Re: [PATCH 5/6 v5] deal with guest panicked event accoring to -onpanicparameter

From: Jan Kiszka
Date: Thu Jun 28 2012 - 04:27:07 EST


On 2012-06-28 03:15, Wen Congyang wrote:
> At 06/27/2012 10:39 PM, Jan Kiszka Wrote:
>> On 2012-06-27 09:02, Wen Congyang wrote:
>>> When the guest is panicked, it will write 0x1 to the port KVM_PV_PORT.
>>> So if qemu reads 0x1 from this port, we can do the folloing three
>>> things according to the parameter -onpanic:
>>> 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
>>>
>>> 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@xxxxxxxxxxxxxx>
>>> ---
>>> kvm-all.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>>> kvm-stub.c | 9 +++++
>>> kvm.h | 3 ++
>>> qemu-options.hx | 15 ++++++++
>>> vl.c | 10 +++++
>>> 5 files changed, 138 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/kvm-all.c b/kvm-all.c
>>> index f8e4328..9494dd2 100644
>>> --- a/kvm-all.c
>>> +++ b/kvm-all.c
>>> @@ -19,6 +19,8 @@
>>> #include <stdarg.h>
>>>
>>> #include <linux/kvm.h>
>>> +#include <linux/kvm_para.h>
>>> +#include <asm/kvm_para.h>
>>>
>>> #include "qemu-common.h"
>>> #include "qemu-barrier.h"
>>> @@ -32,6 +34,9 @@
>>> #include "bswap.h"
>>> #include "memory.h"
>>> #include "exec-memory.h"
>>> +#include "iorange.h"
>>> +#include "qemu-objects.h"
>>> +#include "monitor.h"
>>>
>>> /* This check must be after config-host.h is included */
>>> #ifdef CONFIG_EVENTFD
>>> @@ -1931,3 +1936,99 @@ int kvm_on_sigbus(int code, void *addr)
>>> {
>>> return kvm_arch_on_sigbus(code, addr);
>>> }
>>> +
>>> +/* 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 */
>>> +
>>> +static int panicked_action = PANICKED_REPORT;
>>> +
>>> +static void kvm_pv_port_read(IORange *iorange, uint64_t offset, unsigned width,
>>> + uint64_t *data)
>>> +{
>>> + *data = (1 << KVM_PV_FEATURE_PANICKED);
>>> +}
>>> +
>>> +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(void)
>>> +{
>>> + 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");
>>> + exit(0);
>>> + break;
>>> + case PANICKED_RESET:
>>> + panicked_mon_event("reset");
>>> + qemu_system_reset_request();
>>> + break;
>>> + }
>>> +}
>>> +
>>> +static void kvm_pv_port_write(IORange *iorange, uint64_t offset, unsigned width,
>>> + uint64_t data)
>>> +{
>>> + if (data == KVM_PV_PANICKED) {
>>> + panicked_perform_action();
>>> + }
>>> +}
>>> +
>>> +static void kvm_pv_port_destructor(IORange *iorange)
>>> +{
>>> + g_free(iorange);
>>> +}
>>> +
>>> +static IORangeOps pv_io_range_ops = {
>>> + .read = kvm_pv_port_read,
>>> + .write = kvm_pv_port_write,
>>> + .destructor = kvm_pv_port_destructor,
>>> +};
>>> +
>>> +#if defined(KVM_PV_PORT)
>>> +void kvm_pv_port_init(void)
>>> +{
>>> + IORange *pv_io_range = g_malloc(sizeof(IORange));
>>> +
>>> + iorange_init(pv_io_range, &pv_io_range_ops, KVM_PV_PORT, 1);
>>> + ioport_register(pv_io_range);
>>
>> This modeling is still not ok. We don't open-code ports anymore, we
>> introduce devices. And this doesn't belong inro generic code as it is
>
> Do you mean introducing a new device instead of I/O port?

I mean encapsulating the I/O registration (PIO or MMIO) in a QOM device
and building that device only for target archs that supports it. Already
pointed you to examples in hw/kvm/.

Jan

--
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
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