|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 1/2] vpt: add support for level interrupts
Level trigger interrupts will be asserted regardless of whether the
interrupt is masked, and thus the callback will also be executed.
Add a new 'level' parameter to create_periodic_time in order to create
level triggered timers. None of the current users of vpt are switched
to use level triggered interrupts yet.
Note that periodic level triggered interrupts are not supported. This
is because level triggered interrupts always require a deassert of the
IO-APIC pin, which should be done by the caller of vpt at which point
the caller should also reset the timer if required.
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
Changes since v3:
- Clarify why level triggered interrupts are always asserted.
- Expand commit message to explain why periodic level triggered
interrupts are not supported by vpt.
- Switch the create check to use a conditional in order to avoid
checking the source twice.
---
xen/arch/x86/hvm/hpet.c | 2 +-
xen/arch/x86/hvm/i8254.c | 4 +--
xen/arch/x86/hvm/rtc.c | 2 +-
xen/arch/x86/hvm/vlapic.c | 8 +++---
xen/arch/x86/hvm/vpt.c | 48 ++++++++++++++++++++++++++++-------
xen/include/asm-x86/hvm/vpt.h | 3 ++-
6 files changed, 49 insertions(+), 18 deletions(-)
diff --git a/xen/arch/x86/hvm/hpet.c b/xen/arch/x86/hvm/hpet.c
index f7ef4f7514..72209350ba 100644
--- a/xen/arch/x86/hvm/hpet.c
+++ b/xen/arch/x86/hvm/hpet.c
@@ -302,7 +302,7 @@ static void hpet_set_timer(HPETState *h, unsigned int tn,
create_periodic_time(vhpet_vcpu(h), &h->pt[tn],
hpet_tick_to_ns(h, diff),
oneshot ? 0 : hpet_tick_to_ns(h, h->hpet.period[tn]),
- irq, NULL, NULL);
+ irq, NULL, NULL, false);
}
static inline uint64_t hpet_fixup_reg(
diff --git a/xen/arch/x86/hvm/i8254.c b/xen/arch/x86/hvm/i8254.c
index 992f08dd6c..b8ec56f8d3 100644
--- a/xen/arch/x86/hvm/i8254.c
+++ b/xen/arch/x86/hvm/i8254.c
@@ -191,14 +191,14 @@ static void pit_load_count(PITState *pit, int channel,
int val)
/* Periodic timer. */
TRACE_2D(TRC_HVM_EMUL_PIT_START_TIMER, period, period);
create_periodic_time(v, &pit->pt0, period, period, 0, pit_time_fired,
- &pit->count_load_time[channel]);
+ &pit->count_load_time[channel], false);
break;
case 1:
case 4:
/* One-shot timer. */
TRACE_2D(TRC_HVM_EMUL_PIT_START_TIMER, period, 0);
create_periodic_time(v, &pit->pt0, period, 0, 0, pit_time_fired,
- &pit->count_load_time[channel]);
+ &pit->count_load_time[channel], false);
break;
default:
TRACE_0D(TRC_HVM_EMUL_PIT_STOP_TIMER);
diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c
index cb75b99ed1..96921bb5b5 100644
--- a/xen/arch/x86/hvm/rtc.c
+++ b/xen/arch/x86/hvm/rtc.c
@@ -156,7 +156,7 @@ static void rtc_timer_update(RTCState *s)
{
TRACE_2D(TRC_HVM_EMUL_RTC_START_TIMER, delta, period);
create_periodic_time(v, &s->pt, delta, period,
- RTC_IRQ, rtc_pf_callback, s);
+ RTC_IRQ, rtc_pf_callback, s, false);
}
else
s->check_ticks_since = now;
diff --git a/xen/arch/x86/hvm/vlapic.c b/xen/arch/x86/hvm/vlapic.c
index 1b9f00a0e4..d2ac4b8625 100644
--- a/xen/arch/x86/hvm/vlapic.c
+++ b/xen/arch/x86/hvm/vlapic.c
@@ -762,7 +762,7 @@ static void vlapic_update_timer(struct vlapic *vlapic,
uint32_t lvtt,
create_periodic_time(current, &vlapic->pt, delta,
is_periodic ? period : 0, vlapic->pt.irq,
is_periodic ? vlapic_pt_cb : NULL,
- &vlapic->timer_last_update);
+ &vlapic->timer_last_update, false);
vlapic->timer_last_update = vlapic->pt.last_plt_gtime;
if ( !tmict_updated )
@@ -1166,7 +1166,7 @@ void vlapic_tdt_msr_set(struct vlapic *vlapic, uint64_t
value)
TRC_PAR_LONG(0LL), vlapic->pt.irq);
create_periodic_time(v, &vlapic->pt, delta, 0,
vlapic->pt.irq, vlapic_tdt_pt_cb,
- &vlapic->timer_last_update);
+ &vlapic->timer_last_update, false);
vlapic->timer_last_update = vlapic->pt.last_plt_gtime;
}
else
@@ -1180,7 +1180,7 @@ void vlapic_tdt_msr_set(struct vlapic *vlapic, uint64_t
value)
TRC_PAR_LONG(0LL), vlapic->pt.irq);
create_periodic_time(v, &vlapic->pt, 0, 0,
vlapic->pt.irq, vlapic_tdt_pt_cb,
- &vlapic->timer_last_update);
+ &vlapic->timer_last_update, false);
vlapic->timer_last_update = vlapic->pt.last_plt_gtime;
}
else
@@ -1431,7 +1431,7 @@ static void lapic_rearm(struct vlapic *s)
vlapic_lvtt_period(s) ? period : 0,
s->pt.irq,
vlapic_lvtt_period(s) ? vlapic_pt_cb : NULL,
- &s->timer_last_update);
+ &s->timer_last_update, false);
s->timer_last_update = s->pt.last_plt_gtime;
}
diff --git a/xen/arch/x86/hvm/vpt.c b/xen/arch/x86/hvm/vpt.c
index f655457e03..6ac4c913bb 100644
--- a/xen/arch/x86/hvm/vpt.c
+++ b/xen/arch/x86/hvm/vpt.c
@@ -306,6 +306,7 @@ int pt_update_irq(struct vcpu *v)
struct periodic_time *pt, *temp, *earliest_pt;
uint64_t max_lag;
int irq, pt_vector = -1;
+ bool level;
spin_lock(&v->arch.hvm_vcpu.tm_lock);
@@ -316,7 +317,9 @@ int pt_update_irq(struct vcpu *v)
if ( pt->pending_intr_nr )
{
/* RTC code takes care of disabling the timer itself. */
- if ( (pt->irq != RTC_IRQ || !pt->priv) && pt_irq_masked(pt) )
+ if ( (pt->irq != RTC_IRQ || !pt->priv) && pt_irq_masked(pt) &&
+ /* Level interrupts should be asserted even if masked. */
+ !pt->level )
{
/* suspend timer emulation */
list_del(&pt->list);
@@ -341,6 +344,7 @@ int pt_update_irq(struct vcpu *v)
earliest_pt->irq_issued = 1;
irq = earliest_pt->irq;
+ level = earliest_pt->level;
spin_unlock(&v->arch.hvm_vcpu.tm_lock);
@@ -374,13 +378,37 @@ int pt_update_irq(struct vcpu *v)
break;
case PTSRC_ioapic:
- /*
- * NB: At the moment IO-APIC routed interrupts generated by vpt devices
- * (HPET) are edge-triggered.
- */
- pt_vector = hvm_ioapic_assert(v->domain, irq, false);
+ pt_vector = hvm_ioapic_assert(v->domain, irq, level);
if ( pt_vector < 0 || !vlapic_test_irq(vcpu_vlapic(v), pt_vector) )
+ {
pt_vector = -1;
+ if ( level )
+ {
+ /*
+ * Level interrupts are always asserted because the pin assert
+ * count is incremented regardless of whether the pin is masked
+ * or the vector latched in IRR, so also execute the callback
+ * associated with the timer.
+ */
+ time_cb *cb = NULL;
+ void *cb_priv;
+
+ spin_lock(&v->arch.hvm_vcpu.tm_lock);
+ /* Make sure the timer is still on the list. */
+ list_for_each_entry ( pt, &v->arch.hvm_vcpu.tm_list, list )
+ if ( pt == earliest_pt )
+ {
+ pt_irq_fired(v, pt);
+ cb = pt->cb;
+ cb_priv = pt->priv;
+ break;
+ }
+ spin_unlock(&v->arch.hvm_vcpu.tm_lock);
+
+ if ( cb != NULL )
+ cb(v, cb_priv);
+ }
+ }
break;
}
@@ -447,12 +475,13 @@ void pt_migrate(struct vcpu *v)
void create_periodic_time(
struct vcpu *v, struct periodic_time *pt, uint64_t delta,
- uint64_t period, uint8_t irq, time_cb *cb, void *data)
+ uint64_t period, uint8_t irq, time_cb *cb, void *data, bool level)
{
if ( !pt->source ||
(irq >= NR_ISAIRQS && pt->source == PTSRC_isa) ||
- (irq >= hvm_domain_irq(v->domain)->nr_gsis &&
- pt->source == PTSRC_ioapic) )
+ (level && period) ||
+ (pt->source == PTSRC_ioapic ? irq >=
hvm_domain_irq(v->domain)->nr_gsis
+ : level) )
{
ASSERT_UNREACHABLE();
return;
@@ -480,6 +509,7 @@ void create_periodic_time(
pt->last_plt_gtime = hvm_get_guest_time(pt->vcpu);
pt->irq = irq;
pt->one_shot = !period;
+ pt->level = level;
pt->scheduled = NOW() + delta;
if ( !pt->one_shot )
diff --git a/xen/include/asm-x86/hvm/vpt.h b/xen/include/asm-x86/hvm/vpt.h
index f693c0bcf1..61c26ed8b2 100644
--- a/xen/include/asm-x86/hvm/vpt.h
+++ b/xen/include/asm-x86/hvm/vpt.h
@@ -42,6 +42,7 @@ struct periodic_time {
bool do_not_freeze;
bool irq_issued;
bool warned_timeout_too_short;
+ bool level;
#define PTSRC_isa 1 /* ISA time source */
#define PTSRC_lapic 2 /* LAPIC time source */
#define PTSRC_ioapic 3 /* IOAPIC time source */
@@ -169,7 +170,7 @@ void pt_may_unmask_irq(struct domain *d, struct
periodic_time *vlapic_pt);
*/
void create_periodic_time(
struct vcpu *v, struct periodic_time *pt, uint64_t delta,
- uint64_t period, uint8_t irq, time_cb *cb, void *data);
+ uint64_t period, uint8_t irq, time_cb *cb, void *data, bool level);
void destroy_periodic_time(struct periodic_time *pt);
int pv_pit_handler(int port, int data, int write);
--
2.17.1
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |