2021年3月14日(日) 18:12 Konstantin Nazarov <m...@knazarov.com>:
>
> The Detailed Timing Descriptor has only 12 bits to store the
> resolution. This limits the guest to 4095 pixels.
>
> This patch adds support for the DisplayID extension, that has 2 full
> bytes for that purpose, thus allowing 5k resolutions and above.
>
> Based-on: <20210303152948.59943-2-akihiko.od...@gmail.com>
> Signed-off-by: Konstantin Nazarov <m...@knazarov.com>
> ---
> hw/display/edid-generate.c | 156 +++++++++++++++++++++++++++++--------
> hw/display/vga-pci.c | 2 +-
> qemu-edid.c | 2 +-
> 3 files changed, 124 insertions(+), 36 deletions(-)
>
> diff --git a/hw/display/edid-generate.c b/hw/display/edid-generate.c
> index b0ce583d436..db1e319e2dc 100644
> --- a/hw/display/edid-generate.c
> +++ b/hw/display/edid-generate.c
> @@ -44,6 +44,35 @@ static const struct edid_mode {
> { .xres = 640, .yres = 480, .byte = 35, .bit = 5 },
> };
>
> +typedef struct Timings {
> + uint32_t xfront;
> + uint32_t xsync;
> + uint32_t xblank;
> +
> + uint32_t yfront;
> + uint32_t ysync;
> + uint32_t yblank;
> +
> + uint64_t clock;
> +} Timings;
> +
> +static void generate_timings(Timings *timings, uint32_t refresh_rate,
> + uint32_t xres, uint32_t yres)
> +{
> + /* pull some realistic looking timings out of thin air */
> + timings->xfront = xres * 25 / 100;
> + timings->xsync = xres * 3 / 100;
> + timings->xblank = xres * 35 / 100;
> +
> + timings->yfront = yres * 5 / 1000;
> + timings->ysync = yres * 5 / 1000;
> + timings->yblank = yres * 35 / 1000;
> +
> + timings->clock = ((uint64_t)refresh_rate *
> + (xres + timings->xblank) *
> + (yres + timings->yblank)) / 10000000;
> +}
> +
> static void edid_ext_dta(uint8_t *dta)
> {
> dta[0] = 0x02;
> @@ -129,17 +158,17 @@ static void edid_fill_modes(uint8_t *edid, uint8_t
> *xtra3, uint8_t *dta,
> }
> }
>
> -static void edid_checksum(uint8_t *edid)
> +static void edid_checksum(uint8_t *edid, size_t len)
> {
> uint32_t sum = 0;
> int i;
>
> - for (i = 0; i < 127; i++) {
> + for (i = 0; i < len; i++) {
> sum += edid[i];
> }
> sum &= 0xff;
> if (sum) {
> - edid[127] = 0x100 - sum;
> + edid[len] = 0x100 - sum;
> }
> }
>
> @@ -180,8 +209,8 @@ static void edid_desc_ranges(uint8_t *desc)
> desc[7] = 30;
> desc[8] = 160;
>
> - /* max dot clock (1200 MHz) */
> - desc[9] = 1200 / 10;
> + /* max dot clock (2550 MHz) */
> + desc[9] = 2550 / 10;
>
> /* no extended timing information */
> desc[10] = 0x01;
> @@ -207,38 +236,29 @@ static void edid_desc_timing(uint8_t *desc, uint32_t
> refresh_rate,
> uint32_t xres, uint32_t yres,
> uint32_t xmm, uint32_t ymm)
> {
> - /* pull some realistic looking timings out of thin air */
> - uint32_t xfront = xres * 25 / 100;
> - uint32_t xsync = xres * 3 / 100;
> - uint32_t xblank = xres * 35 / 100;
> -
> - uint32_t yfront = yres * 5 / 1000;
> - uint32_t ysync = yres * 5 / 1000;
> - uint32_t yblank = yres * 35 / 1000;
> -
> - uint64_t clock = (uint64_t)refresh_rate * (xres + xblank) * (yres +
> yblank);
> -
> - stl_le_p(desc, clock / 10000000);
> + Timings timings;
> + generate_timings(&timings, refresh_rate, xres, yres);
> + stl_le_p(desc, timings.clock);
>
> desc[2] = xres & 0xff;
> - desc[3] = xblank & 0xff;
> + desc[3] = timings.xblank & 0xff;
> desc[4] = (((xres & 0xf00) >> 4) |
> - ((xblank & 0xf00) >> 8));
> + ((timings.xblank & 0xf00) >> 8));
>
> desc[5] = yres & 0xff;
> - desc[6] = yblank & 0xff;
> + desc[6] = timings.yblank & 0xff;
> desc[7] = (((yres & 0xf00) >> 4) |
> - ((yblank & 0xf00) >> 8));
> + ((timings.yblank & 0xf00) >> 8));
>
> - desc[8] = xfront & 0xff;
> - desc[9] = xsync & 0xff;
> + desc[8] = timings.xfront & 0xff;
> + desc[9] = timings.xsync & 0xff;
>
> - desc[10] = (((yfront & 0x00f) << 4) |
> - ((ysync & 0x00f) << 0));
> - desc[11] = (((xfront & 0x300) >> 2) |
> - ((xsync & 0x300) >> 4) |
> - ((yfront & 0x030) >> 2) |
> - ((ysync & 0x030) >> 4));
> + desc[10] = (((timings.yfront & 0x00f) << 4) |
> + ((timings.ysync & 0x00f) << 0));
> + desc[11] = (((timings.xfront & 0x300) >> 2) |
> + ((timings.xsync & 0x300) >> 4) |
> + ((timings.yfront & 0x030) >> 2) |
> + ((timings.ysync & 0x030) >> 4));
>
> desc[12] = xmm & 0xff;
> desc[13] = ymm & 0xff;
> @@ -296,15 +316,61 @@ uint32_t qemu_edid_dpi_to_mm(uint32_t dpi, uint32_t res)
> return res * 254 / 10 / dpi;
> }
>
> +static void dummy_displayid(uint8_t *did)
> +{
> + did[0] = 0x70; /* display id extension */
> + did[1] = 0x13; /* version 1.3 */
> + did[2] = 4; /* length */
> + did[3] = 0x03; /* product type (0x03 == standalone display device) */
> + edid_checksum(did + 1, did[2] + 4);
> +}
> +
> +static void qemu_displayid_generate(uint8_t *did, uint32_t refresh_rate,
> + uint32_t xres, uint32_t yres,
> + uint32_t xmm, uint32_t ymm)
> +{
> + Timings timings;
> + generate_timings(&timings, refresh_rate, xres, yres);
> +
> + did[0] = 0x70; /* display id extension */
> + did[1] = 0x13; /* version 1.3 */
> + did[2] = 23; /* length */
> + did[3] = 0x03; /* product type (0x03 == standalone display device) */
> +
> + did[5] = 0x03; /* Detailed Timings Data Block */
> + did[6] = 0x00; /* revision */
> + did[7] = 0x14; /* block length */
> +
> + did[8] = timings.clock & 0xff;
> + did[9] = (timings.clock & 0xff00) >> 8;
> + did[10] = (timings.clock & 0xff0000) >> 16;
> +
> + did[11] = 0x88; /* leave aspect ratio undefined */
> +
> + stw_le_p(did + 12, 0xffff & (xres - 1));
> + stw_le_p(did + 14, 0xffff & (timings.xblank - 1));
> + stw_le_p(did + 16, 0xffff & (timings.xfront - 1));
> + stw_le_p(did + 18, 0xffff & (timings.xsync - 1));
> +
> + stw_le_p(did + 20, 0xffff & (yres - 1));
> + stw_le_p(did + 22, 0xffff & (timings.yblank - 1));
> + stw_le_p(did + 24, 0xffff & (timings.yfront - 1));
> + stw_le_p(did + 26, 0xffff & (timings.ysync - 1));
> +
> + edid_checksum(did + 1, did[2] + 4);
> +}
> +
> void qemu_edid_generate(uint8_t *edid, size_t size,
> qemu_edid_info *info)
> {
> uint32_t desc = 54;
> uint8_t *xtra3 = NULL;
> uint8_t *dta = NULL;
> + uint8_t *did = NULL;
> uint32_t width_mm, height_mm;
> uint32_t refresh_rate = info->refresh_rate ? info->refresh_rate : 75000;
> uint32_t dpi = 100; /* if no width_mm/height_mm */
> + uint32_t large_screen = 0;
>
> /* =============== set defaults =============== */
>
> @@ -320,6 +386,9 @@ void qemu_edid_generate(uint8_t *edid, size_t size,
> if (!info->prefy) {
> info->prefy = 768;
> }
> + if (info->prefx >= 4096 || info->prefy >= 4096) {
> + large_screen = 1;
> + }
> if (info->width_mm && info->height_mm) {
> width_mm = info->width_mm;
> height_mm = info->height_mm;
> @@ -401,9 +470,12 @@ void qemu_edid_generate(uint8_t *edid, size_t size,
>
> /* =============== descriptor blocks =============== */
>
> - edid_desc_timing(edid + desc, refresh_rate, info->prefx, info->prefy,
> - width_mm, height_mm);
> - desc += 18;
> + /* The DTD section has only 12 bits to store the resolution */
> + if (!large_screen) {
> + edid_desc_timing(edid + desc, refresh_rate, info->prefx, info->prefy,
> + width_mm, height_mm);
> + desc += 18;
> + }
>
> edid_desc_ranges(edid + desc);
> desc += 18;
> @@ -429,12 +501,28 @@ void qemu_edid_generate(uint8_t *edid, size_t size,
> desc += 18;
> }
>
> + /* =============== display id extensions =============== */
> +
> + if (size >= 384) {
> + did = edid + 256;
> + dummy_displayid(did);
> + edid[126]++;
> +
> + if (large_screen) {
> + qemu_displayid_generate(did, refresh_rate, info->prefx,
> info->prefy,
> + width_mm, height_mm);
> + }
> + }
> +
> /* =============== finish up =============== */
>
> edid_fill_modes(edid, xtra3, dta, info->maxx, info->maxy);
> - edid_checksum(edid);
> + edid_checksum(edid, 127);
> if (dta) {
> - edid_checksum(dta);
> + edid_checksum(dta, 127);
> + }
> + if (did) {
> + edid_checksum(did, 127);
> }
> }
>
> diff --git a/hw/display/vga-pci.c b/hw/display/vga-pci.c
> index 48d29630ab7..62fb5c38c1f 100644
> --- a/hw/display/vga-pci.c
> +++ b/hw/display/vga-pci.c
> @@ -49,7 +49,7 @@ struct PCIVGAState {
> qemu_edid_info edid_info;
> MemoryRegion mmio;
> MemoryRegion mrs[4];
> - uint8_t edid[256];
> + uint8_t edid[384];
> };
>
> #define TYPE_PCI_VGA "pci-vga"
> diff --git a/qemu-edid.c b/qemu-edid.c
> index 1cd6a951723..028f2d181a1 100644
> --- a/qemu-edid.c
> +++ b/qemu-edid.c
> @@ -41,7 +41,7 @@ static void usage(FILE *out)
> int main(int argc, char *argv[])
> {
> FILE *outfile = NULL;
> - uint8_t blob[256];
> + uint8_t blob[384];
> uint32_t dpi = 100;
> int rc;
>
> --
> 2.24.3 (Apple Git-128)
>
It looks good to me.
Reviewed-by: Akihiko Odaki <akihiko.od...@gmail.com>
