@@ -975,13 +969,17 @@ find_primary_channel_by_offer(const struct vmbus_channel_offer_channel *offer)
 	return channel;
 }
 
-static bool vmbus_is_valid_device(const guid_t *guid)
+static bool vmbus_is_valid_offer(const struct vmbus_channel_offer_channel *offer)
 {
+	const guid_t *guid = &offer->offer.if_type;
 	u16 i;
 
 	if (!hv_is_isolation_supported())
 		return true;
 
+	if (is_hvsock_offer(offer))
+		return true;
+
 	for (i = 0; i < ARRAY_SIZE(vmbus_devs); i++) {
 		if (guid_equal(guid, &vmbus_devs[i].guid))
 			return vmbus_devs[i].allowed_in_isolated;
@@ -1003,7 +1001,7 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
 
 	trace_vmbus_onoffer(offer);
 
-	if (!vmbus_is_valid_device(&offer->offer.if_type)) {
+	if (!vmbus_is_valid_offer(offer)) {
 		pr_err_ratelimited("Invalid offer %d from the host supporting isolation\n",
 				   offer->child_relid);
 		atomic_dec(&vmbus_connection.offer_in_progress);

drivers/hv/connection.c

@@ -47,6 +47,8 @@ EXPORT_SYMBOL_GPL(vmbus_proto_version);
 
 /*
  * Table of VMBus versions listed from newest to oldest.
+ * VERSION_WIN7 and VERSION_WS2008 are no longer supported in
+ * Linux guests and are not listed.
  */
 static __u32 vmbus_versions[] = {
 	VERSION_WIN10_V5_3,
@@ -56,9 +58,7 @@ static __u32 vmbus_versions[] = {
 	VERSION_WIN10_V4_1,
 	VERSION_WIN10,
 	VERSION_WIN8_1,
-	VERSION_WIN8,
-	VERSION_WIN7,
-	VERSION_WS2008
+	VERSION_WIN8
 };
 
 /*

drivers/hv/hv_balloon.c

@@ -1842,7 +1842,7 @@ static int balloon_probe(struct hv_device *dev,
 
 	ret = balloon_connect_vsp(dev);
 	if (ret != 0)
-		return ret;
+		goto connect_error;
 
 	enable_page_reporting();
 	dm_device.state = DM_INITIALIZED;
@@ -1861,6 +1861,7 @@ static int balloon_probe(struct hv_device *dev,
 	dm_device.thread  = NULL;
 	disable_page_reporting();
 	vmbus_close(dev->channel);
+connect_error:
 #ifdef CONFIG_MEMORY_HOTPLUG
 	unregister_memory_notifier(&hv_memory_nb);
 	restore_online_page_callback(&hv_online_page);
@@ -1882,12 +1883,21 @@ static int balloon_remove(struct hv_device *dev)
 	cancel_work_sync(&dm->ha_wrk.wrk);
 
 	kthread_stop(dm->thread);
-	disable_page_reporting();
-	vmbus_close(dev->channel);
+
+	/*
+	 * This is to handle the case when balloon_resume()
+	 * call has failed and some cleanup has been done as
+	 * a part of the error handling.
+	 */
+	if (dm_device.state != DM_INIT_ERROR) {
+		disable_page_reporting();
+		vmbus_close(dev->channel);
 #ifdef CONFIG_MEMORY_HOTPLUG
-	unregister_memory_notifier(&hv_memory_nb);
-	restore_online_page_callback(&hv_online_page);
+		unregister_memory_notifier(&hv_memory_nb);
+		restore_online_page_callback(&hv_online_page);
 #endif
+	}
+
 	spin_lock_irqsave(&dm_device.ha_lock, flags);
 	list_for_each_entry_safe(has, tmp, &dm->ha_region_list, list) {
 		list_for_each_entry_safe(gap, tmp_gap, &has->gap_list, list) {
@@ -1948,6 +1958,7 @@ static int balloon_resume(struct hv_device *dev)
 	vmbus_close(dev->channel);
 out:
 	dm_device.state = DM_INIT_ERROR;
+	disable_page_reporting();
 #ifdef CONFIG_MEMORY_HOTPLUG
 	unregister_memory_notifier(&hv_memory_nb);
 	restore_online_page_callback(&hv_online_page);

drivers/hv/hyperv_vmbus.h

@@ -181,7 +181,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
 
 int hv_ringbuffer_write(struct vmbus_channel *channel,
 			const struct kvec *kv_list, u32 kv_count,
-			u64 requestid);
+			u64 requestid, u64 *trans_id);
 
 int hv_ringbuffer_read(struct vmbus_channel *channel,
 		       void *buffer, u32 buflen, u32 *buffer_actual_len,

drivers/hv/ring_buffer.c

@@ -283,7 +283,7 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
 /* Write to the ring buffer. */
 int hv_ringbuffer_write(struct vmbus_channel *channel,
 			const struct kvec *kv_list, u32 kv_count,
-			u64 requestid)
+			u64 requestid, u64 *trans_id)
 {
 	int i;
 	u32 bytes_avail_towrite;
@@ -294,7 +294,7 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
 	unsigned long flags;
 	struct hv_ring_buffer_info *outring_info = &channel->outbound;
 	struct vmpacket_descriptor *desc = kv_list[0].iov_base;
-	u64 rqst_id = VMBUS_NO_RQSTOR;
+	u64 __trans_id, rqst_id = VMBUS_NO_RQSTOR;
 
 	if (channel->rescind)
 		return -ENODEV;
@@ -353,7 +353,15 @@ int hv_ringbuffer_write(struct vmbus_channel *channel,
 		}
 	}
 	desc = hv_get_ring_buffer(outring_info) + old_write;
-	desc->trans_id = (rqst_id == VMBUS_NO_RQSTOR) ? requestid : rqst_id;
+	__trans_id = (rqst_id == VMBUS_NO_RQSTOR) ? requestid : rqst_id;
+	/*
+	 * Ensure the compiler doesn't generate code that reads the value of
+	 * the transaction ID from the ring buffer, which is shared with the
+	 * Hyper-V host and subject to being changed at any time.
+	 */
+	WRITE_ONCE(desc->trans_id, __trans_id);
+	if (trans_id)
+		*trans_id = __trans_id;
 
 	/* Set previous packet start */
 	prev_indices = hv_get_ring_bufferindices(outring_info);
@@ -421,7 +429,7 @@ int hv_ringbuffer_read(struct vmbus_channel *channel,
 	memcpy(buffer, (const char *)desc + offset, packetlen);
 
 	/* Advance ring index to next packet descriptor */
-	__hv_pkt_iter_next(channel, desc, true);
+	__hv_pkt_iter_next(channel, desc);
 
 	/* Notify host of update */
 	hv_pkt_iter_close(channel);
@@ -456,22 +464,6 @@ static u32 hv_pkt_iter_avail(const struct hv_ring_buffer_info *rbi)
 		return (rbi->ring_datasize - priv_read_loc) + write_loc;
 }
 
-/*
- * Get first vmbus packet without copying it out of the ring buffer
- */
-struct vmpacket_descriptor *hv_pkt_iter_first_raw(struct vmbus_channel *channel)
-{
-	struct hv_ring_buffer_info *rbi = &channel->inbound;
-
-	hv_debug_delay_test(channel, MESSAGE_DELAY);
-
-	if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
-		return NULL;
-
-	return (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
-}
-EXPORT_SYMBOL_GPL(hv_pkt_iter_first_raw);
-
 /*
  * Get first vmbus packet from ring buffer after read_index
  *
@@ -483,11 +475,14 @@ struct vmpacket_descriptor *hv_pkt_iter_first(struct vmbus_channel *channel)
 	struct vmpacket_descriptor *desc, *desc_copy;
 	u32 bytes_avail, pkt_len, pkt_offset;
 
-	desc = hv_pkt_iter_first_raw(channel);
-	if (!desc)
+	hv_debug_delay_test(channel, MESSAGE_DELAY);
+
+	bytes_avail = hv_pkt_iter_avail(rbi);
+	if (bytes_avail < sizeof(struct vmpacket_descriptor))
 		return NULL;
+	bytes_avail = min(rbi->pkt_buffer_size, bytes_avail);
 
-	bytes_avail = min(rbi->pkt_buffer_size, hv_pkt_iter_avail(rbi));
+	desc = (struct vmpacket_descriptor *)(hv_get_ring_buffer(rbi) + rbi->priv_read_index);
 
 	/*
 	 * Ensure the compiler does not use references to incoming Hyper-V values (which
@@ -534,8 +529,7 @@ EXPORT_SYMBOL_GPL(hv_pkt_iter_first);
  */
 struct vmpacket_descriptor *
 __hv_pkt_iter_next(struct vmbus_channel *channel,
-		   const struct vmpacket_descriptor *desc,
-		   bool copy)
+		   const struct vmpacket_descriptor *desc)
 {
 	struct hv_ring_buffer_info *rbi = &channel->inbound;
 	u32 packetlen = desc->len8 << 3;
@@ -548,7 +542,7 @@ __hv_pkt_iter_next(struct vmbus_channel *channel,
 		rbi->priv_read_index -= dsize;
 
 	/* more data? */
-	return copy ? hv_pkt_iter_first(channel) : hv_pkt_iter_first_raw(channel);
+	return hv_pkt_iter_first(channel);
 }
 EXPORT_SYMBOL_GPL(__hv_pkt_iter_next);
 

drivers/hv/vmbus_drv.c

@@ -1263,23 +1263,17 @@ static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
 	unsigned long *recv_int_page;
 	u32 maxbits, relid;
 
-	if (vmbus_proto_version < VERSION_WIN8) {
-		maxbits = MAX_NUM_CHANNELS_SUPPORTED;
-		recv_int_page = vmbus_connection.recv_int_page;
-	} else {
-		/*
-		 * When the host is win8 and beyond, the event page
-		 * can be directly checked to get the id of the channel
-		 * that has the interrupt pending.
-		 */
-		void *page_addr = hv_cpu->synic_event_page;
-		union hv_synic_event_flags *event
-			= (union hv_synic_event_flags *)page_addr +
-						 VMBUS_MESSAGE_SINT;
+	/*
+	 * The event page can be directly checked to get the id of
+	 * the channel that has the interrupt pending.
+	 */
+	void *page_addr = hv_cpu->synic_event_page;
+	union hv_synic_event_flags *event
+		= (union hv_synic_event_flags *)page_addr +
+					 VMBUS_MESSAGE_SINT;
 
-		maxbits = HV_EVENT_FLAGS_COUNT;
-		recv_int_page = event->flags;
-	}
+	maxbits = HV_EVENT_FLAGS_COUNT;
+	recv_int_page = event->flags;
 
 	if (unlikely(!recv_int_page))
 		return;
@@ -1351,40 +1345,10 @@ static void vmbus_isr(void)
 {
 	struct hv_per_cpu_context *hv_cpu
 		= this_cpu_ptr(hv_context.cpu_context);
-	void *page_addr = hv_cpu->synic_event_page;
+	void *page_addr;
 	struct hv_message *msg;
-	union hv_synic_event_flags *event;
-	bool handled = false;
-
-	if (unlikely(page_addr == NULL))
-		return;
-
-	event = (union hv_synic_event_flags *)page_addr +
-					 VMBUS_MESSAGE_SINT;
-	/*
-	 * Check for events before checking for messages. This is the order
-	 * in which events and messages are checked in Windows guests on
-	 * Hyper-V, and the Windows team suggested we do the same.
-	 */
-
-	if ((vmbus_proto_version == VERSION_WS2008) ||
-		(vmbus_proto_version == VERSION_WIN7)) {
-
-		/* Since we are a child, we only need to check bit 0 */
-		if (sync_test_and_clear_bit(0, event->flags))
-			handled = true;
-	} else {
-		/*
-		 * Our host is win8 or above. The signaling mechanism
-		 * has changed and we can directly look at the event page.
-		 * If bit n is set then we have an interrup on the channel
-		 * whose id is n.
-		 */
-		handled = true;
-	}
 
-	if (handled)
-		vmbus_chan_sched(hv_cpu);
+	vmbus_chan_sched(hv_cpu);
 
 	page_addr = hv_cpu->synic_message_page;
 	msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;

drivers/video/fbdev/hyperv_fb.c

@@ -63,6 +63,7 @@
 #define MAX_VMBUS_PKT_SIZE 0x4000
 
 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
+/* Support for VERSION_WIN7 is removed. #define is retained for reference. */
 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
@@ -70,13 +71,7 @@
 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
 
-#define SYNTHVID_DEPTH_WIN7 16
 #define SYNTHVID_DEPTH_WIN8 32
-
-#define SYNTHVID_FB_SIZE_WIN7 (4 * 1024 * 1024)
-#define SYNTHVID_WIDTH_MAX_WIN7 1600
-#define SYNTHVID_HEIGHT_MAX_WIN7 1200
-
 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
 
 #define PCI_VENDOR_ID_MICROSOFT 0x1414
@@ -643,12 +638,6 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
 	case VERSION_WIN8:
 	case VERSION_WIN8_1:
 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
-		if (!ret)
-			break;
-		fallthrough;
-	case VERSION_WS2008:
-	case VERSION_WIN7:
-		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
 		break;
 	default:
 		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
@@ -660,11 +649,7 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
 		goto error;
 	}
 
-	if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
-		screen_depth = SYNTHVID_DEPTH_WIN7;
-	else
-		screen_depth = SYNTHVID_DEPTH_WIN8;
-
+	screen_depth = SYNTHVID_DEPTH_WIN8;
 	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
 		ret = synthvid_get_supported_resolution(hdev);
 		if (ret)
@@ -933,9 +918,7 @@ static void hvfb_get_option(struct fb_info *info)
 	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
 	    (x * y * screen_depth / 8 > screen_fb_size)) ||
 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
-	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
-	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
-	     (x > SYNTHVID_WIDTH_MAX_WIN7 || y > SYNTHVID_HEIGHT_MAX_WIN7))) {
+	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8)) {
 		pr_err("Screen resolution option is out of range: skipped\n");
 		return;
 	}

include/linux/hyperv.h

@@ -230,15 +230,19 @@ static inline u32 hv_get_avail_to_write_percent(
  * two 16 bit quantities: major_number. minor_number.
  *
  * 0 . 13 (Windows Server 2008)
- * 1 . 1  (Windows 7)
- * 2 . 4  (Windows 8)
- * 3 . 0  (Windows 8 R2)
+ * 1 . 1  (Windows 7, WS2008 R2)
+ * 2 . 4  (Windows 8, WS2012)
+ * 3 . 0  (Windows 8.1, WS2012 R2)
  * 4 . 0  (Windows 10)
  * 4 . 1  (Windows 10 RS3)
  * 5 . 0  (Newer Windows 10)
  * 5 . 1  (Windows 10 RS4)
  * 5 . 2  (Windows Server 2019, RS5)
  * 5 . 3  (Windows Server 2022)
+ *
+ * The WS2008 and WIN7 versions are listed here for
+ * completeness but are no longer supported in the
+ * Linux kernel.
  */
 
 #define VERSION_WS2008  ((0 << 16) | (13))
@@ -788,6 +792,7 @@ struct vmbus_requestor {
 
 #define VMBUS_NO_RQSTOR U64_MAX
 #define VMBUS_RQST_ERROR (U64_MAX - 1)
+#define VMBUS_RQST_ADDR_ANY U64_MAX
 /* NetVSC-specific */
 #define VMBUS_RQST_ID_NO_RESPONSE (U64_MAX - 2)
 /* StorVSC-specific */
@@ -1041,13 +1046,36 @@ struct vmbus_channel {
 	u32 max_pkt_size;
 };
 
+#define lock_requestor(channel, flags)					\
+do {									\
+	struct vmbus_requestor *rqstor = &(channel)->requestor;		\
+									\
+	spin_lock_irqsave(&rqstor->req_lock, flags);			\
+} while (0)
+
+static __always_inline void unlock_requestor(struct vmbus_channel *channel,
+					     unsigned long flags)
+{
+	struct vmbus_requestor *rqstor = &channel->requestor;
+
+	spin_unlock_irqrestore(&rqstor->req_lock, flags);
+}
+
 u64 vmbus_next_request_id(struct vmbus_channel *channel, u64 rqst_addr);
+u64 __vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			       u64 rqst_addr);
+u64 vmbus_request_addr_match(struct vmbus_channel *channel, u64 trans_id,
+			     u64 rqst_addr);
 u64 vmbus_request_addr(struct vmbus_channel *channel, u64 trans_id);
 
+static inline bool is_hvsock_offer(const struct vmbus_channel_offer_channel *o)
+{
+	return !!(o->offer.chn_flags & VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER);
+}
+
 static inline bool is_hvsock_channel(const struct vmbus_channel *c)
 {
-	return !!(c->offermsg.offer.chn_flags &
-		  VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER);
+	return is_hvsock_offer(&c->offermsg);
 }
 
 static inline bool is_sub_channel(const struct vmbus_channel *c)
@@ -1161,6 +1189,13 @@ extern int vmbus_open(struct vmbus_channel *channel,
 
 extern void vmbus_close(struct vmbus_channel *channel);
 
+extern int vmbus_sendpacket_getid(struct vmbus_channel *channel,
+				  void *buffer,
+				  u32 bufferLen,
+				  u64 requestid,
+				  u64 *trans_id,
+				  enum vmbus_packet_type type,
+				  u32 flags);
 extern int vmbus_sendpacket(struct vmbus_channel *channel,
 				  void *buffer,
 				  u32 bufferLen,
@@ -1451,12 +1486,14 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size);
 			  0x80, 0x2e, 0x27, 0xed, 0xe1, 0x9f)
 
 /*
- * Linux doesn't support the 3 devices: the first two are for
- * Automatic Virtual Machine Activation, and the third is for
- * Remote Desktop Virtualization.
+ * Linux doesn't support these 4 devices: the first two are for
+ * Automatic Virtual Machine Activation, the third is for
+ * Remote Desktop Virtualization, and the fourth is Initial
+ * Machine Configuration (IMC) used only by Windows guests.
  * {f8e65716-3cb3-4a06-9a60-1889c5cccab5}
  * {3375baf4-9e15-4b30-b765-67acb10d607b}
  * {276aacf4-ac15-426c-98dd-7521ad3f01fe}
+ * {c376c1c3-d276-48d2-90a9-c04748072c60}
  */
 
 #define HV_AVMA1_GUID \
@@ -1471,6 +1508,10 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size);
 	.guid = GUID_INIT(0x276aacf4, 0xac15, 0x426c, 0x98, 0xdd, \
 			  0x75, 0x21, 0xad, 0x3f, 0x01, 0xfe)
 
+#define HV_IMC_GUID \
+	.guid = GUID_INIT(0xc376c1c3, 0xd276, 0x48d2, 0x90, 0xa9, \
+			  0xc0, 0x47, 0x48, 0x07, 0x2c, 0x60)
+
 /*
  * Common header for Hyper-V ICs
  */
@@ -1663,56 +1704,34 @@ static inline u32 hv_pkt_datalen(const struct vmpacket_descriptor *desc)
 	return (desc->len8 << 3) - (desc->offset8 << 3);
 }
 
-
-struct vmpacket_descriptor *
-hv_pkt_iter_first_raw(struct vmbus_channel *channel);
+/* Get packet length associated with descriptor */
+static inline u32 hv_pkt_len(const struct vmpacket_descriptor *desc)
+{
+	return desc->len8 << 3;
+}
 
 struct vmpacket_descriptor *
 hv_pkt_iter_first(struct vmbus_channel *channel);
 
 struct vmpacket_descriptor *
 __hv_pkt_iter_next(struct vmbus_channel *channel,
-		   const struct vmpacket_descriptor *pkt,
-		   bool copy);
+		   const struct vmpacket_descriptor *pkt);
 
 void hv_pkt_iter_close(struct vmbus_channel *channel);
 
 static inline struct vmpacket_descriptor *
-hv_pkt_iter_next_pkt(struct vmbus_channel *channel,
-		     const struct vmpacket_descriptor *pkt,
-		     bool copy)
+hv_pkt_iter_next(struct vmbus_channel *channel,
+		 const struct vmpacket_descriptor *pkt)
 {
 	struct vmpacket_descriptor *nxt;
 
-	nxt = __hv_pkt_iter_next(channel, pkt, copy);
+	nxt = __hv_pkt_iter_next(channel, pkt);
 	if (!nxt)
 		hv_pkt_iter_close(channel);
 
 	return nxt;
 }
 
-/*
- * Get next packet descriptor without copying it out of the ring buffer
- * If at end of list, return NULL and update host.
- */
-static inline struct vmpacket_descriptor *
-hv_pkt_iter_next_raw(struct vmbus_channel *channel,
-		     const struct vmpacket_descriptor *pkt)
-{
-	return hv_pkt_iter_next_pkt(channel, pkt, false);
-}
-
-/*
- * Get next packet descriptor from iterator
- * If at end of list, return NULL and update host.
- */
-static inline struct vmpacket_descriptor *
-hv_pkt_iter_next(struct vmbus_channel *channel,
-		 const struct vmpacket_descriptor *pkt)
-{
-	return hv_pkt_iter_next_pkt(channel, pkt, true);
-}
-
 #define foreach_vmbus_pkt(pkt, channel) \
 	for (pkt = hv_pkt_iter_first(channel); pkt; \
 	    pkt = hv_pkt_iter_next(channel, pkt))

net/vmw_vsock/hyperv_transport.c

@@ -78,6 +78,9 @@ struct hvs_send_buf {
 					 ALIGN((payload_len), 8) + \
 					 VMBUS_PKT_TRAILER_SIZE)
 
+/* Upper bound on the size of a VMbus packet for hv_sock */
+#define HVS_MAX_PKT_SIZE	HVS_PKT_LEN(HVS_MTU_SIZE)
+
 union hvs_service_id {
 	guid_t	srv_id;
 
@@ -378,6 +381,8 @@ static void hvs_open_connection(struct vmbus_channel *chan)
 		rcvbuf = ALIGN(rcvbuf, HV_HYP_PAGE_SIZE);
 	}
 
+	chan->max_pkt_size = HVS_MAX_PKT_SIZE;
+
 	ret = vmbus_open(chan, sndbuf, rcvbuf, NULL, 0, hvs_channel_cb,
 			 conn_from_host ? new : sk);
 	if (ret != 0) {
@@ -572,12 +577,18 @@ static bool hvs_dgram_allow(u32 cid, u32 port)
 static int hvs_update_recv_data(struct hvsock *hvs)
 {
 	struct hvs_recv_buf *recv_buf;
-	u32 payload_len;
+	u32 pkt_len, payload_len;
+
+	pkt_len = hv_pkt_len(hvs->recv_desc);
+
+	if (pkt_len < HVS_HEADER_LEN)
+		return -EIO;
 
 	recv_buf = (struct hvs_recv_buf *)(hvs->recv_desc + 1);
 	payload_len = recv_buf->hdr.data_size;
 
-	if (payload_len > HVS_MTU_SIZE)
+	if (payload_len > pkt_len - HVS_HEADER_LEN ||
+	    payload_len > HVS_MTU_SIZE)
 		return -EIO;
 
 	if (payload_len == 0)
@@ -602,7 +613,9 @@ static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
 		return -EOPNOTSUPP;
 
 	if (need_refill) {
-		hvs->recv_desc = hv_pkt_iter_first_raw(hvs->chan);
+		hvs->recv_desc = hv_pkt_iter_first(hvs->chan);
+		if (!hvs->recv_desc)
+			return -ENOBUFS;
 		ret = hvs_update_recv_data(hvs);
 		if (ret)
 			return ret;
@@ -616,7 +629,7 @@ static ssize_t hvs_stream_dequeue(struct vsock_sock *vsk, struct msghdr *msg,
 
 	hvs->recv_data_len -= to_read;
 	if (hvs->recv_data_len == 0) {
-		hvs->recv_desc = hv_pkt_iter_next_raw(hvs->chan, hvs->recv_desc);
+		hvs->recv_desc = hv_pkt_iter_next(hvs->chan, hvs->recv_desc);
 		if (hvs->recv_desc) {
 			ret = hvs_update_recv_data(hvs);
 			if (ret)