[PATCH] Fix display breakage when resizing the screen (v2)

Avi Kivity
2009-04-05T15:36:54Z

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.

Tested with (Windows|Linux) x (cirrus|std) x (curses|sdl).

Changes from v1:
- fix segfault when switching virtual consoles with curses

Signed-off-by: Avi Kivity <avi@redhat.com>
---
hw/cirrus_vga.c | 11 ++-
hw/vga.c | 275 +++++++++++++++++++++++++++++++------------------------
hw/vga_int.h | 4 +
3 files changed, 170 insertions(+), 120 deletions(-)

diff --git a/hw/cirrus_vga.c b/hw/cirrus_vga.c
index 08fd4c2..223008e 100644
--- a/hw/cirrus_vga.c
+++ b/hw/cirrus_vga.c
@@ -1392,6 +1392,8 @@ cirrus_hook_write_sr(CirrusVGAState * s, unsigned reg_index, int reg_value)
break;
}

+ vga_update_resolution((VGAState *)s);
+
return CIRRUS_HOOK_HANDLED;
}

@@ -1419,6 +1421,7 @@ static void cirrus_write_hidden_dac(CirrusVGAState * s, int reg_value)
#endif
}
s->cirrus_hidden_dac_lockindex = 0;
+ vga_update_resolution((VGAState *)s);
}

/***************************************
@@ -1705,6 +1708,8 @@ cirrus_hook_write_cr(CirrusVGAState * s, unsigned reg_index, int reg_value)
break;
}

+ vga_update_resolution((VGAState *)s);
+
return CIRRUS_HOOK_HANDLED;
}

@@ -2830,6 +2835,7 @@ 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) {
@@ -2923,6 +2929,7 @@ 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) {
@@ -2951,6 +2958,7 @@ static void vga_ioport_write(void *opaque, uint32_t addr, uint32_t val)
s->update_retrace_info((VGAState *) s);
break;
}
+ vga_update_resolution((VGAState *)s);
break;
case 0x3ba:
case 0x3da:
@@ -3157,7 +3165,8 @@ 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/hw/vga.c b/hw/vga.c
index b1e4373..54d0246 100644
--- a/hw/vga.c
+++ b/hw/vga.c
@@ -36,6 +36,10 @@

//#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] = {
0x03,
@@ -393,6 +397,7 @@ 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) {
@@ -433,6 +438,7 @@ 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;
@@ -460,6 +466,7 @@ 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:
@@ -475,6 +482,7 @@ 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) {
@@ -502,6 +510,7 @@ 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:
@@ -581,11 +590,13 @@ 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)
@@ -594,6 +605,7 @@ 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) {
@@ -662,6 +674,7 @@ 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:
{
@@ -682,6 +695,7 @@ 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:
@@ -696,6 +710,7 @@ 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;
@@ -1302,7 +1317,6 @@ 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);
@@ -1314,18 +1328,6 @@ 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);
@@ -1582,39 +1584,21 @@ 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, page_min, page_max, linesize, y_start, double_scan, mask, depth;
- int width, height, shift_control, line_offset, page0, page1, 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;
- 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;
}
@@ -1628,12 +1612,28 @@ 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 (s->ds->surface->pf.depth == 0) {
+ goto dont_touch_display_surface;
+ }
#if defined(WORDS_BIGENDIAN) == defined(TARGET_WORDS_BIGENDIAN)
if (depth == 16 || depth == 32) {
#else
@@ -1650,14 +1650,91 @@ static void vga_draw_graphic(VGAState *s, int full_update)
} else {
qemu_console_resize(s->ds, disp_width, height);
}
+ dont_touch_display_surface:
s->last_scr_width = disp_width;
s->last_scr_height = height;
s->last_width = disp_width;
s->last_height = height;
s->last_line_offset = s->line_offset;
s->last_depth = depth;
- full_update = 1;
- } else if (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;
+ if (s->ds->surface->pf.depth != 0) {
+ qemu_console_resize(s->ds, s->last_scr_width, s->last_scr_height);
+ } else {
+ /*
+ * curses expects width and height to be in character cell
+ * dimensions, not pixels.
+ */
+ s->ds->surface->width = width;
+ s->ds->surface->height = height;
+ dpy_resize(s->ds);
+ }
+ 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_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);
@@ -1666,7 +1743,7 @@ 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;
@@ -1674,7 +1751,7 @@ 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;
@@ -1770,7 +1847,7 @@ 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;
}
}
@@ -1779,7 +1856,7 @@ 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--;
}
@@ -1791,7 +1868,7 @@ 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) {
@@ -1828,29 +1905,17 @@ 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;
@@ -1870,8 +1935,8 @@ 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)
@@ -1915,7 +1980,6 @@ 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;
@@ -1941,6 +2005,7 @@ 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)
@@ -1952,50 +2017,28 @@ void vga_reset(void *opaque)
static void vga_update_text(void *opaque, console_ch_t *chardata)
{
VGAState *s = (VGAState *) opaque;
- int graphic_mode, i, cursor_offset, cursor_visible;
+ int i, cursor_offset, cursor_visible;
int cw, cheight, width, height, size, c_min, c_max;
uint32_t *src;
console_ch_t *dst, val;
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;
- }
+ int full_update = s->want_full_update;

- switch (graphic_mode) {
+ s->want_full_update = 0;
+ switch (s->graphic_mode) {
case GMODE_TEXT:
/* TODO: update palette */
- full_update |= update_basic_params(s);

- /* total width & height */
- cheight = (s->cr[9] & 0x1f) + 1;
- cw = 8;
- if (!(s->sr[1] & 0x01))
- cw = 9;
- if (s->sr[1] & 0x08)
- cw = 16; /* NOTE: no 18 pixel wide */
- width = (s->cr[0x01] + 1);
- if (s->cr[0x06] == 100) {
- /* ugly hack for CGA 160x100x16 - explain me the logic */
- height = 100;
- } else {
- height = s->cr[0x12] |
- ((s->cr[0x07] & 0x02) << 7) |
- ((s->cr[0x07] & 0x40) << 3);
- height = (height + 1) / cheight;
+ vga_get_text_resolution(s, &width, &height, &cw, &cheight);
+
+ if (s->ds->surface->width != width
+ || s->ds->surface->height != height) {
+ s->ds->surface->width = width;
+ s->ds->surface->height = height;
+ dpy_resize(s->ds);
}

+ /* total width & height */
size = (height * width);
if (size > CH_ATTR_SIZE) {
if (!full_update)
@@ -2006,20 +2049,6 @@ static void vga_update_text(void *opaque, console_ch_t *chardata)
break;
}

- if (width != s->last_width || height != s->last_height ||
- cw != s->last_cw || cheight != s->last_ch) {
- s->last_scr_width = width * cw;
- s->last_scr_height = height * cheight;
- s->ds->surface->width = width;
- s->ds->surface->height = height;
- dpy_resize(s->ds);
- s->last_width = width;
- s->last_height = height;
- s->last_ch = cheight;
- s->last_cw = cw;
- full_update = 1;
- }
-
/* Update "hardware" cursor */
cursor_offset = ((s->cr[0x0e] << 8) | s->cr[0x0f]) - s->start_addr;
if (cursor_offset != s->cursor_offset ||
@@ -2218,7 +2247,8 @@ 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;
}

@@ -2641,7 +2671,8 @@ static void vga_screen_dump_common(VGAState *s, const char *filename,
ds->surface = qemu_create_displaysurface(ds, w, h);

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);
@@ -2672,10 +2703,16 @@ static void vga_screen_dump(void *opaque, const char *filename)
{
VGAState *s = (VGAState *)opaque;

- if (!(s->ar_index & 0x20))
- vga_screen_dump_blank(s, filename);
- else if (s->gr[6] & 1)
- vga_screen_dump_graphic(s, filename);
- else
+ switch (s->graphic_mode) {
+ case GMODE_TEXT:
vga_screen_dump_text(s, filename);
+ break;
+ case GMODE_GRAPH:
+ vga_screen_dump_graphic(s, filename);
+ break;
+ case GMODE_BLANK:
+ default:
+ vga_screen_dump_blank(s, filename);
+ break;
+ }
}
diff --git a/hw/vga_int.h b/hw/vga_int.h
index f97e98f..6ab9742 100644
--- a/hw/vga_int.h
+++ b/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);
--
1.6.1.1