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

Pull Hyper-V updates from Sasha Levin:

 - support for new VMBus protocols (Andrea Parri)

 - hibernation support (Dexuan Cui)

 - latency testing framework (Branden Bonaby)

 - decoupling Hyper-V page size from guest page size (Himadri Pandya)

* tag 'hyperv-next-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits)
  Drivers: hv: vmbus: Fix crash handler reset of Hyper-V synic
  drivers/hv: Replace binary semaphore with mutex
  drivers: iommu: hyperv: Make HYPERV_IOMMU only available on x86
  HID: hyperv: Add the support of hibernation
  hv_balloon: Add the support of hibernation
  x86/hyperv: Implement hv_is_hibernation_supported()
  Drivers: hv: balloon: Remove dependencies on guest page size
  Drivers: hv: vmbus: Remove dependencies on guest page size
  x86: hv: Add function to allocate zeroed page for Hyper-V
  Drivers: hv: util: Specify ring buffer size using Hyper-V page size
  Drivers: hv: Specify receive buffer size using Hyper-V page size
  tools: hv: add vmbus testing tool
  drivers: hv: vmbus: Introduce latency testing
  video: hyperv: hyperv_fb: Support deferred IO for Hyper-V frame buffer driver
  video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host
  hv_netvsc: Add the support of hibernation
  hv_sock: Add the support of hibernation
  video: hyperv_fb: Add the support of hibernation
  scsi: storvsc: Add the support of hibernation
  Drivers: hv: vmbus: Add module parameter to cap the VMBus version
  ...

Documentation/ABI/testing/debugfs-hyperv

+What:           /sys/kernel/debug/hyperv/<UUID>/fuzz_test_state
+Date:           October 2019
+KernelVersion:  5.5
+Contact:        Branden Bonaby <brandonbonaby94@gmail.com>
+Description:    Fuzz testing status of a vmbus device, whether its in an ON
+                state or a OFF state
+Users:          Debugging tools
+
+What:           /sys/kernel/debug/hyperv/<UUID>/delay/fuzz_test_buffer_interrupt_delay
+Date:           October 2019
+KernelVersion:  5.5
+Contact:        Branden Bonaby <brandonbonaby94@gmail.com>
+Description:    Fuzz testing buffer interrupt delay value between 0 - 1000
+		 microseconds (inclusive).
+Users:          Debugging tools
+
+What:           /sys/kernel/debug/hyperv/<UUID>/delay/fuzz_test_message_delay
+Date:           October 2019
+KernelVersion:  5.5
+Contact:        Branden Bonaby <brandonbonaby94@gmail.com>
+Description:    Fuzz testing message delay value between 0 - 1000 microseconds
+		 (inclusive).
+Users:          Debugging tools

MAINTAINERS

@@ -7654,6 +7654,7 @@ F:	include/uapi/linux/hyperv.h
 F:	include/asm-generic/mshyperv.h
 F:	tools/hv/
 F:	Documentation/ABI/stable/sysfs-bus-vmbus
+F:	Documentation/ABI/testing/debugfs-hyperv
 
 HYPERBUS SUPPORT
 M:	Vignesh Raghavendra <vigneshr@ti.com>

arch/x86/hyperv/hv_init.c

@@ -7,6 +7,7 @@
  * Author : K. Y. Srinivasan <kys@microsoft.com>
  */
 
+#include <linux/acpi.h>
 #include <linux/efi.h>
 #include <linux/types.h>
 #include <asm/apic.h>
@@ -45,6 +46,14 @@ void *hv_alloc_hyperv_page(void)
 }
 EXPORT_SYMBOL_GPL(hv_alloc_hyperv_page);
 
+void *hv_alloc_hyperv_zeroed_page(void)
+{
+        BUILD_BUG_ON(PAGE_SIZE != HV_HYP_PAGE_SIZE);
+
+        return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+}
+EXPORT_SYMBOL_GPL(hv_alloc_hyperv_zeroed_page);
+
 void hv_free_hyperv_page(unsigned long addr)
 {
 	free_page(addr);
@@ -437,3 +446,9 @@ bool hv_is_hyperv_initialized(void)
 	return hypercall_msr.enable;
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
+
+bool hv_is_hibernation_supported(void)
+{
+	return acpi_sleep_state_supported(ACPI_STATE_S4);
+}
+EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);

arch/x86/include/asm/mshyperv.h

@@ -219,6 +219,7 @@ static inline struct hv_vp_assist_page *hv_get_vp_assist_page(unsigned int cpu)
 void __init hyperv_init(void);
 void hyperv_setup_mmu_ops(void);
 void *hv_alloc_hyperv_page(void);
+void *hv_alloc_hyperv_zeroed_page(void);
 void hv_free_hyperv_page(unsigned long addr);
 void hyperv_reenlightenment_intr(struct pt_regs *regs);
 void set_hv_tscchange_cb(void (*cb)(void));

drivers/hid/hid-hyperv.c

@@ -192,6 +192,9 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
 	if (desc->bLength == 0)
 		goto cleanup;
 
+	/* The pointer is not NULL when we resume from hibernation */
+	if (input_device->hid_desc != NULL)
+		kfree(input_device->hid_desc);
 	input_device->hid_desc = kmemdup(desc, desc->bLength, GFP_ATOMIC);
 
 	if (!input_device->hid_desc)
@@ -203,6 +206,9 @@ static void mousevsc_on_receive_device_info(struct mousevsc_dev *input_device,
 		goto cleanup;
 	}
 
+	/* The pointer is not NULL when we resume from hibernation */
+	if (input_device->report_desc != NULL)
+		kfree(input_device->report_desc);
 	input_device->report_desc = kzalloc(input_device->report_desc_size,
 					  GFP_ATOMIC);
 
@@ -342,6 +348,8 @@ static int mousevsc_connect_to_vsp(struct hv_device *device)
 	struct mousevsc_prt_msg *request;
 	struct mousevsc_prt_msg *response;
 
+	reinit_completion(&input_dev->wait_event);
+
 	request = &input_dev->protocol_req;
 	memset(request, 0, sizeof(struct mousevsc_prt_msg));
 
@@ -541,6 +549,30 @@ static int mousevsc_remove(struct hv_device *dev)
 	return 0;
 }
 
+static int mousevsc_suspend(struct hv_device *dev)
+{
+	vmbus_close(dev->channel);
+
+	return 0;
+}
+
+static int mousevsc_resume(struct hv_device *dev)
+{
+	int ret;
+
+	ret = vmbus_open(dev->channel,
+			 INPUTVSC_SEND_RING_BUFFER_SIZE,
+			 INPUTVSC_RECV_RING_BUFFER_SIZE,
+			 NULL, 0,
+			 mousevsc_on_channel_callback,
+			 dev);
+	if (ret)
+		return ret;
+
+	ret = mousevsc_connect_to_vsp(dev);
+	return ret;
+}
+
 static const struct hv_vmbus_device_id id_table[] = {
 	/* Mouse guid */
 	{ HV_MOUSE_GUID, },
@@ -554,6 +586,8 @@ static struct  hv_driver mousevsc_drv = {
 	.id_table = id_table,
 	.probe = mousevsc_probe,
 	.remove = mousevsc_remove,
+	.suspend = mousevsc_suspend,
+	.resume = mousevsc_resume,
 	.driver = {
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},

drivers/hv/Makefile

@@ -9,4 +9,5 @@ CFLAGS_hv_balloon.o = -I$(src)
 hv_vmbus-y := vmbus_drv.o \
 		 hv.o connection.o channel.o \
 		 channel_mgmt.o ring_buffer.o hv_trace.o
+hv_vmbus-$(CONFIG_HYPERV_TESTING)	+= hv_debugfs.o
 hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_fcopy.o hv_utils_transport.o

drivers/hv/connection.c

@@ -14,6 +14,7 @@
 #include <linux/wait.h>
 #include <linux/delay.h>
 #include <linux/mm.h>
+#include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/hyperv.h>
@@ -40,29 +41,30 @@ EXPORT_SYMBOL_GPL(vmbus_connection);
 __u32 vmbus_proto_version;
 EXPORT_SYMBOL_GPL(vmbus_proto_version);
 
-static __u32 vmbus_get_next_version(__u32 current_version)
-{
-	switch (current_version) {
-	case (VERSION_WIN7):
-		return VERSION_WS2008;
-
-	case (VERSION_WIN8):
-		return VERSION_WIN7;
-
-	case (VERSION_WIN8_1):
-		return VERSION_WIN8;
-
-	case (VERSION_WIN10):
-		return VERSION_WIN8_1;
+/*
+ * Table of VMBus versions listed from newest to oldest.
+ */
+static __u32 vmbus_versions[] = {
+	VERSION_WIN10_V5_2,
+	VERSION_WIN10_V5_1,
+	VERSION_WIN10_V5,
+	VERSION_WIN10_V4_1,
+	VERSION_WIN10,
+	VERSION_WIN8_1,
+	VERSION_WIN8,
+	VERSION_WIN7,
+	VERSION_WS2008
+};
 
-	case (VERSION_WIN10_V5):
-		return VERSION_WIN10;
+/*
+ * Maximal VMBus protocol version guests can negotiate.  Useful to cap the
+ * VMBus version for testing and debugging purpose.
+ */
+static uint max_version = VERSION_WIN10_V5_2;
 
-	case (VERSION_WS2008):
-	default:
-		return VERSION_INVAL;
-	}
-}
+module_param(max_version, uint, S_IRUGO);
+MODULE_PARM_DESC(max_version,
+		 "Maximal VMBus protocol version which can be negotiated");
 
 int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
 {
@@ -80,12 +82,12 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
 	msg->vmbus_version_requested = version;
 
 	/*
-	 * VMBus protocol 5.0 (VERSION_WIN10_V5) requires that we must use
-	 * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,
+	 * VMBus protocol 5.0 (VERSION_WIN10_V5) and higher require that we must
+	 * use VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate Contact Message,
 	 * and for subsequent messages, we must use the Message Connection ID
 	 * field in the host-returned Version Response Message. And, with
-	 * VERSION_WIN10_V5, we don't use msg->interrupt_page, but we tell
-	 * the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for
+	 * VERSION_WIN10_V5 and higher, we don't use msg->interrupt_page, but we
+	 * tell the host explicitly that we still use VMBUS_MESSAGE_SINT(2) for
 	 * compatibility.
 	 *
 	 * On old hosts, we should always use VMBUS_MESSAGE_CONNECTION_ID (1).
@@ -169,8 +171,8 @@ int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version)
  */
 int vmbus_connect(void)
 {
-	int ret = 0;
 	struct vmbus_channel_msginfo *msginfo = NULL;
+	int i, ret = 0;
 	__u32 version;
 
 	/* Initialize the vmbus connection */
@@ -206,7 +208,7 @@ int vmbus_connect(void)
 	 * abstraction stuff
 	 */
 	vmbus_connection.int_page =
-	(void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 0);
+	(void *)hv_alloc_hyperv_zeroed_page();
 	if (vmbus_connection.int_page == NULL) {
 		ret = -ENOMEM;
 		goto cleanup;
@@ -215,14 +217,14 @@ int vmbus_connect(void)
 	vmbus_connection.recv_int_page = vmbus_connection.int_page;
 	vmbus_connection.send_int_page =
 		(void *)((unsigned long)vmbus_connection.int_page +
-			(PAGE_SIZE >> 1));
+			(HV_HYP_PAGE_SIZE >> 1));
 
 	/*
 	 * Setup the monitor notification facility. The 1st page for
 	 * parent->child and the 2nd page for child->parent
 	 */
-	vmbus_connection.monitor_pages[0] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
-	vmbus_connection.monitor_pages[1] = (void *)__get_free_pages((GFP_KERNEL|__GFP_ZERO), 0);
+	vmbus_connection.monitor_pages[0] = (void *)hv_alloc_hyperv_zeroed_page();
+	vmbus_connection.monitor_pages[1] = (void *)hv_alloc_hyperv_zeroed_page();
 	if ((vmbus_connection.monitor_pages[0] == NULL) ||
 	    (vmbus_connection.monitor_pages[1] == NULL)) {
 		ret = -ENOMEM;
@@ -244,21 +246,21 @@ int vmbus_connect(void)
 	 * version.
 	 */
 
-	version = VERSION_CURRENT;
+	for (i = 0; ; i++) {
+		if (i == ARRAY_SIZE(vmbus_versions))
+			goto cleanup;
+
+		version = vmbus_versions[i];
+		if (version > max_version)
+			continue;
 
-	do {
 		ret = vmbus_negotiate_version(msginfo, version);
 		if (ret == -ETIMEDOUT)
 			goto cleanup;
 
 		if (vmbus_connection.conn_state == CONNECTED)
 			break;
-
-		version = vmbus_get_next_version(version);
-	} while (version != VERSION_INVAL);
-
-	if (version == VERSION_INVAL)
-		goto cleanup;
+	}
 
 	vmbus_proto_version = version;
 	pr_info("Vmbus version:%d.%d\n",
@@ -295,12 +297,12 @@ void vmbus_disconnect(void)
 		destroy_workqueue(vmbus_connection.work_queue);
 
 	if (vmbus_connection.int_page) {
-		free_pages((unsigned long)vmbus_connection.int_page, 0);
+		hv_free_hyperv_page((unsigned long)vmbus_connection.int_page);
 		vmbus_connection.int_page = NULL;
 	}
 
-	free_pages((unsigned long)vmbus_connection.monitor_pages[0], 0);
-	free_pages((unsigned long)vmbus_connection.monitor_pages[1], 0);
+	hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[0]);
+	hv_free_hyperv_page((unsigned long)vmbus_connection.monitor_pages[1]);
 	vmbus_connection.monitor_pages[0] = NULL;
 	vmbus_connection.monitor_pages[1] = NULL;
 }
@@ -361,6 +363,7 @@ void vmbus_on_event(unsigned long data)
 
 	trace_vmbus_on_event(channel);
 
+	hv_debug_delay_test(channel, INTERRUPT_DELAY);
 	do {
 		void (*callback_fn)(void *);
 
@@ -413,7 +416,7 @@ int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep)
 		case HV_STATUS_INVALID_CONNECTION_ID:
 			/*
 			 * See vmbus_negotiate_version(): VMBus protocol 5.0
-			 * requires that we must use
+			 * and higher require that we must use
 			 * VMBUS_MESSAGE_CONNECTION_ID_4 for the Initiate
 			 * Contact message, but on old hosts that only
 			 * support VMBus protocol 4.0 or lower, here we get

drivers/hv/hv_balloon.c

@@ -23,6 +23,9 @@
 #include <linux/percpu_counter.h>
 
 #include <linux/hyperv.h>
+#include <asm/hyperv-tlfs.h>
+
+#include <asm/mshyperv.h>
 
 #define CREATE_TRACE_POINTS
 #include "hv_trace_balloon.h"
@@ -341,8 +344,6 @@ struct dm_unballoon_response {
  *
  * mem_range: Memory range to hot add.
  *
- * On Linux we currently don't support this since we cannot hot add
- * arbitrary granularity of memory.
  */
 
 struct dm_hot_add {
@@ -457,6 +458,7 @@ struct hot_add_wrk {
 	struct work_struct wrk;
 };
 
+static bool allow_hibernation;
 static bool hot_add = true;
 static bool do_hot_add;
 /*
@@ -477,7 +479,7 @@ module_param(pressure_report_delay, uint, (S_IRUGO | S_IWUSR));
 MODULE_PARM_DESC(pressure_report_delay, "Delay in secs in reporting pressure");
 static atomic_t trans_id = ATOMIC_INIT(0);
 
-static int dm_ring_size = (5 * PAGE_SIZE);
+static int dm_ring_size = 20 * 1024;
 
 /*
  * Driver specific state.
@@ -493,10 +495,10 @@ enum hv_dm_state {
 };
 
 
-static __u8 recv_buffer[PAGE_SIZE];
-static __u8 balloon_up_send_buffer[PAGE_SIZE];
-#define PAGES_IN_2M	512
-#define HA_CHUNK (32 * 1024)
+static __u8 recv_buffer[HV_HYP_PAGE_SIZE];
+static __u8 balloon_up_send_buffer[HV_HYP_PAGE_SIZE];
+#define PAGES_IN_2M (2 * 1024 * 1024 / PAGE_SIZE)
+#define HA_CHUNK (128 * 1024 * 1024 / PAGE_SIZE)
 
 struct hv_dynmem_device {
 	struct hv_device *dev;
@@ -1053,8 +1055,12 @@ static void hot_add_req(struct work_struct *dummy)
 	else
 		resp.result = 0;
 
-	if (!do_hot_add || (resp.page_count == 0))
+	if (!do_hot_add || resp.page_count == 0) {
+		if (!allow_hibernation)
 			pr_err("Memory hot add failed\n");
+		else
+			pr_info("Ignore hot-add request!\n");
+	}
 
 	dm->state = DM_INITIALIZED;
 	resp.hdr.trans_id = atomic_inc_return(&trans_id);
@@ -1076,7 +1082,7 @@ static void process_info(struct hv_dynmem_device *dm, struct dm_info_msg *msg)
 			__u64 *max_page_count = (__u64 *)&info_hdr[1];
 
 			pr_info("Max. dynamic memory size: %llu MB\n",
-				(*max_page_count) >> (20 - PAGE_SHIFT));
+				(*max_page_count) >> (20 - HV_HYP_PAGE_SHIFT));
 		}
 
 		break;
@@ -1218,7 +1224,7 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm,
 
 	for (i = 0; (i * alloc_unit) < num_pages; i++) {
 		if (bl_resp->hdr.size + sizeof(union dm_mem_page_range) >
-			PAGE_SIZE)
+			HV_HYP_PAGE_SIZE)
 			return i * alloc_unit;
 
 		/*
@@ -1274,9 +1280,9 @@ static void balloon_up(struct work_struct *dummy)
 
 	/*
 	 * We will attempt 2M allocations. However, if we fail to
-	 * allocate 2M chunks, we will go back to 4k allocations.
+	 * allocate 2M chunks, we will go back to PAGE_SIZE allocations.
 	 */
-	alloc_unit = 512;
+	alloc_unit = PAGES_IN_2M;
 
 	avail_pages = si_mem_available();
 	floor = compute_balloon_floor();
@@ -1292,7 +1298,7 @@ static void balloon_up(struct work_struct *dummy)
 	}
 
 	while (!done) {
-		memset(balloon_up_send_buffer, 0, PAGE_SIZE);
+		memset(balloon_up_send_buffer, 0, HV_HYP_PAGE_SIZE);
 		bl_resp = (struct dm_balloon_response *)balloon_up_send_buffer;
 		bl_resp->hdr.type = DM_BALLOON_RESPONSE;
 		bl_resp->hdr.size = sizeof(struct dm_balloon_response);
@@ -1491,7 +1497,7 @@ static void balloon_onchannelcallback(void *context)
 
 	memset(recv_buffer, 0, sizeof(recv_buffer));
 	vmbus_recvpacket(dev->channel, recv_buffer,
-			 PAGE_SIZE, &recvlen, &requestid);
+			 HV_HYP_PAGE_SIZE, &recvlen, &requestid);
 
 	if (recvlen > 0) {
 		dm_msg = (struct dm_message *)recv_buffer;
@@ -1509,6 +1515,11 @@ static void balloon_onchannelcallback(void *context)
 			break;
 
 		case DM_BALLOON_REQUEST:
+			if (allow_hibernation) {
+				pr_info("Ignore balloon-up request!\n");
+				break;
+			}
+
 			if (dm->state == DM_BALLOON_UP)
 				pr_warn("Currently ballooning\n");
 			bal_msg = (struct dm_balloon *)recv_buffer;
@@ -1518,6 +1529,11 @@ static void balloon_onchannelcallback(void *context)
 			break;
 
 		case DM_UNBALLOON_REQUEST:
+			if (allow_hibernation) {
+				pr_info("Ignore balloon-down request!\n");
+				break;
+			}
+
 			dm->state = DM_BALLOON_DOWN;
 			balloon_down(dm,
 				 (struct dm_unballoon_request *)recv_buffer);
@@ -1623,6 +1639,11 @@ static int balloon_connect_vsp(struct hv_device *dev)
 	cap_msg.hdr.size = sizeof(struct dm_capabilities);
 	cap_msg.hdr.trans_id = atomic_inc_return(&trans_id);
 
+	/*
+	 * When hibernation (i.e. virtual ACPI S4 state) is enabled, the host
+	 * currently still requires the bits to be set, so we have to add code
+	 * to fail the host's hot-add and balloon up/down requests, if any.
+	 */
 	cap_msg.caps.cap_bits.balloon = 1;
 	cap_msg.caps.cap_bits.hot_add = 1;
 
@@ -1672,6 +1693,10 @@ static int balloon_probe(struct hv_device *dev,
 {
 	int ret;
 
+	allow_hibernation = hv_is_hibernation_supported();
+	if (allow_hibernation)
+		hot_add = false;
+
 #ifdef CONFIG_MEMORY_HOTPLUG
 	do_hot_add = hot_add;
 #else
@@ -1711,6 +1736,8 @@ static int balloon_probe(struct hv_device *dev,
 	return 0;
 
 probe_error:
+	dm_device.state = DM_INIT_ERROR;
+	dm_device.thread  = NULL;
 	vmbus_close(dev->channel);
 #ifdef CONFIG_MEMORY_HOTPLUG
 	unregister_memory_notifier(&hv_memory_nb);
@@ -1752,6 +1779,59 @@ static int balloon_remove(struct hv_device *dev)
 	return 0;
 }
 
+static int balloon_suspend(struct hv_device *hv_dev)
+{
+	struct hv_dynmem_device *dm = hv_get_drvdata(hv_dev);
+
+	tasklet_disable(&hv_dev->channel->callback_event);
+
+	cancel_work_sync(&dm->balloon_wrk.wrk);
+	cancel_work_sync(&dm->ha_wrk.wrk);
+
+	if (dm->thread) {
+		kthread_stop(dm->thread);
+		dm->thread = NULL;
+		vmbus_close(hv_dev->channel);
+	}
+
+	tasklet_enable(&hv_dev->channel->callback_event);
+
+	return 0;
+
+}
+
+static int balloon_resume(struct hv_device *dev)
+{
+	int ret;
+
+	dm_device.state = DM_INITIALIZING;
+
+	ret = balloon_connect_vsp(dev);
+
+	if (ret != 0)
+		goto out;
+
+	dm_device.thread =
+		 kthread_run(dm_thread_func, &dm_device, "hv_balloon");
+	if (IS_ERR(dm_device.thread)) {
+		ret = PTR_ERR(dm_device.thread);
+		dm_device.thread = NULL;
+		goto close_channel;
+	}
+
+	dm_device.state = DM_INITIALIZED;
+	return 0;
+close_channel:
+	vmbus_close(dev->channel);
+out:
+	dm_device.state = DM_INIT_ERROR;
+#ifdef CONFIG_MEMORY_HOTPLUG
+	unregister_memory_notifier(&hv_memory_nb);
+	restore_online_page_callback(&hv_online_page);
+#endif
+	return ret;
+}
+
 static const struct hv_vmbus_device_id id_table[] = {
 	/* Dynamic Memory Class ID */
 	/* 525074DC-8985-46e2-8057-A307DC18A502 */
@@ -1766,6 +1846,8 @@ static  struct hv_driver balloon_drv = {
 	.id_table = id_table,
 	.probe =  balloon_probe,
 	.remove =  balloon_remove,
+	.suspend = balloon_suspend,
+	.resume = balloon_resume,
 	.driver = {
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},

drivers/hv/hv_debugfs.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Authors:
+ *   Branden Bonaby <brandonbonaby94@gmail.com>
+ */
+
+#include <linux/hyperv.h>
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+
+#include "hyperv_vmbus.h"
+
+struct dentry *hv_debug_root;
+
+static int hv_debugfs_delay_get(void *data, u64 *val)
+{
+	*val = *(u32 *)data;
+	return 0;
+}
+
+static int hv_debugfs_delay_set(void *data, u64 val)
+{
+	if (val > 1000)
+		return -EINVAL;
+	*(u32 *)data = val;
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_delay_fops, hv_debugfs_delay_get,
+			 hv_debugfs_delay_set, "%llu\n");
+
+static int hv_debugfs_state_get(void *data, u64 *val)
+{
+	*val = *(bool *)data;
+	return 0;
+}
+
+static int hv_debugfs_state_set(void *data, u64 val)
+{
+	if (val == 1)
+		*(bool *)data = true;
+	else if (val == 0)
+		*(bool *)data = false;
+	else
+		return -EINVAL;
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(hv_debugfs_state_fops, hv_debugfs_state_get,
+			 hv_debugfs_state_set, "%llu\n");
+
+/* Setup delay files to store test values */
+static int hv_debug_delay_files(struct hv_device *dev, struct dentry *root)
+{
+	struct vmbus_channel *channel = dev->channel;
+	char *buffer = "fuzz_test_buffer_interrupt_delay";
+	char *message = "fuzz_test_message_delay";
+	int *buffer_val = &channel->fuzz_testing_interrupt_delay;
+	int *message_val = &channel->fuzz_testing_message_delay;
+	struct dentry *buffer_file, *message_file;
+
+	buffer_file = debugfs_create_file(buffer, 0644, root,
+					  buffer_val,
+					  &hv_debugfs_delay_fops);
+	if (IS_ERR(buffer_file)) {
+		pr_debug("debugfs_hyperv: file %s not created\n", buffer);
+		return PTR_ERR(buffer_file);
+	}
+
+	message_file = debugfs_create_file(message, 0644, root,
+					   message_val,
+					   &hv_debugfs_delay_fops);
+	if (IS_ERR(message_file)) {
+		pr_debug("debugfs_hyperv: file %s not created\n", message);
+		return PTR_ERR(message_file);
+	}
+
+	return 0;
+}
+
+/* Setup test state value for vmbus device */
+static int hv_debug_set_test_state(struct hv_device *dev, struct dentry *root)
+{
+	struct vmbus_channel *channel = dev->channel;
+	bool *state = &channel->fuzz_testing_state;
+	char *status = "fuzz_test_state";
+	struct dentry *test_state;
+
+	test_state = debugfs_create_file(status, 0644, root,
+					 state,
+					 &hv_debugfs_state_fops);
+	if (IS_ERR(test_state)) {
+		pr_debug("debugfs_hyperv: file %s not created\n", status);
+		return PTR_ERR(test_state);
+	}
+
+	return 0;
+}
+
+/* Bind hv device to a dentry for debugfs */
+static void hv_debug_set_dir_dentry(struct hv_device *dev, struct dentry *root)
+{
+	if (hv_debug_root)
+		dev->debug_dir = root;
+}
+
+/* Create all test dentry's and names for fuzz testing */
+int hv_debug_add_dev_dir(struct hv_device *dev)
+{
+	const char *device = dev_name(&dev->device);
+	char *delay_name = "delay";
+	struct dentry *delay, *dev_root;
+	int ret;
+
+	if (!IS_ERR(hv_debug_root)) {
+		dev_root = debugfs_create_dir(device, hv_debug_root);
+		if (IS_ERR(dev_root)) {
+			pr_debug("debugfs_hyperv: hyperv/%s/ not created\n",
+				 device);
+			return PTR_ERR(dev_root);
+		}
+		hv_debug_set_test_state(dev, dev_root);
+		hv_debug_set_dir_dentry(dev, dev_root);
+		delay = debugfs_create_dir(delay_name, dev_root);
+
+		if (IS_ERR(delay)) {
+			pr_debug("debugfs_hyperv: hyperv/%s/%s/ not created\n",
+				 device, delay_name);
+			return PTR_ERR(delay);
+		}
+		ret = hv_debug_delay_files(dev, delay);
+
+		return ret;
+	}
+	pr_debug("debugfs_hyperv: hyperv/ not in root debugfs path\n");
+	return PTR_ERR(hv_debug_root);
+}
+
+/* Remove dentry associated with released hv device */
+void hv_debug_rm_dev_dir(struct hv_device *dev)
+{
+	if (!IS_ERR(hv_debug_root))
+		debugfs_remove_recursive(dev->debug_dir);
+}
+
+/* Remove all dentrys associated with vmbus testing */
+void hv_debug_rm_all_dir(void)
+{
+	debugfs_remove_recursive(hv_debug_root);
+}
+
+/* Delay buffer/message reads on a vmbus channel */
+void hv_debug_delay_test(struct vmbus_channel *channel, enum delay delay_type)
+{
+	struct vmbus_channel *test_channel =    channel->primary_channel ?
+						channel->primary_channel :
+						channel;
+	bool state = test_channel->fuzz_testing_state;
+
+	if (state) {
+		if (delay_type == 0)
+			udelay(test_channel->fuzz_testing_interrupt_delay);
+		else
+			udelay(test_channel->fuzz_testing_message_delay);
+	}
+}
+
+/* Initialize top dentry for vmbus testing */
+int hv_debug_init(void)
+{
+	hv_debug_root = debugfs_create_dir("hyperv", NULL);
+	if (IS_ERR(hv_debug_root)) {
+		pr_debug("debugfs_hyperv: hyperv/ not created\n");
+		return PTR_ERR(hv_debug_root);
+	}
+	return 0;
+}

drivers/hv/hv_fcopy.c

@@ -13,6 +13,7 @@
 #include <linux/workqueue.h>
 #include <linux/hyperv.h>
 #include <linux/sched.h>
+#include <asm/hyperv-tlfs.h>
 
 #include "hyperv_vmbus.h"
 #include "hv_utils_transport.h"
@@ -234,7 +235,7 @@ void hv_fcopy_onchannelcallback(void *context)
 	if (fcopy_transaction.state > HVUTIL_READY)
 		return;
 
-	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
+	vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen,
 			 &requestid);
 	if (recvlen <= 0)
 		return;

drivers/hv/hv_kvp.c

@@ -27,6 +27,7 @@
 #include <linux/connector.h>
 #include <linux/workqueue.h>
 #include <linux/hyperv.h>
+#include <asm/hyperv-tlfs.h>
 
 #include "hyperv_vmbus.h"
 #include "hv_utils_transport.h"
@@ -661,7 +662,7 @@ void hv_kvp_onchannelcallback(void *context)
 	if (kvp_transaction.state > HVUTIL_READY)
 		return;
 
-	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 4, &recvlen,
+	vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 4, &recvlen,
 			 &requestid);
 
 	if (recvlen > 0) {

drivers/hv/hv_snapshot.c

@@ -12,6 +12,7 @@
 #include <linux/connector.h>
 #include <linux/workqueue.h>
 #include <linux/hyperv.h>
+#include <asm/hyperv-tlfs.h>
 
 #include "hyperv_vmbus.h"
 #include "hv_utils_transport.h"
@@ -297,7 +298,7 @@ void hv_vss_onchannelcallback(void *context)
 	if (vss_transaction.state > HVUTIL_READY)
 		return;
 
-	vmbus_recvpacket(channel, recv_buffer, PAGE_SIZE * 2, &recvlen,
+	vmbus_recvpacket(channel, recv_buffer, HV_HYP_PAGE_SIZE * 2, &recvlen,
 			 &requestid);
 
 	if (recvlen > 0) {

drivers/hv/hv_util.c

@@ -136,7 +136,7 @@ static void shutdown_onchannelcallback(void *context)
 	struct icmsg_hdr *icmsghdrp;
 
 	vmbus_recvpacket(channel, shut_txf_buf,
-			 PAGE_SIZE, &recvlen, &requestid);
+			 HV_HYP_PAGE_SIZE, &recvlen, &requestid);
 
 	if (recvlen > 0) {
 		icmsghdrp = (struct icmsg_hdr *)&shut_txf_buf[
@@ -284,7 +284,7 @@ static void timesync_onchannelcallback(void *context)
 	u8 *time_txf_buf = util_timesynch.recv_buffer;
 
 	vmbus_recvpacket(channel, time_txf_buf,
-			 PAGE_SIZE, &recvlen, &requestid);
+			 HV_HYP_PAGE_SIZE, &recvlen, &requestid);
 
 	if (recvlen > 0) {
 		icmsghdrp = (struct icmsg_hdr *)&time_txf_buf[
@@ -346,7 +346,7 @@ static void heartbeat_onchannelcallback(void *context)
 	while (1) {
 
 		vmbus_recvpacket(channel, hbeat_txf_buf,
-				 PAGE_SIZE, &recvlen, &requestid);
+				 HV_HYP_PAGE_SIZE, &recvlen, &requestid);
 
 		if (!recvlen)
 			break;
@@ -390,7 +390,7 @@ static int util_probe(struct hv_device *dev,
 		(struct hv_util_service *)dev_id->driver_data;
 	int ret;
 
-	srv->recv_buffer = kmalloc(PAGE_SIZE * 4, GFP_KERNEL);
+	srv->recv_buffer = kmalloc(HV_HYP_PAGE_SIZE * 4, GFP_KERNEL);
 	if (!srv->recv_buffer)
 		return -ENOMEM;
 	srv->channel = dev->channel;
@@ -413,8 +413,9 @@ static int util_probe(struct hv_device *dev,
 
 	hv_set_drvdata(dev, srv);
 
-	ret = vmbus_open(dev->channel, 4 * PAGE_SIZE, 4 * PAGE_SIZE, NULL, 0,
-			srv->util_cb, dev->channel);
+	ret = vmbus_open(dev->channel, 4 * HV_HYP_PAGE_SIZE,
+			 4 * HV_HYP_PAGE_SIZE, NULL, 0, srv->util_cb,
+			 dev->channel);
 	if (ret)
 		goto error;
 

drivers/hv/hyperv_vmbus.h

@@ -385,4 +385,35 @@ enum hvutil_device_state {
 	HVUTIL_DEVICE_DYING,     /* driver unload is in progress */
 };
 
+enum delay {
+	INTERRUPT_DELAY = 0,
+	MESSAGE_DELAY   = 1,
+};
+
+#ifdef CONFIG_HYPERV_TESTING
+
+int hv_debug_add_dev_dir(struct hv_device *dev);
+void hv_debug_rm_dev_dir(struct hv_device *dev);
+void hv_debug_rm_all_dir(void);
+int hv_debug_init(void);
+void hv_debug_delay_test(struct vmbus_channel *channel, enum delay delay_type);
+
+#else /* CONFIG_HYPERV_TESTING */
+
+static inline void hv_debug_rm_dev_dir(struct hv_device *dev) {};
+static inline void hv_debug_rm_all_dir(void) {};
+static inline void hv_debug_delay_test(struct vmbus_channel *channel,
+				       enum delay delay_type) {};
+static inline int hv_debug_init(void)
+{
+	return -1;
+}
+
+static inline int hv_debug_add_dev_dir(struct hv_device *dev)
+{
+	return -1;
+}
+
+#endif /* CONFIG_HYPERV_TESTING */
+
 #endif /* _HYPERV_VMBUS_H */

drivers/hv/ring_buffer.c

@@ -396,6 +396,7 @@ struct vmpacket_descriptor *hv_pkt_iter_first(struct vmbus_channel *channel)
 	struct hv_ring_buffer_info *rbi = &channel->inbound;
 	struct vmpacket_descriptor *desc;
 
+	hv_debug_delay_test(channel, MESSAGE_DELAY);
 	if (hv_pkt_iter_avail(rbi) < sizeof(struct vmpacket_descriptor))
 		return NULL;
 
@@ -421,6 +422,7 @@ __hv_pkt_iter_next(struct vmbus_channel *channel,
 	u32 packetlen = desc->len8 << 3;
 	u32 dsize = rbi->ring_datasize;
 
+	hv_debug_delay_test(channel, MESSAGE_DELAY);
 	/* bump offset to next potential packet */
 	rbi->priv_read_index += packetlen + VMBUS_PKT_TRAILER;
 	if (rbi->priv_read_index >= dsize)

drivers/hv/vmbus_drv.c

@@ -79,7 +79,7 @@ static struct notifier_block hyperv_panic_block = {
 static const char *fb_mmio_name = "fb_range";
 static struct resource *fb_mmio;
 static struct resource *hyperv_mmio;
-static DEFINE_SEMAPHORE(hyperv_mmio_lock);
+static DEFINE_MUTEX(hyperv_mmio_lock);
 
 static int vmbus_exists(void)
 {
@@ -960,6 +960,8 @@ static void vmbus_device_release(struct device *device)
 	struct hv_device *hv_dev = device_to_hv_device(device);
 	struct vmbus_channel *channel = hv_dev->channel;
 
+	hv_debug_rm_dev_dir(hv_dev);
+
 	mutex_lock(&vmbus_connection.channel_mutex);
 	hv_process_channel_removal(channel);
 	mutex_unlock(&vmbus_connection.channel_mutex);
@@ -1273,7 +1275,7 @@ static void hv_kmsg_dump(struct kmsg_dumper *dumper,
 	 * Write dump contents to the page. No need to synchronize; panic should
 	 * be single-threaded.
 	 */
-	kmsg_dump_get_buffer(dumper, true, hv_panic_page, PAGE_SIZE,
+	kmsg_dump_get_buffer(dumper, true, hv_panic_page, HV_HYP_PAGE_SIZE,
 			     &bytes_written);
 	if (bytes_written)
 		hyperv_report_panic_msg(panic_pa, bytes_written);
@@ -1373,7 +1375,7 @@ static int vmbus_bus_init(void)
 		 */
 		hv_get_crash_ctl(hyperv_crash_ctl);
 		if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
-			hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
+			hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
 			if (hv_panic_page) {
 				ret = kmsg_dump_register(&hv_kmsg_dumper);
 				if (ret)
@@ -1401,7 +1403,7 @@ static int vmbus_bus_init(void)
 	hv_remove_vmbus_irq();
 
 	bus_unregister(&hv_bus);
-	free_page((unsigned long)hv_panic_page);
+	hv_free_hyperv_page((unsigned long)hv_panic_page);
 	unregister_sysctl_table(hv_ctl_table_hdr);
 	hv_ctl_table_hdr = NULL;
 	return ret;
@@ -1809,6 +1811,7 @@ int vmbus_device_register(struct hv_device *child_device_obj)
 		pr_err("Unable to register primary channeln");
 		goto err_kset_unregister;
 	}
+	hv_debug_add_dev_dir(child_device_obj);
 
 	return 0;
 
@@ -2010,7 +2013,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 	int retval;
 
 	retval = -ENXIO;
-	down(&hyperv_mmio_lock);
+	mutex_lock(&hyperv_mmio_lock);
 
 	/*
 	 * If overlaps with frame buffers are allowed, then first attempt to
@@ -2057,7 +2060,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
 	}
 
 exit:
-	up(&hyperv_mmio_lock);
+	mutex_unlock(&hyperv_mmio_lock);
 	return retval;
 }
 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
@@ -2074,7 +2077,7 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size)
 {
 	struct resource *iter;
 
-	down(&hyperv_mmio_lock);
+	mutex_lock(&hyperv_mmio_lock);
 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
 		if ((iter->start >= start + size) || (iter->end <= start))
 			continue;
@@ -2082,7 +2085,7 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size)
 		__release_region(iter, start, size);
 	}
 	release_mem_region(start, size);
-	up(&hyperv_mmio_lock);
+	mutex_unlock(&hyperv_mmio_lock);
 
 }
 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
@@ -2215,8 +2218,7 @@ static int vmbus_bus_resume(struct device *dev)
 	 * We only use the 'vmbus_proto_version', which was in use before
 	 * hibernation, to re-negotiate with the host.
 	 */
-	if (vmbus_proto_version == VERSION_INVAL ||
-	    vmbus_proto_version == 0) {
+	if (!vmbus_proto_version) {
 		pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
 		return -EINVAL;
 	}
@@ -2303,7 +2305,7 @@ static void hv_crash_handler(struct pt_regs *regs)
 	vmbus_connection.conn_state = DISCONNECTED;
 	cpu = smp_processor_id();
 	hv_stimer_cleanup(cpu);
-	hv_synic_cleanup(cpu);
+	hv_synic_disable_regs(cpu);
 	hyperv_cleanup();
 };
 
@@ -2373,6 +2375,7 @@ static int __init hv_acpi_init(void)
 		ret = -ETIMEDOUT;
 		goto cleanup;
 	}
+	hv_debug_init();
 
 	ret = vmbus_bus_init();
 	if (ret)
@@ -2409,6 +2412,8 @@ static void __exit vmbus_exit(void)
 
 		tasklet_kill(&hv_cpu->msg_dpc);
 	}
+	hv_debug_rm_all_dir();
+
 	vmbus_free_channels();
 
 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {

drivers/iommu/Kconfig

@@ -467,7 +467,7 @@ config QCOM_IOMMU
 
 config HYPERV_IOMMU
 	bool "Hyper-V x2APIC IRQ Handling"
-	depends on HYPERV
+	depends on HYPERV && X86
 	select IOMMU_API
 	default HYPERV
 	help

drivers/net/hyperv/hyperv_net.h

@@ -955,6 +955,9 @@ struct net_device_context {
 	u32 vf_alloc;
 	/* Serial number of the VF to team with */
 	u32 vf_serial;
+
+	/* Used to temporarily save the config info across hibernation */
+	struct netvsc_device_info *saved_netvsc_dev_info;
 };
 
 /* Per channel data */

drivers/net/hyperv/netvsc_drv.c

@@ -2424,6 +2424,61 @@ static int netvsc_remove(struct hv_device *dev)
 	return 0;
 }
 
+static int netvsc_suspend(struct hv_device *dev)
+{
+	struct net_device_context *ndev_ctx;
+	struct net_device *vf_netdev, *net;
+	struct netvsc_device *nvdev;
+	int ret;
+
+	net = hv_get_drvdata(dev);
+
+	ndev_ctx = netdev_priv(net);
+	cancel_delayed_work_sync(&ndev_ctx->dwork);
+
+	rtnl_lock();
+
+	nvdev = rtnl_dereference(ndev_ctx->nvdev);
+	if (nvdev == NULL) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
+	if (vf_netdev)
+		netvsc_unregister_vf(vf_netdev);
+
+	/* Save the current config info */
+	ndev_ctx->saved_netvsc_dev_info = netvsc_devinfo_get(nvdev);
+
+	ret = netvsc_detach(net, nvdev);
+out:
+	rtnl_unlock();
+
+	return ret;
+}
+
+static int netvsc_resume(struct hv_device *dev)
+{
+	struct net_device *net = hv_get_drvdata(dev);
+	struct net_device_context *net_device_ctx;
+	struct netvsc_device_info *device_info;
+	int ret;
+
+	rtnl_lock();
+
+	net_device_ctx = netdev_priv(net);
+	device_info = net_device_ctx->saved_netvsc_dev_info;
+
+	ret = netvsc_attach(net, device_info);
+
+	rtnl_unlock();
+
+	kfree(device_info);
+	net_device_ctx->saved_netvsc_dev_info = NULL;
+
+	return ret;
+}
 static const struct hv_vmbus_device_id id_table[] = {
 	/* Network guid */
 	{ HV_NIC_GUID, },
@@ -2438,6 +2493,8 @@ static struct  hv_driver netvsc_drv = {
 	.id_table = id_table,
 	.probe = netvsc_probe,
 	.remove = netvsc_remove,
+	.suspend = netvsc_suspend,
+	.resume = netvsc_resume,
 	.driver = {
 		.probe_type = PROBE_FORCE_SYNCHRONOUS,
 	},

drivers/scsi/storvsc_drv.c

@@ -1727,6 +1727,13 @@ static const struct hv_vmbus_device_id id_table[] = {
 
 MODULE_DEVICE_TABLE(vmbus, id_table);
 
+static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
+
+static bool hv_dev_is_fc(struct hv_device *hv_dev)
+{
+	return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
+}
+
 static int storvsc_probe(struct hv_device *device,
 			const struct hv_vmbus_device_id *dev_id)
 {
@@ -1934,11 +1941,45 @@ static int storvsc_remove(struct hv_device *dev)
 	return 0;
 }
 
+static int storvsc_suspend(struct hv_device *hv_dev)
+{
+	struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
+	struct Scsi_Host *host = stor_device->host;
+	struct hv_host_device *host_dev = shost_priv(host);
+
+	storvsc_wait_to_drain(stor_device);
+
+	drain_workqueue(host_dev->handle_error_wq);
+
+	vmbus_close(hv_dev->channel);
+
+	memset(stor_device->stor_chns, 0,
+	       num_possible_cpus() * sizeof(void *));
+
+	kfree(stor_device->stor_chns);
+	stor_device->stor_chns = NULL;
+
+	cpumask_clear(&stor_device->alloced_cpus);
+
+	return 0;
+}
+
+static int storvsc_resume(struct hv_device *hv_dev)
+{
+	int ret;
+
+	ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
+				     hv_dev_is_fc(hv_dev));
+	return ret;
+}
+
 static struct hv_driver storvsc_drv = {
 	.name = KBUILD_MODNAME,
 	.id_table = id_table,
 	.probe = storvsc_probe,
 	.remove = storvsc_remove,
+	.suspend = storvsc_suspend,
+	.resume = storvsc_resume,
 	.driver = {
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},

drivers/video/fbdev/Kconfig

@@ -2214,6 +2214,7 @@ config FB_HYPERV
 	select FB_CFB_FILLRECT
 	select FB_CFB_COPYAREA
 	select FB_CFB_IMAGEBLIT
+	select FB_DEFERRED_IO
 	help
 	  This framebuffer driver supports Microsoft Hyper-V Synthetic Video.
 

drivers/video/fbdev/hyperv_fb.c

@@ -23,6 +23,14 @@
  *
  * Portrait orientation is also supported:
  *     For example: video=hyperv_fb:864x1152
+ *
+ * When a Windows 10 RS5+ host is used, the virtual machine screen
+ * resolution is obtained from the host. The "video=hyperv_fb" option is
+ * not needed, but still can be used to overwrite what the host specifies.
+ * The VM resolution on the host could be set by executing the powershell
+ * "set-vmvideo" command. For example
+ *     set-vmvideo -vmname name -horizontalresolution:1920 \
+ * -verticalresolution:1200 -resolutiontype single
  */
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -34,6 +42,7 @@
 #include <linux/fb.h>
 #include <linux/pci.h>
 #include <linux/efi.h>
+#include <linux/console.h>
 
 #include <linux/hyperv.h>
 
@@ -44,6 +53,10 @@
 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
 #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_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
@@ -82,16 +95,25 @@ enum synthvid_msg_type {
 	SYNTHVID_POINTER_SHAPE		= 8,
 	SYNTHVID_FEATURE_CHANGE		= 9,
 	SYNTHVID_DIRT			= 10,
+	SYNTHVID_RESOLUTION_REQUEST	= 13,
+	SYNTHVID_RESOLUTION_RESPONSE	= 14,
 
-	SYNTHVID_MAX			= 11
+	SYNTHVID_MAX			= 15
 };
 
+#define		SYNTHVID_EDID_BLOCK_SIZE	128
+#define		SYNTHVID_MAX_RESOLUTION_COUNT	64
+
+struct hvd_screen_info {
+	u16 width;
+	u16 height;
+} __packed;
+
 struct synthvid_msg_hdr {
 	u32 type;
 	u32 size;  /* size of this header + payload after this field*/
 } __packed;
 
-
 struct synthvid_version_req {
 	u32 version;
 } __packed;
@@ -102,6 +124,19 @@ struct synthvid_version_resp {
 	u8 max_video_outputs;
 } __packed;
 
+struct synthvid_supported_resolution_req {
+	u8 maximum_resolution_count;
+} __packed;
+
+struct synthvid_supported_resolution_resp {
+	u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
+	u8 resolution_count;
+	u8 default_resolution_index;
+	u8 is_standard;
+	struct hvd_screen_info
+		supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
+} __packed;
+
 struct synthvid_vram_location {
 	u64 user_ctx;
 	u8 is_vram_gpa_specified;
@@ -187,6 +222,8 @@ struct synthvid_msg {
 		struct synthvid_pointer_shape ptr_shape;
 		struct synthvid_feature_change feature_chg;
 		struct synthvid_dirt dirt;
+		struct synthvid_supported_resolution_req resolution_req;
+		struct synthvid_supported_resolution_resp resolution_resp;
 	};
 } __packed;
 
@@ -201,6 +238,7 @@ struct synthvid_msg {
 #define RING_BUFSIZE (256 * 1024)
 #define VSP_TIMEOUT (10 * HZ)
 #define HVFB_UPDATE_DELAY (HZ / 20)
+#define HVFB_ONDEMAND_THROTTLE (HZ / 20)
 
 struct hvfb_par {
 	struct fb_info *info;
@@ -211,6 +249,7 @@ struct hvfb_par {
 
 	struct delayed_work dwork;
 	bool update;
+	bool update_saved; /* The value of 'update' before hibernation */
 
 	u32 pseudo_palette[16];
 	u8 init_buf[MAX_VMBUS_PKT_SIZE];
@@ -220,12 +259,25 @@ struct hvfb_par {
 	bool synchronous_fb;
 
 	struct notifier_block hvfb_panic_nb;
+
+	/* Memory for deferred IO and frame buffer itself */
+	unsigned char *dio_vp;
+	unsigned char *mmio_vp;
+	unsigned long mmio_pp;
+
+	/* Dirty rectangle, protected by delayed_refresh_lock */
+	int x1, y1, x2, y2;
+	bool delayed_refresh;
+	spinlock_t delayed_refresh_lock;
 };
 
 static uint screen_width = HVFB_WIDTH;
 static uint screen_height = HVFB_HEIGHT;
+static uint screen_width_max = HVFB_WIDTH;
+static uint screen_height_max = HVFB_HEIGHT;
 static uint screen_depth;
 static uint screen_fb_size;
+static uint dio_fb_size; /* FB size for deferred IO */
 
 /* Send message to Hyper-V host */
 static inline int synthvid_send(struct hv_device *hdev,
@@ -312,28 +364,88 @@ static int synthvid_send_ptr(struct hv_device *hdev)
 }
 
 /* Send updated screen area (dirty rectangle) location to host */
-static int synthvid_update(struct fb_info *info)
+static int
+synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
 {
 	struct hv_device *hdev = device_to_hv_device(info->device);
 	struct synthvid_msg msg;
 
 	memset(&msg, 0, sizeof(struct synthvid_msg));
+	if (x2 == INT_MAX)
+		x2 = info->var.xres;
+	if (y2 == INT_MAX)
+		y2 = info->var.yres;
 
 	msg.vid_hdr.type = SYNTHVID_DIRT;
 	msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 		sizeof(struct synthvid_dirt);
 	msg.dirt.video_output = 0;
 	msg.dirt.dirt_count = 1;
-	msg.dirt.rect[0].x1 = 0;
-	msg.dirt.rect[0].y1 = 0;
-	msg.dirt.rect[0].x2 = info->var.xres;
-	msg.dirt.rect[0].y2 = info->var.yres;
+	msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
+	msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
+	msg.dirt.rect[0].x2 =
+		(x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
+	msg.dirt.rect[0].y2 =
+		(y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
 
 	synthvid_send(hdev, &msg);
 
 	return 0;
 }
 
+static void hvfb_docopy(struct hvfb_par *par,
+			unsigned long offset,
+			unsigned long size)
+{
+	if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
+	    size == 0 || offset >= dio_fb_size)
+		return;
+
+	if (offset + size > dio_fb_size)
+		size = dio_fb_size - offset;
+
+	memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
+}
+
+/* Deferred IO callback */
+static void synthvid_deferred_io(struct fb_info *p,
+				 struct list_head *pagelist)
+{
+	struct hvfb_par *par = p->par;
+	struct page *page;
+	unsigned long start, end;
+	int y1, y2, miny, maxy;
+
+	miny = INT_MAX;
+	maxy = 0;
+
+	/*
+	 * Merge dirty pages. It is possible that last page cross
+	 * over the end of frame buffer row yres. This is taken care of
+	 * in synthvid_update function by clamping the y2
+	 * value to yres.
+	 */
+	list_for_each_entry(page, pagelist, lru) {
+		start = page->index << PAGE_SHIFT;
+		end = start + PAGE_SIZE - 1;
+		y1 = start / p->fix.line_length;
+		y2 = end / p->fix.line_length;
+		miny = min_t(int, miny, y1);
+		maxy = max_t(int, maxy, y2);
+
+		/* Copy from dio space to mmio address */
+		if (par->fb_ready)
+			hvfb_docopy(par, start, PAGE_SIZE);
+	}
+
+	if (par->fb_ready && par->update)
+		synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
+}
+
+static struct fb_deferred_io synthvid_defio = {
+	.delay		= HZ / 20,
+	.deferred_io	= synthvid_deferred_io,
+};
 
 /*
  * Actions on received messages from host:
@@ -354,6 +466,7 @@ static void synthvid_recv_sub(struct hv_device *hdev)
 
 	/* Complete the wait event */
 	if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
+	    msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
 	    msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
 		memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
 		complete(&par->wait);
@@ -400,6 +513,17 @@ static void synthvid_receive(void *ctx)
 	} while (bytes_recvd > 0 && ret == 0);
 }
 
+/* Check if the ver1 version is equal or greater than ver2 */
+static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
+{
+	if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
+	    (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
+	     SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
+		return true;
+
+	return false;
+}
+
 /* Check synthetic video protocol version with the host */
 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
 {
@@ -428,6 +552,64 @@ static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
 	}
 
 	par->synthvid_version = ver;
+	pr_info("Synthvid Version major %d, minor %d\n",
+		SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
+
+out:
+	return ret;
+}
+
+/* Get current resolution from the host */
+static int synthvid_get_supported_resolution(struct hv_device *hdev)
+{
+	struct fb_info *info = hv_get_drvdata(hdev);
+	struct hvfb_par *par = info->par;
+	struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
+	int ret = 0;
+	unsigned long t;
+	u8 index;
+	int i;
+
+	memset(msg, 0, sizeof(struct synthvid_msg));
+	msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
+	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
+		sizeof(struct synthvid_supported_resolution_req);
+
+	msg->resolution_req.maximum_resolution_count =
+		SYNTHVID_MAX_RESOLUTION_COUNT;
+	synthvid_send(hdev, msg);
+
+	t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
+	if (!t) {
+		pr_err("Time out on waiting resolution response\n");
+			ret = -ETIMEDOUT;
+			goto out;
+	}
+
+	if (msg->resolution_resp.resolution_count == 0) {
+		pr_err("No supported resolutions\n");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	index = msg->resolution_resp.default_resolution_index;
+	if (index >= msg->resolution_resp.resolution_count) {
+		pr_err("Invalid resolution index: %d\n", index);
+		ret = -ENODEV;
+		goto out;
+	}
+
+	for (i = 0; i < msg->resolution_resp.resolution_count; i++) {
+		screen_width_max = max_t(unsigned int, screen_width_max,
+		    msg->resolution_resp.supported_resolution[i].width);
+		screen_height_max = max_t(unsigned int, screen_height_max,
+		    msg->resolution_resp.supported_resolution[i].height);
+	}
+
+	screen_width =
+		msg->resolution_resp.supported_resolution[index].width;
+	screen_height =
+		msg->resolution_resp.supported_resolution[index].height;
 
 out:
 	return ret;
@@ -448,11 +630,27 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
 	}
 
 	/* Negotiate the protocol version with host */
-	if (vmbus_proto_version == VERSION_WS2008 ||
-	    vmbus_proto_version == VERSION_WIN7)
-		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
-	else
+	switch (vmbus_proto_version) {
+	case VERSION_WIN10:
+	case VERSION_WIN10_V5:
+		ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
+		if (!ret)
+			break;
+		/* Fallthrough */
+	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);
+		break;
+	}
 
 	if (ret) {
 		pr_err("Synthetic video device version not accepted\n");
@@ -464,6 +662,12 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
 	else
 		screen_depth = SYNTHVID_DEPTH_WIN8;
 
+	if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
+		ret = synthvid_get_supported_resolution(hdev);
+		if (ret)
+			pr_info("Failed to get supported resolution from host, use default\n");
+	}
+
 	screen_fb_size = hdev->channel->offermsg.offer.
 				mmio_megabytes * 1024 * 1024;
 
@@ -488,7 +692,7 @@ static int synthvid_send_config(struct hv_device *hdev)
 	msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
 	msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
 		sizeof(struct synthvid_vram_location);
-	msg->vram.user_ctx = msg->vram.vram_gpa = info->fix.smem_start;
+	msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
 	msg->vram.is_vram_gpa_specified = 1;
 	synthvid_send(hdev, msg);
 
@@ -498,7 +702,7 @@ static int synthvid_send_config(struct hv_device *hdev)
 		ret = -ETIMEDOUT;
 		goto out;
 	}
-	if (msg->vram_ack.user_ctx != info->fix.smem_start) {
+	if (msg->vram_ack.user_ctx != par->mmio_pp) {
 		pr_err("Unable to set VRAM location\n");
 		ret = -ENODEV;
 		goto out;
@@ -515,19 +719,77 @@ static int synthvid_send_config(struct hv_device *hdev)
 
 /*
  * Delayed work callback:
- * It is called at HVFB_UPDATE_DELAY or longer time interval to process
- * screen updates. It is re-scheduled if further update is necessary.
+ * It is scheduled to call whenever update request is received and it has
+ * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
  */
 static void hvfb_update_work(struct work_struct *w)
 {
 	struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
 	struct fb_info *info = par->info;
+	unsigned long flags;
+	int x1, x2, y1, y2;
+	int j;
 
-	if (par->fb_ready)
-		synthvid_update(info);
+	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
+	/* Reset the request flag */
+	par->delayed_refresh = false;
 
-	if (par->update)
-		schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
+	/* Store the dirty rectangle to local variables */
+	x1 = par->x1;
+	x2 = par->x2;
+	y1 = par->y1;
+	y2 = par->y2;
+
+	/* Clear dirty rectangle */
+	par->x1 = par->y1 = INT_MAX;
+	par->x2 = par->y2 = 0;
+
+	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
+
+	if (x1 > info->var.xres || x2 > info->var.xres ||
+	    y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
+		return;
+
+	/* Copy the dirty rectangle to frame buffer memory */
+	for (j = y1; j < y2; j++) {
+		hvfb_docopy(par,
+			    j * info->fix.line_length +
+			    (x1 * screen_depth / 8),
+			    (x2 - x1) * screen_depth / 8);
+	}
+
+	/* Refresh */
+	if (par->fb_ready && par->update)
+		synthvid_update(info, x1, y1, x2, y2);
+}
+
+/*
+ * Control the on-demand refresh frequency. It schedules a delayed
+ * screen update if it has not yet.
+ */
+static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
+					   int x1, int y1, int w, int h)
+{
+	unsigned long flags;
+	int x2 = x1 + w;
+	int y2 = y1 + h;
+
+	spin_lock_irqsave(&par->delayed_refresh_lock, flags);
+
+	/* Merge dirty rectangle */
+	par->x1 = min_t(int, par->x1, x1);
+	par->y1 = min_t(int, par->y1, y1);
+	par->x2 = max_t(int, par->x2, x2);
+	par->y2 = max_t(int, par->y2, y2);
+
+	/* Schedule a delayed screen update if not yet */
+	if (par->delayed_refresh == false) {
+		schedule_delayed_work(&par->dwork,
+				      HVFB_ONDEMAND_THROTTLE);
+		par->delayed_refresh = true;
+	}
+
+	spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
 }
 
 static int hvfb_on_panic(struct notifier_block *nb,
@@ -539,7 +801,8 @@ static int hvfb_on_panic(struct notifier_block *nb,
 	par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
 	par->synchronous_fb = true;
 	info = par->info;
-	synthvid_update(info);
+	hvfb_docopy(par, 0, dio_fb_size);
+	synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
 
 	return NOTIFY_DONE;
 }
@@ -600,7 +863,10 @@ static void hvfb_cfb_fillrect(struct fb_info *p,
 
 	cfb_fillrect(p, rect);
 	if (par->synchronous_fb)
-		synthvid_update(p);
+		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
+	else
+		hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
+					       rect->width, rect->height);
 }
 
 static void hvfb_cfb_copyarea(struct fb_info *p,
@@ -610,7 +876,10 @@ static void hvfb_cfb_copyarea(struct fb_info *p,
 
 	cfb_copyarea(p, area);
 	if (par->synchronous_fb)
-		synthvid_update(p);
+		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
+	else
+		hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
+					       area->width, area->height);
 }
 
 static void hvfb_cfb_imageblit(struct fb_info *p,
@@ -620,7 +889,10 @@ static void hvfb_cfb_imageblit(struct fb_info *p,
 
 	cfb_imageblit(p, image);
 	if (par->synchronous_fb)
-		synthvid_update(p);
+		synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
+	else
+		hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
+					       image->width, image->height);
 }
 
 static struct fb_ops hvfb_ops = {
@@ -653,6 +925,8 @@ static void hvfb_get_option(struct fb_info *info)
 	}
 
 	if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
+	    (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
+	    (x > screen_width_max || y > screen_height_max)) ||
 	    (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
 	     x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
 	    (par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
@@ -677,6 +951,9 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 	resource_size_t pot_start, pot_end;
 	int ret;
 
+	dio_fb_size =
+		screen_width * screen_height * screen_depth / 8;
+
 	if (gen2vm) {
 		pot_start = 0;
 		pot_end = -1;
@@ -689,8 +966,12 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 		}
 
 		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
-		    pci_resource_len(pdev, 0) < screen_fb_size)
+		    pci_resource_len(pdev, 0) < screen_fb_size) {
+			pr_err("Resource not available or (0x%lx < 0x%lx)\n",
+			       (unsigned long) pci_resource_len(pdev, 0),
+			       (unsigned long) screen_fb_size);
 			goto err1;
+		}
 
 		pot_end = pci_resource_end(pdev, 0);
 		pot_start = pot_end - screen_fb_size + 1;
@@ -707,9 +988,14 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 	if (!fb_virt)
 		goto err2;
 
+	/* Allocate memory for deferred IO */
+	par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
+	if (par->dio_vp == NULL)
+		goto err3;
+
 	info->apertures = alloc_apertures(1);
 	if (!info->apertures)
-		goto err3;
+		goto err4;
 
 	if (gen2vm) {
 		info->apertures->ranges[0].base = screen_info.lfb_base;
@@ -721,16 +1007,23 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
 	}
 
+	/* Physical address of FB device */
+	par->mmio_pp = par->mem->start;
+	/* Virtual address of FB device */
+	par->mmio_vp = (unsigned char *) fb_virt;
+
 	info->fix.smem_start = par->mem->start;
-	info->fix.smem_len = screen_fb_size;
-	info->screen_base = fb_virt;
-	info->screen_size = screen_fb_size;
+	info->fix.smem_len = dio_fb_size;
+	info->screen_base = par->dio_vp;
+	info->screen_size = dio_fb_size;
 
 	if (!gen2vm)
 		pci_dev_put(pdev);
 
 	return 0;
 
+err4:
+	vfree(par->dio_vp);
 err3:
 	iounmap(fb_virt);
 err2:
@@ -748,6 +1041,7 @@ static void hvfb_putmem(struct fb_info *info)
 {
 	struct hvfb_par *par = info->par;
 
+	vfree(par->dio_vp);
 	iounmap(info->screen_base);
 	vmbus_free_mmio(par->mem->start, screen_fb_size);
 	par->mem = NULL;
@@ -771,6 +1065,11 @@ static int hvfb_probe(struct hv_device *hdev,
 	init_completion(&par->wait);
 	INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
 
+	par->delayed_refresh = false;
+	spin_lock_init(&par->delayed_refresh_lock);
+	par->x1 = par->y1 = INT_MAX;
+	par->x2 = par->y2 = 0;
+
 	/* Connect to VSP */
 	hv_set_drvdata(hdev, info);
 	ret = synthvid_connect_vsp(hdev);
@@ -779,17 +1078,16 @@ static int hvfb_probe(struct hv_device *hdev,
 		goto error1;
 	}
 
+	hvfb_get_option(info);
+	pr_info("Screen resolution: %dx%d, Color depth: %d\n",
+		screen_width, screen_height, screen_depth);
+
 	ret = hvfb_getmem(hdev, info);
 	if (ret) {
 		pr_err("No memory for framebuffer\n");
 		goto error2;
 	}
 
-	hvfb_get_option(info);
-	pr_info("Screen resolution: %dx%d, Color depth: %d\n",
-		screen_width, screen_height, screen_depth);
-
-
 	/* Set up fb_info */
 	info->flags = FBINFO_DEFAULT;
 
@@ -823,6 +1121,10 @@ static int hvfb_probe(struct hv_device *hdev,
 	info->fbops = &hvfb_ops;
 	info->pseudo_palette = par->pseudo_palette;
 
+	/* Initialize deferred IO */
+	info->fbdefio = &synthvid_defio;
+	fb_deferred_io_init(info);
+
 	/* Send config to host */
 	ret = synthvid_send_config(hdev);
 	if (ret)
@@ -844,6 +1146,7 @@ static int hvfb_probe(struct hv_device *hdev,
 	return 0;
 
 error:
+	fb_deferred_io_cleanup(info);
 	hvfb_putmem(info);
 error2:
 	vmbus_close(hdev->channel);
@@ -866,6 +1169,8 @@ static int hvfb_remove(struct hv_device *hdev)
 	par->update = false;
 	par->fb_ready = false;
 
+	fb_deferred_io_cleanup(info);
+
 	unregister_framebuffer(info);
 	cancel_delayed_work_sync(&par->dwork);
 
@@ -878,6 +1183,61 @@ static int hvfb_remove(struct hv_device *hdev)
 	return 0;
 }
 
+static int hvfb_suspend(struct hv_device *hdev)
+{
+	struct fb_info *info = hv_get_drvdata(hdev);
+	struct hvfb_par *par = info->par;
+
+	console_lock();
+
+	/* 1 means do suspend */
+	fb_set_suspend(info, 1);
+
+	cancel_delayed_work_sync(&par->dwork);
+
+	par->update_saved = par->update;
+	par->update = false;
+	par->fb_ready = false;
+
+	vmbus_close(hdev->channel);
+
+	console_unlock();
+
+	return 0;
+}
+
+static int hvfb_resume(struct hv_device *hdev)
+{
+	struct fb_info *info = hv_get_drvdata(hdev);
+	struct hvfb_par *par = info->par;
+	int ret;
+
+	console_lock();
+
+	ret = synthvid_connect_vsp(hdev);
+	if (ret != 0)
+		goto out;
+
+	ret = synthvid_send_config(hdev);
+	if (ret != 0) {
+		vmbus_close(hdev->channel);
+		goto out;
+	}
+
+	par->fb_ready = true;
+	par->update = par->update_saved;
+
+	schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
+
+	/* 0 means do resume */
+	fb_set_suspend(info, 0);
+
+out:
+	console_unlock();
+
+	return ret;
+}
+
 
 static const struct pci_device_id pci_stub_id_table[] = {
 	{
@@ -901,6 +1261,8 @@ static struct hv_driver hvfb_drv = {
 	.id_table = id_table,
 	.probe = hvfb_probe,
 	.remove = hvfb_remove,
+	.suspend = hvfb_suspend,
+	.resume = hvfb_resume,
 	.driver = {
 		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},

include/asm-generic/mshyperv.h

@@ -166,10 +166,12 @@ static inline int cpumask_to_vpset(struct hv_vpset *vpset,
 void hyperv_report_panic(struct pt_regs *regs, long err);
 void hyperv_report_panic_msg(phys_addr_t pa, size_t size);
 bool hv_is_hyperv_initialized(void);
+bool hv_is_hibernation_supported(void);
 void hyperv_cleanup(void);
 void hv_setup_sched_clock(void *sched_clock);
 #else /* CONFIG_HYPERV */
 static inline bool hv_is_hyperv_initialized(void) { return false; }
+static inline bool hv_is_hibernation_supported(void) { return false; }
 static inline void hyperv_cleanup(void) {}
 #endif /* CONFIG_HYPERV */
 

include/linux/hyperv.h

@@ -182,7 +182,10 @@ static inline u32 hv_get_avail_to_write_percent(
  * 2 . 4  (Windows 8)
  * 3 . 0  (Windows 8 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)
  */
 
 #define VERSION_WS2008  ((0 << 16) | (13))
@@ -190,11 +193,10 @@ static inline u32 hv_get_avail_to_write_percent(
 #define VERSION_WIN8    ((2 << 16) | (4))
 #define VERSION_WIN8_1    ((3 << 16) | (0))
 #define VERSION_WIN10 ((4 << 16) | (0))
+#define VERSION_WIN10_V4_1 ((4 << 16) | (1))
 #define VERSION_WIN10_V5 ((5 << 16) | (0))
-
-#define VERSION_INVAL -1
-
-#define VERSION_CURRENT VERSION_WIN10_V5
+#define VERSION_WIN10_V5_1 ((5 << 16) | (1))
+#define VERSION_WIN10_V5_2 ((5 << 16) | (2))
 
 /* Make maximum size of pipe payload of 16K */
 #define MAX_PIPE_DATA_PAYLOAD		(sizeof(u8) * 16384)
@@ -932,6 +934,21 @@ struct vmbus_channel {
 	 * full outbound ring buffer.
 	 */
 	u64 out_full_first;
+
+	/* enabling/disabling fuzz testing on the channel (default is false)*/
+	bool fuzz_testing_state;
+
+	/*
+	 * Interrupt delay will delay the guest from emptying the ring buffer
+	 * for a specific amount of time. The delay is in microseconds and will
+	 * be between 1 to a maximum of 1000, its default is 0 (no delay).
+	 * The  Message delay will delay guest reading on a per message basis
+	 * in microseconds between 1 to 1000 with the default being 0
+	 * (no delay).
+	 */
+	u32 fuzz_testing_interrupt_delay;
+	u32 fuzz_testing_message_delay;
+
 };
 
 static inline bool is_hvsock_channel(const struct vmbus_channel *c)
@@ -1180,6 +1197,10 @@ struct hv_device {
 
 	struct vmbus_channel *channel;
 	struct kset	     *channels_kset;
+
+	/* place holder to keep track of the dir for hv device in debugfs */
+	struct dentry *debug_dir;
+
 };
 
 

lib/Kconfig.debug

@@ -2167,4 +2167,11 @@ config IO_STRICT_DEVMEM
 
 source "arch/$(SRCARCH)/Kconfig.debug"
 
+config HYPERV_TESTING
+	bool "Microsoft Hyper-V driver testing"
+	default n
+	depends on HYPERV && DEBUG_FS
+	help
+	  Select this option to enable Hyper-V vmbus testing.
+
 endmenu # Kernel hacking

net/vmw_vsock/hyperv_transport.c

@@ -922,6 +922,24 @@ static int hvs_remove(struct hv_device *hdev)
 	return 0;
 }
 
+/* hv_sock connections can not persist across hibernation, and all the hv_sock
+ * channels are forced to be rescinded before hibernation: see
+ * vmbus_bus_suspend(). Here the dummy hvs_suspend() and hvs_resume()
+ * are only needed because hibernation requires that every vmbus device's
+ * driver should have a .suspend and .resume callback: see vmbus_suspend().
+ */
+static int hvs_suspend(struct hv_device *hv_dev)
+{
+	/* Dummy */
+	return 0;
+}
+
+static int hvs_resume(struct hv_device *dev)
+{
+	/* Dummy */
+	return 0;
+}
+
 /* This isn't really used. See vmbus_match() and vmbus_probe() */
 static const struct hv_vmbus_device_id id_table[] = {
 	{},
@@ -933,6 +951,8 @@ static struct hv_driver hvs_drv = {
 	.id_table	= id_table,
 	.probe		= hvs_probe,
 	.remove		= hvs_remove,
+	.suspend	= hvs_suspend,
+	.resume		= hvs_resume,
 };
 
 static int __init hvs_init(void)

tools/hv/vmbus_testing

+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0
+#
+# Program to allow users to fuzz test Hyper-V drivers
+# by interfacing with Hyper-V debugfs attributes.
+# Current test methods available:
+#       1. delay testing
+#
+# Current file/directory structure of hyper-V debugfs:
+#       /sys/kernel/debug/hyperv/UUID
+#       /sys/kernel/debug/hyperv/UUID/<test-state filename>
+#       /sys/kernel/debug/hyperv/UUID/<test-method sub-directory>
+#
+# author: Branden Bonaby <brandonbonaby94@gmail.com>
+
+import os
+import cmd
+import argparse
+import glob
+from argparse import RawDescriptionHelpFormatter
+from argparse import RawTextHelpFormatter
+from enum import Enum
+
+# Do not change unless, you change the debugfs attributes
+# in /drivers/hv/debugfs.c. All fuzz testing
+# attributes will start with "fuzz_test".
+
+# debugfs path for hyperv must exist before proceeding
+debugfs_hyperv_path = "/sys/kernel/debug/hyperv"
+if not os.path.isdir(debugfs_hyperv_path):
+        print("{} doesn't exist/check permissions".format(debugfs_hyperv_path))
+        exit(-1)
+
+class dev_state(Enum):
+        off = 0
+        on = 1
+
+# File names, that correspond to the files created in
+# /drivers/hv/debugfs.c
+class f_names(Enum):
+        state_f = "fuzz_test_state"
+        buff_f =  "fuzz_test_buffer_interrupt_delay"
+        mess_f =  "fuzz_test_message_delay"
+
+# Both single_actions and all_actions are used
+# for error checking and to allow for some subparser
+# names to be abbreviated. Do not abbreviate the
+# test method names, as it will become less intuitive
+# as to what the user can do. If you do decide to
+# abbreviate the test method name, make sure the main
+# function reflects this change.
+
+all_actions = [
+        "disable_all",
+        "D",
+        "enable_all",
+        "view_all",
+        "V"
+]
+
+single_actions = [
+        "disable_single",
+        "d",
+        "enable_single",
+        "view_single",
+        "v"
+]
+
+def main():
+
+        file_map = recursive_file_lookup(debugfs_hyperv_path, dict())
+        args = parse_args()
+        if (not args.action):
+                print ("Error, no options selected...exiting")
+                exit(-1)
+        arg_set = { k for (k,v) in vars(args).items() if v and k != "action" }
+        arg_set.add(args.action)
+        path = args.path if "path" in arg_set else None
+        if (path and path[-1] == "/"):
+                path = path[:-1]
+        validate_args_path(path, arg_set, file_map)
+        if (path and "enable_single" in arg_set):
+            state_path = locate_state(path, file_map)
+            set_test_state(state_path, dev_state.on.value, args.quiet)
+
+        # Use subparsers as the key for different actions
+        if ("delay" in arg_set):
+                validate_delay_values(args.delay_time)
+                if (args.enable_all):
+                        set_delay_all_devices(file_map, args.delay_time,
+                                              args.quiet)
+                else:
+                        set_delay_values(path, file_map, args.delay_time,
+                                         args.quiet)
+        elif ("disable_all" in arg_set or "D" in arg_set):
+                disable_all_testing(file_map)
+        elif ("disable_single" in arg_set or "d" in arg_set):
+                disable_testing_single_device(path, file_map)
+        elif ("view_all" in arg_set or "V" in arg_set):
+                get_all_devices_test_status(file_map)
+        elif ("view_single" in arg_set or  "v" in arg_set):
+                get_device_test_values(path, file_map)
+
+# Get the state location
+def locate_state(device, file_map):
+        return file_map[device][f_names.state_f.value]
+
+# Validate delay values to make sure they are acceptable to
+# enable delays on a device
+def validate_delay_values(delay):
+
+        if (delay[0]  == -1 and delay[1] == -1):
+                print("\nError, At least 1 value must be greater than 0")
+                exit(-1)
+        for i in delay:
+                if (i < -1 or i == 0 or i > 1000):
+                        print("\nError, Values must be  equal to -1 "
+                              "or be > 0 and <= 1000")
+                        exit(-1)
+
+# Validate argument path
+def validate_args_path(path, arg_set, file_map):
+
+        if (not path and any(element in arg_set for element in single_actions)):
+                print("Error, path (-p) REQUIRED for the specified option. "
+                      "Use (-h) to check usage.")
+                exit(-1)
+        elif (path and any(item in arg_set for item in all_actions)):
+                print("Error, path (-p) NOT REQUIRED for the specified option. "
+                      "Use (-h) to check usage." )
+                exit(-1)
+        elif (path not in file_map and any(item in arg_set
+                                           for item in single_actions)):
+                print("Error, path '{}' not a valid vmbus device".format(path))
+                exit(-1)
+
+# display Testing status of single device
+def get_device_test_values(path, file_map):
+
+        for name in file_map[path]:
+                file_location = file_map[path][name]
+                print( name + " = " + str(read_test_files(file_location)))
+
+# Create a map of the vmbus devices and their associated files
+# [key=device, value = [key = filename, value = file path]]
+def recursive_file_lookup(path, file_map):
+
+        for f_path in glob.iglob(path + '**/*'):
+                if (os.path.isfile(f_path)):
+                        if (f_path.rsplit("/",2)[0] == debugfs_hyperv_path):
+                                directory = f_path.rsplit("/",1)[0]
+                        else:
+                                directory = f_path.rsplit("/",2)[0]
+                        f_name = f_path.split("/")[-1]
+                        if (file_map.get(directory)):
+                                file_map[directory].update({f_name:f_path})
+                        else:
+                                file_map[directory] = {f_name:f_path}
+                elif (os.path.isdir(f_path)):
+                        recursive_file_lookup(f_path,file_map)
+        return file_map
+
+# display Testing state of devices
+def get_all_devices_test_status(file_map):
+
+        for device in file_map:
+                if (get_test_state(locate_state(device, file_map)) is 1):
+                        print("Testing = ON for: {}"
+                              .format(device.split("/")[5]))
+                else:
+                        print("Testing = OFF for: {}"
+                              .format(device.split("/")[5]))
+
+# read the vmbus device files, path must be absolute path before calling
+def read_test_files(path):
+        try:
+                with open(path,"r") as f:
+                        file_value = f.readline().strip()
+                return int(file_value)
+
+        except IOError as e:
+                errno, strerror = e.args
+                print("I/O error({0}): {1} on file {2}"
+                      .format(errno, strerror, path))
+                exit(-1)
+        except ValueError:
+                print ("Element to int conversion error in: \n{}".format(path))
+                exit(-1)
+
+# writing to vmbus device files, path must be absolute path before calling
+def write_test_files(path, value):
+
+        try:
+                with open(path,"w") as f:
+                        f.write("{}".format(value))
+        except IOError as e:
+                errno, strerror = e.args
+                print("I/O error({0}): {1} on file {2}"
+                      .format(errno, strerror, path))
+                exit(-1)
+
+# set testing state of device
+def set_test_state(state_path, state_value, quiet):
+
+        write_test_files(state_path, state_value)
+        if (get_test_state(state_path) is 1):
+                if (not quiet):
+                        print("Testing = ON for device: {}"
+                              .format(state_path.split("/")[5]))
+        else:
+                if (not quiet):
+                        print("Testing = OFF for device: {}"
+                              .format(state_path.split("/")[5]))
+
+# get testing state of device
+def get_test_state(state_path):
+        #state == 1 - test = ON
+        #state == 0 - test = OFF
+        return  read_test_files(state_path)
+
+# write 1 - 1000 microseconds, into a single device using the
+# fuzz_test_buffer_interrupt_delay and fuzz_test_message_delay
+# debugfs attributes
+def set_delay_values(device, file_map, delay_length, quiet):
+
+        try:
+                interrupt = file_map[device][f_names.buff_f.value]
+                message = file_map[device][f_names.mess_f.value]
+
+                # delay[0]- buffer interrupt delay, delay[1]- message delay
+                if (delay_length[0] >= 0 and delay_length[0] <= 1000):
+                        write_test_files(interrupt, delay_length[0])
+                if (delay_length[1] >= 0 and delay_length[1] <= 1000):
+                        write_test_files(message, delay_length[1])
+                if (not quiet):
+                        print("Buffer delay testing = {} for: {}"
+                              .format(read_test_files(interrupt),
+                                      interrupt.split("/")[5]))
+                        print("Message delay testing = {} for: {}"
+                              .format(read_test_files(message),
+                                      message.split("/")[5]))
+        except IOError as e:
+                errno, strerror = e.args
+                print("I/O error({0}): {1} on files {2}{3}"
+                      .format(errno, strerror, interrupt, message))
+                exit(-1)
+
+# enabling delay testing on all devices
+def set_delay_all_devices(file_map, delay, quiet):
+
+        for device in (file_map):
+                set_test_state(locate_state(device, file_map),
+                               dev_state.on.value,
+                               quiet)
+                set_delay_values(device, file_map, delay, quiet)
+
+# disable all testing on a SINGLE device.
+def disable_testing_single_device(device, file_map):
+
+        for name in file_map[device]:
+                file_location = file_map[device][name]
+                write_test_files(file_location, dev_state.off.value)
+        print("ALL testing now OFF for {}".format(device.split("/")[-1]))
+
+# disable all testing on ALL devices
+def disable_all_testing(file_map):
+
+        for device in file_map:
+                disable_testing_single_device(device, file_map)
+
+def parse_args():
+        parser = argparse.ArgumentParser(prog = "vmbus_testing",usage ="\n"
+                "%(prog)s [delay]   [-h] [-e|-E] -t [-p]\n"
+                "%(prog)s [view_all       | V]      [-h]\n"
+                "%(prog)s [disable_all    | D]      [-h]\n"
+                "%(prog)s [disable_single | d]      [-h|-p]\n"
+                "%(prog)s [view_single    | v]      [-h|-p]\n"
+                "%(prog)s --version\n",
+                description = "\nUse lsvmbus to get vmbus device type "
+                "information.\n" "\nThe debugfs root path is "
+                "/sys/kernel/debug/hyperv",
+                formatter_class = RawDescriptionHelpFormatter)
+        subparsers = parser.add_subparsers(dest = "action")
+        parser.add_argument("--version", action = "version",
+                version = '%(prog)s 0.1.0')
+        parser.add_argument("-q","--quiet", action = "store_true",
+                help = "silence none important test messages."
+                       " This will only work when enabling testing"
+                       " on a device.")
+        # Use the path parser to hold the --path attribute so it can
+        # be shared between subparsers. Also do the same for the state
+        # parser, as all testing methods will use --enable_all and
+        # enable_single.
+        path_parser = argparse.ArgumentParser(add_help=False)
+        path_parser.add_argument("-p","--path", metavar = "",
+                help = "Debugfs path to a vmbus device. The path "
+                "must be the absolute path to the device.")
+        state_parser = argparse.ArgumentParser(add_help=False)
+        state_group = state_parser.add_mutually_exclusive_group(required = True)
+        state_group.add_argument("-E", "--enable_all", action = "store_const",
+                                 const = "enable_all",
+                                 help = "Enable the specified test type "
+                                 "on ALL vmbus devices.")
+        state_group.add_argument("-e", "--enable_single",
+                                 action = "store_const",
+                                 const = "enable_single",
+                                 help = "Enable the specified test type on a "
+                                 "SINGLE vmbus device.")
+        parser_delay = subparsers.add_parser("delay",
+                        parents = [state_parser, path_parser],
+                        help = "Delay the ring buffer interrupt or the "
+                        "ring buffer message reads in microseconds.",
+                        prog = "vmbus_testing",
+                        usage = "%(prog)s [-h]\n"
+                        "%(prog)s -E -t [value] [value]\n"
+                        "%(prog)s -e -t [value] [value] -p",
+                        description = "Delay the ring buffer interrupt for "
+                        "vmbus devices, or delay the ring buffer message "
+                        "reads for vmbus devices (both in microseconds). This "
+                        "is only on the host to guest channel.")
+        parser_delay.add_argument("-t", "--delay_time", metavar = "", nargs = 2,
+                        type = check_range, default =[0,0], required = (True),
+                        help = "Set [buffer] & [message] delay time. "
+                        "Value constraints: -1 == value "
+                        "or 0 < value <= 1000.\n"
+                        "Use -1 to keep the previous value for that delay "
+                        "type, or a value > 0 <= 1000 to change the delay "
+                        "time.")
+        parser_dis_all = subparsers.add_parser("disable_all",
+                        aliases = ['D'], prog = "vmbus_testing",
+                        usage = "%(prog)s [disable_all | D] -h\n"
+                        "%(prog)s [disable_all | D]\n",
+                        help = "Disable ALL testing on ALL vmbus devices.",
+                        description = "Disable ALL testing on ALL vmbus "
+                        "devices.")
+        parser_dis_single = subparsers.add_parser("disable_single",
+                        aliases = ['d'],
+                        parents = [path_parser], prog = "vmbus_testing",
+                        usage = "%(prog)s [disable_single | d] -h\n"
+                        "%(prog)s [disable_single | d] -p\n",
+                        help = "Disable ALL testing on a SINGLE vmbus device.",
+                        description = "Disable ALL testing on a SINGLE vmbus "
+                        "device.")
+        parser_view_all = subparsers.add_parser("view_all", aliases = ['V'],
+                        help = "View the test state for ALL vmbus devices.",
+                        prog = "vmbus_testing",
+                        usage = "%(prog)s [view_all | V] -h\n"
+                        "%(prog)s [view_all | V]\n",
+                        description = "This shows the test state for ALL the "
+                        "vmbus devices.")
+        parser_view_single = subparsers.add_parser("view_single",
+                        aliases = ['v'],parents = [path_parser],
+                        help = "View the test values for a SINGLE vmbus "
+                        "device.",
+                        description = "This shows the test values for a SINGLE "
+                        "vmbus device.", prog = "vmbus_testing",
+                        usage = "%(prog)s [view_single | v] -h\n"
+                        "%(prog)s [view_single | v] -p")
+
+        return  parser.parse_args()
+
+# value checking for range checking input in parser
+def check_range(arg1):
+
+        try:
+                val = int(arg1)
+        except ValueError as err:
+                raise argparse.ArgumentTypeError(str(err))
+        if val < -1 or val > 1000:
+                message = ("\n\nvalue must be -1 or  0 < value <= 1000. "
+                           "Value program received: {}\n").format(val)
+                raise argparse.ArgumentTypeError(message)
+        return val
+
+if __name__ == "__main__":
+        main()