qxl: create slots on post_load in vga state

Submitted by Alon Levy on Oct. 25, 2011, 1:39 p.m.

Details

Message ID 1319549990-26462-1-git-send-email-alevy@redhat.com
State New
Headers show

Commit Message

Alon Levy Oct. 25, 2011, 1:39 p.m.
RHBZ 740547

If we migrate when the device is in vga state the guest
still believes the slots are created, and will cause operations
that reference the slots, causing a "panic: virtual address out of range"
on the first of them. Easy to see by migrating in vga mode with
a driver loaded, for instance windows cmd window in full screen mode,
and then exiting vga mode back to native mode will cause said panic.

Fixed by doing the slot recreation in post_load for vga mode as well.
Note that compat does not require any changes because it creates it's
only slot by a side effect of QXL_IO_SET_MODE.

Signed-off-by: Alon Levy <alevy@redhat.com>
---
v4:
 don't print unused delta in qxl_create_memslots
v3:
 no need to create slots in compat mode, they are created by qxl_set_mode.

 hw/qxl.c |   26 +++++++++++++++++++-------
 1 files changed, 19 insertions(+), 7 deletions(-)

Comments

Gerd Hoffmann Oct. 27, 2011, 11:56 a.m.
On 10/25/11 15:39, Alon Levy wrote:
> RHBZ 740547
> 
> If we migrate when the device is in vga state the guest
> still believes the slots are created, and will cause operations
> that reference the slots, causing a "panic: virtual address out of range"
> on the first of them. Easy to see by migrating in vga mode with
> a driver loaded, for instance windows cmd window in full screen mode,
> and then exiting vga mode back to native mode will cause said panic.
> 
> Fixed by doing the slot recreation in post_load for vga mode as well.
> Note that compat does not require any changes because it creates it's
> only slot by a side effect of QXL_IO_SET_MODE.
> 
> Signed-off-by: Alon Levy <alevy@redhat.com>
> ---
> v4:
>  don't print unused delta in qxl_create_memslots
> v3:
>  no need to create slots in compat mode, they are created by qxl_set_mode.
> 

Patch added to spice patch queue.

thanks,
  Gerd

Patch hide | download patch | download mbox

diff --git a/hw/qxl.c b/hw/qxl.c
index 03848ed..f332dbf 100644
--- a/hw/qxl.c
+++ b/hw/qxl.c
@@ -1662,12 +1662,25 @@  static int qxl_pre_load(void *opaque)
     return 0;
 }
 
+static void qxl_create_memslots(PCIQXLDevice *d)
+{
+    int i;
+
+    for (i = 0; i < NUM_MEMSLOTS; i++) {
+        if (!d->guest_slots[i].active) {
+            continue;
+        }
+        dprint(d, 1, "%s: restoring guest slot %d\n", __func__, i);
+        qxl_add_memslot(d, i, 0, QXL_SYNC);
+    }
+}
+
 static int qxl_post_load(void *opaque, int version)
 {
     PCIQXLDevice* d = opaque;
     uint8_t *ram_start = d->vga.vram_ptr;
     QXLCommandExt *cmds;
-    int in, out, i, newmode;
+    int in, out, newmode;
 
     dprint(d, 1, "%s: start\n", __FUNCTION__);
 
@@ -1684,19 +1697,16 @@  static int qxl_post_load(void *opaque, int version)
         qxl_mode_to_string(d->mode));
     newmode = d->mode;
     d->mode = QXL_MODE_UNDEFINED;
+
     switch (newmode) {
     case QXL_MODE_UNDEFINED:
         break;
     case QXL_MODE_VGA:
+        qxl_create_memslots(d);
         qxl_enter_vga_mode(d);
         break;
     case QXL_MODE_NATIVE:
-        for (i = 0; i < NUM_MEMSLOTS; i++) {
-            if (!d->guest_slots[i].active) {
-                continue;
-            }
-            qxl_add_memslot(d, i, 0, QXL_SYNC);
-        }
+        qxl_create_memslots(d);
         qxl_create_guest_primary(d, 1, QXL_SYNC);
 
         /* replay surface-create and cursor-set commands */
@@ -1719,6 +1729,8 @@  static int qxl_post_load(void *opaque, int version)
 
         break;
     case QXL_MODE_COMPAT:
+        /* note: no need to call qxl_create_memslots, qxl_set_mode
+         * creates the mem slot. */
         qxl_set_mode(d, d->shadow_rom.mode, 1);
         break;
     }