Il 06/03/2014 15:39, Andreas Färber ha scritto:
> Am 06.03.2014 15:33, schrieb Paolo Bonzini:
>> Il 06/03/2014 14:37, Mark Wu ha scritto:
>>> Thanks for your reply! I need confirm I am understanding your comments
>>> correctly. I think you're suggesting to traverse the pci devices and
>>> check if it owns the I/O port 0x3d4 to detect if the vga device
>>> is initialized. But it seems not be able to resolve the bug. Because
>>> the machine initialization code runs before the generic device
>>> initialization, the I/O port 0x3d4 will not be registered at the time
>>> machine initializes. So it can't change the return value of
>>> pci_vga_init. The return value is checked in ppc code, which causes the
>>> bug.
>>
>> Right. What about looking for any PCI device with VGA class?
>
> Since VGA doesn't need to be PCI (e.g., ISA, SysBus) maybe it would be a
> good idea to add a QOM interface to those devices?
Actually, I now understand the problem better. All of this happens
before the VGA device is even created, so it cannot be done with QOM.
It's basically a command-line parsing problem.
There are four cases:
1) "-vga none" on the command line
2) "-device VGA" on the command line
3) "-nodefaults" on the command line
4) "-nodefaults -device VGA" on the command line
sPAPR wants to enable graphics in the second and fourth case. However,
this is not exactly what the patch does, as I read it, because it actually
enables graphics in the third and fourth cases, and not in the second
case. Both the third and the fourth case have !has_defaults, and with
has_defaults == 0 you always have default_vga == 0.
The last three cases have "default_vga == 0" in vl.c. The problem is
that -nodefaults sets default_vga to 0 too early. Perhaps something
like this would work:
diff --git a/vl.c b/vl.c
index 685a7a9..d9afff4 100644
--- a/vl.c
+++ b/vl.c
@@ -213,6 +213,7 @@ ---> add a new variable
enum xen_mode xen_mode = XEN_EMULATE;
static int tcg_tb_size;
+static int no_defaults = 0;
static int default_serial = 1;
static int default_parallel = 1;
static int default_virtcon = 1;
@@ -2041,7 +2042,7 @@ ---> select_vgahw is never called with VGA_DEVICE
{
const char *opts;
- vga_interface_type = VGA_NONE;
+ assert(vga_interface_type == VGA_NONE);
if (strstart(p, "std", &opts)) {
if (vga_available()) {
vga_interface_type = VGA_STD;
@@ -2825,7 +2826,7 @@ ---> need to detect -vga
const char *loadvm = NULL;
QEMUMachine *machine;
const char *cpu_model;
- const char *vga_model = "none";
+ const char *vga_model = NULL;
const char *qtest_chrdev = NULL;
const char *qtest_log = NULL;
const char *pid_file = NULL;
@@ -3682,16 +3683,7 @@ ---> just set a flag here
runstate_set(RUN_STATE_INMIGRATE);
break;
case QEMU_OPTION_nodefaults:
- default_serial = 0;
- default_parallel = 0;
- default_virtcon = 0;
- default_sclp = 0;
- default_monitor = 0;
- default_net = 0;
- default_floppy = 0;
- default_cdrom = 0;
- default_sdcard = 0;
- default_vga = 0;
+ no_defaults = 1;
break;
case QEMU_OPTION_xen_domid:
if (!(xen_available())) {
@@ -3918,27 +3910,35 @@ ---> detect "-device VGA" here, also disable defaults
for -nodefaults
qemu_opts_foreach(qemu_find_opts("device"), default_driver_check, NULL, 0);
qemu_opts_foreach(qemu_find_opts("global"), default_driver_check, NULL, 0);
- if (machine->no_serial) {
+ if (!vga_model && !default_vga) {
+ vga_interface_type = VGA_DEVICE;
+ }
+ if (no_defaults || machine->no_serial) {
default_serial = 0;
}
- if (machine->no_parallel) {
+ if (no_defaults || machine->no_parallel) {
default_parallel = 0;
}
- if (!machine->use_virtcon) {
+ if (no_defaults || !machine->use_virtcon) {
default_virtcon = 0;
}
- if (!machine->use_sclp) {
+ if (no_defaults || !machine->use_sclp) {
default_sclp = 0;
}
- if (machine->no_floppy) {
+ if (no_defaults || machine->no_floppy) {
default_floppy = 0;
}
- if (machine->no_cdrom) {
+ if (no_defaults || machine->no_cdrom) {
default_cdrom = 0;
}
- if (machine->no_sdcard) {
+ if (no_defaults || machine->no_sdcard) {
default_sdcard = 0;
}
+ if (no_defaults) {
+ default_monitor = 0;
+ default_net = 0;
+ default_vga = 0;
+ }
if (is_daemonized()) {
/* According to documentation and historically, -nographic redirects
@@ -4243,7 +4243,9 @@ ---> only call select_vgahw for "-vga" (or the default
VGA, see the if ending here)
vga_model = "std";
}
}
- select_vgahw(vga_model);
+ if (vga_model) {
+ select_vgahw(vga_model);
+ }
if (watchdog) {
i = select_watchdog(watchdog);
