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video: hyperv: hyperv_fb: Obtain screen resolution from Hyper-V host
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Beginning from Windows 10 RS5+, VM screen resolution is obtained from host.
The "video=hyperv_fb" boot time 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.

Signed-off-by: Iouri Tarassov <iourit@microsoft.com>
Signed-off-by: Wei Hu <weh@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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Wei Hu authored and Sasha Levin committed Nov 4, 2019
1 parent 99f937b commit b389f9c
Showing 1 changed file with 147 additions and 12 deletions.
159 changes: 147 additions & 12 deletions drivers/video/fbdev/hyperv_fb.c
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Original file line number Diff line number Diff line change
Expand Up @@ -23,6 +23,14 @@
*
* Portrait orientation is also supported:
* For example: video=hyperv_fb:864x1152
*
* When a Windows 10 RS5+ host is used, the virtual machine screen
* resolution is obtained from the host. The "video=hyperv_fb" option is
* not needed, but still can be used to overwrite what the host specifies.
* The VM resolution on the host could be set by executing the powershell
* "set-vmvideo" command. For example
* set-vmvideo -vmname name -horizontalresolution:1920 \
* -verticalresolution:1200 -resolutiontype single
*/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Expand All @@ -45,6 +53,10 @@
#define SYNTHVID_VERSION(major, minor) ((minor) << 16 | (major))
#define SYNTHVID_VERSION_WIN7 SYNTHVID_VERSION(3, 0)
#define SYNTHVID_VERSION_WIN8 SYNTHVID_VERSION(3, 2)
#define SYNTHVID_VERSION_WIN10 SYNTHVID_VERSION(3, 5)

#define SYNTHVID_VER_GET_MAJOR(ver) (ver & 0x0000ffff)
#define SYNTHVID_VER_GET_MINOR(ver) ((ver & 0xffff0000) >> 16)

#define SYNTHVID_DEPTH_WIN7 16
#define SYNTHVID_DEPTH_WIN8 32
Expand Down Expand Up @@ -83,16 +95,25 @@ enum synthvid_msg_type {
SYNTHVID_POINTER_SHAPE = 8,
SYNTHVID_FEATURE_CHANGE = 9,
SYNTHVID_DIRT = 10,
SYNTHVID_RESOLUTION_REQUEST = 13,
SYNTHVID_RESOLUTION_RESPONSE = 14,

SYNTHVID_MAX = 11
SYNTHVID_MAX = 15
};

#define SYNTHVID_EDID_BLOCK_SIZE 128
#define SYNTHVID_MAX_RESOLUTION_COUNT 64

struct hvd_screen_info {
u16 width;
u16 height;
} __packed;

struct synthvid_msg_hdr {
u32 type;
u32 size; /* size of this header + payload after this field*/
} __packed;


struct synthvid_version_req {
u32 version;
} __packed;
Expand All @@ -103,6 +124,19 @@ struct synthvid_version_resp {
u8 max_video_outputs;
} __packed;

struct synthvid_supported_resolution_req {
u8 maximum_resolution_count;
} __packed;

struct synthvid_supported_resolution_resp {
u8 edid_block[SYNTHVID_EDID_BLOCK_SIZE];
u8 resolution_count;
u8 default_resolution_index;
u8 is_standard;
struct hvd_screen_info
supported_resolution[SYNTHVID_MAX_RESOLUTION_COUNT];
} __packed;

struct synthvid_vram_location {
u64 user_ctx;
u8 is_vram_gpa_specified;
Expand Down Expand Up @@ -188,6 +222,8 @@ struct synthvid_msg {
struct synthvid_pointer_shape ptr_shape;
struct synthvid_feature_change feature_chg;
struct synthvid_dirt dirt;
struct synthvid_supported_resolution_req resolution_req;
struct synthvid_supported_resolution_resp resolution_resp;
};
} __packed;

Expand Down Expand Up @@ -226,6 +262,8 @@ struct hvfb_par {

static uint screen_width = HVFB_WIDTH;
static uint screen_height = HVFB_HEIGHT;
static uint screen_width_max = HVFB_WIDTH;
static uint screen_height_max = HVFB_HEIGHT;
static uint screen_depth;
static uint screen_fb_size;

Expand Down Expand Up @@ -356,6 +394,7 @@ static void synthvid_recv_sub(struct hv_device *hdev)

/* Complete the wait event */
if (msg->vid_hdr.type == SYNTHVID_VERSION_RESPONSE ||
msg->vid_hdr.type == SYNTHVID_RESOLUTION_RESPONSE ||
msg->vid_hdr.type == SYNTHVID_VRAM_LOCATION_ACK) {
memcpy(par->init_buf, msg, MAX_VMBUS_PKT_SIZE);
complete(&par->wait);
Expand Down Expand Up @@ -402,6 +441,17 @@ static void synthvid_receive(void *ctx)
} while (bytes_recvd > 0 && ret == 0);
}

/* Check if the ver1 version is equal or greater than ver2 */
static inline bool synthvid_ver_ge(u32 ver1, u32 ver2)
{
if (SYNTHVID_VER_GET_MAJOR(ver1) > SYNTHVID_VER_GET_MAJOR(ver2) ||
(SYNTHVID_VER_GET_MAJOR(ver1) == SYNTHVID_VER_GET_MAJOR(ver2) &&
SYNTHVID_VER_GET_MINOR(ver1) >= SYNTHVID_VER_GET_MINOR(ver2)))
return true;

return false;
}

/* Check synthetic video protocol version with the host */
static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
{
Expand Down Expand Up @@ -430,6 +480,64 @@ static int synthvid_negotiate_ver(struct hv_device *hdev, u32 ver)
}

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

out:
return ret;
}

/* Get current resolution from the host */
static int synthvid_get_supported_resolution(struct hv_device *hdev)
{
struct fb_info *info = hv_get_drvdata(hdev);
struct hvfb_par *par = info->par;
struct synthvid_msg *msg = (struct synthvid_msg *)par->init_buf;
int ret = 0;
unsigned long t;
u8 index;
int i;

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

msg->resolution_req.maximum_resolution_count =
SYNTHVID_MAX_RESOLUTION_COUNT;
synthvid_send(hdev, msg);

t = wait_for_completion_timeout(&par->wait, VSP_TIMEOUT);
if (!t) {
pr_err("Time out on waiting resolution response\n");
ret = -ETIMEDOUT;
goto out;
}

if (msg->resolution_resp.resolution_count == 0) {
pr_err("No supported resolutions\n");
ret = -ENODEV;
goto out;
}

index = msg->resolution_resp.default_resolution_index;
if (index >= msg->resolution_resp.resolution_count) {
pr_err("Invalid resolution index: %d\n", index);
ret = -ENODEV;
goto out;
}

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

screen_width =
msg->resolution_resp.supported_resolution[index].width;
screen_height =
msg->resolution_resp.supported_resolution[index].height;

out:
return ret;
Expand All @@ -450,11 +558,27 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
}

/* Negotiate the protocol version with host */
if (vmbus_proto_version == VERSION_WS2008 ||
vmbus_proto_version == VERSION_WIN7)
ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
else
switch (vmbus_proto_version) {
case VERSION_WIN10:
case VERSION_WIN10_V5:
ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
if (!ret)
break;
/* Fallthrough */
case VERSION_WIN8:
case VERSION_WIN8_1:
ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN8);
if (!ret)
break;
/* Fallthrough */
case VERSION_WS2008:
case VERSION_WIN7:
ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN7);
break;
default:
ret = synthvid_negotiate_ver(hdev, SYNTHVID_VERSION_WIN10);
break;
}

if (ret) {
pr_err("Synthetic video device version not accepted\n");
Expand All @@ -466,6 +590,12 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
else
screen_depth = SYNTHVID_DEPTH_WIN8;

if (synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10)) {
ret = synthvid_get_supported_resolution(hdev);
if (ret)
pr_info("Failed to get supported resolution from host, use default\n");
}

screen_fb_size = hdev->channel->offermsg.offer.
mmio_megabytes * 1024 * 1024;

Expand Down Expand Up @@ -655,6 +785,8 @@ static void hvfb_get_option(struct fb_info *info)
}

if (x < HVFB_WIDTH_MIN || y < HVFB_HEIGHT_MIN ||
(synthvid_ver_ge(par->synthvid_version, SYNTHVID_VERSION_WIN10) &&
(x > screen_width_max || y > screen_height_max)) ||
(par->synthvid_version == SYNTHVID_VERSION_WIN8 &&
x * y * screen_depth / 8 > SYNTHVID_FB_SIZE_WIN8) ||
(par->synthvid_version == SYNTHVID_VERSION_WIN7 &&
Expand Down Expand Up @@ -691,8 +823,12 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
}

if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
pci_resource_len(pdev, 0) < screen_fb_size)
pci_resource_len(pdev, 0) < screen_fb_size) {
pr_err("Resource not available or (0x%lx < 0x%lx)\n",
(unsigned long) pci_resource_len(pdev, 0),
(unsigned long) screen_fb_size);
goto err1;
}

pot_end = pci_resource_end(pdev, 0);
pot_start = pot_end - screen_fb_size + 1;
Expand Down Expand Up @@ -781,17 +917,16 @@ static int hvfb_probe(struct hv_device *hdev,
goto error1;
}

hvfb_get_option(info);
pr_info("Screen resolution: %dx%d, Color depth: %d\n",
screen_width, screen_height, screen_depth);

ret = hvfb_getmem(hdev, info);
if (ret) {
pr_err("No memory for framebuffer\n");
goto error2;
}

hvfb_get_option(info);
pr_info("Screen resolution: %dx%d, Color depth: %d\n",
screen_width, screen_height, screen_depth);


/* Set up fb_info */
info->flags = FBINFO_DEFAULT;

Expand Down

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