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/aperture.h>
49 #include <linux/module.h>
50 #include <linux/kernel.h>
51 #include <linux/vmalloc.h>
52 #include <linux/init.h>
53 #include <linux/completion.h>
55 #include <linux/pci.h>
56 #include <linux/panic_notifier.h>
57 #include <linux/efi.h>
58 #include <linux/console.h>
60 #include <linux/hyperv.h>
63 /* Hyper-V Synthetic Video Protocol definitions and structures */
64 #define MAX_VMBUS_PKT_SIZE 0x4000
66 #define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
67 /* Support for VERSION_WIN7 is removed. #define is retained for reference. */
68 #define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
69 #define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
70 #define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)
72 #define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
73 #define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)
75 #define SYNTHVID_DEPTH_WIN8 32
76 #define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)
86 u32 size; /* size of message after this field */
90 enum synthvid_msg_type {
92 SYNTHVID_VERSION_REQUEST = 1,
93 SYNTHVID_VERSION_RESPONSE = 2,
94 SYNTHVID_VRAM_LOCATION = 3,
95 SYNTHVID_VRAM_LOCATION_ACK = 4,
96 SYNTHVID_SITUATION_UPDATE = 5,
97 SYNTHVID_SITUATION_UPDATE_ACK = 6,
98 SYNTHVID_POINTER_POSITION = 7,
99 SYNTHVID_POINTER_SHAPE = 8,
100 SYNTHVID_FEATURE_CHANGE = 9,
102 SYNTHVID_RESOLUTION_REQUEST = 13,
103 SYNTHVID_RESOLUTION_RESPONSE = 14,
108 #define SYNTHVID_EDID_BLOCK_SIZE 128
109 #define SYNTHVID_MAX_RESOLUTION_COUNT 64
111 struct hvd_screen_info {
116 struct synthvid_msg_hdr {
118 u32 size; /* size of this header + payload after this field*/
121 struct synthvid_version_req {
125 struct synthvid_version_resp {
128 u8 max_video_outputs;
131 struct synthvid_supported_resolution_req {
132 u8 maximum_resolution_count;
135 struct synthvid_supported_resolution_resp {
136 u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
138 u8 default_resolution_index;
140 struct hvd_screen_info
141 supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
144 struct synthvid_vram_location {
146 u8 is_vram_gpa_specified;
150 struct synthvid_vram_location_ack {
154 struct video_output_situation {
163 struct synthvid_situation_update {
165 u8 video_output_count;
166 struct video_output_situation video_output[1];
169 struct synthvid_situation_update_ack {
173 struct synthvid_pointer_position {
181 #define CURSOR_MAX_X 96
182 #define CURSOR_MAX_Y 96
183 #define CURSOR_ARGB_PIXEL_SIZE 4
184 #define CURSOR_MAX_SIZE (CURSOR_MAX_X * CURSOR_MAX_Y * CURSOR_ARGB_PIXEL_SIZE)
185 #define CURSOR_COMPLETE (-1)
187 struct synthvid_pointer_shape {
190 u32 width; /* CURSOR_MAX_X at most */
191 u32 height; /* CURSOR_MAX_Y at most */
192 u32 hot_x; /* hotspot relative to upper-left of pointer image */
197 struct synthvid_feature_change {
199 u8 is_ptr_pos_needed;
200 u8 is_ptr_shape_needed;
205 s32 x1, y1; /* top left corner */
206 s32 x2, y2; /* bottom right corner, exclusive */
209 struct synthvid_dirt {
215 struct synthvid_msg {
216 struct pipe_msg_hdr pipe_hdr;
217 struct synthvid_msg_hdr vid_hdr;
219 struct synthvid_version_req ver_req;
220 struct synthvid_version_resp ver_resp;
221 struct synthvid_vram_location vram;
222 struct synthvid_vram_location_ack vram_ack;
223 struct synthvid_situation_update situ;
224 struct synthvid_situation_update_ack situ_ack;
225 struct synthvid_pointer_position ptr_pos;
226 struct synthvid_pointer_shape ptr_shape;
227 struct synthvid_feature_change feature_chg;
228 struct synthvid_dirt dirt;
229 struct synthvid_supported_resolution_req resolution_req;
230 struct synthvid_supported_resolution_resp resolution_resp;
235 /* FB driver definitions and structures */
236 #define HVFB_WIDTH 1152 /* default screen width */
237 #define HVFB_HEIGHT 864 /* default screen height */
238 #define HVFB_WIDTH_MIN 640
239 #define HVFB_HEIGHT_MIN 480
241 #define RING_BUFSIZE (256 * 1024)
242 #define VSP_TIMEOUT (10 * HZ)
243 #define HVFB_UPDATE_DELAY (HZ / 20)
244 #define HVFB_ONDEMAND_THROTTLE (HZ / 20)
247 struct fb_info *info;
248 struct resource *mem;
249 bool fb_ready; /* fb device is ready */
250 struct completion wait;
251 u32 synthvid_version;
253 struct delayed_work dwork;
255 bool update_saved; /* The value of 'update' before hibernation */
257 u32 pseudo_palette[16];
258 u8 init_buf[MAX_VMBUS_PKT_SIZE];
259 u8 recv_buf[MAX_VMBUS_PKT_SIZE];
261 /* If true, the VSC notifies the VSP on every framebuffer change */
264 /* If true, need to copy from deferred IO mem to framebuffer mem */
267 struct notifier_block hvfb_panic_nb;
269 /* Memory for deferred IO and frame buffer itself */
270 unsigned char *dio_vp;
271 unsigned char *mmio_vp;
274 /* Dirty rectangle, protected by delayed_refresh_lock */
276 bool delayed_refresh;
277 spinlock_t delayed_refresh_lock;
280 static uint screen_width = HVFB_WIDTH;
281 static uint screen_height = HVFB_HEIGHT;
282 static uint screen_depth;
283 static uint screen_fb_size;
284 static uint dio_fb_size; /* FB size for deferred IO */
286 /* Send message to Hyper-V host */
287 static inline int synthvid_send(struct hv_device *hdev,
288 struct synthvid_msg *msg)
290 static atomic64_t request_id = ATOMIC64_INIT(0);
293 msg->pipe_hdr.type = PIPE_MSG_DATA;
294 msg->pipe_hdr.size = msg->vid_hdr.size;
296 ret = vmbus_sendpacket(hdev->channel, msg,
297 msg->vid_hdr.size + sizeof(struct pipe_msg_hdr),
298 atomic64_inc_return(&request_id),
299 VM_PKT_DATA_INBAND, 0);
302 pr_err_ratelimited("Unable to send packet via vmbus; error %d\n", ret);
308 /* Send screen resolution info to host */
309 static int synthvid_send_situ(struct hv_device *hdev)
311 struct fb_info *info = hv_get_drvdata(hdev);
312 struct synthvid_msg msg;
317 memset(&msg, 0, sizeof(struct synthvid_msg));
319 msg.vid_hdr.type = SYNTHVID_SITUATION_UPDATE;
320 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
321 sizeof(struct synthvid_situation_update);
322 msg.situ.user_ctx = 0;
323 msg.situ.video_output_count = 1;
324 msg.situ.video_output[0].active = 1;
325 msg.situ.video_output[0].vram_offset = 0;
326 msg.situ.video_output[0].depth_bits = info->var.bits_per_pixel;
327 msg.situ.video_output[0].width_pixels = info->var.xres;
328 msg.situ.video_output[0].height_pixels = info->var.yres;
329 msg.situ.video_output[0].pitch_bytes = info->fix.line_length;
331 synthvid_send(hdev, &msg);
336 /* Send mouse pointer info to host */
337 static int synthvid_send_ptr(struct hv_device *hdev)
339 struct synthvid_msg msg;
341 memset(&msg, 0, sizeof(struct synthvid_msg));
342 msg.vid_hdr.type = SYNTHVID_POINTER_POSITION;
343 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
344 sizeof(struct synthvid_pointer_position);
345 msg.ptr_pos.is_visible = 1;
346 msg.ptr_pos.video_output = 0;
347 msg.ptr_pos.image_x = 0;
348 msg.ptr_pos.image_y = 0;
349 synthvid_send(hdev, &msg);
351 memset(&msg, 0, sizeof(struct synthvid_msg));
352 msg.vid_hdr.type = SYNTHVID_POINTER_SHAPE;
353 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
354 sizeof(struct synthvid_pointer_shape);
355 msg.ptr_shape.part_idx = CURSOR_COMPLETE;
356 msg.ptr_shape.is_argb = 1;
357 msg.ptr_shape.width = 1;
358 msg.ptr_shape.height = 1;
359 msg.ptr_shape.hot_x = 0;
360 msg.ptr_shape.hot_y = 0;
361 msg.ptr_shape.data[0] = 0;
362 msg.ptr_shape.data[1] = 1;
363 msg.ptr_shape.data[2] = 1;
364 msg.ptr_shape.data[3] = 1;
365 synthvid_send(hdev, &msg);
370 /* Send updated screen area (dirty rectangle) location to host */
372 synthvid_update(struct fb_info *info, int x1, int y1, int x2, int y2)
374 struct hv_device *hdev = device_to_hv_device(info->device);
375 struct synthvid_msg msg;
377 memset(&msg, 0, sizeof(struct synthvid_msg));
383 msg.vid_hdr.type = SYNTHVID_DIRT;
384 msg.vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
385 sizeof(struct synthvid_dirt);
386 msg.dirt.video_output = 0;
387 msg.dirt.dirt_count = 1;
388 msg.dirt.rect[0].x1 = (x1 > x2) ? 0 : x1;
389 msg.dirt.rect[0].y1 = (y1 > y2) ? 0 : y1;
390 msg.dirt.rect[0].x2 =
391 (x2 < x1 || x2 > info->var.xres) ? info->var.xres : x2;
392 msg.dirt.rect[0].y2 =
393 (y2 < y1 || y2 > info->var.yres) ? info->var.yres : y2;
395 synthvid_send(hdev, &msg);
400 static void hvfb_docopy(struct hvfb_par *par,
401 unsigned long offset,
404 if (!par || !par->mmio_vp || !par->dio_vp || !par->fb_ready ||
405 size == 0 || offset >= dio_fb_size)
408 if (offset + size > dio_fb_size)
409 size = dio_fb_size - offset;
411 memcpy(par->mmio_vp + offset, par->dio_vp + offset, size);
414 /* Deferred IO callback */
415 static void synthvid_deferred_io(struct fb_info *p, struct list_head *pagereflist)
417 struct hvfb_par *par = p->par;
418 struct fb_deferred_io_pageref *pageref;
419 unsigned long start, end;
420 int y1, y2, miny, maxy;
426 * Merge dirty pages. It is possible that last page cross
427 * over the end of frame buffer row yres. This is taken care of
428 * in synthvid_update function by clamping the y2
431 list_for_each_entry(pageref, pagereflist, list) {
432 start = pageref->offset;
433 end = start + PAGE_SIZE - 1;
434 y1 = start / p->fix.line_length;
435 y2 = end / p->fix.line_length;
436 miny = min_t(int, miny, y1);
437 maxy = max_t(int, maxy, y2);
439 /* Copy from dio space to mmio address */
440 if (par->fb_ready && par->need_docopy)
441 hvfb_docopy(par, start, PAGE_SIZE);
444 if (par->fb_ready && par->update)
445 synthvid_update(p, 0, miny, p->var.xres, maxy + 1);
448 static struct fb_deferred_io synthvid_defio = {
450 .deferred_io = synthvid_deferred_io,
454 * Actions on received messages from host:
455 * Complete the wait event.
456 * Or, reply with screen and cursor info.
458 static void synthvid_recv_sub(struct hv_device *hdev)
460 struct fb_info *info = hv_get_drvdata(hdev);
461 struct hvfb_par *par;
462 struct synthvid_msg *msg;
468 msg = (struct synthvid_msg *)par->recv_buf;
470 /* Complete the wait event */
471 if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
472 msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
473 msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
474 memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
475 complete(&par->wait);
479 /* Reply with screen and cursor info */
480 if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
482 synthvid_send_ptr(hdev);
483 synthvid_send_situ(hdev);
486 par->update = msg->feature_chg.is_dirt_needed;
488 schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
492 /* Receive callback for messages from the host */
493 static void synthvid_receive(void *ctx)
495 struct hv_device *hdev = ctx;
496 struct fb_info *info = hv_get_drvdata(hdev);
497 struct hvfb_par *par;
498 struct synthvid_msg *recv_buf;
507 recv_buf = (struct synthvid_msg *)par->recv_buf;
510 ret = vmbus_recvpacket(hdev->channel, recv_buf,
512 &bytes_recvd, &req_id);
513 if (bytes_recvd > 0 &&
514 recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
515 synthvid_recv_sub(hdev);
516 } while (bytes_recvd > 0 && ret == 0);
519 /* Check if the ver1 version is equal or greater than ver2 */
520 static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
522 if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
523 (SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
524 SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
530 /* Check synthetic video protocol version with the host */
531 static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
533 struct fb_info *info = hv_get_drvdata(hdev);
534 struct hvfb_par *par = info->par;
535 struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
539 memset(msg, 0, sizeof(struct synthvid_msg));
540 msg->vid_hdr.type = SYNTHVID_VERSION_REQUEST;
541 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
542 sizeof(struct synthvid_version_req);
543 msg->ver_req.version = ver;
544 synthvid_send(hdev, msg);
546 t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
548 pr_err("Time out on waiting version response\n");
552 if (!msg->ver_resp.is_accepted) {
557 par->synthvid_version = ver;
558 pr_info("Synthvid Version major %d, minor %d\n",
559 SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));
565 /* Get current resolution from the host */
566 static int synthvid_get_supported_resolution(struct hv_device *hdev)
568 struct fb_info *info = hv_get_drvdata(hdev);
569 struct hvfb_par *par = info->par;
570 struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
575 memset(msg, 0, sizeof(struct synthvid_msg));
576 msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
577 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
578 sizeof(struct synthvid_supported_resolution_req);
580 msg->resolution_req.maximum_resolution_count =
581 SYNTHVID_MAX_RESOLUTION_COUNT;
582 synthvid_send(hdev, msg);
584 t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
586 pr_err("Time out on waiting resolution response\n");
591 if (msg->resolution_resp.resolution_count == 0) {
592 pr_err("No supported resolutions\n");
597 index = msg->resolution_resp.default_resolution_index;
598 if (index >= msg->resolution_resp.resolution_count) {
599 pr_err("Invalid resolution index: %d\n", index);
605 msg->resolution_resp.supported_resolution[index].width;
607 msg->resolution_resp.supported_resolution[index].height;
613 /* Connect to VSP (Virtual Service Provider) on host */
614 static int synthvid_connect_vsp(struct hv_device *hdev)
616 struct fb_info *info = hv_get_drvdata(hdev);
617 struct hvfb_par *par = info->par;
620 ret = vmbus_open(hdev->channel, RING_BUFSIZE, RING_BUFSIZE,
621 NULL, 0, synthvid_receive, hdev);
623 pr_err("Unable to open vmbus channel\n");
627 /* Negotiate the protocol version with host */
628 switch (vmbus_proto_version) {
630 case VERSION_WIN10_V5:
631 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
637 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
640 ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
645 pr_err("Synthetic video device version not accepted\n");
649 screen_depth = SYNTHVID_DEPTH_WIN8;
650 if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
651 ret = synthvid_get_supported_resolution(hdev);
653 pr_info("Failed to get supported resolution from host, use default\n");
656 screen_fb_size = hdev->channel->offermsg.offer.
657 mmio_megabytes * 1024 * 1024;
662 vmbus_close(hdev->channel);
666 /* Send VRAM and Situation messages to the host */
667 static int synthvid_send_config(struct hv_device *hdev)
669 struct fb_info *info = hv_get_drvdata(hdev);
670 struct hvfb_par *par = info->par;
671 struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
675 /* Send VRAM location */
676 memset(msg, 0, sizeof(struct synthvid_msg));
677 msg->vid_hdr.type = SYNTHVID_VRAM_LOCATION;
678 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
679 sizeof(struct synthvid_vram_location);
680 msg->vram.user_ctx = msg->vram.vram_gpa = par->mmio_pp;
681 msg->vram.is_vram_gpa_specified = 1;
682 synthvid_send(hdev, msg);
684 t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
686 pr_err("Time out on waiting vram location ack\n");
690 if (msg->vram_ack.user_ctx != par->mmio_pp) {
691 pr_err("Unable to set VRAM location\n");
696 /* Send pointer and situation update */
697 synthvid_send_ptr(hdev);
698 synthvid_send_situ(hdev);
706 * Delayed work callback:
707 * It is scheduled to call whenever update request is received and it has
708 * not been called in last HVFB_ONDEMAND_THROTTLE time interval.
710 static void hvfb_update_work(struct work_struct *w)
712 struct hvfb_par *par = container_of(w, struct hvfb_par, dwork.work);
713 struct fb_info *info = par->info;
718 spin_lock_irqsave(&par->delayed_refresh_lock, flags);
719 /* Reset the request flag */
720 par->delayed_refresh = false;
722 /* Store the dirty rectangle to local variables */
728 /* Clear dirty rectangle */
729 par->x1 = par->y1 = INT_MAX;
730 par->x2 = par->y2 = 0;
732 spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
734 if (x1 > info->var.xres || x2 > info->var.xres ||
735 y1 > info->var.yres || y2 > info->var.yres || x2 <= x1)
738 /* Copy the dirty rectangle to frame buffer memory */
739 if (par->need_docopy)
740 for (j = y1; j < y2; j++)
742 j * info->fix.line_length +
743 (x1 * screen_depth / 8),
744 (x2 - x1) * screen_depth / 8);
747 if (par->fb_ready && par->update)
748 synthvid_update(info, x1, y1, x2, y2);
752 * Control the on-demand refresh frequency. It schedules a delayed
753 * screen update if it has not yet.
755 static void hvfb_ondemand_refresh_throttle(struct hvfb_par *par,
756 int x1, int y1, int w, int h)
762 spin_lock_irqsave(&par->delayed_refresh_lock, flags);
764 /* Merge dirty rectangle */
765 par->x1 = min_t(int, par->x1, x1);
766 par->y1 = min_t(int, par->y1, y1);
767 par->x2 = max_t(int, par->x2, x2);
768 par->y2 = max_t(int, par->y2, y2);
770 /* Schedule a delayed screen update if not yet */
771 if (par->delayed_refresh == false) {
772 schedule_delayed_work(&par->dwork,
773 HVFB_ONDEMAND_THROTTLE);
774 par->delayed_refresh = true;
777 spin_unlock_irqrestore(&par->delayed_refresh_lock, flags);
780 static int hvfb_on_panic(struct notifier_block *nb,
781 unsigned long e, void *p)
783 struct hv_device *hdev;
784 struct hvfb_par *par;
785 struct fb_info *info;
787 par = container_of(nb, struct hvfb_par, hvfb_panic_nb);
789 hdev = device_to_hv_device(info->device);
791 if (hv_ringbuffer_spinlock_busy(hdev->channel))
794 par->synchronous_fb = true;
795 if (par->need_docopy)
796 hvfb_docopy(par, 0, dio_fb_size);
797 synthvid_update(info, 0, 0, INT_MAX, INT_MAX);
802 /* Framebuffer operation handlers */
804 static int hvfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
806 if (var->xres < HVFB_WIDTH_MIN || var->yres < HVFB_HEIGHT_MIN ||
807 var->xres > screen_width || var->yres > screen_height ||
808 var->bits_per_pixel != screen_depth)
811 var->xres_virtual = var->xres;
812 var->yres_virtual = var->yres;
817 static int hvfb_set_par(struct fb_info *info)
819 struct hv_device *hdev = device_to_hv_device(info->device);
821 return synthvid_send_situ(hdev);
825 static inline u32 chan_to_field(u32 chan, struct fb_bitfield *bf)
827 return ((chan & 0xffff) >> (16 - bf->length)) << bf->offset;
830 static int hvfb_setcolreg(unsigned regno, unsigned red, unsigned green,
831 unsigned blue, unsigned transp, struct fb_info *info)
833 u32 *pal = info->pseudo_palette;
838 pal[regno] = chan_to_field(red, &info->var.red)
839 | chan_to_field(green, &info->var.green)
840 | chan_to_field(blue, &info->var.blue)
841 | chan_to_field(transp, &info->var.transp);
846 static int hvfb_blank(int blank, struct fb_info *info)
848 return 1; /* get fb_blank to set the colormap to all black */
851 static void hvfb_cfb_fillrect(struct fb_info *p,
852 const struct fb_fillrect *rect)
854 struct hvfb_par *par = p->par;
856 cfb_fillrect(p, rect);
857 if (par->synchronous_fb)
858 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
860 hvfb_ondemand_refresh_throttle(par, rect->dx, rect->dy,
861 rect->width, rect->height);
864 static void hvfb_cfb_copyarea(struct fb_info *p,
865 const struct fb_copyarea *area)
867 struct hvfb_par *par = p->par;
869 cfb_copyarea(p, area);
870 if (par->synchronous_fb)
871 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
873 hvfb_ondemand_refresh_throttle(par, area->dx, area->dy,
874 area->width, area->height);
877 static void hvfb_cfb_imageblit(struct fb_info *p,
878 const struct fb_image *image)
880 struct hvfb_par *par = p->par;
882 cfb_imageblit(p, image);
883 if (par->synchronous_fb)
884 synthvid_update(p, 0, 0, INT_MAX, INT_MAX);
886 hvfb_ondemand_refresh_throttle(par, image->dx, image->dy,
887 image->width, image->height);
890 static const struct fb_ops hvfb_ops = {
891 .owner = THIS_MODULE,
892 .fb_check_var = hvfb_check_var,
893 .fb_set_par = hvfb_set_par,
894 .fb_setcolreg = hvfb_setcolreg,
895 .fb_fillrect = hvfb_cfb_fillrect,
896 .fb_copyarea = hvfb_cfb_copyarea,
897 .fb_imageblit = hvfb_cfb_imageblit,
898 .fb_blank = hvfb_blank,
899 .fb_mmap = fb_deferred_io_mmap,
903 /* Get options from kernel paramenter "video=" */
904 static void hvfb_get_option(struct fb_info *info)
906 struct hvfb_par *par = info->par;
907 char *opt = NULL, *p;
910 if (fb_get_options(KBUILD_MODNAME, &opt) || !opt || !*opt)
913 p = strsep(&opt, "x");
914 if (!*p || kstrtouint(p, 0, &x) ||
915 !opt || !*opt || kstrtouint(opt, 0, &y)) {
916 pr_err("Screen option is invalid: skipped\n");
920 if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
921 (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
922 (x * y * screen_depth / 8 > screen_fb_size)) ||
923 (par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
924 x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8)) {
925 pr_err("Screen resolution option is out of range: skipped\n");
935 * Allocate enough contiguous physical memory.
936 * Return physical address if succeeded or -1 if failed.
938 static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
939 unsigned int request_size)
941 struct page *page = NULL;
942 dma_addr_t dma_handle;
944 phys_addr_t paddr = 0;
945 unsigned int order = get_order(request_size);
947 if (request_size == 0)
950 if (order < MAX_ORDER) {
951 /* Call alloc_pages if the size is less than 2^MAX_ORDER */
952 page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
956 paddr = (page_to_pfn(page) << PAGE_SHIFT);
958 /* Allocate from CMA */
959 hdev->device.coherent_dma_mask = DMA_BIT_MASK(64);
961 vmem = dma_alloc_coherent(&hdev->device,
962 round_up(request_size, PAGE_SIZE),
964 GFP_KERNEL | __GFP_NOWARN);
969 paddr = virt_to_phys(vmem);
975 /* Release contiguous physical memory */
976 static void hvfb_release_phymem(struct hv_device *hdev,
977 phys_addr_t paddr, unsigned int size)
979 unsigned int order = get_order(size);
981 if (order < MAX_ORDER)
982 __free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
984 dma_free_coherent(&hdev->device,
985 round_up(size, PAGE_SIZE),
991 /* Get framebuffer memory from Hyper-V video pci space */
992 static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
994 struct hvfb_par *par = info->par;
995 struct pci_dev *pdev = NULL;
996 void __iomem *fb_virt;
997 int gen2vm = efi_enabled(EFI_BOOT);
1001 info->apertures = alloc_apertures(1);
1002 if (!info->apertures)
1006 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
1007 PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
1009 pr_err("Unable to find PCI Hyper-V video\n");
1013 info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
1014 info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
1017 * For Gen 1 VM, we can directly use the contiguous memory
1018 * from VM. If we succeed, deferred IO happens directly
1019 * on this allocated framebuffer memory, avoiding extra
1022 paddr = hvfb_get_phymem(hdev, screen_fb_size);
1023 if (paddr != (phys_addr_t) -1) {
1024 par->mmio_pp = paddr;
1025 par->mmio_vp = par->dio_vp = __va(paddr);
1027 info->fix.smem_start = paddr;
1028 info->fix.smem_len = screen_fb_size;
1029 info->screen_base = par->mmio_vp;
1030 info->screen_size = screen_fb_size;
1032 par->need_docopy = false;
1035 pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
1037 info->apertures->ranges[0].base = screen_info.lfb_base;
1038 info->apertures->ranges[0].size = screen_info.lfb_size;
1042 * Cannot use the contiguous physical memory.
1043 * Allocate mmio space for framebuffer.
1046 screen_width * screen_height * screen_depth / 8;
1048 ret = vmbus_allocate_mmio(&par->mem, hdev, 0, -1,
1049 screen_fb_size, 0x100000, true);
1051 pr_err("Unable to allocate framebuffer memory\n");
1056 * Map the VRAM cacheable for performance. This is also required for
1057 * VM Connect to display properly for ARM64 Linux VM, as the host also
1058 * maps the VRAM cacheable.
1060 fb_virt = ioremap_cache(par->mem->start, screen_fb_size);
1064 /* Allocate memory for deferred IO */
1065 par->dio_vp = vzalloc(round_up(dio_fb_size, PAGE_SIZE));
1066 if (par->dio_vp == NULL)
1069 /* Physical address of FB device */
1070 par->mmio_pp = par->mem->start;
1071 /* Virtual address of FB device */
1072 par->mmio_vp = (unsigned char *) fb_virt;
1074 info->fix.smem_start = par->mem->start;
1075 info->fix.smem_len = dio_fb_size;
1076 info->screen_base = par->dio_vp;
1077 info->screen_size = dio_fb_size;
1080 aperture_remove_conflicting_devices(info->apertures->ranges[0].base,
1081 info->apertures->ranges[0].size,
1082 false, KBUILD_MODNAME);
1085 /* framebuffer is reallocated, clear screen_info to avoid misuse from kexec */
1086 screen_info.lfb_size = 0;
1087 screen_info.lfb_base = 0;
1088 screen_info.orig_video_isVGA = 0;
1098 vmbus_free_mmio(par->mem->start, screen_fb_size);
1107 /* Release the framebuffer */
1108 static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
1110 struct hvfb_par *par = info->par;
1112 if (par->need_docopy) {
1114 iounmap(info->screen_base);
1115 vmbus_free_mmio(par->mem->start, screen_fb_size);
1117 hvfb_release_phymem(hdev, info->fix.smem_start,
1125 static int hvfb_probe(struct hv_device *hdev,
1126 const struct hv_vmbus_device_id *dev_id)
1128 struct fb_info *info;
1129 struct hvfb_par *par;
1132 info = framebuffer_alloc(sizeof(struct hvfb_par), &hdev->device);
1138 par->fb_ready = false;
1139 par->need_docopy = true;
1140 init_completion(&par->wait);
1141 INIT_DELAYED_WORK(&par->dwork, hvfb_update_work);
1143 par->delayed_refresh = false;
1144 spin_lock_init(&par->delayed_refresh_lock);
1145 par->x1 = par->y1 = INT_MAX;
1146 par->x2 = par->y2 = 0;
1148 /* Connect to VSP */
1149 hv_set_drvdata(hdev, info);
1150 ret = synthvid_connect_vsp(hdev);
1152 pr_err("Unable to connect to VSP\n");
1156 hvfb_get_option(info);
1157 pr_info("Screen resolution: %dx%d, Color depth: %d, Frame buffer size: %d\n",
1158 screen_width, screen_height, screen_depth, screen_fb_size);
1160 ret = hvfb_getmem(hdev, info);
1162 pr_err("No memory for framebuffer\n");
1166 /* Set up fb_info */
1167 info->flags = FBINFO_DEFAULT;
1169 info->var.xres_virtual = info->var.xres = screen_width;
1170 info->var.yres_virtual = info->var.yres = screen_height;
1171 info->var.bits_per_pixel = screen_depth;
1173 if (info->var.bits_per_pixel == 16) {
1174 info->var.red = (struct fb_bitfield){11, 5, 0};
1175 info->var.green = (struct fb_bitfield){5, 6, 0};
1176 info->var.blue = (struct fb_bitfield){0, 5, 0};
1177 info->var.transp = (struct fb_bitfield){0, 0, 0};
1179 info->var.red = (struct fb_bitfield){16, 8, 0};
1180 info->var.green = (struct fb_bitfield){8, 8, 0};
1181 info->var.blue = (struct fb_bitfield){0, 8, 0};
1182 info->var.transp = (struct fb_bitfield){24, 8, 0};
1185 info->var.activate = FB_ACTIVATE_NOW;
1186 info->var.height = -1;
1187 info->var.width = -1;
1188 info->var.vmode = FB_VMODE_NONINTERLACED;
1190 strcpy(info->fix.id, KBUILD_MODNAME);
1191 info->fix.type = FB_TYPE_PACKED_PIXELS;
1192 info->fix.visual = FB_VISUAL_TRUECOLOR;
1193 info->fix.line_length = screen_width * screen_depth / 8;
1194 info->fix.accel = FB_ACCEL_NONE;
1196 info->fbops = &hvfb_ops;
1197 info->pseudo_palette = par->pseudo_palette;
1199 /* Initialize deferred IO */
1200 info->fbdefio = &synthvid_defio;
1201 fb_deferred_io_init(info);
1203 /* Send config to host */
1204 ret = synthvid_send_config(hdev);
1208 ret = register_framebuffer(info);
1210 pr_err("Unable to register framebuffer\n");
1214 par->fb_ready = true;
1216 par->synchronous_fb = false;
1217 par->hvfb_panic_nb.notifier_call = hvfb_on_panic;
1218 atomic_notifier_chain_register(&panic_notifier_list,
1219 &par->hvfb_panic_nb);
1224 fb_deferred_io_cleanup(info);
1225 hvfb_putmem(hdev, info);
1227 vmbus_close(hdev->channel);
1229 cancel_delayed_work_sync(&par->dwork);
1230 hv_set_drvdata(hdev, NULL);
1231 framebuffer_release(info);
1236 static int hvfb_remove(struct hv_device *hdev)
1238 struct fb_info *info = hv_get_drvdata(hdev);
1239 struct hvfb_par *par = info->par;
1241 atomic_notifier_chain_unregister(&panic_notifier_list,
1242 &par->hvfb_panic_nb);
1244 par->update = false;
1245 par->fb_ready = false;
1247 fb_deferred_io_cleanup(info);
1249 unregister_framebuffer(info);
1250 cancel_delayed_work_sync(&par->dwork);
1252 vmbus_close(hdev->channel);
1253 hv_set_drvdata(hdev, NULL);
1255 hvfb_putmem(hdev, info);
1256 framebuffer_release(info);
1261 static int hvfb_suspend(struct hv_device *hdev)
1263 struct fb_info *info = hv_get_drvdata(hdev);
1264 struct hvfb_par *par = info->par;
1268 /* 1 means do suspend */
1269 fb_set_suspend(info, 1);
1271 cancel_delayed_work_sync(&par->dwork);
1272 cancel_delayed_work_sync(&info->deferred_work);
1274 par->update_saved = par->update;
1275 par->update = false;
1276 par->fb_ready = false;
1278 vmbus_close(hdev->channel);
1285 static int hvfb_resume(struct hv_device *hdev)
1287 struct fb_info *info = hv_get_drvdata(hdev);
1288 struct hvfb_par *par = info->par;
1293 ret = synthvid_connect_vsp(hdev);
1297 ret = synthvid_send_config(hdev);
1299 vmbus_close(hdev->channel);
1303 par->fb_ready = true;
1304 par->update = par->update_saved;
1306 schedule_delayed_work(&info->deferred_work, info->fbdefio->delay);
1307 schedule_delayed_work(&par->dwork, HVFB_UPDATE_DELAY);
1309 /* 0 means do resume */
1310 fb_set_suspend(info, 0);
1319 static const struct pci_device_id pci_stub_id_table[] = {
1321 .vendor = PCI_VENDOR_ID_MICROSOFT,
1322 .device = PCI_DEVICE_ID_HYPERV_VIDEO,
1324 { /* end of list */ }
1327 static const struct hv_vmbus_device_id id_table[] = {
1328 /* Synthetic Video Device GUID */
1333 MODULE_DEVICE_TABLE(pci, pci_stub_id_table);
1334 MODULE_DEVICE_TABLE(vmbus, id_table);
1336 static struct hv_driver hvfb_drv = {
1337 .name = KBUILD_MODNAME,
1338 .id_table = id_table,
1339 .probe = hvfb_probe,
1340 .remove = hvfb_remove,
1341 .suspend = hvfb_suspend,
1342 .resume = hvfb_resume,
1344 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1348 static int hvfb_pci_stub_probe(struct pci_dev *pdev,
1349 const struct pci_device_id *ent)
1354 static void hvfb_pci_stub_remove(struct pci_dev *pdev)
1358 static struct pci_driver hvfb_pci_stub_driver = {
1359 .name = KBUILD_MODNAME,
1360 .id_table = pci_stub_id_table,
1361 .probe = hvfb_pci_stub_probe,
1362 .remove = hvfb_pci_stub_remove,
1364 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1368 static int __init hvfb_drv_init(void)
1372 ret = vmbus_driver_register(&hvfb_drv);
1376 ret = pci_register_driver(&hvfb_pci_stub_driver);
1378 vmbus_driver_unregister(&hvfb_drv);
1385 static void __exit hvfb_drv_exit(void)
1387 pci_unregister_driver(&hvfb_pci_stub_driver);
1388 vmbus_driver_unregister(&hvfb_drv);
1391 module_init(hvfb_drv_init);
1392 module_exit(hvfb_drv_exit);
1394 MODULE_LICENSE("GPL");
1395 MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Video Frame Buffer Driver");