On 17/08/2021 21.26, Jose R. Ziviani wrote:
If users try to add an isa-vga device that was already registered,
still in command line, qemu will crash:
$ qemu-system-mips64el -M pica61 -device isa-vga
RAMBlock "vga.vram" already registered, abort!
Aborted (core dumped)
That particular board registers the device automaticaly, so it's
not obvious that a VGA device already exists. This patch changes
this behavior by displaying a message and exiting without crashing.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/44
Signed-off-by: Jose R. Ziviani <jzivi...@suse.de>
---
v3 to v4: Used object_resolve_path_type instead of qemu_ram_block_by_name
and copied the message from virgl, to give the same user exp.
v2 to v3: Improved error message
v1 to v2: Use error_setg instead of error_report
hw/display/vga-isa.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/hw/display/vga-isa.c b/hw/display/vga-isa.c
index 90851e730b..8cea84f2be 100644
--- a/hw/display/vga-isa.c
+++ b/hw/display/vga-isa.c
@@ -33,6 +33,7 @@
#include "hw/loader.h"
#include "hw/qdev-properties.h"
#include "qom/object.h"
+#include "qapi/error.h"
#define TYPE_ISA_VGA "isa-vga"
OBJECT_DECLARE_SIMPLE_TYPE(ISAVGAState, ISA_VGA)
@@ -61,6 +62,15 @@ static void vga_isa_realizefn(DeviceState *dev, Error **errp)
MemoryRegion *vga_io_memory;
const MemoryRegionPortio *vga_ports, *vbe_ports;
+ /*
+ * make sure this device is not being added twice, if so
+ * exit without crashing qemu
+ */
+ if (object_resolve_path_type("", TYPE_ISA_VGA, NULL)) {
+ error_setg(errp, "at most one %s device is permitted", TYPE_ISA_VGA);
+ return;
+ }
+
s->global_vmstate = true;
vga_common_init(s, OBJECT(dev));
s->legacy_address_space = isa_address_space(isadev);
Reviewed-by: Thomas Huth <th...@redhat.com>
