On Wed, Apr 14, 2021 at 12:28:43PM +0200, Jan Beulich wrote:
> On 31.03.2021 12:33, Roger Pau Monne wrote:
> > ---
> > xen/arch/x86/hvm/svm/intr.c | 3 -
> > xen/arch/x86/hvm/vmx/intr.c | 59 ------
> > xen/arch/x86/hvm/vpt.c | 334 ++++++++++++++--------------------
> > xen/include/asm-x86/hvm/vpt.h | 5 +-
> > 4 files changed, 143 insertions(+), 258 deletions(-)
>
> Nice.
>
> > @@ -285,189 +238,144 @@ static void pt_irq_fired(struct vcpu *v, struct
> > periodic_time *pt)
> > list_del(&pt->list);
> > pt->on_list = false;
> > pt->pending_intr_nr = 0;
> > +
> > + return;
> > }
> > - else if ( mode_is(v->domain, one_missed_tick_pending) ||
> > - mode_is(v->domain, no_missed_ticks_pending) )
> > +
> > + if ( mode_is(v->domain, one_missed_tick_pending) ||
> > + mode_is(v->domain, no_missed_ticks_pending) )
> > {
> > - pt->last_plt_gtime = hvm_get_guest_time(v);
> > pt_process_missed_ticks(pt);
> > pt->pending_intr_nr = 0; /* 'collapse' all missed ticks */
> > + }
> > + else if ( !pt->pending_intr_nr )
> > + pt_process_missed_ticks(pt);
>
> Did you lose a -- here? I.e. does the condition mean to match ...
>
> > + if ( !pt->pending_intr_nr )
> > set_timer(&pt->timer, pt->scheduled);
> > +}
> > +
> > +static void pt_timer_fn(void *data)
> > +{
> > + struct periodic_time *pt = data;
> > + struct vcpu *v;
> > + time_cb *cb = NULL;
> > + void *cb_priv;
> > + unsigned int irq;
> > +
> > + pt_lock(pt);
> > +
> > + v = pt->vcpu;
> > + irq = pt->irq;
> > +
> > + if ( inject_interrupt(pt) )
> > + {
> > + pt->scheduled += pt->period;
> > + pt->do_not_freeze = 0;
> > + cb = pt->cb;
> > + cb_priv = pt->priv;
> > }
> > else
> > {
> > - pt->last_plt_gtime += pt->period;
> > - if ( --pt->pending_intr_nr == 0 )
>
> ... this original code? Otherwise I can't see why the condition
> guards a pt_process_missed_ticks() invocation.
I think the logic here changed enough to not match anymore. Certainly
pending_intr_nr shouldn't be decreased there, as pt_irq_fired is
invoked after an EOI in this patch, instead of being invoked when a
vpt related interrupt was injected. I think I should better rename
pt_irq_fired to pt_irq_eoi and that would make it clearer.
FWIW, decreasing pending_intr_nr should only be done after an
inject_interrupt call.
> > @@ -617,20 +556,29 @@ void pt_adjust_global_vcpu_target(struct vcpu *v)
> > write_unlock(&pl_time->vhpet.lock);
> > }
> >
> > -
> > static void pt_resume(struct periodic_time *pt)
> > {
> > + struct vcpu *v;
> > + time_cb *cb = NULL;
> > + void *cb_priv;
> > +
> > if ( pt->vcpu == NULL )
> > return;
> >
> > pt_lock(pt);
> > - if ( pt->pending_intr_nr && !pt->on_list )
> > + if ( pt->pending_intr_nr && !pt->on_list && inject_interrupt(pt) )
> > {
> > + pt->pending_intr_nr--;
> > + cb = pt->cb;
> > + cb_priv = pt->priv;
> > + v = pt->vcpu;
> > pt->on_list = 1;
> > list_add(&pt->list, &pt->vcpu->arch.hvm.tm_list);
> > - vcpu_kick(pt->vcpu);
> > }
> > pt_unlock(pt);
> > +
> > + if ( cb )
> > + cb(v, cb_priv);
> > }
>
> I'm afraid until we raise our supported gcc versions baseline, v and
> cb_priv will need an initializer at the top of the function just like
> cb.
Will add such initializations.
Thanks, Roger.
