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Diffstat (limited to 'drivers/video/fbdev/hyperv_fb.c')
-rw-r--r--drivers/video/fbdev/hyperv_fb.c1413
1 files changed, 1413 insertions, 0 deletions
diff --git a/drivers/video/fbdev/hyperv_fb.c b/drivers/video/fbdev/hyperv_fb.c
new file mode 100644
index 000000000..f0a66a344
--- /dev/null
+++ b/drivers/video/fbdev/hyperv_fb.c
@@ -0,0 +1,1413 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2012, Microsoft Corporation.
+ *
+ * Author:
+ * Haiyang Zhang <haiyangz@microsoft.com>
+ */
+
+/*
+ * Hyper-V Synthetic Video Frame Buffer Driver
+ *
+ * This is the driver for the Hyper-V Synthetic Video, which supports
+ * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
+ * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
+ * or earlier.
+ *
+ * It also solves the double mouse cursor issue of the emulated video mode.
+ *
+ * The default screen resolution is 1152x864, which may be changed by a
+ * kernel parameter:
+ * video=hyperv_fb:<width>x<height>
+ * For example: video=hyperv_fb:1280x1024
+ *
+ * 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
+ *
+ * Gen 1 VMs also support direct using VM's physical memory for framebuffer.
+ * It could improve the efficiency and performance for framebuffer and VM.
+ * This requires to allocate contiguous physical memory from Linux kernel's
+ * CMA memory allocator. To enable this, supply a kernel parameter to give
+ * enough memory space to CMA allocator for framebuffer. For example:
+ * cma=130m
+ * This gives 130MB memory to CMA allocator that can be allocated to
+ * framebuffer. For reference, 8K resolution (7680x4320) takes about
+ * 127MB memory.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/vmalloc.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/fb.h>
+#include <linux/pci.h>
+#include <linux/efi.h>
+#include <linux/console.h>
+
+#include <linux/hyperv.h>
+
+
+/* Hyper-V Synthetic Video Protocol definitions and structures */
+#define MAX_VMBUS_PKT_SIZE 0x4000
+
+#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
+
+#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
+#define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
+
+
+enum pipe_msg_type {
+ PIPE_MSG_INVALID,
+ PIPE_MSG_DATA,
+ PIPE_MSG_MAX
+};
+
+struct pipe_msg_hdr {
+ u32 type;
+ u32 size; /* size of message after this field */
+} __packed;
+
+
+enum synthvid_msg_type {
+ SYNTHVID_ERROR = 0,
+ SYNTHVID_VERSION_REQUEST = 1,
+ SYNTHVID_VERSION_RESPONSE = 2,
+ SYNTHVID_VRAM_LOCATION = 3,
+ SYNTHVID_VRAM_LOCATION_ACK = 4,
+ SYNTHVID_SITUATION_UPDATE = 5,
+ SYNTHVID_SITUATION_UPDATE_ACK = 6,
+ SYNTHVID_POINTER_POSITION = 7,
+ SYNTHVID_POINTER_SHAPE = 8,
+ SYNTHVID_FEATURE_CHANGE = 9,
+ SYNTHVID_DIRT = 10,
+ SYNTHVID_RESOLUTION_REQUEST = 13,
+ SYNTHVID_RESOLUTION_RESPONSE = 14,
+
+ 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;
+
+struct synthvid_version_resp {
+ u32 version;
+ u8 is_accepted;
+ 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;
+ u64 vram_gpa;
+} __packed;
+
+struct synthvid_vram_location_ack {
+ u64 user_ctx;
+} __packed;
+
+struct video_output_situation {
+ u8 active;
+ u32 vram_offset;
+ u8 depth_bits;
+ u32 width_pixels;
+ u32 height_pixels;
+ u32 pitch_bytes;
+} __packed;
+
+struct synthvid_situation_update {
+ u64 user_ctx;
+ u8 video_output_count;
+ struct video_output_situation video_output[1];
+} __packed;
+
+struct synthvid_situation_update_ack {
+ u64 user_ctx;
+} __packed;
+
+struct synthvid_pointer_position {
+ u8 is_visible;
+ u8 video_output;
+ s32 image_x;
+ s32 image_y;
+} __packed;
+
+
+#define CURSOR_MAX_X 96
+#define CURSOR_MAX_Y 96
+#define CURSOR_ARGB_PIXEL_SIZE 4
+#define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
+#define CURSOR_COMPLETE (-1)
+
+struct synthvid_pointer_shape {
+ u8 part_idx;
+ u8 is_argb;
+ u32 width; /* CURSOR_MAX_X at most */
+ u32 height; /* CURSOR_MAX_Y at most */
+ u32 hot_x; /* hotspot relative to upper-left of pointer image */
+ u32 hot_y;
+ u8 data[4];
+} __packed;
+
+struct synthvid_feature_change {
+ u8 is_dirt_needed;
+ u8 is_ptr_pos_needed;
+ u8 is_ptr_shape_needed;
+ u8 is_situ_needed;
+} __packed;
+
+struct rect {
+ s32 x1, y1; /* top left corner */
+ s32 x2, y2; /* bottom right corner, exclusive */
+} __packed;
+
+struct synthvid_dirt {
+ u8 video_output;
+ u8 dirt_count;
+ struct rect rect[1];
+} __packed;
+
+struct synthvid_msg {
+ struct pipe_msg_hdr pipe_hdr;
+ struct synthvid_msg_hdr vid_hdr;
+ union {
+ struct synthvid_version_req ver_req;
+ struct synthvid_version_resp ver_resp;
+ struct synthvid_vram_location vram;
+ struct synthvid_vram_location_ack vram_ack;
+ struct synthvid_situation_update situ;
+ struct synthvid_situation_update_ack situ_ack;
+ struct synthvid_pointer_position ptr_pos;
+ 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;
+
+
+/* FB driver definitions and structures */
+#define HVFB_WIDTH 1152 /* default screen width */
+#define HVFB_HEIGHT 864 /* default screen height */
+#define HVFB_WIDTH_MIN 640
+#define HVFB_HEIGHT_MIN 480
+
+#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;
+ struct resource *mem;
+ bool fb_ready; /* fb device is ready */
+ struct completion wait;
+ u32 synthvid_version;
+
+ 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];
+ u8 recv_buf[MAX_VMBUS_PKT_SIZE];
+
+ /* If true, the VSC notifies the VSP on every framebuffer change */
+ bool synchronous_fb;
+
+ /* If true, need to copy from deferred IO mem to framebuffer mem */
+ bool need_docopy;
+
+ struct notifier_block hvfb_panic_nb;
+
+ /* Memory for deferred IO and frame buffer itself */
+ unsigned char *dio_vp;
+ unsigned char *mmio_vp;
+ phys_addr_t 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_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,
+ struct synthvid_msg *msg)
+{
+ static atomic64_t request_id = ATOMIC64_INIT(0);
+ int ret;
+
+ msg->pipe_hdr.type = PIPE_MSG_DATA;
+ msg->pipe_hdr.size = msg->vid_hdr.size;
+
+ ret = vmbus_sendpacket(hdev->channel, msg,
+ msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
+ atomic64_inc_return(&request_id),
+ VM_PKT_DATA_INBAND, 0);
+
+ if (ret)
+ pr_err("Unable to send packet via vmbus\n");
+
+ return ret;
+}
+
+
+/* Send screen resolution info to host */
+static int synthvid_send_situ(struct hv_device *hdev)
+{
+ struct fb_info *info = hv_get_drvdata(hdev);
+ struct synthvid_msg msg;
+
+ if (!info)
+ return -ENODEV;
+
+ memset(&msg, 0, sizeof(struct synthvid_msg));
+
+ msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
+ msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
+ sizeof(struct synthvid_situation_update);
+ msg.situ.user_ctx = 0;
+ msg.situ.video_output_count = 1;
+ msg.situ.video_output[0].active = 1;
+ msg.situ.video_output[0].vram_offset = 0;
+ msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
+ msg.situ.video_output[0].width_pixels = info->var.xres;
+ msg.situ.video_output[0].height_pixels = info->var.yres;
+ msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
+
+ synthvid_send(hdev, &msg);
+
+ return 0;
+}
+
+/* Send mouse pointer info to host */
+static int synthvid_send_ptr(struct hv_device *hdev)
+{
+ struct synthvid_msg msg;
+
+ memset(&msg, 0, sizeof(struct synthvid_msg));
+ msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
+ msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
+ sizeof(struct synthvid_pointer_position);
+ msg.ptr_pos.is_visible = 1;
+ msg.ptr_pos.video_output = 0;
+ msg.ptr_pos.image_x = 0;
+ msg.ptr_pos.image_y = 0;
+ synthvid_send(hdev, &msg);
+
+ memset(&msg, 0, sizeof(struct synthvid_msg));
+ msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
+ msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
+ sizeof(struct synthvid_pointer_shape);
+ msg.ptr_shape.part_idx = CURSOR_COMPLETE;
+ msg.ptr_shape.is_argb = 1;
+ msg.ptr_shape.width = 1;
+ msg.ptr_shape.height = 1;
+ msg.ptr_shape.hot_x = 0;
+ msg.ptr_shape.hot_y = 0;
+ msg.ptr_shape.data[0] = 0;
+ msg.ptr_shape.data[1] = 1;
+ msg.ptr_shape.data[2] = 1;
+ msg.ptr_shape.data[3] = 1;
+ synthvid_send(hdev, &msg);
+
+ return 0;
+}
+
+/* Send updated screen area (dirty rectangle) location to host */
+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 = (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 && par->need_docopy)
+ 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:
+ * Complete the wait event.
+ * Or, reply with screen and cursor info.
+ */
+static void synthvid_recv_sub(struct hv_device *hdev)
+{
+ struct fb_info *info = hv_get_drvdata(hdev);
+ struct hvfb_par *par;
+ struct synthvid_msg *msg;
+
+ if (!info)
+ return;
+
+ par = info->par;
+ msg = (struct synthvid_msg *)par->recv_buf;
+
+ /* 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);
+ return;
+ }
+
+ /* Reply with screen and cursor info */
+ if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
+ if (par->fb_ready) {
+ synthvid_send_ptr(hdev);
+ synthvid_send_situ(hdev);
+ }
+
+ par->update = msg->feature_chg.is_dirt_needed;
+ if (par->update)
+ schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
+ }
+}
+
+/* Receive callback for messages from the host */
+static void synthvid_receive(void *ctx)
+{
+ struct hv_device *hdev = ctx;
+ struct fb_info *info = hv_get_drvdata(hdev);
+ struct hvfb_par *par;
+ struct synthvid_msg *recv_buf;
+ u32 bytes_recvd;
+ u64 req_id;
+ int ret;
+
+ if (!info)
+ return;
+
+ par = info->par;
+ recv_buf = (struct synthvid_msg *)par->recv_buf;
+
+ do {
+ ret = vmbus_recvpacket(hdev->channel, recv_buf,
+ MAX_VMBUS_PKT_SIZE,
+ &bytes_recvd, &req_id);
+ if (bytes_recvd > 0 &&
+ recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
+ synthvid_recv_sub(hdev);
+ } 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)
+{
+ 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;
+
+ memset(msg, 0, sizeof(struct synthvid_msg));
+ msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
+ msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
+ sizeof(struct synthvid_version_req);
+ msg->ver_req.version = ver;
+ synthvid_send(hdev, msg);
+
+ t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
+ if (!t) {
+ pr_err("Time out on waiting version response\n");
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+ if (!msg->ver_resp.is_accepted) {
+ ret = -ENODEV;
+ goto out;
+ }
+
+ 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;
+
+ 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;
+ }
+
+ screen_width =
+ msg->resolution_resp.supported_resolution[index].width;
+ screen_height =
+ msg->resolution_resp.supported_resolution[index].height;
+
+out:
+ return ret;
+}
+
+/* Connect to VSP (Virtual Service Provider) on host */
+static int synthvid_connect_vsp(struct hv_device *hdev)
+{
+ struct fb_info *info = hv_get_drvdata(hdev);
+ struct hvfb_par *par = info->par;
+ int ret;
+
+ ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
+ NULL, 0, synthvid_receive, hdev);
+ if (ret) {
+ pr_err("Unable to open vmbus channel\n");
+ return ret;
+ }
+
+ /* Negotiate the protocol version with host */
+ 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");
+ goto error;
+ }
+
+ if (par->synthvid_version == SYNTHVID_VERSION_WIN7)
+ screen_depth = SYNTHVID_DEPTH_WIN7;
+ 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;
+
+ return 0;
+
+error:
+ vmbus_close(hdev->channel);
+ return ret;
+}
+
+/* Send VRAM and Situation messages to the host */
+static int synthvid_send_config(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;
+
+ /* Send VRAM location */
+ memset(msg, 0, sizeof(struct synthvid_msg));
+ 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 = par->mmio_pp;
+ msg->vram.is_vram_gpa_specified = 1;
+ synthvid_send(hdev, msg);
+
+ t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
+ if (!t) {
+ pr_err("Time out on waiting vram location ack\n");
+ ret = -ETIMEDOUT;
+ goto out;
+ }
+ if (msg->vram_ack.user_ctx != par->mmio_pp) {
+ pr_err("Unable to set VRAM location\n");
+ ret = -ENODEV;
+ goto out;
+ }
+
+ /* Send pointer and situation update */
+ synthvid_send_ptr(hdev);
+ synthvid_send_situ(hdev);
+
+out:
+ return ret;
+}
+
+
+/*
+ * Delayed work callback:
+ * 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;
+
+ spin_lock_irqsave(&par->delayed_refresh_lock, flags);
+ /* Reset the request flag */
+ par->delayed_refresh = false;
+
+ /* 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 */
+ if (par->need_docopy)
+ 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,
+ unsigned long e, void *p)
+{
+ struct hv_device *hdev;
+ struct hvfb_par *par;
+ struct fb_info *info;
+
+ par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
+ info = par->info;
+ hdev = device_to_hv_device(info->device);
+
+ if (hv_ringbuffer_spinlock_busy(hdev->channel))
+ return NOTIFY_DONE;
+
+ par->synchronous_fb = true;
+ if (par->need_docopy)
+ hvfb_docopy(par, 0, dio_fb_size);
+ synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
+
+ return NOTIFY_DONE;
+}
+
+/* Framebuffer operation handlers */
+
+static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
+{
+ if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
+ var->xres > screen_width || var->yres > screen_height ||
+ var->bits_per_pixel != screen_depth)
+ return -EINVAL;
+
+ var->xres_virtual = var->xres;
+ var->yres_virtual = var->yres;
+
+ return 0;
+}
+
+static int hvfb_set_par(struct fb_info *info)
+{
+ struct hv_device *hdev = device_to_hv_device(info->device);
+
+ return synthvid_send_situ(hdev);
+}
+
+
+static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
+{
+ return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
+}
+
+static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
+ unsigned blue, unsigned transp, struct fb_info *info)
+{
+ u32 *pal = info->pseudo_palette;
+
+ if (regno > 15)
+ return -EINVAL;
+
+ pal[regno] = chan_to_field(red, &info->var.red)
+ | chan_to_field(green, &info->var.green)
+ | chan_to_field(blue, &info->var.blue)
+ | chan_to_field(transp, &info->var.transp);
+
+ return 0;
+}
+
+static int hvfb_blank(int blank, struct fb_info *info)
+{
+ return 1; /* get fb_blank to set the colormap to all black */
+}
+
+static void hvfb_cfb_fillrect(struct fb_info *p,
+ const struct fb_fillrect *rect)
+{
+ struct hvfb_par *par = p->par;
+
+ cfb_fillrect(p, rect);
+ if (par->synchronous_fb)
+ 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,
+ const struct fb_copyarea *area)
+{
+ struct hvfb_par *par = p->par;
+
+ cfb_copyarea(p, area);
+ if (par->synchronous_fb)
+ 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,
+ const struct fb_image *image)
+{
+ struct hvfb_par *par = p->par;
+
+ cfb_imageblit(p, image);
+ if (par->synchronous_fb)
+ synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
+ else
+ hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
+ image->width, image->height);
+}
+
+static const struct fb_ops hvfb_ops = {
+ .owner = THIS_MODULE,
+ .fb_check_var = hvfb_check_var,
+ .fb_set_par = hvfb_set_par,
+ .fb_setcolreg = hvfb_setcolreg,
+ .fb_fillrect = hvfb_cfb_fillrect,
+ .fb_copyarea = hvfb_cfb_copyarea,
+ .fb_imageblit = hvfb_cfb_imageblit,
+ .fb_blank = hvfb_blank,
+};
+
+
+/* Get options from kernel paramenter "video=" */
+static void hvfb_get_option(struct fb_info *info)
+{
+ struct hvfb_par *par = info->par;
+ char *opt = NULL, *p;
+ uint x = 0, y = 0;
+
+ if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
+ return;
+
+ p = strsep(&opt, "x");
+ if (!*p || kstrtouint(p, 0, &x) ||
+ !opt || !*opt || kstrtouint(opt, 0, &y)) {
+ pr_err("Screen option is invalid: skipped\n");
+ return;
+ }
+
+ if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
+ (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))) {
+ pr_err("Screen resolution option is out of range: skipped\n");
+ return;
+ }
+
+ screen_width = x;
+ screen_height = y;
+ return;
+}
+
+/*
+ * Allocate enough contiguous physical memory.
+ * Return physical address if succeeded or -1 if failed.
+ */
+static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
+ unsigned int request_size)
+{
+ struct page *page = NULL;
+ dma_addr_t dma_handle;
+ void *vmem;
+ phys_addr_t paddr = 0;
+ unsigned int order = get_order(request_size);
+
+ if (request_size == 0)
+ return -1;
+
+ if (order < MAX_ORDER) {
+ /* Call alloc_pages if the size is less than 2^MAX_ORDER */
+ page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+ if (!page)
+ return -1;
+
+ paddr = (page_to_pfn(page) << PAGE_SHIFT);
+ } else {
+ /* Allocate from CMA */
+ hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
+
+ vmem = dma_alloc_coherent(&hdev->device,
+ round_up(request_size, PAGE_SIZE),
+ &dma_handle,
+ GFP_KERNEL | __GFP_NOWARN);
+
+ if (!vmem)
+ return -1;
+
+ paddr = virt_to_phys(vmem);
+ }
+
+ return paddr;
+}
+
+/* Release contiguous physical memory */
+static void hvfb_release_phymem(struct hv_device *hdev,
+ phys_addr_t paddr, unsigned int size)
+{
+ unsigned int order = get_order(size);
+
+ if (order < MAX_ORDER)
+ __free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
+ else
+ dma_free_coherent(&hdev->device,
+ round_up(size, PAGE_SIZE),
+ phys_to_virt(paddr),
+ paddr);
+}
+
+
+/* Get framebuffer memory from Hyper-V video pci space */
+static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
+{
+ struct hvfb_par *par = info->par;
+ struct pci_dev *pdev = NULL;
+ void __iomem *fb_virt;
+ int gen2vm = efi_enabled(EFI_BOOT);
+ phys_addr_t paddr;
+ int ret;
+
+ info->apertures = alloc_apertures(1);
+ if (!info->apertures)
+ return -ENOMEM;
+
+ if (!gen2vm) {
+ pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
+ PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
+ if (!pdev) {
+ pr_err("Unable to find PCI Hyper-V video\n");
+ return -ENODEV;
+ }
+
+ info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
+ info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
+
+ /*
+ * For Gen 1 VM, we can directly use the contiguous memory
+ * from VM. If we succeed, deferred IO happens directly
+ * on this allocated framebuffer memory, avoiding extra
+ * memory copy.
+ */
+ paddr = hvfb_get_phymem(hdev, screen_fb_size);
+ if (paddr != (phys_addr_t) -1) {
+ par->mmio_pp = paddr;
+ par->mmio_vp = par->dio_vp = __va(paddr);
+
+ info->fix.smem_start = paddr;
+ info->fix.smem_len = screen_fb_size;
+ info->screen_base = par->mmio_vp;
+ info->screen_size = screen_fb_size;
+
+ par->need_docopy = false;
+ goto getmem_done;
+ }
+ pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
+ } else {
+ info->apertures->ranges[0].base = screen_info.lfb_base;
+ info->apertures->ranges[0].size = screen_info.lfb_size;
+ }
+
+ /*
+ * Cannot use the contiguous physical memory.
+ * Allocate mmio space for framebuffer.
+ */
+ dio_fb_size =
+ screen_width * screen_height * screen_depth / 8;
+
+ ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
+ screen_fb_size, 0x100000, true);
+ if (ret != 0) {
+ pr_err("Unable to allocate framebuffer memory\n");
+ goto err1;
+ }
+
+ /*
+ * Map the VRAM cacheable for performance. This is also required for
+ * VM Connect to display properly for ARM64 Linux VM, as the host also
+ * maps the VRAM cacheable.
+ */
+ fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
+ 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;
+
+ /* 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 = dio_fb_size;
+ info->screen_base = par->dio_vp;
+ info->screen_size = dio_fb_size;
+
+getmem_done:
+ remove_conflicting_framebuffers(info->apertures,
+ KBUILD_MODNAME, false);
+
+ if (gen2vm) {
+ /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
+ screen_info.lfb_size = 0;
+ screen_info.lfb_base = 0;
+ screen_info.orig_video_isVGA = 0;
+ } else {
+ pci_dev_put(pdev);
+ }
+
+ return 0;
+
+err3:
+ iounmap(fb_virt);
+err2:
+ vmbus_free_mmio(par->mem->start, screen_fb_size);
+ par->mem = NULL;
+err1:
+ if (!gen2vm)
+ pci_dev_put(pdev);
+
+ return -ENOMEM;
+}
+
+/* Release the framebuffer */
+static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
+{
+ struct hvfb_par *par = info->par;
+
+ if (par->need_docopy) {
+ vfree(par->dio_vp);
+ iounmap(info->screen_base);
+ vmbus_free_mmio(par->mem->start, screen_fb_size);
+ } else {
+ hvfb_release_phymem(hdev, info->fix.smem_start,
+ screen_fb_size);
+ }
+
+ par->mem = NULL;
+}
+
+
+static int hvfb_probe(struct hv_device *hdev,
+ const struct hv_vmbus_device_id *dev_id)
+{
+ struct fb_info *info;
+ struct hvfb_par *par;
+ int ret;
+
+ info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
+ if (!info)
+ return -ENOMEM;
+
+ par = info->par;
+ par->info = info;
+ par->fb_ready = false;
+ par->need_docopy = true;
+ 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);
+ if (ret) {
+ pr_err("Unable to connect to VSP\n");
+ goto error1;
+ }
+
+ hvfb_get_option(info);
+ pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
+ screen_width, screen_height, screen_depth, screen_fb_size);
+
+ ret = hvfb_getmem(hdev, info);
+ if (ret) {
+ pr_err("No memory for framebuffer\n");
+ goto error2;
+ }
+
+ /* Set up fb_info */
+ info->flags = FBINFO_DEFAULT;
+
+ info->var.xres_virtual = info->var.xres = screen_width;
+ info->var.yres_virtual = info->var.yres = screen_height;
+ info->var.bits_per_pixel = screen_depth;
+
+ if (info->var.bits_per_pixel == 16) {
+ info->var.red = (struct fb_bitfield){11, 5, 0};
+ info->var.green = (struct fb_bitfield){5, 6, 0};
+ info->var.blue = (struct fb_bitfield){0, 5, 0};
+ info->var.transp = (struct fb_bitfield){0, 0, 0};
+ } else {
+ info->var.red = (struct fb_bitfield){16, 8, 0};
+ info->var.green = (struct fb_bitfield){8, 8, 0};
+ info->var.blue = (struct fb_bitfield){0, 8, 0};
+ info->var.transp = (struct fb_bitfield){24, 8, 0};
+ }
+
+ info->var.activate = FB_ACTIVATE_NOW;
+ info->var.height = -1;
+ info->var.width = -1;
+ info->var.vmode = FB_VMODE_NONINTERLACED;
+
+ strcpy(info->fix.id, KBUILD_MODNAME);
+ info->fix.type = FB_TYPE_PACKED_PIXELS;
+ info->fix.visual = FB_VISUAL_TRUECOLOR;
+ info->fix.line_length = screen_width * screen_depth / 8;
+ info->fix.accel = FB_ACCEL_NONE;
+
+ 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)
+ goto error;
+
+ ret = register_framebuffer(info);
+ if (ret) {
+ pr_err("Unable to register framebuffer\n");
+ goto error;
+ }
+
+ par->fb_ready = true;
+
+ par->synchronous_fb = false;
+ par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &par->hvfb_panic_nb);
+
+ return 0;
+
+error:
+ fb_deferred_io_cleanup(info);
+ hvfb_putmem(hdev, info);
+error2:
+ vmbus_close(hdev->channel);
+error1:
+ cancel_delayed_work_sync(&par->dwork);
+ hv_set_drvdata(hdev, NULL);
+ framebuffer_release(info);
+ return ret;
+}
+
+
+static int hvfb_remove(struct hv_device *hdev)
+{
+ struct fb_info *info = hv_get_drvdata(hdev);
+ struct hvfb_par *par = info->par;
+
+ atomic_notifier_chain_unregister(&panic_notifier_list,
+ &par->hvfb_panic_nb);
+
+ par->update = false;
+ par->fb_ready = false;
+
+ fb_deferred_io_cleanup(info);
+
+ unregister_framebuffer(info);
+ cancel_delayed_work_sync(&par->dwork);
+
+ vmbus_close(hdev->channel);
+ hv_set_drvdata(hdev, NULL);
+
+ hvfb_putmem(hdev, info);
+ framebuffer_release(info);
+
+ 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);
+ cancel_delayed_work_sync(&info->deferred_work);
+
+ 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(&info->deferred_work, info->fbdefio->delay);
+ 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[] = {
+ {
+ .vendor = PCI_VENDOR_ID_MICROSOFT,
+ .device = PCI_DEVICE_ID_HYPERV_VIDEO,
+ },
+ { /* end of list */ }
+};
+
+static const struct hv_vmbus_device_id id_table[] = {
+ /* Synthetic Video Device GUID */
+ {HV_SYNTHVID_GUID},
+ {}
+};
+
+MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+static struct hv_driver hvfb_drv = {
+ .name = KBUILD_MODNAME,
+ .id_table = id_table,
+ .probe = hvfb_probe,
+ .remove = hvfb_remove,
+ .suspend = hvfb_suspend,
+ .resume = hvfb_resume,
+ .driver = {
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ },
+};
+
+static int hvfb_pci_stub_probe(struct pci_dev *pdev,
+ const struct pci_device_id *ent)
+{
+ return 0;
+}
+
+static void hvfb_pci_stub_remove(struct pci_dev *pdev)
+{
+}
+
+static struct pci_driver hvfb_pci_stub_driver = {
+ .name = KBUILD_MODNAME,
+ .id_table = pci_stub_id_table,
+ .probe = hvfb_pci_stub_probe,
+ .remove = hvfb_pci_stub_remove,
+ .driver = {
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ }
+};
+
+static int __init hvfb_drv_init(void)
+{
+ int ret;
+
+ ret = vmbus_driver_register(&hvfb_drv);
+ if (ret != 0)
+ return ret;
+
+ ret = pci_register_driver(&hvfb_pci_stub_driver);
+ if (ret != 0) {
+ vmbus_driver_unregister(&hvfb_drv);
+ return ret;
+ }
+
+ return 0;
+}
+
+static void __exit hvfb_drv_exit(void)
+{
+ pci_unregister_driver(&hvfb_pci_stub_driver);
+ vmbus_driver_unregister(&hvfb_drv);
+}
+
+module_init(hvfb_drv_init);
+module_exit(hvfb_drv_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");