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

[Wen Congyang]

At 08/24/2012 02:30 PM, Jan Kiszka Wrote:
> On 2012-08-24 08:33, Wen Congyang wrote:
>> At 08/24/2012 02:21 PM, Jan Kiszka Wrote:
>>> On 2012-08-24 08:05, Wen Congyang wrote:
>>>> 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 <address@hidden>
>>>>>> ---
>>>>>>  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 <address@hidden>
>>>>>> + *
>>>>>> + * 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.
>>>
>>> Yeah, but that is a bit ugly and another reason to go for a proper kvm-stub.
>>
>> Yes, it is ugly. I will add a stub function in kvm-stub. And the header
>> file asm/kvm_para.h can be included unconditionally. And "#ifdef 
>> KVM_PV_EVENT_PORT"
>> can be dropped.
> 
> Actually, not asm/kvm_para.h but linux/kvm_para.h. And you will then
> only need it in pv_event.c.

OK.

Thanks
Wen Congyang
> 
> Jan
> 
>