Re: [Qemu-devel] [PATCH v19 3/7] introduce a new qom device to deal with panicked event

[Markus Armbruster <armbru@redhat.com>]

Hu Tao <hutao@cn.fujitsu.com> writes:

> pvpanic device is used to send guest panic event from guest to qemu.
>
> When guest panic happens, pvpanic device driver will write a event
> number to IO port 0x505(which is the IO port occupied by pvpanic device,
> by default). On receiving the event, pvpanic device will pause guest
> cpu(s), and send a qmp event QEVENT_GUEST_PANICKED.
>
> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
> Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> ---
>  hw/misc/Makefile.objs |   2 +
>  hw/misc/pvpanic.c     | 123 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 125 insertions(+)
>  create mode 100644 hw/misc/pvpanic.c
>
> diff --git a/hw/misc/Makefile.objs b/hw/misc/Makefile.objs
> index 03699c3..d72ea83 100644
> --- a/hw/misc/Makefile.objs
> +++ b/hw/misc/Makefile.objs
> @@ -38,3 +38,5 @@ obj-$(CONFIG_OMAP) += omap_tap.o
>  obj-$(CONFIG_PXA2XX) += pxa2xx_pcmcia.o
>  obj-$(CONFIG_SLAVIO) += slavio_misc.o
>  obj-$(CONFIG_ZYNQ) += zynq_slcr.o
> +
> +common-obj-y += pvpanic.o
> diff --git a/hw/misc/pvpanic.c b/hw/misc/pvpanic.c
> new file mode 100644
> index 0000000..c3adcdf
> --- /dev/null
> +++ b/hw/misc/pvpanic.c
> @@ -0,0 +1,123 @@
> +/*
> + * QEMU simulated pvpanic device.
> + *
> + * Copyright Fujitsu, Corp. 2013
> + *
> + * Authors:
> + *     Wen Congyang <wency@cn.fujitsu.com>
> + *     Hu Tao <hutao@cn.fujitsu.com>
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + *
> + */
> +
> +#include <qapi/qmp/qobject.h>
> +#include <qapi/qmp/qjson.h>
> +#include <monitor/monitor.h>
> +#include <sysemu/sysemu.h>
> +#include <sysemu/kvm.h>
> +
> +/* The bit of supported pv event */
> +#define PVPANIC_F_PANICKED      0
> +
> +/* The pv event value */
> +#define PVPANIC_PANICKED        (1 << PVPANIC_F_PANICKED)
> +
> +#define TYPE_ISA_PVPANIC_DEVICE    "pvpanic"
> +#define ISA_PVPANIC_DEVICE(obj)    \
> +    OBJECT_CHECK(PVPanicState, (obj), TYPE_ISA_PVPANIC_DEVICE)
> +
> +static void panicked_mon_event(const char *action)
> +{
> +    QObject *data;
> +
> +    data = qobject_from_jsonf("{ 'action': %s }", action);
> +    monitor_protocol_event(QEVENT_GUEST_PANICKED, data);
> +    qobject_decref(data);
> +}
> +
> +static void handle_event(int event)
> +{
> +    static bool logged;
> +
> +    if (event & ~PVPANIC_PANICKED && !logged) {
> +        fprintf(stderr, "pvpanic: unknown event %#x.\n", event);
> +        logged = true;
> +    }

qemu_log_mask(LOG_GUEST_ERROR, ...)?

Could be done on top, without a respin.

> +
> +    if (event & PVPANIC_PANICKED) {
> +        panicked_mon_event("pause");
> +        vm_stop(RUN_STATE_GUEST_PANICKED);
> +        return;
> +    }
> +}
[...]