Re: [Qemu-devel] [PATCH 2/2] pc: remove DEBUG_BIOS define and QEMU exit I/O ports

[Hervé Poussineau]

Anthony Liguori a écrit :
> On 07/06/2012 04:53 PM, Hervé Poussineau wrote:
> > Debug output ports (enabled by DEBUG_BIOS define) can be replaced by:
> > -chardev stdio,id=debugcon,mux=on
> > -device isa-debugcon,iobase=0x402,chardev=debugcon
> > -device isa-debugcon,iobase=0x403,chardev=debugcon
> > -device isa-debugcon,iobase=0x500,chardev=debugcon
> > -device isa-debugcon,iobase=0x503,chardev=debugcon
> >
> > QEMU exit (which can be guest triggered) can be replaced by:
> > -device isa-debugexit,iobase=0x501
> > -device isa-debugexit,iobase=0x501,access-size=2
> > -device isa-debugexit,iobase=0x502,access-size=2
> >
> > Signed-off-by: Hervé Poussineau<address@hidden>
> > ---
> >
> > Anthony, this patch is a follow-up of a patch I sent in March 2012:
> > http://lists.gnu.org/archive/html/qemu-devel/2012-03/msg00031.html
> >
> > Will you accept this approach, where your regression suite will require
> > a new parameter "-device isa-debugexit,iobase=0x501" ?

[...]

> > @@ -602,18 +577,8 @@ static void *bochs_bios_init(void)
> >       uint64_t *numa_fw_cfg;
> >       int i, j;
> >
> > -    register_ioport_write(0x400, 1, 2, bochs_bios_write, NULL);
> > -    register_ioport_write(0x401, 1, 2, bochs_bios_write, NULL);
> > -    register_ioport_write(0x402, 1, 1, bochs_bios_write, NULL);
> > -    register_ioport_write(0x403, 1, 1, bochs_bios_write, NULL);
> >       register_ioport_write(0x8900, 1, 1, bochs_bios_write, NULL);
> >
> > -    register_ioport_write(0x501, 1, 1, bochs_bios_write, NULL);
> > -    register_ioport_write(0x501, 1, 2, bochs_bios_write, NULL);
> > -    register_ioport_write(0x502, 1, 2, bochs_bios_write, NULL);
> > -    register_ioport_write(0x500, 1, 1, bochs_bios_write, NULL);
> > -    register_ioport_write(0x503, 1, 1, bochs_bios_write, NULL);
> > -
> >       fw_cfg = fw_cfg_init(BIOS_CFG_IOPORT, BIOS_CFG_IOPORT + 1, 0, 0);
> >
> >       fw_cfg_add_i32(fw_cfg, FW_CFG_ID, 1);
>
> Removing this from the default PC breaks compatibility.  I don't mind 
> having a way to disable it but it needs to be there by default.
>
> Among other things, my test suite depends on these ports.

OK for keeping them on compat PC machines.
However, for current ones (1.2 or later), I don't want to have them by 
default as it is an QEMU exit which is guest triggerable.
Will you accept this approach, where your regression suite will require
a new parameter "-device isa-debugexit,iobase=0x501" ?

Regards,

Hervé