Archipelago » qemu

/*

 * QEMU VMware-SVGA "chipset".

 *

 * Copyright (c) 2007 Andrzej Zaborowski  <balrog@zabor.org>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "vl.h"

#define VERBOSE

#define EMBED_STDVGA

#undef DIRECT_VRAM

#define HW_RECT_ACCEL

#define HW_FILL_ACCEL

#define HW_MOUSE_ACCEL

#ifdef EMBED_STDVGA

# include "vga_int.h"

#endif

struct vmsvga_state_s {

#ifdef EMBED_STDVGA

    VGA_STATE_COMMON

#endif

    int width;

    int height;

    int invalidated;

    int depth;

    int bypp;

    int enable;

    int config;

    struct {

        int id;

        int x;

        int y;

        int on;

    } cursor;

#ifndef EMBED_STDVGA

    DisplayState *ds;

    int vram_size;

#endif

    uint8_t *vram;

    int index;

    int scratch_size;

    uint32_t *scratch;

    int new_width;

    int new_height;

    uint32_t guest;

    uint32_t svgaid;

    uint32_t wred;

    uint32_t wgreen;

    uint32_t wblue;

    int syncing;

    int fb_size;

    union {

        uint32_t *fifo;

        struct __attribute__((__packed__)) {

            uint32_t min;

            uint32_t max;

            uint32_t next_cmd;

            uint32_t stop;

            /* Add registers here when adding capabilities.  */

            uint32_t fifo[0];

        } *cmd;

    };

#define REDRAW_FIFO_LEN        512

    struct vmsvga_rect_s {

        int x, y, w, h;

    } redraw_fifo[REDRAW_FIFO_LEN];

    int redraw_fifo_first, redraw_fifo_last;

};

struct pci_vmsvga_state_s {

    PCIDevice card;

    struct vmsvga_state_s chip;

};

#define SVGA_MAGIC                0x900000UL

#define SVGA_MAKE_ID(ver)        (SVGA_MAGIC << 8 | (ver))

#define SVGA_ID_0                SVGA_MAKE_ID(0)

#define SVGA_ID_1                SVGA_MAKE_ID(1)

#define SVGA_ID_2                SVGA_MAKE_ID(2)

#define SVGA_LEGACY_BASE_PORT        0x4560

#define SVGA_INDEX_PORT                0x0

#define SVGA_VALUE_PORT                0x1

#define SVGA_BIOS_PORT                0x2

#define SVGA_VERSION_2

#ifdef SVGA_VERSION_2

# define SVGA_ID                SVGA_ID_2

# define SVGA_IO_BASE                SVGA_LEGACY_BASE_PORT

# define SVGA_IO_MUL                1

# define SVGA_FIFO_SIZE                0x10000

# define SVGA_MEM_BASE                0xec000000

# define SVGA_PCI_DEVICE_ID        PCI_DEVICE_ID_VMWARE_SVGA2

#else

# define SVGA_ID                SVGA_ID_1

# define SVGA_IO_BASE                SVGA_LEGACY_BASE_PORT

# define SVGA_IO_MUL                4

# define SVGA_FIFO_SIZE                0x10000

# define SVGA_MEM_BASE                0xec000000

# define SVGA_PCI_DEVICE_ID        PCI_DEVICE_ID_VMWARE_SVGA

#endif

enum {

    /* ID 0, 1 and 2 registers */

    SVGA_REG_ID = 0,

    SVGA_REG_ENABLE = 1,

    SVGA_REG_WIDTH = 2,

    SVGA_REG_HEIGHT = 3,

    SVGA_REG_MAX_WIDTH = 4,

    SVGA_REG_MAX_HEIGHT = 5,

    SVGA_REG_DEPTH = 6,

    SVGA_REG_BITS_PER_PIXEL = 7,        /* Current bpp in the guest */

    SVGA_REG_PSEUDOCOLOR = 8,

    SVGA_REG_RED_MASK = 9,

    SVGA_REG_GREEN_MASK = 10,

    SVGA_REG_BLUE_MASK = 11,

    SVGA_REG_BYTES_PER_LINE = 12,

    SVGA_REG_FB_START = 13,

    SVGA_REG_FB_OFFSET = 14,

    SVGA_REG_VRAM_SIZE = 15,

    SVGA_REG_FB_SIZE = 16,

    /* ID 1 and 2 registers */

    SVGA_REG_CAPABILITIES = 17,

    SVGA_REG_MEM_START = 18,                /* Memory for command FIFO */

    SVGA_REG_MEM_SIZE = 19,

    SVGA_REG_CONFIG_DONE = 20,                /* Set when memory area configured */

    SVGA_REG_SYNC = 21,                        /* Write to force synchronization */

    SVGA_REG_BUSY = 22,                        /* Read to check if sync is done */

    SVGA_REG_GUEST_ID = 23,                /* Set guest OS identifier */

    SVGA_REG_CURSOR_ID = 24,                /* ID of cursor */

    SVGA_REG_CURSOR_X = 25,                /* Set cursor X position */

    SVGA_REG_CURSOR_Y = 26,                /* Set cursor Y position */

    SVGA_REG_CURSOR_ON = 27,                /* Turn cursor on/off */

    SVGA_REG_HOST_BITS_PER_PIXEL = 28,        /* Current bpp in the host */

    SVGA_REG_SCRATCH_SIZE = 29,                /* Number of scratch registers */

    SVGA_REG_MEM_REGS = 30,                /* Number of FIFO registers */

    SVGA_REG_NUM_DISPLAYS = 31,                /* Number of guest displays */

    SVGA_REG_PITCHLOCK = 32,                /* Fixed pitch for all modes */

    SVGA_PALETTE_BASE = 1024,                /* Base of SVGA color map */

    SVGA_PALETTE_END  = SVGA_PALETTE_BASE + 767,

    SVGA_SCRATCH_BASE = SVGA_PALETTE_BASE + 768,

};

#define SVGA_CAP_NONE                        0

#define SVGA_CAP_RECT_FILL                (1 << 0)

#define SVGA_CAP_RECT_COPY                (1 << 1)

#define SVGA_CAP_RECT_PAT_FILL                (1 << 2)

#define SVGA_CAP_LEGACY_OFFSCREEN        (1 << 3)

#define SVGA_CAP_RASTER_OP                (1 << 4)

#define SVGA_CAP_CURSOR                        (1 << 5)

#define SVGA_CAP_CURSOR_BYPASS                (1 << 6)

#define SVGA_CAP_CURSOR_BYPASS_2        (1 << 7)

#define SVGA_CAP_8BIT_EMULATION                (1 << 8)

#define SVGA_CAP_ALPHA_CURSOR                (1 << 9)

#define SVGA_CAP_GLYPH                        (1 << 10)

#define SVGA_CAP_GLYPH_CLIPPING                (1 << 11)

#define SVGA_CAP_OFFSCREEN_1                (1 << 12)

#define SVGA_CAP_ALPHA_BLEND                (1 << 13)

#define SVGA_CAP_3D                        (1 << 14)

#define SVGA_CAP_EXTENDED_FIFO                (1 << 15)

#define SVGA_CAP_MULTIMON                (1 << 16)

#define SVGA_CAP_PITCHLOCK                (1 << 17)

/*

 * FIFO offsets (seen as an array of 32-bit words)

 */

enum {

    /*

     * The original defined FIFO offsets

     */

    SVGA_FIFO_MIN = 0,

    SVGA_FIFO_MAX,        /* The distance from MIN to MAX must be at least 10K */

    SVGA_FIFO_NEXT_CMD,

    SVGA_FIFO_STOP,

    /*

     * Additional offsets added as of SVGA_CAP_EXTENDED_FIFO

     */

    SVGA_FIFO_CAPABILITIES = 4,

    SVGA_FIFO_FLAGS,

    SVGA_FIFO_FENCE,

    SVGA_FIFO_3D_HWVERSION,

    SVGA_FIFO_PITCHLOCK,

};

#define SVGA_FIFO_CAP_NONE                0

#define SVGA_FIFO_CAP_FENCE                (1 << 0)

#define SVGA_FIFO_CAP_ACCELFRONT        (1 << 1)

#define SVGA_FIFO_CAP_PITCHLOCK                (1 << 2)

#define SVGA_FIFO_FLAG_NONE                0

#define SVGA_FIFO_FLAG_ACCELFRONT        (1 << 0)

/* These values can probably be changed arbitrarily.  */

#define SVGA_SCRATCH_SIZE                0x8000

#define SVGA_MAX_WIDTH                        2360

#define SVGA_MAX_HEIGHT                        1770

#ifdef VERBOSE

# define GUEST_OS_BASE                0x5001

static const char *vmsvga_guest_id[] = {

    [0x0] = "Dos",

    [0x1] = "Windows 3.1",

    [0x2] = "Windows 95",

    [0x3] = "Windows 98",

    [0x4] = "Windows ME",

    [0x5] = "Windows NT",

    [0x6] = "Windows 2000",

    [0x7] = "Linux",

    [0x8] = "OS/2",

    [0x9] = "Unknown",

    [0xa] = "BSD",

    [0xb] = "Whistler",

};

#endif

enum {

    SVGA_CMD_INVALID_CMD = 0,

    SVGA_CMD_UPDATE = 1,

    SVGA_CMD_RECT_FILL = 2,

    SVGA_CMD_RECT_COPY = 3,

    SVGA_CMD_DEFINE_BITMAP = 4,

    SVGA_CMD_DEFINE_BITMAP_SCANLINE = 5,

    SVGA_CMD_DEFINE_PIXMAP = 6,

    SVGA_CMD_DEFINE_PIXMAP_SCANLINE = 7,

    SVGA_CMD_RECT_BITMAP_FILL = 8,

    SVGA_CMD_RECT_PIXMAP_FILL = 9,

    SVGA_CMD_RECT_BITMAP_COPY = 10,

    SVGA_CMD_RECT_PIXMAP_COPY = 11,

    SVGA_CMD_FREE_OBJECT = 12,

    SVGA_CMD_RECT_ROP_FILL = 13,

    SVGA_CMD_RECT_ROP_COPY = 14,

    SVGA_CMD_RECT_ROP_BITMAP_FILL = 15,

    SVGA_CMD_RECT_ROP_PIXMAP_FILL = 16,

    SVGA_CMD_RECT_ROP_BITMAP_COPY = 17,

    SVGA_CMD_RECT_ROP_PIXMAP_COPY = 18,

    SVGA_CMD_DEFINE_CURSOR = 19,

    SVGA_CMD_DISPLAY_CURSOR = 20,

    SVGA_CMD_MOVE_CURSOR = 21,

    SVGA_CMD_DEFINE_ALPHA_CURSOR = 22,

    SVGA_CMD_DRAW_GLYPH = 23,

    SVGA_CMD_DRAW_GLYPH_CLIPPED = 24,

    SVGA_CMD_UPDATE_VERBOSE = 25,

    SVGA_CMD_SURFACE_FILL = 26,

    SVGA_CMD_SURFACE_COPY = 27,

    SVGA_CMD_SURFACE_ALPHA_BLEND = 28,

    SVGA_CMD_FRONT_ROP_FILL = 29,

    SVGA_CMD_FENCE = 30,

};

/* Legal values for the SVGA_REG_CURSOR_ON register in cursor bypass mode */

enum {

    SVGA_CURSOR_ON_HIDE = 0,

    SVGA_CURSOR_ON_SHOW = 1,

    SVGA_CURSOR_ON_REMOVE_FROM_FB = 2,

    SVGA_CURSOR_ON_RESTORE_TO_FB = 3,

};

static inline void vmsvga_update_rect(struct vmsvga_state_s *s,

                int x, int y, int w, int h)

{

#ifndef DIRECT_VRAM

    int line = h;

    int bypl = s->bypp * s->width;

    int width = s->bypp * w;

    int start = s->bypp * x + bypl * y;

    uint8_t *src = s->vram + start;

    uint8_t *dst = s->ds->data + start;

    for (; line > 0; line --, src += bypl, dst += bypl)

        memcpy(dst, src, width);

#endif

    dpy_update(s->ds, x, y, w, h);

}

static inline void vmsvga_update_screen(struct vmsvga_state_s *s)

{

#ifndef DIRECT_VRAM

    memcpy(s->ds->data, s->vram, s->bypp * s->width * s->height);

#endif

    dpy_update(s->ds, 0, 0, s->width, s->height);

}

#ifdef DIRECT_VRAM

# define vmsvga_update_rect_delayed        vmsvga_update_rect

#else

static inline void vmsvga_update_rect_delayed(struct vmsvga_state_s *s,

                int x, int y, int w, int h)

{

    struct vmsvga_rect_s *rect = &s->redraw_fifo[s->redraw_fifo_last ++];

    s->redraw_fifo_last &= REDRAW_FIFO_LEN - 1;

    rect->x = x;

    rect->y = y;

    rect->w = w;

    rect->h = h;

}

#endif

static inline void vmsvga_update_rect_flush(struct vmsvga_state_s *s)

{

    struct vmsvga_rect_s *rect;

    if (s->invalidated) {

        s->redraw_fifo_first = s->redraw_fifo_last;

        return;

    }

    /* Overlapping region updates can be optimised out here - if someone

     * knows a smart algorithm to do that, please share.  */

    while (s->redraw_fifo_first != s->redraw_fifo_last) {

        rect = &s->redraw_fifo[s->redraw_fifo_first ++];

        s->redraw_fifo_first &= REDRAW_FIFO_LEN - 1;

        vmsvga_update_rect(s, rect->x, rect->y, rect->w, rect->h);

    }

}

#ifdef HW_RECT_ACCEL

static inline void vmsvga_copy_rect(struct vmsvga_state_s *s,

                int x0, int y0, int x1, int y1, int w, int h)

{

# ifdef DIRECT_VRAM

    uint8_t *vram = s->ds->data;

# else

    uint8_t *vram = s->vram;

# endif

    int bypl = s->bypp * s->width;

    int width = s->bypp * w;

    int line = h;

    uint8_t *ptr[2];

# ifdef DIRECT_VRAM

    if (s->ds->dpy_copy)

        s->ds->dpy_copy(s->ds, x0, y0, x1, y1, w, h);

    else

# endif

    {

        if (y1 > y0) {

            ptr[0] = vram + s->bypp * x0 + bypl * (y0 + h - 1);

            ptr[1] = vram + s->bypp * x1 + bypl * (y1 + h - 1);

            for (; line > 0; line --, ptr[0] -= bypl, ptr[1] -= bypl)

                memmove(ptr[1], ptr[0], width);

        } else {

            ptr[0] = vram + s->bypp * x0 + bypl * y0;

            ptr[1] = vram + s->bypp * x1 + bypl * y1;

            for (; line > 0; line --, ptr[0] += bypl, ptr[1] += bypl)

                memmove(ptr[1], ptr[0], width);

        }

    }

    vmsvga_update_rect_delayed(s, x1, y1, w, h);

}

#endif

#ifdef HW_FILL_ACCEL

static inline void vmsvga_fill_rect(struct vmsvga_state_s *s,

                uint32_t c, int x, int y, int w, int h)

{

# ifdef DIRECT_VRAM

    uint8_t *vram = s->ds->data;

# else

    uint8_t *vram = s->vram;

# endif

    int bypp = s->bypp;

    int bypl = bypp * s->width;

    int width = bypp * w;

    int line = h;

    int column;

    uint8_t *fst = vram + bypp * x + bypl * y;

    uint8_t *dst;

    uint8_t *src;

    uint8_t col[4];

# ifdef DIRECT_VRAM

    if (s->ds->dpy_fill)

        s->ds->dpy_fill(s->ds, x, y, w, h, c);

    else

# endif

    {

        col[0] = c;

        col[1] = c >> 8;

        col[2] = c >> 16;

        col[3] = c >> 24;

        if (line --) {

            dst = fst;

            src = col;

            for (column = width; column > 0; column --) {

                *(dst ++) = *(src ++);

                if (src - col == bypp)

                    src = col;

            }

            dst = fst;

            for (; line > 0; line --) {

                dst += bypl;

                memcpy(dst, fst, width);

            }

        }

    }

    vmsvga_update_rect_delayed(s, x, y, w, h);

}

#endif

struct vmsvga_cursor_definition_s {

    int width;

    int height;

    int id;

    int bpp;

    int hot_x;

    int hot_y;

    uint32_t mask[1024];

    uint32_t image[1024];

};

#define SVGA_BITMAP_SIZE(w, h)                ((((w) + 31) >> 5) * (h))

#define SVGA_PIXMAP_SIZE(w, h, bpp)        (((((w) * (bpp)) + 31) >> 5) * (h))

#ifdef HW_MOUSE_ACCEL

static inline void vmsvga_cursor_define(struct vmsvga_state_s *s,

                struct vmsvga_cursor_definition_s *c)

{

    int i;

    for (i = SVGA_BITMAP_SIZE(c->width, c->height) - 1; i >= 0; i --)

        c->mask[i] = ~c->mask[i];

    if (s->ds->cursor_define)

        s->ds->cursor_define(c->width, c->height, c->bpp, c->hot_x, c->hot_y,

                        (uint8_t *) c->image, (uint8_t *) c->mask);

}

#endif

static inline int vmsvga_fifo_empty(struct vmsvga_state_s *s)

{

    if (!s->config || !s->enable)

        return 0;

    return (s->cmd->next_cmd == s->cmd->stop);

}

static inline uint32_t vmsvga_fifo_read(struct vmsvga_state_s *s)

{

    uint32_t cmd = s->fifo[s->cmd->stop >> 2];

    s->cmd->stop += 4;

    if (s->cmd->stop >= s->cmd->max)

        s->cmd->stop = s->cmd->min;

    return cmd;

}

static void vmsvga_fifo_run(struct vmsvga_state_s *s)

{

    uint32_t cmd, colour;

    int args = 0;

    int x, y, dx, dy, width, height;

    struct vmsvga_cursor_definition_s cursor;

    while (!vmsvga_fifo_empty(s))

        switch (cmd = vmsvga_fifo_read(s)) {

        case SVGA_CMD_UPDATE:

        case SVGA_CMD_UPDATE_VERBOSE:

            x = vmsvga_fifo_read(s);

            y = vmsvga_fifo_read(s);

            width = vmsvga_fifo_read(s);

            height = vmsvga_fifo_read(s);

            vmsvga_update_rect_delayed(s, x, y, width, height);

            break;

        case SVGA_CMD_RECT_FILL:

            colour = vmsvga_fifo_read(s);

            x = vmsvga_fifo_read(s);

            y = vmsvga_fifo_read(s);

            width = vmsvga_fifo_read(s);

            height = vmsvga_fifo_read(s);

#ifdef HW_FILL_ACCEL

            vmsvga_fill_rect(s, colour, x, y, width, height);

            break;

#else

            goto badcmd;

#endif

        case SVGA_CMD_RECT_COPY:

            x = vmsvga_fifo_read(s);

            y = vmsvga_fifo_read(s);

            dx = vmsvga_fifo_read(s);

            dy = vmsvga_fifo_read(s);

            width = vmsvga_fifo_read(s);

            height = vmsvga_fifo_read(s);

#ifdef HW_RECT_ACCEL

            vmsvga_copy_rect(s, x, y, dx, dy, width, height);

            break;

#else

            goto badcmd;

#endif

        case SVGA_CMD_DEFINE_CURSOR:

            cursor.id = vmsvga_fifo_read(s);

            cursor.hot_x = vmsvga_fifo_read(s);

            cursor.hot_y = vmsvga_fifo_read(s);

            cursor.width = x = vmsvga_fifo_read(s);

            cursor.height = y = vmsvga_fifo_read(s);

            vmsvga_fifo_read(s);

            cursor.bpp = vmsvga_fifo_read(s);

            for (args = 0; args < SVGA_BITMAP_SIZE(x, y); args ++)

                cursor.mask[args] = vmsvga_fifo_read(s);

            for (args = 0; args < SVGA_PIXMAP_SIZE(x, y, cursor.bpp); args ++)

                cursor.image[args] = vmsvga_fifo_read(s);

#ifdef HW_MOUSE_ACCEL

            vmsvga_cursor_define(s, &cursor);

            break;

#else

            args = 0;

            goto badcmd;

#endif

        /*

         * Other commands that we at least know the number of arguments

         * for so we can avoid FIFO desync if driver uses them illegally.

         */

        case SVGA_CMD_DEFINE_ALPHA_CURSOR:

            vmsvga_fifo_read(s);

            vmsvga_fifo_read(s);

            vmsvga_fifo_read(s);

            x = vmsvga_fifo_read(s);

            y = vmsvga_fifo_read(s);

            args = x * y;

            goto badcmd;

        case SVGA_CMD_RECT_ROP_FILL:

            args = 6;

            goto badcmd;

        case SVGA_CMD_RECT_ROP_COPY:

            args = 7;

            goto badcmd;

        case SVGA_CMD_DRAW_GLYPH_CLIPPED:

            vmsvga_fifo_read(s);

            vmsvga_fifo_read(s);

            args = 7 + (vmsvga_fifo_read(s) >> 2);

            goto badcmd;

        case SVGA_CMD_SURFACE_ALPHA_BLEND:

            args = 12;

            goto badcmd;

        /*

         * Other commands that are not listed as depending on any

         * CAPABILITIES bits, but are not described in the README either.

         */

        case SVGA_CMD_SURFACE_FILL:

        case SVGA_CMD_SURFACE_COPY:

        case SVGA_CMD_FRONT_ROP_FILL:

        case SVGA_CMD_FENCE:

        case SVGA_CMD_INVALID_CMD:

            break; /* Nop */

        default:

        badcmd:

            while (args --)

                vmsvga_fifo_read(s);

            printf("%s: Unknown command 0x%02x in SVGA command FIFO\n",

                            __FUNCTION__, cmd);

            break;

        }

    s->syncing = 0;

}

static uint32_t vmsvga_index_read(void *opaque, uint32_t address)

{

    struct vmsvga_state_s *s = (struct vmsvga_state_s *) opaque;

    return s->index;

}

static void vmsvga_index_write(void *opaque, uint32_t address, uint32_t index)

{

    struct vmsvga_state_s *s = (struct vmsvga_state_s *) opaque;

    s->index = index;

}

static uint32_t vmsvga_value_read(void *opaque, uint32_t address)

{

    uint32_t caps;

    struct vmsvga_state_s *s = (struct vmsvga_state_s *) opaque;

    switch (s->index) {

    case SVGA_REG_ID:

        return s->svgaid;

    case SVGA_REG_ENABLE:

        return s->enable;

    case SVGA_REG_WIDTH:

        return s->width;

    case SVGA_REG_HEIGHT:

        return s->height;

    case SVGA_REG_MAX_WIDTH:

        return SVGA_MAX_WIDTH;

    case SVGA_REG_MAX_HEIGHT:

        return SVGA_MAX_WIDTH;

    case SVGA_REG_DEPTH:

        return s->depth;

    case SVGA_REG_BITS_PER_PIXEL:

        return (s->depth + 7) & ~7;

    case SVGA_REG_PSEUDOCOLOR:

        return 0x0;

    case SVGA_REG_RED_MASK:

        return s->wred;

    case SVGA_REG_GREEN_MASK:

        return s->wgreen;

    case SVGA_REG_BLUE_MASK:

        return s->wblue;

    case SVGA_REG_BYTES_PER_LINE:

        return ((s->depth + 7) >> 3) * s->new_width;

    case SVGA_REG_FB_START:

        return SVGA_MEM_BASE;

    case SVGA_REG_FB_OFFSET:

        return 0x0;

    case SVGA_REG_VRAM_SIZE:

        return s->vram_size - SVGA_FIFO_SIZE;

    case SVGA_REG_FB_SIZE:

        return s->fb_size;

    case SVGA_REG_CAPABILITIES:

        caps = SVGA_CAP_NONE;

#ifdef HW_RECT_ACCEL

        caps |= SVGA_CAP_RECT_COPY;

#endif

#ifdef HW_FILL_ACCEL

        caps |= SVGA_CAP_RECT_FILL;

#endif

#ifdef HW_MOUSE_ACCEL

        if (s->ds->mouse_set)

            caps |= SVGA_CAP_CURSOR | SVGA_CAP_CURSOR_BYPASS_2 |

                    SVGA_CAP_CURSOR_BYPASS;

#endif

        return caps;

    case SVGA_REG_MEM_START:

        return SVGA_MEM_BASE + s->vram_size - SVGA_FIFO_SIZE;

    case SVGA_REG_MEM_SIZE:

        return SVGA_FIFO_SIZE;

    case SVGA_REG_CONFIG_DONE:

        return s->config;

    case SVGA_REG_SYNC:

    case SVGA_REG_BUSY:

        return s->syncing;

    case SVGA_REG_GUEST_ID:

        return s->guest;

    case SVGA_REG_CURSOR_ID:

        return s->cursor.id;

    case SVGA_REG_CURSOR_X:

        return s->cursor.x;

    case SVGA_REG_CURSOR_Y:

        return s->cursor.x;

    case SVGA_REG_CURSOR_ON:

        return s->cursor.on;

    case SVGA_REG_HOST_BITS_PER_PIXEL:

        return (s->depth + 7) & ~7;

    case SVGA_REG_SCRATCH_SIZE:

        return s->scratch_size;

    case SVGA_REG_MEM_REGS:

    case SVGA_REG_NUM_DISPLAYS:

    case SVGA_REG_PITCHLOCK:

    case SVGA_PALETTE_BASE ... SVGA_PALETTE_END:

        return 0;

    default:

        if (s->index >= SVGA_SCRATCH_BASE &&

                s->index < SVGA_SCRATCH_BASE + s->scratch_size)

            return s->scratch[s->index - SVGA_SCRATCH_BASE];

        printf("%s: Bad register %02x\n", __FUNCTION__, s->index);

    }

    return 0;

}

static void vmsvga_value_write(void *opaque, uint32_t address, uint32_t value)

{

    struct vmsvga_state_s *s = (struct vmsvga_state_s *) opaque;

    switch (s->index) {

    case SVGA_REG_ID:

        if (value == SVGA_ID_2 || value == SVGA_ID_1 || value == SVGA_ID_0)

            s->svgaid = value;

        break;

    case SVGA_REG_ENABLE:

        s->enable = s->config = value & s->config;

        s->width = -1;

        s->height = -1;

        s->invalidated = 1;

#ifdef EMBED_STDVGA

        s->invalidate(opaque);

#endif

        if (s->enable)

            s->fb_size = ((s->depth + 7) >> 3) * s->new_width * s->new_height;

        break;

    case SVGA_REG_WIDTH:

        s->new_width = value;

        s->invalidated = 1;

        break;

    case SVGA_REG_HEIGHT:

        s->new_height = value;

        s->invalidated = 1;

        break;

    case SVGA_REG_DEPTH:

    case SVGA_REG_BITS_PER_PIXEL:

        if (value != s->depth) {

            printf("%s: Bad colour depth: %i bits\n", __FUNCTION__, value);

            s->config = 0;

        }

        break;

    case SVGA_REG_CONFIG_DONE:

        if (value) {

            s->fifo = (uint32_t *) &s->vram[s->vram_size - SVGA_FIFO_SIZE];

            /* Check range and alignment.  */

            if ((s->cmd->min | s->cmd->max |

                        s->cmd->next_cmd | s->cmd->stop) & 3)

                break;

            if (s->cmd->min < (uint8_t *) s->cmd->fifo - (uint8_t *) s->fifo)

                break;

            if (s->cmd->max > SVGA_FIFO_SIZE)

                break;

            if (s->cmd->max < s->cmd->min + 10 * 1024)

                break;

        }

        s->config = value;

        break;

    case SVGA_REG_SYNC:

        s->syncing = 1;

        vmsvga_fifo_run(s); /* Or should we just wait for update_display? */

        break;

    case SVGA_REG_GUEST_ID:

        s->guest = value;

#ifdef VERBOSE

        if (value >= GUEST_OS_BASE && value < GUEST_OS_BASE +

                sizeof(vmsvga_guest_id) / sizeof(*vmsvga_guest_id))

            printf("%s: guest runs %s.\n", __FUNCTION__,

                            vmsvga_guest_id[value - GUEST_OS_BASE]);

#endif

        break;

    case SVGA_REG_CURSOR_ID:

        s->cursor.id = value;

        break;

    case SVGA_REG_CURSOR_X:

        s->cursor.x = value;

        break;

    case SVGA_REG_CURSOR_Y:

        s->cursor.y = value;

        break;

    case SVGA_REG_CURSOR_ON:

        s->cursor.on |= (value == SVGA_CURSOR_ON_SHOW);

        s->cursor.on &= (value != SVGA_CURSOR_ON_HIDE);

#ifdef HW_MOUSE_ACCEL

        if (s->ds->mouse_set && value <= SVGA_CURSOR_ON_SHOW)

            s->ds->mouse_set(s->cursor.x, s->cursor.y, s->cursor.on);

#endif

        break;

    case SVGA_REG_MEM_REGS:

    case SVGA_REG_NUM_DISPLAYS:

    case SVGA_REG_PITCHLOCK:

    case SVGA_PALETTE_BASE ... SVGA_PALETTE_END:

        break;

    default:

        if (s->index >= SVGA_SCRATCH_BASE &&

                s->index < SVGA_SCRATCH_BASE + s->scratch_size) {

            s->scratch[s->index - SVGA_SCRATCH_BASE] = value;

            break;

        }

        printf("%s: Bad register %02x\n", __FUNCTION__, s->index);

    }

}

static uint32_t vmsvga_bios_read(void *opaque, uint32_t address)

{

    printf("%s: what are we supposed to return?\n", __FUNCTION__);

    return 0xcafe;

}

static void vmsvga_bios_write(void *opaque, uint32_t address, uint32_t data)

{

    printf("%s: what are we supposed to do with (%08x)?\n",

                    __FUNCTION__, data);

}

static inline void vmsvga_size(struct vmsvga_state_s *s)

{

    if (s->new_width != s->width || s->new_height != s->height) {

        s->width = s->new_width;

        s->height = s->new_height;

        dpy_resize(s->ds, s->width, s->height);

        s->invalidated = 1;

    }

}

static void vmsvga_update_display(void *opaque)

{

    struct vmsvga_state_s *s = (struct vmsvga_state_s *) opaque;

    if (!s->enable) {

#ifdef EMBED_STDVGA

        s->update(opaque);

#endif

        return;

    }

    vmsvga_size(s);

    vmsvga_fifo_run(s);

    vmsvga_update_rect_flush(s);

    /*

     * Is it more efficient to look at vram VGA-dirty bits or wait

     * for the driver to issue SVGA_CMD_UPDATE?

     */

    if (s->invalidated) {

        s->invalidated = 0;

        vmsvga_update_screen(s);

    }

}

static void vmsvga_reset(struct vmsvga_state_s *s)

{

    s->index = 0;

    s->enable = 0;

    s->config = 0;

    s->width = -1;

    s->height = -1;

    s->svgaid = SVGA_ID;

    s->depth = s->ds->depth ? s->ds->depth : 24;

    s->bypp = (s->depth + 7) >> 3;