Re: [PATCH v9 5/6] introduce a new qom device to deal with panicked event

[Wen Congyang <wency@cn.fujitsu.com>]

At 08/23/2012 06:51 PM, Jan Kiszka Wrote:
> On 2012-08-23 04:32, Wen Congyang wrote:
>> If the target is x86/x86_64, the guest's kernel will write 0x01 to the
>> port KVM_PV_EVENT_PORT when it is panciked. This patch introduces a new
>> qom device kvm_pv_ioport to listen this I/O port, and deal with panicked
>> event according to panicked_action's value. The possible actions are:
>> 1. emit QEVENT_GUEST_PANICKED only
>> 2. emit QEVENT_GUEST_PANICKED and pause the guest
>> 3. emit QEVENT_GUEST_PANICKED and poweroff the guest
>> 4. emit QEVENT_GUEST_PANICKED and reset the guest
>>
>> I/O ports does not work for some targets(for example: s390). And you
>> can implement another qom device, and include it's code into pv_event.c
>> for such target.
>>
>> Note: if we emit QEVENT_GUEST_PANICKED only, and the management
>> application does not receive this event(the management may not
>> run when the event is emitted), the management won't know the
>> guest is panicked.
>>
>> Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
>> ---
>>  hw/kvm/Makefile.objs |    2 +-
>>  hw/kvm/pv_event.c    |  190 ++++++++++++++++++++++++++++++++++++++++++++++++++
>>  hw/pc_piix.c         |    9 +++
>>  kvm.h                |    2 +
>>  4 files changed, 202 insertions(+), 1 deletions(-)
>>  create mode 100644 hw/kvm/pv_event.c
>>
>> diff --git a/hw/kvm/Makefile.objs b/hw/kvm/Makefile.objs
>> index 226497a..23e3b30 100644
>> --- a/hw/kvm/Makefile.objs
>> +++ b/hw/kvm/Makefile.objs
>> @@ -1 +1 @@
>> -obj-$(CONFIG_KVM) += clock.o apic.o i8259.o ioapic.o i8254.o
>> +obj-$(CONFIG_KVM) += clock.o apic.o i8259.o ioapic.o i8254.o pv_event.o
>> diff --git a/hw/kvm/pv_event.c b/hw/kvm/pv_event.c
>> new file mode 100644
>> index 0000000..c03dd22
>> --- /dev/null
>> +++ b/hw/kvm/pv_event.c
>> @@ -0,0 +1,190 @@
>> +/*
>> + * QEMU KVM support, paravirtual event device
>> + *
>> + * Copyright Fujitsu, Corp. 2012
>> + *
>> + * Authors:
>> + *     Wen Congyang <wency@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 <linux/kvm_para.h>
>> +#include <asm/kvm_para.h>
>> +#include <qobject.h>
>> +#include <qjson.h>
>> +#include <monitor.h>
>> +#include <sysemu.h>
>> +#include <kvm.h>
>> +
>> +/* Possible values for action parameter. */
>> +#define PANICKED_REPORT     1   /* emit QEVENT_GUEST_PANICKED only */
>> +#define PANICKED_PAUSE      2   /* emit QEVENT_GUEST_PANICKED and pause VM */
>> +#define PANICKED_POWEROFF   3   /* emit QEVENT_GUEST_PANICKED and quit VM */
>> +#define PANICKED_RESET      4   /* emit QEVENT_GUEST_PANICKED and reset VM */
>> +
>> +#define PV_EVENT_DRIVER     "kvm_pv_event"
>> +
>> +struct PVEventAction {
>> +    char *panicked_action;
>> +    int panicked_action_value;
>> +};
>> +
>> +#define DEFINE_PV_EVENT_PROPERTIES(_state, _conf)   \
>> +    DEFINE_PROP_STRING("panicked_action", _state, _conf.panicked_action)
>> +
>> +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 panicked_perform_action(uint32_t panicked_action)
>> +{
>> +    switch (panicked_action) {
>> +    case PANICKED_REPORT:
>> +        panicked_mon_event("report");
>> +        break;
>> +
>> +    case PANICKED_PAUSE:
>> +        panicked_mon_event("pause");
>> +        vm_stop(RUN_STATE_GUEST_PANICKED);
>> +        break;
>> +
>> +    case PANICKED_POWEROFF:
>> +        panicked_mon_event("poweroff");
>> +        qemu_system_shutdown_request();
>> +        break;
>> +
>> +    case PANICKED_RESET:
>> +        panicked_mon_event("reset");
>> +        qemu_system_reset_request();
>> +        break;
>> +    }
>> +}
>> +
>> +static uint64_t supported_event(void)
>> +{
>> +    return 1 << KVM_PV_FEATURE_PANICKED;
>> +}
>> +
>> +static void handle_event(int event, struct PVEventAction *conf)
>> +{
>> +    if (event == KVM_PV_EVENT_PANICKED) {
>> +        panicked_perform_action(conf->panicked_action_value);
>> +    }
>> +}
>> +
>> +static int pv_event_init(struct PVEventAction *conf)
>> +{
>> +    if (!conf->panicked_action) {
>> +        conf->panicked_action_value = PANICKED_REPORT;
>> +    } else if (strcasecmp(conf->panicked_action, "none") == 0) {
>> +        conf->panicked_action_value = PANICKED_REPORT;
>> +    } else if (strcasecmp(conf->panicked_action, "pause") == 0) {
>> +        conf->panicked_action_value = PANICKED_PAUSE;
>> +    } else if (strcasecmp(conf->panicked_action, "poweroff") == 0) {
>> +        conf->panicked_action_value = PANICKED_POWEROFF;
>> +    } else if (strcasecmp(conf->panicked_action, "reset") == 0) {
>> +        conf->panicked_action_value = PANICKED_RESET;
>> +    } else {
>> +        return -1;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>> +#if defined(KVM_PV_EVENT_PORT)
>> +
>> +#include "hw/isa.h"
>> +
>> +typedef struct {
>> +    ISADevice dev;
>> +    struct PVEventAction conf;
>> +    MemoryRegion ioport;
>> +} PVIOPortState;
>> +
>> +static uint64_t pv_io_read(void *opaque, target_phys_addr_t addr, unsigned size)
>> +{
>> +    return supported_event();
>> +}
>> +
>> +static void pv_io_write(void *opaque, target_phys_addr_t addr, uint64_t val,
>> +                        unsigned size)
>> +{
>> +    PVIOPortState *s = opaque;
>> +
>> +    handle_event(val, &s->conf);
>> +}
>> +
>> +static const MemoryRegionOps pv_io_ops = {
>> +    .read = pv_io_read,
>> +    .write = pv_io_write,
>> +    .impl = {
>> +        .min_access_size = 4,
>> +        .max_access_size = 4,
>> +    },
>> +};
>> +
>> +static int pv_ioport_initfn(ISADevice *dev)
>> +{
>> +    PVIOPortState *s = DO_UPCAST(PVIOPortState, dev, dev);
>> +
>> +    if (pv_event_init(&s->conf) < 0) {
>> +        return -1;
>> +    }
>> +
>> +    memory_region_init_io(&s->ioport, &pv_io_ops, s, "pv_event", 1);
>> +    isa_register_ioport(dev, &s->ioport, KVM_PV_EVENT_PORT);
>> +
>> +    return 0;
>> +}
>> +
>> +static Property pv_ioport_properties[] = {
>> +    DEFINE_PV_EVENT_PROPERTIES(PVIOPortState, conf),
>> +    DEFINE_PROP_END_OF_LIST(),
>> +};
>> +
>> +static void pv_ioport_class_init(ObjectClass *klass, void *data)
>> +{
>> +    DeviceClass *dc = DEVICE_CLASS(klass);
>> +    ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
>> +
>> +    ic->init = pv_ioport_initfn;
>> +    dc->no_user = 1;
>> +    dc->props = pv_ioport_properties;
>> +}
>> +
>> +static TypeInfo pv_ioport_info = {
>> +    .name          = PV_EVENT_DRIVER,
>> +    .parent        = TYPE_ISA_DEVICE,
>> +    .instance_size = sizeof(PVIOPortState),
>> +    .class_init    = pv_ioport_class_init,
>> +};
>> +
>> +static void pv_ioport_register_types(void)
>> +{
>> +    type_register_static(&pv_ioport_info);
>> +}
>> +
>> +type_init(pv_ioport_register_types)
>> +
>> +void kvm_pv_event_init(void *opaque)
>> +{
>> +    ISABus *bus = opaque;
>> +    ISADevice *dev;
>> +
>> +    dev = isa_create(bus, PV_EVENT_DRIVER);
>> +    qdev_init_nofail(&dev->qdev);
>> +}
>> +
>> +#else
>> +void kvm_pv_event_init(void *opaque)
>> +{
> 
> Some comment that this stub requires an implementation whenever it is
> actually built would be helpful. Something that explains a different
> transport than PIO will be needed.

OK

> 
>> +}
>> +#endif
>> diff --git a/hw/pc_piix.c b/hw/pc_piix.c
>> index 88ff041..f73fb85 100644
>> --- a/hw/pc_piix.c
>> +++ b/hw/pc_piix.c
>> @@ -46,6 +46,9 @@
>>  #ifdef CONFIG_XEN
>>  #  include <xen/hvm/hvm_info_table.h>
>>  #endif
>> +#ifdef CONFIG_KVM
>> +#   include <asm/kvm_para.h>
>> +#endif
>>  
>>  #define MAX_IDE_BUS 2
>>  
>> @@ -285,6 +288,12 @@ static void pc_init1(MemoryRegion *system_memory,
>>      if (pci_enabled) {
>>          pc_pci_device_init(pci_bus);
>>      }
>> +
>> +#ifdef KVM_PV_EVENT_PORT
> 
> This file is x86-only, and there we have KVM_PV_EVENT_PORT
> unconditionally. So drop the #ifdef.
> 
>> +    if (kvm_enabled()) {
>> +        kvm_pv_event_init(isa_bus);
> 
> But you are missing a kvm-stub entry for kvm_pv_event_init. A
> --disable-kvm build should be broken for that reason.

Hmm, KVM_PV_EVENT_PORT is defined in asm/kvm_para.h, and I include
this file only when CONFIG_KVM is defined. So --disable-kvm build
does not be broken in my test.

Thanks
Wen Congyang

> 
>> +    }
>> +#endif
>>  }
>>  
>>  static void pc_init_pci(ram_addr_t ram_size,
>> diff --git a/kvm.h b/kvm.h
>> index 5b8f588..41ce1b2 100644
>> --- a/kvm.h
>> +++ b/kvm.h
>> @@ -276,4 +276,6 @@ int kvm_irqchip_add_irqfd(KVMState *s, int fd, int virq);
>>  int kvm_irqchip_remove_irqfd(KVMState *s, int fd, int virq);
>>  int kvm_irqchip_add_irq_notifier(KVMState *s, EventNotifier *n, int virq);
>>  int kvm_irqchip_remove_irq_notifier(KVMState *s, EventNotifier *n, int virq);
>> +
>> +void kvm_pv_event_init(void *opaque);
>>  #endif
>>
> 
> Jan
>