[1/2] debugexit: support for custom exit port (LGPL VGA BIOS port 0x501) v2

From: Hervé Poussineau <hpoussin@reactos.org>

Add generic support for simple I/O port which, when written to, cause
QEMU to exit with the given written value.

There is no vmstate associated with the debugging port, simply because
the entire interface is a single, stateless, write-only port.

Changes from v1:

 * Changing PIO from MMIO, as requested during review.

Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
---
 hw/debugexit.c        | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++
 hw/i386/Makefile.objs |  2 +-
 2 files changed, 76 insertions(+), 1 deletion(-)
 create mode 100644 hw/debugexit.c

On 2012-10-09 15:03, Lucas Meneghel Rodrigues wrote:
> From: Hervé Poussineau <hpoussin@reactos.org>
> 
> Add generic support for simple I/O port which, when written to, cause
> QEMU to exit with the given written value.
> 
> There is no vmstate associated with the debugging port, simply because
> the entire interface is a single, stateless, write-only port.
> 
> Changes from v1:
> 
>  * Changing PIO from MMIO, as requested during review.
> 
> Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
> ---
>  hw/debugexit.c        | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/i386/Makefile.objs |  2 +-
>  2 files changed, 76 insertions(+), 1 deletion(-)
>  create mode 100644 hw/debugexit.c
> 
> diff --git a/hw/debugexit.c b/hw/debugexit.c
> new file mode 100644
> index 0000000..fe4608c
> --- /dev/null
> +++ b/hw/debugexit.c
> @@ -0,0 +1,75 @@
> +/*
> + * QEMU debug exit port ("LGPL'ed-VGA-BIOS-style port 501/502") emulation
> + *
> + * Copyright (c) 2012 Herve Poussineau
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
> + * See the GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License along
> + * with this program; if not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include "isa.h"
> +#include "exec-memory.h"
> +
> +typedef struct ISADebugExitState {
> +    ISADevice dev;
> +    uint32_t iobase;
> +    uint8_t access_size;
> +} ISADebugExitState;
> +
> +static void debugexit_ioport_write(void *opaque, uint32_t addr, uint32_t val)
> +{
> +    exit((val << 1) | 1);
> +}
> +
> +static int debugexit_isa_initfn(ISADevice *dev)
> +{
> +    ISADebugExitState *isa = DO_UPCAST(ISADebugExitState, dev, dev);
> +
> +    const struct MemoryRegionPortio debugexit_portio_list[] = {
> +        { isa->iobase, 1, isa->access_size, .write = debugexit_ioport_write, },
> +        PORTIO_END_OF_LIST(),
> +    };
> +    PortioList *debugexit_port_list = g_new(PortioList, 1);
> +    portio_list_init(debugexit_port_list, debugexit_portio_list,
> +                     NULL, "isa-debugexit");
> +    portio_list_add(debugexit_port_list, get_system_io(), 0x0);

Please use a memory region (the example I cited should contain a pattern
for that as well). Portio lists are for scattered ports.

> +    return 0;
> +}
> +
> +static Property debugexit_isa_properties[] = {
> +    DEFINE_PROP_HEX32("iobase", ISADebugExitState, iobase, 0x501),
> +    DEFINE_PROP_UINT8("access-size", ISADebugExitState, access_size, 1),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void debugexit_isa_class_initfn(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
> +    ic->init = debugexit_isa_initfn;
> +    dc->props = debugexit_isa_properties;
> +}
> +
> +static TypeInfo debugexit_isa_info = {
> +    .name          = "isa-debugexit",
> +    .parent        = TYPE_ISA_DEVICE,
> +    .instance_size = sizeof(ISADebugExitState),
> +    .class_init    = debugexit_isa_class_initfn,
> +};
> +
> +static void debugexit_register_types(void)
> +{
> +    type_register_static(&debugexit_isa_info);
> +}
> +
> +type_init(debugexit_register_types)
> diff --git a/hw/i386/Makefile.objs b/hw/i386/Makefile.objs
> index 8c764bb..b34c61c 100644
> --- a/hw/i386/Makefile.objs
> +++ b/hw/i386/Makefile.objs
> @@ -3,7 +3,7 @@ obj-y += apic_common.o apic.o kvmvapic.o
>  obj-y += sga.o ioapic_common.o ioapic.o piix_pci.o
>  obj-y += vmport.o
>  obj-y += pci-hotplug.o smbios.o wdt_ib700.o
> -obj-y += debugcon.o multiboot.o
> +obj-y += debugcon.o debugexit.o multiboot.o
>  obj-y += pc_piix.o
>  obj-y += pc_sysfw.o
>  obj-$(CONFIG_XEN) += xen_platform.o xen_apic.o
> 

Jan