[Qemu-devel] [post 1.1 PATCH] hw/qxl: disallow non sync io for revision >= 3

[Alon Levy]

The guest drivers should already know how to use async for revision 3.
But since it's still possible to have an older driver with revision 3
that doesn't check for the revision, require a new parameter
"force_async", which we can later turn to 1 by default.

Signed-off-by: Alon Levy <address@hidden>
---
 hw/qxl.c |   18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/hw/qxl.c b/hw/qxl.c
index 6c11e70..451e8e5 100644
--- a/hw/qxl.c
+++ b/hw/qxl.c
@@ -1316,6 +1316,23 @@ static void ioport_write(void *opaque, 
target_phys_addr_t addr,
         return;
     }
 
+    if (d->force_async && d->revision >= 3) {
+        switch (io_port) {
+        case QXL_IO_UPDATE_AREA:
+        case QXL_IO_MEMSLOT_ADD:
+        case QXL_IO_CREATE_PRIMARY:
+        case QXL_IO_DESTROY_PRIMARY:
+        case QXL_IO_DESTROY_SURFACE_WAIT:
+        case QXL_IO_DESTROY_ALL_SURFACES:
+            qxl_guest_bug(d, "sync io %d not supported for revision >= 3",
+                          io_port);
+            return;
+            break;
+        default:
+            break;
+        }
+    }
+
     /* we change the io_port to avoid ifdeffery in the main switch */
     orig_io_port = io_port;
     switch (io_port) {
@@ -2036,6 +2053,7 @@ static Property qxl_properties[] = {
         DEFINE_PROP_UINT32("ram_size_mb",  PCIQXLDevice, ram_size_mb, -1),
         DEFINE_PROP_UINT32("vram_size_mb", PCIQXLDevice, vram32_size_mb, -1),
         DEFINE_PROP_UINT32("vram64_size_mb", PCIQXLDevice, vram_size_mb, -1),
+        DEFINE_PROP_UINT32("force_async", PCIQXLDevice, force_async, 0),
         DEFINE_PROP_END_OF_LIST(),
 };
 
-- 
1.7.10.1