1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2012, Microsoft Corporation.
6 * Haiyang Zhang <haiyangz@microsoft.com>
10 * Hyper-V Synthetic Video Frame Buffer Driver
12 * This is the driver for the Hyper-V Synthetic Video, which supports
13 * screen resolution up to Full HD 1920x1080 with 32 bit color on Windows
14 * Server 2012, and 1600x1200 with 16 bit color on Windows Server 2008 R2
17 * It also solves the double mouse cursor issue of the emulated video mode.
19 * The default screen resolution is 1152x864, which may be changed by a
21 * video=hyperv_fb:<width>x<height>
22 * For example: video=hyperv_fb:1280x1024
24 * Portrait orientation is also supported:
25 * For example: video=hyperv_fb:864x1152
27 * When a Windows 10 RS5+ host is used, the virtual machine screen
28 * resolution is obtained from the host. The "video=hyperv_fb" option is
29 * not needed, but still can be used to overwrite what the host specifies.
30 * The VM resolution on the host could be set by executing the powershell
31 * "set-vmvideo" command. For example
32 * set-vmvideo -vmname name -horizontalresolution:1920 \
33 * -verticalresolution:1200 -resolutiontype single
35 * Gen 1 VMs also support direct using VM's physical memory for framebuffer.
36 * It could improve the efficiency and performance for framebuffer and VM.
37 * This requires to allocate contiguous physical memory from Linux kernel's
38 * CMA memory allocator. To enable this, supply a kernel parameter to give
39 * enough memory space to CMA allocator for framebuffer. For example:
41 * This gives 130MB memory to CMA allocator that can be allocated to
42 * framebuffer. For reference, 8K resolution (7680x4320) takes about
46 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 #include <linux/module.h>
49 #include <linux/kernel.h>
50 #include <linux/vmalloc.h>
51 #include <linux/init.h>
52 #include <linux/completion.h>
54 #include <linux/pci.h>
55 #include <linux/panic_notifier.h>
56 #include <linux/efi.h>
57 #include <linux/console.h>
59 #include <linux/hyperv.h>
62 /* Hyper-V Synthetic Video Protocol definitions and structures */
63 #define MAX_VMBUS_PKT_SIZE 0x4000
65 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
66 /* Support for VERSION_WIN7 is removed. #define is retained for reference. */
67 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
68 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
69 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
71 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
72 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
74 #define SYNTHVID_DEPTH_WIN8 32
75 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
77 #define PCI_VENDOR_ID_MICROSOFT 0x1414
78 #define PCI_DEVICE_ID_HYPERV_VIDEO 0x5353
89 u32 size; /* size of message after this field */
93 enum synthvid_msg_type {
95 SYNTHVID_VERSION_REQUEST = 1,
96 SYNTHVID_VERSION_RESPONSE = 2,
97 SYNTHVID_VRAM_LOCATION = 3,
98 SYNTHVID_VRAM_LOCATION_ACK = 4,
99 SYNTHVID_SITUATION_UPDATE = 5,
100 SYNTHVID_SITUATION_UPDATE_ACK = 6,
101 SYNTHVID_POINTER_POSITION = 7,
102 SYNTHVID_POINTER_SHAPE = 8,
103 SYNTHVID_FEATURE_CHANGE = 9,
105 SYNTHVID_RESOLUTION_REQUEST = 13,
106 SYNTHVID_RESOLUTION_RESPONSE = 14,
111 #define SYNTHVID_EDID_BLOCK_SIZE 128
112 #define SYNTHVID_MAX_RESOLUTION_COUNT 64
114 struct hvd_screen_info {
119 struct synthvid_msg_hdr {
121 u32 size; /* size of this header + payload after this field*/
124 struct synthvid_version_req {
128 struct synthvid_version_resp {
131 u8 max_video_outputs;
134 struct synthvid_supported_resolution_req {
135 u8 maximum_resolution_count;
138 struct synthvid_supported_resolution_resp {
139 u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
141 u8 default_resolution_index;
143 struct hvd_screen_info
144 supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
147 struct synthvid_vram_location {
149 u8 is_vram_gpa_specified;
153 struct synthvid_vram_location_ack {
157 struct video_output_situation {
166 struct synthvid_situation_update {
168 u8 video_output_count;
169 struct video_output_situation video_output[1];
172 struct synthvid_situation_update_ack {
176 struct synthvid_pointer_position {
184 #define CURSOR_MAX_X 96
185 #define CURSOR_MAX_Y 96
186 #define CURSOR_ARGB_PIXEL_SIZE 4
187 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
188 #define CURSOR_COMPLETE (-1)
190 struct synthvid_pointer_shape {
193 u32 width; /* CURSOR_MAX_X at most */
194 u32 height; /* CURSOR_MAX_Y at most */
195 u32 hot_x; /* hotspot relative to upper-left of pointer image */
200 struct synthvid_feature_change {
202 u8 is_ptr_pos_needed;
203 u8 is_ptr_shape_needed;
208 s32 x1, y1; /* top left corner */
209 s32 x2, y2; /* bottom right corner, exclusive */
212 struct synthvid_dirt {
218 struct synthvid_msg {
219 struct pipe_msg_hdr pipe_hdr;
220 struct synthvid_msg_hdr vid_hdr;
222 struct synthvid_version_req ver_req;
223 struct synthvid_version_resp ver_resp;
224 struct synthvid_vram_location vram;
225 struct synthvid_vram_location_ack vram_ack;
226 struct synthvid_situation_update situ;
227 struct synthvid_situation_update_ack situ_ack;
228 struct synthvid_pointer_position ptr_pos;
229 struct synthvid_pointer_shape ptr_shape;
230 struct synthvid_feature_change feature_chg;
231 struct synthvid_dirt dirt;
232 struct synthvid_supported_resolution_req resolution_req;
233 struct synthvid_supported_resolution_resp resolution_resp;
238 /* FB driver definitions and structures */
239 #define HVFB_WIDTH 1152 /* default screen width */
240 #define HVFB_HEIGHT 864 /* default screen height */
241 #define HVFB_WIDTH_MIN 640
242 #define HVFB_HEIGHT_MIN 480
244 #define RING_BUFSIZE (256 * 1024)
245 #define VSP_TIMEOUT (10 * HZ)
246 #define HVFB_UPDATE_DELAY (HZ / 20)
247 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
250 struct fb_info *info;
251 struct resource *mem;
252 bool fb_ready; /* fb device is ready */
253 struct completion wait;
254 u32 synthvid_version;
256 struct delayed_work dwork;
258 bool update_saved; /* The value of 'update' before hibernation */
260 u32 pseudo_palette[16];
261 u8 init_buf[MAX_VMBUS_PKT_SIZE];
262 u8 recv_buf[MAX_VMBUS_PKT_SIZE];
264 /* If true, the VSC notifies the VSP on every framebuffer change */
267 /* If true, need to copy from deferred IO mem to framebuffer mem */
270 struct notifier_block hvfb_panic_nb;
272 /* Memory for deferred IO and frame buffer itself */
273 unsigned char *dio_vp;
274 unsigned char *mmio_vp;
277 /* Dirty rectangle, protected by delayed_refresh_lock */
279 bool delayed_refresh;
280 spinlock_t delayed_refresh_lock;
283 static uint screen_width = HVFB_WIDTH;
284 static uint screen_height = HVFB_HEIGHT;
285 static uint screen_depth;
286 static uint screen_fb_size;
287 static uint dio_fb_size; /* FB size for deferred IO */
289 /* Send message to Hyper-V host */
290 static inline int synthvid_send(struct hv_device *hdev,
291 struct synthvid_msg *msg)
293 static atomic64_t request_id = ATOMIC64_INIT(0);
296 msg->pipe_hdr.type = PIPE_MSG_DATA;
297 msg->pipe_hdr.size = msg->vid_hdr.size;
299 ret = vmbus_sendpacket(hdev->channel, msg,
300 msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
301 atomic64_inc_return(&request_id),
302 VM_PKT_DATA_INBAND, 0);
305 pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
311 /* Send screen resolution info to host */
312 static int synthvid_send_situ(struct hv_device *hdev)
314 struct fb_info *info = hv_get_drvdata(hdev);
315 struct synthvid_msg msg;
320 memset(&msg, 0, sizeof(struct synthvid_msg));
322 msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
323 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
324 sizeof(struct synthvid_situation_update);
325 msg.situ.user_ctx = 0;
326 msg.situ.video_output_count = 1;
327 msg.situ.video_output[0].active = 1;
328 msg.situ.video_output[0].vram_offset = 0;
329 msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
330 msg.situ.video_output[0].width_pixels = info->var.xres;
331 msg.situ.video_output[0].height_pixels = info->var.yres;
332 msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
334 synthvid_send(hdev, &msg);
339 /* Send mouse pointer info to host */
340 static int synthvid_send_ptr(struct hv_device *hdev)
342 struct synthvid_msg msg;
344 memset(&msg, 0, sizeof(struct synthvid_msg));
345 msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
346 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
347 sizeof(struct synthvid_pointer_position);
348 msg.ptr_pos.is_visible = 1;
349 msg.ptr_pos.video_output = 0;
350 msg.ptr_pos.image_x = 0;
351 msg.ptr_pos.image_y = 0;
352 synthvid_send(hdev, &msg);
354 memset(&msg, 0, sizeof(struct synthvid_msg));
355 msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
356 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
357 sizeof(struct synthvid_pointer_shape);
358 msg.ptr_shape.part_idx = CURSOR_COMPLETE;
359 msg.ptr_shape.is_argb = 1;
360 msg.ptr_shape.width = 1;
361 msg.ptr_shape.height = 1;
362 msg.ptr_shape.hot_x = 0;
363 msg.ptr_shape.hot_y = 0;
364 msg.ptr_shape.data[0] = 0;
365 msg.ptr_shape.data[1] = 1;
366 msg.ptr_shape.data[2] = 1;
367 msg.ptr_shape.data[3] = 1;
368 synthvid_send(hdev, &msg);
373 /* Send updated screen area (dirty rectangle) location to host */
375 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
377 struct hv_device *hdev = device_to_hv_device(info->device);
378 struct synthvid_msg msg;
380 memset(&msg, 0, sizeof(struct synthvid_msg));
386 msg.vid_hdr.type = SYNTHVID_DIRT;
387 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
388 sizeof(struct synthvid_dirt);
389 msg.dirt.video_output = 0;
390 msg.dirt.dirt_count = 1;
391 msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
392 msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
393 msg.dirt.rect[0].x2 =
394 (x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
395 msg.dirt.rect[0].y2 =
396 (y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
398 synthvid_send(hdev, &msg);
403 static void hvfb_docopy(struct hvfb_par *par,
404 unsigned long offset,
407 if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
408 size == 0 || offset >= dio_fb_size)
411 if (offset + size > dio_fb_size)
412 size = dio_fb_size - offset;
414 memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
417 /* Deferred IO callback */
418 static void synthvid_deferred_io(struct fb_info *p, struct list_head *pagereflist)
420 struct hvfb_par *par = p->par;
421 struct fb_deferred_io_pageref *pageref;
422 unsigned long start, end;
423 int y1, y2, miny, maxy;
429 * Merge dirty pages. It is possible that last page cross
430 * over the end of frame buffer row yres. This is taken care of
431 * in synthvid_update function by clamping the y2
434 list_for_each_entry(pageref, pagereflist, list) {
435 start = pageref->offset;
436 end = start + PAGE_SIZE - 1;
437 y1 = start / p->fix.line_length;
438 y2 = end / p->fix.line_length;
439 miny = min_t(int, miny, y1);
440 maxy = max_t(int, maxy, y2);
442 /* Copy from dio space to mmio address */
443 if (par->fb_ready && par->need_docopy)
444 hvfb_docopy(par, start, PAGE_SIZE);
447 if (par->fb_ready && par->update)
448 synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
451 static struct fb_deferred_io synthvid_defio = {
453 .deferred_io = synthvid_deferred_io,
457 * Actions on received messages from host:
458 * Complete the wait event.
459 * Or, reply with screen and cursor info.
461 static void synthvid_recv_sub(struct hv_device *hdev)
463 struct fb_info *info = hv_get_drvdata(hdev);
464 struct hvfb_par *par;
465 struct synthvid_msg *msg;
471 msg = (struct synthvid_msg *)par->recv_buf;
473 /* Complete the wait event */
474 if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
475 msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
476 msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
477 memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
478 complete(&par->wait);
482 /* Reply with screen and cursor info */
483 if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
485 synthvid_send_ptr(hdev);
486 synthvid_send_situ(hdev);
489 par->update = msg->feature_chg.is_dirt_needed;
491 schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
495 /* Receive callback for messages from the host */
496 static void synthvid_receive(void *ctx)
498 struct hv_device *hdev = ctx;
499 struct fb_info *info = hv_get_drvdata(hdev);
500 struct hvfb_par *par;
501 struct synthvid_msg *recv_buf;
510 recv_buf = (struct synthvid_msg *)par->recv_buf;
513 ret = vmbus_recvpacket(hdev->channel, recv_buf,
515 &bytes_recvd, &req_id);
516 if (bytes_recvd > 0 &&
517 recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
518 synthvid_recv_sub(hdev);
519 } while (bytes_recvd > 0 && ret == 0);
522 /* Check if the ver1 version is equal or greater than ver2 */
523 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
525 if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
526 (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
527 SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
533 /* Check synthetic video protocol version with the host */
534 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
536 struct fb_info *info = hv_get_drvdata(hdev);
537 struct hvfb_par *par = info->par;
538 struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
542 memset(msg, 0, sizeof(struct synthvid_msg));
543 msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
544 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
545 sizeof(struct synthvid_version_req);
546 msg->ver_req.version = ver;
547 synthvid_send(hdev, msg);
549 t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
551 pr_err("Time out on waiting version response\n");
555 if (!msg->ver_resp.is_accepted) {
560 par->synthvid_version = ver;
561 pr_info("Synthvid Version major %d, minor %d\n",
562 SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
568 /* Get current resolution from the host */
569 static int synthvid_get_supported_resolution(struct hv_device *hdev)
571 struct fb_info *info = hv_get_drvdata(hdev);
572 struct hvfb_par *par = info->par;
573 struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
578 memset(msg, 0, sizeof(struct synthvid_msg));
579 msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
580 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
581 sizeof(struct synthvid_supported_resolution_req);
583 msg->resolution_req.maximum_resolution_count =
584 SYNTHVID_MAX_RESOLUTION_COUNT;
585 synthvid_send(hdev, msg);
587 t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
589 pr_err("Time out on waiting resolution response\n");
594 if (msg->resolution_resp.resolution_count == 0) {
595 pr_err("No supported resolutions\n");
600 index = msg->resolution_resp.default_resolution_index;
601 if (index >= msg->resolution_resp.resolution_count) {
602 pr_err("Invalid resolution index: %d\n", index);
608 msg->resolution_resp.supported_resolution[index].width;
610 msg->resolution_resp.supported_resolution[index].height;
616 /* Connect to VSP (Virtual Service Provider) on host */
617 static int synthvid_connect_vsp(struct hv_device *hdev)
619 struct fb_info *info = hv_get_drvdata(hdev);
620 struct hvfb_par *par = info->par;
623 ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
624 NULL, 0, synthvid_receive, hdev);
626 pr_err("Unable to open vmbus channel\n");
630 /* Negotiate the protocol version with host */
631 switch (vmbus_proto_version) {
633 case VERSION_WIN10_V5:
634 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
640 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
643 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
648 pr_err("Synthetic video device version not accepted\n");
652 screen_depth = SYNTHVID_DEPTH_WIN8;
653 if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
654 ret = synthvid_get_supported_resolution(hdev);
656 pr_info("Failed to get supported resolution from host, use default\n");
659 screen_fb_size = hdev->channel->offermsg.offer.
660 mmio_megabytes * 1024 * 1024;
665 vmbus_close(hdev->channel);
669 /* Send VRAM and Situation messages to the host */
670 static int synthvid_send_config(struct hv_device *hdev)
672 struct fb_info *info = hv_get_drvdata(hdev);
673 struct hvfb_par *par = info->par;
674 struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
678 /* Send VRAM location */
679 memset(msg, 0, sizeof(struct synthvid_msg));
680 msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
681 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
682 sizeof(struct synthvid_vram_location);
683 msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
684 msg->vram.is_vram_gpa_specified = 1;
685 synthvid_send(hdev, msg);
687 t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
689 pr_err("Time out on waiting vram location ack\n");
693 if (msg->vram_ack.user_ctx != par->mmio_pp) {
694 pr_err("Unable to set VRAM location\n");
699 /* Send pointer and situation update */
700 synthvid_send_ptr(hdev);
701 synthvid_send_situ(hdev);
709 * Delayed work callback:
710 * It is scheduled to call whenever update request is received and it has
711 * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
713 static void hvfb_update_work(struct work_struct *w)
715 struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
716 struct fb_info *info = par->info;
721 spin_lock_irqsave(&par->delayed_refresh_lock, flags);
722 /* Reset the request flag */
723 par->delayed_refresh = false;
725 /* Store the dirty rectangle to local variables */
731 /* Clear dirty rectangle */
732 par->x1 = par->y1 = INT_MAX;
733 par->x2 = par->y2 = 0;
735 spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
737 if (x1 > info->var.xres || x2 > info->var.xres ||
738 y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
741 /* Copy the dirty rectangle to frame buffer memory */
742 if (par->need_docopy)
743 for (j = y1; j < y2; j++)
745 j * info->fix.line_length +
746 (x1 * screen_depth / 8),
747 (x2 - x1) * screen_depth / 8);
750 if (par->fb_ready && par->update)
751 synthvid_update(info, x1, y1, x2, y2);
755 * Control the on-demand refresh frequency. It schedules a delayed
756 * screen update if it has not yet.
758 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
759 int x1, int y1, int w, int h)
765 spin_lock_irqsave(&par->delayed_refresh_lock, flags);
767 /* Merge dirty rectangle */
768 par->x1 = min_t(int, par->x1, x1);
769 par->y1 = min_t(int, par->y1, y1);
770 par->x2 = max_t(int, par->x2, x2);
771 par->y2 = max_t(int, par->y2, y2);
773 /* Schedule a delayed screen update if not yet */
774 if (par->delayed_refresh == false) {
775 schedule_delayed_work(&par->dwork,
776 HVFB_ONDEMAND_THROTTLE);
777 par->delayed_refresh = true;
780 spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
783 static int hvfb_on_panic(struct notifier_block *nb,
784 unsigned long e, void *p)
786 struct hvfb_par *par;
787 struct fb_info *info;
789 par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
790 par->synchronous_fb = true;
792 if (par->need_docopy)
793 hvfb_docopy(par, 0, dio_fb_size);
794 synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
799 /* Framebuffer operation handlers */
801 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
803 if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
804 var->xres > screen_width || var->yres > screen_height ||
805 var->bits_per_pixel != screen_depth)
808 var->xres_virtual = var->xres;
809 var->yres_virtual = var->yres;
814 static int hvfb_set_par(struct fb_info *info)
816 struct hv_device *hdev = device_to_hv_device(info->device);
818 return synthvid_send_situ(hdev);
822 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
824 return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
827 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
828 unsigned blue, unsigned transp, struct fb_info *info)
830 u32 *pal = info->pseudo_palette;
835 pal[regno] = chan_to_field(red, &info->var.red)
836 | chan_to_field(green, &info->var.green)
837 | chan_to_field(blue, &info->var.blue)
838 | chan_to_field(transp, &info->var.transp);
843 static int hvfb_blank(int blank, struct fb_info *info)
845 return 1; /* get fb_blank to set the colormap to all black */
848 static void hvfb_cfb_fillrect(struct fb_info *p,
849 const struct fb_fillrect *rect)
851 struct hvfb_par *par = p->par;
853 cfb_fillrect(p, rect);
854 if (par->synchronous_fb)
855 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
857 hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
858 rect->width, rect->height);
861 static void hvfb_cfb_copyarea(struct fb_info *p,
862 const struct fb_copyarea *area)
864 struct hvfb_par *par = p->par;
866 cfb_copyarea(p, area);
867 if (par->synchronous_fb)
868 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
870 hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
871 area->width, area->height);
874 static void hvfb_cfb_imageblit(struct fb_info *p,
875 const struct fb_image *image)
877 struct hvfb_par *par = p->par;
879 cfb_imageblit(p, image);
880 if (par->synchronous_fb)
881 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
883 hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
884 image->width, image->height);
887 static const struct fb_ops hvfb_ops = {
888 .owner = THIS_MODULE,
889 .fb_check_var = hvfb_check_var,
890 .fb_set_par = hvfb_set_par,
891 .fb_setcolreg = hvfb_setcolreg,
892 .fb_fillrect = hvfb_cfb_fillrect,
893 .fb_copyarea = hvfb_cfb_copyarea,
894 .fb_imageblit = hvfb_cfb_imageblit,
895 .fb_blank = hvfb_blank,
896 .fb_mmap = fb_deferred_io_mmap,
900 /* Get options from kernel paramenter "video=" */
901 static void hvfb_get_option(struct fb_info *info)
903 struct hvfb_par *par = info->par;
904 char *opt = NULL, *p;
907 if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
910 p = strsep(&opt, "x");
911 if (!*p || kstrtouint(p, 0, &x) ||
912 !opt || !*opt || kstrtouint(opt, 0, &y)) {
913 pr_err("Screen option is invalid: skipped\n");
917 if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
918 (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
919 (x * y * screen_depth / 8 > screen_fb_size)) ||
920 (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
921 x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8)) {
922 pr_err("Screen resolution option is out of range: skipped\n");
932 * Allocate enough contiguous physical memory.
933 * Return physical address if succeeded or -1 if failed.
935 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
936 unsigned int request_size)
938 struct page *page = NULL;
939 dma_addr_t dma_handle;
941 phys_addr_t paddr = 0;
942 unsigned int order = get_order(request_size);
944 if (request_size == 0)
947 if (order < MAX_ORDER) {
948 /* Call alloc_pages if the size is less than 2^MAX_ORDER */
949 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
953 paddr = (page_to_pfn(page) << PAGE_SHIFT);
955 /* Allocate from CMA */
956 hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
958 vmem = dma_alloc_coherent(&hdev->device,
959 round_up(request_size, PAGE_SIZE),
961 GFP_KERNEL | __GFP_NOWARN);
966 paddr = virt_to_phys(vmem);
972 /* Release contiguous physical memory */
973 static void hvfb_release_phymem(struct hv_device *hdev,
974 phys_addr_t paddr, unsigned int size)
976 unsigned int order = get_order(size);
978 if (order < MAX_ORDER)
979 __free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
981 dma_free_coherent(&hdev->device,
982 round_up(size, PAGE_SIZE),
988 /* Get framebuffer memory from Hyper-V video pci space */
989 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
991 struct hvfb_par *par = info->par;
992 struct pci_dev *pdev = NULL;
993 void __iomem *fb_virt;
994 int gen2vm = efi_enabled(EFI_BOOT);
998 info->apertures = alloc_apertures(1);
999 if (!info->apertures)
1003 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1004 PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1006 pr_err("Unable to find PCI Hyper-V video\n");
1010 info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1011 info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1014 * For Gen 1 VM, we can directly use the contiguous memory
1015 * from VM. If we succeed, deferred IO happens directly
1016 * on this allocated framebuffer memory, avoiding extra
1019 paddr = hvfb_get_phymem(hdev, screen_fb_size);
1020 if (paddr != (phys_addr_t) -1) {
1021 par->mmio_pp = paddr;
1022 par->mmio_vp = par->dio_vp = __va(paddr);
1024 info->fix.smem_start = paddr;
1025 info->fix.smem_len = screen_fb_size;
1026 info->screen_base = par->mmio_vp;
1027 info->screen_size = screen_fb_size;
1029 par->need_docopy = false;
1032 pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1034 info->apertures->ranges[0].base = screen_info.lfb_base;
1035 info->apertures->ranges[0].size = screen_info.lfb_size;
1039 * Cannot use the contiguous physical memory.
1040 * Allocate mmio space for framebuffer.
1043 screen_width * screen_height * screen_depth / 8;
1045 ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
1046 screen_fb_size, 0x100000, true);
1048 pr_err("Unable to allocate framebuffer memory\n");
1053 * Map the VRAM cacheable for performance. This is also required for
1054 * VM Connect to display properly for ARM64 Linux VM, as the host also
1055 * maps the VRAM cacheable.
1057 fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1061 /* Allocate memory for deferred IO */
1062 par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1063 if (par->dio_vp == NULL)
1066 /* Physical address of FB device */
1067 par->mmio_pp = par->mem->start;
1068 /* Virtual address of FB device */
1069 par->mmio_vp = (unsigned char *) fb_virt;
1071 info->fix.smem_start = par->mem->start;
1072 info->fix.smem_len = dio_fb_size;
1073 info->screen_base = par->dio_vp;
1074 info->screen_size = dio_fb_size;
1077 remove_conflicting_framebuffers(info->apertures,
1078 KBUILD_MODNAME, false);
1081 /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1082 screen_info.lfb_size = 0;
1083 screen_info.lfb_base = 0;
1084 screen_info.orig_video_isVGA = 0;
1094 vmbus_free_mmio(par->mem->start, screen_fb_size);
1103 /* Release the framebuffer */
1104 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1106 struct hvfb_par *par = info->par;
1108 if (par->need_docopy) {
1110 iounmap(info->screen_base);
1111 vmbus_free_mmio(par->mem->start, screen_fb_size);
1113 hvfb_release_phymem(hdev, info->fix.smem_start,
1121 static int hvfb_probe(struct hv_device *hdev,
1122 const struct hv_vmbus_device_id *dev_id)
1124 struct fb_info *info;
1125 struct hvfb_par *par;
1128 info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1134 par->fb_ready = false;
1135 par->need_docopy = true;
1136 init_completion(&par->wait);
1137 INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1139 par->delayed_refresh = false;
1140 spin_lock_init(&par->delayed_refresh_lock);
1141 par->x1 = par->y1 = INT_MAX;
1142 par->x2 = par->y2 = 0;
1144 /* Connect to VSP */
1145 hv_set_drvdata(hdev, info);
1146 ret = synthvid_connect_vsp(hdev);
1148 pr_err("Unable to connect to VSP\n");
1152 hvfb_get_option(info);
1153 pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1154 screen_width, screen_height, screen_depth, screen_fb_size);
1156 ret = hvfb_getmem(hdev, info);
1158 pr_err("No memory for framebuffer\n");
1162 /* Set up fb_info */
1163 info->flags = FBINFO_DEFAULT;
1165 info->var.xres_virtual = info->var.xres = screen_width;
1166 info->var.yres_virtual = info->var.yres = screen_height;
1167 info->var.bits_per_pixel = screen_depth;
1169 if (info->var.bits_per_pixel == 16) {
1170 info->var.red = (struct fb_bitfield){11, 5, 0};
1171 info->var.green = (struct fb_bitfield){5, 6, 0};
1172 info->var.blue = (struct fb_bitfield){0, 5, 0};
1173 info->var.transp = (struct fb_bitfield){0, 0, 0};
1175 info->var.red = (struct fb_bitfield){16, 8, 0};
1176 info->var.green = (struct fb_bitfield){8, 8, 0};
1177 info->var.blue = (struct fb_bitfield){0, 8, 0};
1178 info->var.transp = (struct fb_bitfield){24, 8, 0};
1181 info->var.activate = FB_ACTIVATE_NOW;
1182 info->var.height = -1;
1183 info->var.width = -1;
1184 info->var.vmode = FB_VMODE_NONINTERLACED;
1186 strcpy(info->fix.id, KBUILD_MODNAME);
1187 info->fix.type = FB_TYPE_PACKED_PIXELS;
1188 info->fix.visual = FB_VISUAL_TRUECOLOR;
1189 info->fix.line_length = screen_width * screen_depth / 8;
1190 info->fix.accel = FB_ACCEL_NONE;
1192 info->fbops = &hvfb_ops;
1193 info->pseudo_palette = par->pseudo_palette;
1195 /* Initialize deferred IO */
1196 info->fbdefio = &synthvid_defio;
1197 fb_deferred_io_init(info);
1199 /* Send config to host */
1200 ret = synthvid_send_config(hdev);
1204 ret = register_framebuffer(info);
1206 pr_err("Unable to register framebuffer\n");
1210 par->fb_ready = true;
1212 par->synchronous_fb = false;
1213 par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1214 atomic_notifier_chain_register(&panic_notifier_list,
1215 &par->hvfb_panic_nb);
1220 fb_deferred_io_cleanup(info);
1221 hvfb_putmem(hdev, info);
1223 vmbus_close(hdev->channel);
1225 cancel_delayed_work_sync(&par->dwork);
1226 hv_set_drvdata(hdev, NULL);
1227 framebuffer_release(info);
1232 static int hvfb_remove(struct hv_device *hdev)
1234 struct fb_info *info = hv_get_drvdata(hdev);
1235 struct hvfb_par *par = info->par;
1237 atomic_notifier_chain_unregister(&panic_notifier_list,
1238 &par->hvfb_panic_nb);
1240 par->update = false;
1241 par->fb_ready = false;
1243 fb_deferred_io_cleanup(info);
1245 unregister_framebuffer(info);
1246 cancel_delayed_work_sync(&par->dwork);
1248 vmbus_close(hdev->channel);
1249 hv_set_drvdata(hdev, NULL);
1251 hvfb_putmem(hdev, info);
1252 framebuffer_release(info);
1257 static int hvfb_suspend(struct hv_device *hdev)
1259 struct fb_info *info = hv_get_drvdata(hdev);
1260 struct hvfb_par *par = info->par;
1264 /* 1 means do suspend */
1265 fb_set_suspend(info, 1);
1267 cancel_delayed_work_sync(&par->dwork);
1268 cancel_delayed_work_sync(&info->deferred_work);
1270 par->update_saved = par->update;
1271 par->update = false;
1272 par->fb_ready = false;
1274 vmbus_close(hdev->channel);
1281 static int hvfb_resume(struct hv_device *hdev)
1283 struct fb_info *info = hv_get_drvdata(hdev);
1284 struct hvfb_par *par = info->par;
1289 ret = synthvid_connect_vsp(hdev);
1293 ret = synthvid_send_config(hdev);
1295 vmbus_close(hdev->channel);
1299 par->fb_ready = true;
1300 par->update = par->update_saved;
1302 schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1303 schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1305 /* 0 means do resume */
1306 fb_set_suspend(info, 0);
1315 static const struct pci_device_id pci_stub_id_table[] = {
1317 .vendor = PCI_VENDOR_ID_MICROSOFT,
1318 .device = PCI_DEVICE_ID_HYPERV_VIDEO,
1320 { /* end of list */ }
1323 static const struct hv_vmbus_device_id id_table[] = {
1324 /* Synthetic Video Device GUID */
1329 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1330 MODULE_DEVICE_TABLE(vmbus, id_table);
1332 static struct hv_driver hvfb_drv = {
1333 .name = KBUILD_MODNAME,
1334 .id_table = id_table,
1335 .probe = hvfb_probe,
1336 .remove = hvfb_remove,
1337 .suspend = hvfb_suspend,
1338 .resume = hvfb_resume,
1340 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1344 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1345 const struct pci_device_id *ent)
1350 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1354 static struct pci_driver hvfb_pci_stub_driver = {
1355 .name = KBUILD_MODNAME,
1356 .id_table = pci_stub_id_table,
1357 .probe = hvfb_pci_stub_probe,
1358 .remove = hvfb_pci_stub_remove,
1360 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1364 static int __init hvfb_drv_init(void)
1368 ret = vmbus_driver_register(&hvfb_drv);
1372 ret = pci_register_driver(&hvfb_pci_stub_driver);
1374 vmbus_driver_unregister(&hvfb_drv);
1381 static void __exit hvfb_drv_exit(void)
1383 pci_unregister_driver(&hvfb_pci_stub_driver);
1384 vmbus_driver_unregister(&hvfb_drv);
1387 module_init(hvfb_drv_init);
1388 module_exit(hvfb_drv_exit);
1390 MODULE_LICENSE("GPL");
1391 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");