Re: [Qemu-devel] [PATCH 1/2] debugexit: support for custom exit port (e.g LGPL'ed VGA BIOS port 0x501)

[Andreas Färber]

Am 06.07.2012 23:53, schrieb Hervé Poussineau:
> 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.
> 
> Signed-off-by: Hervé Poussineau <address@hidden>
> ---
>  hw/debugexit.c        |   68 
> +++++++++++++++++++++++++++++++++++++++++++++++++
>  hw/i386/Makefile.objs |    2 +-
>  2 files changed, 69 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..72ddf31
> --- /dev/null
> +++ b/hw/debugexit.c
> @@ -0,0 +1,68 @@
> +/*
> + * 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"
> +
> +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);

I understand you're just moving code from patch 2/2 here, but in another
thread it was stated that exit()ing from such writes can do bad things
to the block layer (cleanups not happening) and should be replaced by
qemu_request_shutdown() or something like that...

Andreas

> +}
> +
> +static int debugexit_isa_initfn(ISADevice *dev)
> +{
> +    ISADebugExitState *isa = DO_UPCAST(ISADebugExitState, dev, dev);
> +
> +    register_ioport_write(isa->iobase, 1, isa->access_size,
> +                          debugexit_ioport_write, NULL);
> +    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 eb171b7..23be2d3 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
> 


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