From 8ad63a93a482d5c3354b97463633394456a157d5 Mon Sep 17 00:00:00 2001

From: Avi Kivity <avi@redhat.com>

Date: Thu, 2 Apr 2009 22:17:50 +0300

Subject: [PATCH 1/1] kvm: qemu: Fix display breakage when resizing the screen

When the vga resolution changes, a new display surface is not allocated

immediately; instead that is deferred until the next update.  However,

if we're running without a display client attached, that won't happen

and the next bitblt is likely to cause a segfault by overflowing the

display surface.

Fix by reallocating the display immediately when the resolution changes.

Signed-off-by: Avi Kivity <avi@redhat.com>

---

 qemu/hw/cirrus_vga.c |   10 ++-

 qemu/hw/vga.c        |  205 +++++++++++++++++++++++++++++--------------------

 qemu/hw/vga_int.h    |    4 +

 3 files changed, 134 insertions(+), 85 deletions(-)

diff --git a/qemu/hw/cirrus_vga.c b/qemu/hw/cirrus_vga.c

index 0ab0f14..7bd0482 100644

--- a/qemu/hw/cirrus_vga.c

+++ b/qemu/hw/cirrus_vga.c

@@ -1399,6 +1399,8 @@ cirrus_hook_write_sr(CirrusVGAState * s, unsigned reg_index, int reg_value)

 	break;

     }

+    vga_update_resolution((VGAState *)s);

+

     return CIRRUS_HOOK_HANDLED;

 }

@@ -1426,6 +1428,7 @@ static void cirrus_write_hidden_dac(CirrusVGAState * s, int reg_value)

 #endif

     }

     s->cirrus_hidden_dac_lockindex = 0;

+    vga_update_resolution((VGAState *)s);

 }

 /***************************************

@@ -1712,6 +1715,8 @@ cirrus_hook_write_cr(CirrusVGAState * s, unsigned reg_index, int reg_value)

 	break;

     }

+    vga_update_resolution((VGAState *)s);

+

     return CIRRUS_HOOK_HANDLED;

 }

@@ -2839,6 +2844,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

 	if (s->ar_flip_flop == 0) {

 	    val &= 0x3f;

 	    s->ar_index = val;

+            vga_update_resolution((VGAState *)s);

 	} else {

 	    index = s->ar_index & 0x1f;

 	    switch (index) {

@@ -2932,6 +2938,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

 	    /* can always write bit 4 of CR7 */

 	    if (s->cr_index == 7)

 		s->cr[7] = (s->cr[7] & ~0x10) | (val & 0x10);

+            vga_update_resolution((VGAState *)s);

 	    return;

 	}

 	switch (s->cr_index) {

@@ -3166,7 +3173,8 @@ static int cirrus_vga_load(QEMUFile *f, void *opaque, int version_id)

     cirrus_update_memory_access(s);

     /* force refresh */

-    s->graphic_mode = -1;

+    vga_update_resolution((VGAState *)s);

+    s->want_full_update = 1;

     cirrus_update_bank_ptr(s, 0);

     cirrus_update_bank_ptr(s, 1);

     return 0;

diff --git a/qemu/hw/vga.c b/qemu/hw/vga.c

index d4fddf9..9a950d3 100644

--- a/qemu/hw/vga.c

+++ b/qemu/hw/vga.c

@@ -37,6 +37,10 @@

 //#define DEBUG_BOCHS_VBE

+#define GMODE_TEXT     0

+#define GMODE_GRAPH    1

+#define GMODE_BLANK 2

+

 /* force some bits to zero */

 const uint8_t sr_mask[8] = {

     (uint8_t)~0xfc,

@@ -394,6 +398,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

         if (s->ar_flip_flop == 0) {

             val &= 0x3f;

             s->ar_index = val;

+            vga_update_resolution(s);

         } else {

             index = s->ar_index & 0x1f;

             switch(index) {

@@ -434,6 +439,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

 #endif

         s->sr[s->sr_index] = val & sr_mask[s->sr_index];

         if (s->sr_index == 1) s->update_retrace_info(s);

+        vga_update_resolution(s);

         break;

     case 0x3c7:

         s->dac_read_index = val;

@@ -461,6 +467,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

         printf("vga: write GR%x = 0x%02x\n", s->gr_index, val);

 #endif

         s->gr[s->gr_index] = val & gr_mask[s->gr_index];

+        vga_update_resolution(s);

         break;

     case 0x3b4:

     case 0x3d4:

@@ -476,6 +483,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

             /* can always write bit 4 of CR7 */

             if (s->cr_index == 7)

                 s->cr[7] = (s->cr[7] & ~0x10) | (val & 0x10);

+            vga_update_resolution(s);

             return;

         }

         switch(s->cr_index) {

@@ -503,6 +511,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)

             s->update_retrace_info(s);

             break;

         }

+        vga_update_resolution(s);

         break;

     case 0x3ba:

     case 0x3da:

@@ -582,11 +591,13 @@ static void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)

             if ((val <= VBE_DISPI_MAX_XRES) && ((val & 7) == 0)) {

                 s->vbe_regs[s->vbe_index] = val;

             }

+            vga_update_resolution(s);

             break;

         case VBE_DISPI_INDEX_YRES:

             if (val <= VBE_DISPI_MAX_YRES) {

                 s->vbe_regs[s->vbe_index] = val;

             }

+            vga_update_resolution(s);

             break;

         case VBE_DISPI_INDEX_BPP:

             if (val == 0)

@@ -595,6 +606,7 @@ static void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)

                 val == 16 || val == 24 || val == 32) {

                 s->vbe_regs[s->vbe_index] = val;

             }

+            vga_update_resolution(s);

             break;

         case VBE_DISPI_INDEX_BANK:

             if (s->vbe_regs[VBE_DISPI_INDEX_BPP] == 4) {

@@ -663,6 +675,7 @@ static void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)

             }

             s->dac_8bit = (val & VBE_DISPI_8BIT_DAC) > 0;

             s->vbe_regs[s->vbe_index] = val;

+            vga_update_resolution(s);

             break;

         case VBE_DISPI_INDEX_VIRT_WIDTH:

             {

@@ -683,6 +696,7 @@ static void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)

                 s->vbe_regs[VBE_DISPI_INDEX_VIRT_HEIGHT] = h;

                 s->vbe_line_offset = line_offset;

             }

+            vga_update_resolution(s);

             break;

         case VBE_DISPI_INDEX_X_OFFSET:

         case VBE_DISPI_INDEX_Y_OFFSET:

@@ -697,6 +711,7 @@ static void vbe_ioport_write_data(void *opaque, uint32_t addr, uint32_t val)

                     s->vbe_start_addr += x * ((s->vbe_regs[VBE_DISPI_INDEX_BPP] + 7) >> 3);

                 s->vbe_start_addr >>= 2;

             }

+            vga_update_resolution(s);

             break;

         default:

             break;

@@ -1300,7 +1315,6 @@ static void vga_draw_text(VGAState *s, int full_update)

         s->plane_updated = 0;

         full_update = 1;

     }

-    full_update |= update_basic_params(s);

     line_offset = s->line_offset;

     s1 = s->vram_ptr + (s->start_addr * 4);

@@ -1312,18 +1326,6 @@ static void vga_draw_text(VGAState *s, int full_update)

         return;

     }

-    if (width != s->last_width || height != s->last_height ||

-        cw != s->last_cw || cheight != s->last_ch || s->last_depth) {

-        s->last_scr_width = width * cw;

-        s->last_scr_height = height * cheight;

-        qemu_console_resize(s->ds, s->last_scr_width, s->last_scr_height);

-        s->last_depth = 0;

-        s->last_width = width;

-        s->last_height = height;

-        s->last_ch = cheight;

-        s->last_cw = cw;

-        full_update = 1;

-    }

     s->rgb_to_pixel =

         rgb_to_pixel_dup_table[get_depth_index(s->ds)];

     full_update |= update_palette16(s);

@@ -1580,40 +1582,20 @@ static void vga_sync_dirty_bitmap(VGAState *s)

     vga_dirty_log_start(s);

 }

-/*

- * graphic modes

- */

-static void vga_draw_graphic(VGAState *s, int full_update)

+static void vga_update_resolution_graphics(VGAState *s)

 {

-    int y1, y, update, linesize, y_start, double_scan, mask, depth;

-    int width, height, shift_control, line_offset, bwidth, bits;

+    int depth = s->get_bpp(s);

+    int width, height, shift_control, double_scan;

     int disp_width, multi_scan, multi_run;

-    uint8_t *d;

-    uint32_t v, addr1, addr;

-    long page0, page1, page_min, page_max;

-    vga_draw_line_func *vga_draw_line;

-

-    full_update |= update_basic_params(s);

-

-    if (!full_update)

-        vga_sync_dirty_bitmap(s);

     s->get_resolution(s, &width, &height);

-    disp_width = width;

     shift_control = (s->gr[0x05] >> 5) & 3;

     double_scan = (s->cr[0x09] >> 7);

-    if (shift_control != 1) {

-        multi_scan = (((s->cr[0x09] & 0x1f) + 1) << double_scan) - 1;

-    } else {

-        /* in CGA modes, multi_scan is ignored */

-        /* XXX: is it correct ? */

-        multi_scan = double_scan;

-    }

-    multi_run = multi_scan;

+

     if (shift_control != s->shift_control ||

         double_scan != s->double_scan) {

-        full_update = 1;

+        s->want_full_update = 1;

         s->shift_control = shift_control;

         s->double_scan = double_scan;

     }

@@ -1627,12 +1609,25 @@ static void vga_draw_graphic(VGAState *s, int full_update)

             disp_width <<= 1;

         }

     }

+    disp_width = width;

+

+    if (shift_control != 1) {

+        multi_scan = (((s->cr[0x09] & 0x1f) + 1) << double_scan) - 1;

+    } else {

+        /* in CGA modes, multi_scan is ignored */

+        /* XXX: is it correct ? */

+        multi_scan = double_scan;

+    }

+

+    multi_run = multi_scan;

-    depth = s->get_bpp(s);

     if (s->line_offset != s->last_line_offset ||

         disp_width != s->last_width ||

         height != s->last_height ||

-        s->last_depth != depth) {

+        s->last_depth != depth ||

+        s->multi_run != multi_run ||

+        s->multi_scan != multi_scan ||

+        s->want_full_update) {

 #if defined(WORDS_BIGENDIAN) == defined(TARGET_WORDS_BIGENDIAN)

         if (depth == 16 || depth == 32) {

 #else

@@ -1659,8 +1654,74 @@ static void vga_draw_graphic(VGAState *s, int full_update)

         s->last_height = height;

         s->last_line_offset = s->line_offset;

         s->last_depth = depth;

-        full_update = 1;

-    } else if (is_graphic_console() && is_buffer_shared(s->ds->surface) &&

+        s->multi_run = multi_run;

+        s->multi_scan = multi_scan;

+        s->want_full_update = 1;

+    }

+}

+

+static void vga_update_resolution_text(VGAState *s)

+{

+    int width, height, cw, cheight;

+

+    vga_get_text_resolution(s, &width, &height, &cw, &cheight);

+    if (width != s->last_width || height != s->last_height ||

+        cw != s->last_cw || cheight != s->last_ch || s->last_depth) {

+        s->last_scr_width = width * cw;

+        s->last_scr_height = height * cheight;

+        qemu_console_resize(s->ds, s->last_scr_width, s->last_scr_height);

+        s->last_depth = 0;

+        s->last_width = width;

+        s->last_height = height;

+        s->last_ch = cheight;

+        s->last_cw = cw;

+        s->want_full_update = 1;

+    }

+}

+

+void vga_update_resolution(VGAState *s)

+{

+    int graphic_mode;

+

+    if (!(s->ar_index & 0x20)) {

+        graphic_mode = GMODE_BLANK;

+    } else {

+        graphic_mode = s->gr[6] & 1;

+    }

+    if (graphic_mode != s->graphic_mode) {

+        s->graphic_mode = graphic_mode;

+        s->want_full_update = 1;

+    }

+    s->want_full_update |= update_basic_params(s);

+    switch (graphic_mode) {

+    case GMODE_TEXT:

+        vga_update_resolution_text(s);

+        break;

+    case GMODE_GRAPH:

+        vga_update_resolution_graphics(s);

+        break;

+    }

+}

+

+/*

+ * graphic modes

+ */

+static void vga_draw_graphic(VGAState *s, int full_update)

+{

+    int y1, y, update, linesize, y_start, mask;

+    int width, height, line_offset, bwidth, bits;

+    int multi_run;

+    uint8_t *d;

+    uint32_t v, addr1, addr;

+    long page0, page1, page_min, page_max;

+    vga_draw_line_func *vga_draw_line;

+

+    if (!full_update)

+        vga_sync_dirty_bitmap(s);

+

+    s->get_resolution(s, &width, &height);

+    multi_run = s->multi_run;

+    if (is_graphic_console() && is_buffer_shared(s->ds->surface) &&

                (full_update || s->ds->surface->data != s->vram_ptr + (s->start_addr * 4))) {

         s->ds->surface->data = s->vram_ptr + (s->start_addr * 4);

         dpy_setdata(s->ds);

@@ -1669,7 +1730,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)

     s->rgb_to_pixel =

         rgb_to_pixel_dup_table[get_depth_index(s->ds)];

-    if (shift_control == 0) {

+    if (s->shift_control == 0) {

         full_update |= update_palette16(s);

         if (s->sr[0x01] & 8) {

             v = VGA_DRAW_LINE4D2;

@@ -1677,7 +1738,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)

             v = VGA_DRAW_LINE4;

         }

         bits = 4;

-    } else if (shift_control == 1) {

+    } else if (s->shift_control == 1) {

         full_update |= update_palette16(s);

         if (s->sr[0x01] & 8) {

             v = VGA_DRAW_LINE2D2;

@@ -1773,7 +1834,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)

             if (y_start >= 0) {

                 /* flush to display */

                 dpy_update(s->ds, 0, y_start,

-                           disp_width, y - y_start);

+                           s->last_width, y - y_start);

                 y_start = -1;

             }

         }

@@ -1782,7 +1843,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)

             if ((y1 & mask) == mask)

                 addr1 += line_offset;

             y1++;

-            multi_run = multi_scan;

+            multi_run = s->multi_scan;

         } else {

             multi_run--;

         }

@@ -1794,7 +1855,7 @@ static void vga_draw_graphic(VGAState *s, int full_update)

     if (y_start >= 0) {

         /* flush to display */

         dpy_update(s->ds, 0, y_start,

-                   disp_width, y - y_start);

+                   s->last_width, y - y_start);

     }

     /* reset modified pages */

     if (page_max != -1) {

@@ -1831,29 +1892,17 @@ static void vga_draw_blank(VGAState *s, int full_update)

                s->last_scr_width, s->last_scr_height);

 }

-#define GMODE_TEXT     0

-#define GMODE_GRAPH    1

-#define GMODE_BLANK 2

-

 static void vga_update_display(void *opaque)

 {

     VGAState *s = (VGAState *)opaque;

-    int full_update, graphic_mode;

+    int full_update;

     if (ds_get_bits_per_pixel(s->ds) == 0) {

         /* nothing to do */

     } else {

-        full_update = 0;

-        if (!(s->ar_index & 0x20)) {

-            graphic_mode = GMODE_BLANK;

-        } else {

-            graphic_mode = s->gr[6] & 1;

-        }

-        if (graphic_mode != s->graphic_mode) {

-            s->graphic_mode = graphic_mode;

-            full_update = 1;

-        }

-        switch(graphic_mode) {

+        full_update = s->want_full_update;

+        s->want_full_update = 0;

+        switch(s->graphic_mode) {

         case GMODE_TEXT:

             vga_draw_text(s, full_update);

             break;

@@ -1876,8 +1925,8 @@ static void vga_invalidate_display(void *opaque)

 {

     VGAState *s = (VGAState *)opaque;

-    s->last_width = -1;

-    s->last_height = -1;

+    vga_update_resolution(s);

+    s->want_full_update = 1;

 }

 void vga_reset(void *opaque)

@@ -1921,7 +1970,6 @@ void vga_reset(void *opaque)

     s->vbe_bank_mask = (s->vram_size >> 16) - 1;

 #endif

     memset(s->font_offsets, '\0', sizeof(s->font_offsets));

-    s->graphic_mode = -1; /* force full update */

     s->shift_control = 0;

     s->double_scan = 0;

     s->line_offset = 0;

@@ -1947,6 +1995,7 @@ void vga_reset(void *opaque)

         memset(&s->retrace_info, 0, sizeof (s->retrace_info));

         break;

     }

+    vga_update_resolution(s);

 }

 #define TEXTMODE_X(x)	((x) % width)

@@ -1965,24 +2014,9 @@ static void vga_update_text(void *opaque, console_ch_t *chardata)

     char msg_buffer[80];

     int full_update = 0;

-    if (!(s->ar_index & 0x20)) {

-        graphic_mode = GMODE_BLANK;

-    } else {

-        graphic_mode = s->gr[6] & 1;

-    }

-    if (graphic_mode != s->graphic_mode) {

-        s->graphic_mode = graphic_mode;

-        full_update = 1;

-    }

-    if (s->last_width == -1) {

-        s->last_width = 0;

-        full_update = 1;

-    }

-

     switch (graphic_mode) {

     case GMODE_TEXT:

         /* TODO: update palette */

-        full_update |= update_basic_params(s);

         /* total width & height */

         cheight = (s->cr[9] & 0x1f) + 1;

@@ -2224,7 +2258,8 @@ static int vga_load(QEMUFile *f, void *opaque, int version_id)

 #endif

     /* force refresh */

-    s->graphic_mode = -1;

+    vga_update_resolution(s);

+    s->want_full_update = 1;

     return 0;

 }

@@ -2418,7 +2453,8 @@ void vga_bios_init(VGAState *s)

     memcpy(s->palette, palette_model, 192);

     s->bank_offset = 0;

-    s->graphic_mode = -1;

+    vga_update_resolution(s);

+    s->want_full_update = 1;

     /* TODO: add vbe support if enabled */

 }

@@ -2803,7 +2839,8 @@ static void vga_screen_dump_common(VGAState *s, const char *filename,

     ds->surface = qemu_create_displaysurface(w, h, 32, 4 * w);

     s->ds = ds;

-    s->graphic_mode = -1;

+    vga_update_resolution(s);

+    s->want_full_update = 1;

     vga_update_display(s);

     ppm_save(filename, ds->surface);

diff --git a/qemu/hw/vga_int.h b/qemu/hw/vga_int.h

index 8ba8a60..71ffeb5 100644

--- a/qemu/hw/vga_int.h

+++ b/qemu/hw/vga_int.h

@@ -147,8 +147,11 @@ typedef void (* vga_update_retrace_info_fn)(struct VGAState *s);

     DisplayState *ds;                                                   \

     uint32_t font_offsets[2];                                           \

     int graphic_mode;                                                   \

+    int want_full_update;                                               \

     uint8_t shift_control;                                              \

     uint8_t double_scan;                                                \

+    uint8_t multi_run;                                                  \

+    uint8_t multi_scan;                                                 \

     uint32_t line_offset;                                               \

     uint32_t line_compare;                                              \

     uint32_t start_addr;                                                \

@@ -195,6 +198,7 @@ void vga_common_init(VGAState *s, uint8_t *vga_ram_base,

                      ram_addr_t vga_ram_offset, int vga_ram_size);

 void vga_init(VGAState *s);

 void vga_reset(void *s);

+void vga_update_resolution(VGAState *s);

 void vga_dirty_log_start(VGAState *s);

 void vga_dirty_log_stop(VGAState *s);

-- 

1.6.0.6