ioemu/qemu vga: save and restore vram buffer (take 2)

The existing stdvga driver from xen-unstable tools/ioemu/hw/vga* does
not save the emulated VGA memory contents.  The symptoms include video
malfunction after restore, including black screen (which can often be
fixed by asking the guest to redraw) but also missing font setup etc.
The attached patch fixes this by saving the entire VGA memory buffer,
just like the Xen ioemu Cirrus emulator does.

Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

diff --git a/tools/ioemu/hw/vga.c b/tools/ioemu/hw/vga.c
index cb34f289fb556ae9ee353676841699f04bd524b1..17538bbddc5332b0c145c5bbc142be1c849415e5 100644 (file)
--- a/tools/ioemu/hw/vga.c
+++ b/tools/ioemu/hw/vga.c
@@ -1742,6 +1742,7 @@ static CPUWriteMemoryFunc *vga_mem_write[3] = {
 static void vga_save(QEMUFile *f, void *opaque)
 {
     VGAState *s = opaque;
+    uint32_t vram_size;
 #ifdef CONFIG_BOCHS_VBE
     int i;
 #endif
@@ -1783,17 +1784,21 @@ static void vga_save(QEMUFile *f, void *opaque)
 #else
     qemu_put_byte(f, 0);
 #endif
+    vram_size = s->vram_size;
+    qemu_put_be32s(f, &vram_size); 
+    qemu_put_buffer(f, s->vram_ptr, s->vram_size); 
 }
 
 static int vga_load(QEMUFile *f, void *opaque, int version_id)
 {
     VGAState *s = opaque;
     int is_vbe, ret;
+    uint32_t vram_size;
 #ifdef CONFIG_BOCHS_VBE
     int i;
 #endif
 
-    if (version_id > 2)
+    if (version_id > 3)
         return -EINVAL;
 
     if (s->pci_dev && version_id >= 2) {
@@ -1839,6 +1844,13 @@ static int vga_load(QEMUFile *f, void *opaque, int version_id)
     if (is_vbe)
         return -EINVAL;
 #endif
+    if (version_id >= 3) {
+       /* people who restore old images may be lucky ... */
+       qemu_get_be32s(f, &vram_size);
+       if (vram_size != s->vram_size)
+           return -EINVAL;
+       qemu_get_buffer(f, s->vram_ptr, s->vram_size); 
+    }
 
     /* force refresh */
     s->graphic_mode = -1;
@@ -2052,7 +2064,7 @@ static void vga_init(VGAState *s)
 {
     int vga_io_memory;
 
-    register_savevm("vga", 0, 2, vga_save, vga_load, s);
+    register_savevm("vga", 0, 3, vga_save, vga_load, s);
 
     register_ioport_write(0x3c0, 16, 1, vga_ioport_write, s);