Quelle  hyperv_drm_proto.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2021 Microsoft
 *
 * Portions of this code is derived from hyperv_fb.c
 */

#include <linux/hyperv.h>

#include <drm/drm_print.h>
#include <drm/drm_simple_kms_helper.h>

#include "hyperv_drm.h"

#define VMBUS_RING_BUFSIZE (256 * 1024)
#define VMBUS_VSP_TIMEOUT (10 * HZ)

#define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
#define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
#define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)

/* Support for VERSION_WIN7 is removed. #define is retained for reference. */
#define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
#define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
#define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)

#define SYNTHVID_DEPTH_WIN8 32
#define SYNTHVID_WIDTH_WIN8 1600
#define SYNTHVID_HEIGHT_WIN8 1200
#define SYNTHVID_FB_SIZE_WIN8 (8 * 1024 * 1024)

enum pipe_msg_type {
 PIPE_MSG_INVALID,
 PIPE_MSG_DATA,
 PIPE_MSG_MAX
};

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
};

struct pipe_msg_hdr {
 u32 type;
 u32 size; /* size of message after this field */
} __packed;

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_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 SYNTHVID_CURSOR_MAX_X 96
#define SYNTHVID_CURSOR_MAX_Y 96
#define SYNTHVID_CURSOR_ARGB_PIXEL_SIZE 4
#define SYNTHVID_CURSOR_MAX_SIZE (SYNTHVID_CURSOR_MAX_X * \
 SYNTHVID_CURSOR_MAX_Y * SYNTHVID_CURSOR_ARGB_PIXEL_SIZE)
#define SYNTHVID_CURSOR_COMPLETE (-1)

struct synthvid_pointer_shape {
 u8 part_idx;
 u8 is_argb;
 u32 width; /* SYNTHVID_CURSOR_MAX_X at most */
 u32 height; /* SYNTHVID_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;

#define SYNTHVID_EDID_BLOCK_SIZE 128
#define SYNTHVID_MAX_RESOLUTION_COUNT 64

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_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;

static inline bool hyperv_version_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;
}

static inline int hyperv_sendpacket(struct hv_device *hdev, struct synthvid_msg *msg)
{
 static atomic64_t request_id = ATOMIC64_INIT(0);
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 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)
  drm_err_ratelimited(&hv->dev, "Unable to send packet via vmbus; error %d\n", ret);

 return ret;
}

static int hyperv_negotiate_version(struct hv_device *hdev, u32 ver)
{
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct synthvid_msg *msg = (struct synthvid_msg *)hv->init_buf;
 struct drm_device *dev = &hv->dev;
 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;
 hyperv_sendpacket(hdev, msg);

 t = wait_for_completion_timeout(&hv->wait, VMBUS_VSP_TIMEOUT);
 if (!t) {
  drm_err(dev, "Time out on waiting version response\n");
  return -ETIMEDOUT;
 }

 if (!msg->ver_resp.is_accepted) {
  drm_err(dev, "Version request not accepted\n");
  return -ENODEV;
 }

 hv->synthvid_version = ver;
 drm_info(dev, "Synthvid Version major %d, minor %d\n",
   SYNTHVID_VER_GET_MAJOR(ver), SYNTHVID_VER_GET_MINOR(ver));

 return 0;
}

int hyperv_update_vram_location(struct hv_device *hdev, phys_addr_t vram_pp)
{
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct synthvid_msg *msg = (struct synthvid_msg *)hv->init_buf;
 struct drm_device *dev = &hv->dev;
 unsigned long t;

 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 = vram_pp;
 msg->vram.vram_gpa = vram_pp;
 msg->vram.is_vram_gpa_specified = 1;
 hyperv_sendpacket(hdev, msg);

 t = wait_for_completion_timeout(&hv->wait, VMBUS_VSP_TIMEOUT);
 if (!t) {
  drm_err(dev, "Time out on waiting vram location ack\n");
  return -ETIMEDOUT;
 }
 if (msg->vram_ack.user_ctx != vram_pp) {
  drm_err(dev, "Unable to set VRAM location\n");
  return -ENODEV;
 }

 return 0;
}

int hyperv_update_situation(struct hv_device *hdev, u8 active, u32 bpp,
       u32 w, u32 h, u32 pitch)
{
 struct synthvid_msg msg;

 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 = active;
 /* vram_offset should always be 0 */
 msg.situ.video_output[0].vram_offset = 0;
 msg.situ.video_output[0].depth_bits = bpp;
 msg.situ.video_output[0].width_pixels = w;
 msg.situ.video_output[0].height_pixels = h;
 msg.situ.video_output[0].pitch_bytes = pitch;

 hyperv_sendpacket(hdev, &msg);

 return 0;
}

/*
 * Hyper-V supports a hardware cursor feature. It's not used by Linux VM,
 * but the Hyper-V host still draws a point as an extra mouse pointer,
 * which is unwanted, especially when Xorg is running.
 *
 * The hyperv_fb driver uses synthvid_send_ptr() to hide the unwanted
 * pointer, by setting msg.ptr_pos.is_visible = 1 and setting the
 * msg.ptr_shape.data. Note: setting msg.ptr_pos.is_visible to 0 doesn't
 * work in tests.
 *
 * Copy synthvid_send_ptr() to hyperv_drm and rename it to
 * hyperv_hide_hw_ptr(). Note: hyperv_hide_hw_ptr() is also called in the
 * handler of the SYNTHVID_FEATURE_CHANGE event, otherwise the host still
 * draws an extra unwanted mouse pointer after the VM Connection window is
 * closed and reopened.
 */
int hyperv_hide_hw_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;
 hyperv_sendpacket(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 = SYNTHVID_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;
 hyperv_sendpacket(hdev, &msg);

 return 0;
}

int hyperv_update_dirt(struct hv_device *hdev, struct drm_rect *rect)
{
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct synthvid_msg msg;

 if (!hv->dirt_needed)
  return 0;

 memset(&msg, 0, sizeof(struct synthvid_msg));

 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 = rect->x1;
 msg.dirt.rect[0].y1 = rect->y1;
 msg.dirt.rect[0].x2 = rect->x2;
 msg.dirt.rect[0].y2 = rect->y2;

 hyperv_sendpacket(hdev, &msg);

 return 0;
}

static int hyperv_get_supported_resolution(struct hv_device *hdev)
{
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct synthvid_msg *msg = (struct synthvid_msg *)hv->init_buf;
 struct drm_device *dev = &hv->dev;
 unsigned long t;
 u8 index;
 int i;

 memset(msg, 0, sizeof(struct synthvid_msg));
 msg->vid_hdr.type = SYNTHVID_RESOLUTION_REQUEST;
 msg->vid_hdr.size = sizeof(struct synthvid_msg_hdr) +
  sizeof(struct synthvid_supported_resolution_req);
 msg->resolution_req.maximum_resolution_count =
  SYNTHVID_MAX_RESOLUTION_COUNT;
 hyperv_sendpacket(hdev, msg);

 t = wait_for_completion_timeout(&hv->wait, VMBUS_VSP_TIMEOUT);
 if (!t) {
  drm_err(dev, "Time out on waiting resolution response\n");
  return -ETIMEDOUT;
 }

 if (msg->resolution_resp.resolution_count == 0) {
  drm_err(dev, "No supported resolutions\n");
  return -ENODEV;
 }

 index = msg->resolution_resp.default_resolution_index;
 if (index >= msg->resolution_resp.resolution_count) {
  drm_err(dev, "Invalid resolution index: %d\n", index);
  return -ENODEV;
 }

 for (i = 0; i < msg->resolution_resp.resolution_count; i++) {
  hv->screen_width_max = max_t(u32, hv->screen_width_max,
   msg->resolution_resp.supported_resolution[i].width);
  hv->screen_height_max = max_t(u32, hv->screen_height_max,
   msg->resolution_resp.supported_resolution[i].height);
 }

 hv->preferred_width =
  msg->resolution_resp.supported_resolution[index].width;
 hv->preferred_height =
  msg->resolution_resp.supported_resolution[index].height;

 return 0;
}

static void hyperv_receive_sub(struct hv_device *hdev)
{
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct synthvid_msg *msg;

 if (!hv)
  return;

 msg = (struct synthvid_msg *)hv->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(hv->init_buf, msg, VMBUS_MAX_PACKET_SIZE);
  complete(&hv->wait);
  return;
 }

 if (msg->vid_hdr.type == SYNTHVID_FEATURE_CHANGE) {
  hv->dirt_needed = msg->feature_chg.is_dirt_needed;
  if (hv->dirt_needed)
   hyperv_hide_hw_ptr(hv->hdev);
 }
}

static void hyperv_receive(void *ctx)
{
 struct hv_device *hdev = ctx;
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct synthvid_msg *recv_buf;
 u32 bytes_recvd;
 u64 req_id;
 int ret;

 if (!hv)
  return;

 recv_buf = (struct synthvid_msg *)hv->recv_buf;

 do {
  ret = vmbus_recvpacket(hdev->channel, recv_buf,
           VMBUS_MAX_PACKET_SIZE,
           &bytes_recvd, &req_id);
  if (bytes_recvd > 0 &&
      recv_buf->pipe_hdr.type == PIPE_MSG_DATA)
   hyperv_receive_sub(hdev);
 } while (bytes_recvd > 0 && ret == 0);
}

int hyperv_connect_vsp(struct hv_device *hdev)
{
 struct hyperv_drm_device *hv = hv_get_drvdata(hdev);
 struct drm_device *dev = &hv->dev;
 int ret;

 ret = vmbus_open(hdev->channel, VMBUS_RING_BUFSIZE, VMBUS_RING_BUFSIZE,
    NULL, 0, hyperv_receive, hdev);
 if (ret) {
  drm_err(dev, "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 = hyperv_negotiate_version(hdev, SYNTHVID_VERSION_WIN10);
  if (!ret)
   break;
  fallthrough;
 case VERSION_WIN8:
 case VERSION_WIN8_1:
  ret = hyperv_negotiate_version(hdev, SYNTHVID_VERSION_WIN8);
  break;
 default:
  ret = hyperv_negotiate_version(hdev, SYNTHVID_VERSION_WIN10);
  break;
 }

 if (ret) {
  drm_err(dev, "Synthetic video device version not accepted %d\n", ret);
  goto error;
 }

 hv->screen_depth = SYNTHVID_DEPTH_WIN8;

 if (hyperv_version_ge(hv->synthvid_version, SYNTHVID_VERSION_WIN10)) {
  ret = hyperv_get_supported_resolution(hdev);
  if (ret)
   drm_err(dev, "Failed to get supported resolution from host, use default\n");
 } else {
  hv->screen_width_max = SYNTHVID_WIDTH_WIN8;
  hv->screen_height_max = SYNTHVID_HEIGHT_WIN8;
 }

 hv->mmio_megabytes = hdev->channel->offermsg.offer.mmio_megabytes;

 return 0;

error:
 vmbus_close(hdev->channel);
 return ret;
}