Re: [Qemu-devel] [PATCH v4] mc146818rtc: add rtc-reset-reinjection QMP command

["Michael S. Tsirkin" <mst@redhat.com>]

On Wed, Jun 25, 2014 at 03:51:30PM -0400, Luiz Capitulino wrote:
> On Wed, 25 Jun 2014 14:40:12 +0300
> "Michael S. Tsirkin" <mst@redhat.com> wrote:
> 
> > It is necessary to reset RTC interrupt reinjection backlog if
> > guest time is synchronized via a different mechanism, such as
> > QGA's guest-set-time command.
> > 
> > Failing to do so causes both corrections to be applied (summed),
> > resulting in an incorrect guest time.
> > 
> > Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
> > Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> 
> Should this go via qmp tree or are you going to apply it to your tree?

It's applied in my tree.

> > ---
> > 
> > Marcelo, is this right?
> > 
> > Changes from v3:
> >     rebase on top of master
> >     fixes error code
> >     drop dead code
> > 
> >  qapi-schema.json       | 12 ++++++++++++
> >  hw/timer/mc146818rtc.c | 18 ++++++++++++++++++
> >  monitor.c              |  7 +++++++
> >  qmp-commands.hx        | 23 +++++++++++++++++++++++
> >  4 files changed, 60 insertions(+)
> > 
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index f490403..a282805 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -3288,3 +3288,15 @@
> >  # Since: 2.1
> >  ##
> >  { 'command': 'query-acpi-ospm-status', 'returns': ['ACPIOSTInfo'] }
> > +
> > +##
> > +# @rtc-reset-reinjection
> > +#
> > +# This command will reset the RTC interrupt reinjection backlog.
> > +# Can be used if another mechanism to synchronize guest time
> > +# is in effect, for example QEMU guest agent's guest-set-time
> > +# command.
> > +#
> > +# Since: 2.1
> > +##
> > +{ 'command': 'rtc-reset-reinjection' }
> > diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
> > index 1201f90..5bd8710 100644
> > --- a/hw/timer/mc146818rtc.c
> > +++ b/hw/timer/mc146818rtc.c
> > @@ -26,6 +26,7 @@
> >  #include "sysemu/sysemu.h"
> >  #include "hw/timer/mc146818rtc.h"
> >  #include "qapi/visitor.h"
> > +#include "qmp-commands.h"
> >  
> >  #ifdef TARGET_I386
> >  #include "hw/i386/apic.h"
> > @@ -84,6 +85,7 @@ typedef struct RTCState {
> >      Notifier clock_reset_notifier;
> >      LostTickPolicy lost_tick_policy;
> >      Notifier suspend_notifier;
> > +    QLIST_ENTRY(RTCState) link;
> >  } RTCState;
> >  
> >  static void rtc_set_time(RTCState *s);
> > @@ -522,6 +524,20 @@ static void rtc_get_time(RTCState *s, struct tm *tm)
> >          rtc_from_bcd(s, s->cmos_data[RTC_CENTURY]) * 100 - 1900;
> >  }
> >  
> > +static QLIST_HEAD(, RTCState) rtc_devices =
> > +    QLIST_HEAD_INITIALIZER(rtc_devices);
> > +
> > +#ifdef TARGET_I386
> > +void qmp_rtc_reset_reinjection(Error **errp)
> > +{
> > +    RTCState *s;
> > +
> > +    QLIST_FOREACH(s, &rtc_devices, link) {
> > +        s->irq_coalesced = 0;
> > +    }
> > +}
> > +#endif
> > +
> >  static void rtc_set_time(RTCState *s)
> >  {
> >      struct tm tm;
> > @@ -910,6 +926,8 @@ ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq)
> >      } else {
> >          isa_init_irq(isadev, &s->irq, RTC_ISA_IRQ);
> >      }
> > +    QLIST_INSERT_HEAD(&rtc_devices, s, link);
> > +
> >      return isadev;
> >  }
> >  
> > diff --git a/monitor.c b/monitor.c
> > index 8c17f89..f7a0206 100644
> > --- a/monitor.c
> > +++ b/monitor.c
> > @@ -5483,3 +5483,10 @@ QemuOptsList qemu_mon_opts = {
> >          { /* end of list */ }
> >      },
> >  };
> > +
> > +#ifndef TARGET_I386
> > +void qmp_rtc_reset_reinjection(Error **errp)
> > +{
> > +    error_set(errp, QERR_FEATURE_DISABLED, "rtc-reset-reinjection");
> > +}
> > +#endif
> > diff --git a/qmp-commands.hx b/qmp-commands.hx
> > index e4a1c80..17c09de 100644
> > --- a/qmp-commands.hx
> > +++ b/qmp-commands.hx
> > @@ -3661,3 +3661,26 @@ Example:
> >                   { "slot": "3", "slot-type": "DIMM", "source": 0, "status": 0}
> >     ]}
> >  EQMP
> > +
> > +#if defined TARGET_I386
> > +    {
> > +        .name       = "rtc-reset-reinjection",
> > +        .args_type  = "",
> > +        .mhandler.cmd_new = qmp_marshal_input_rtc_reset_reinjection,
> > +    },
> > +#endif
> > +
> > +SQMP
> > +rtc-reset-reinjection
> > +---------------------
> > +
> > +Reset the RTC interrupt reinjection backlog.
> > +
> > +Arguments: None.
> > +
> > +Example:
> > +
> > +-> { "execute": "rtc-reset-reinjection" }
> > +<- { "return": {} }
> > +
> > +EQMP