From patchwork Thu Apr 28 14:24:59 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v3, 4/5] hpet 'driftfix': add code in update_irq() to detect coalesced interrupts (x86 apic only) Date: Thu, 28 Apr 2011 04:24:59 -0000 From: Ulrich Obergfell X-Patchwork-Id: 93225 Message-Id: <1304000700-3640-5-git-send-email-uobergfe@redhat.com> To: qemu-devel@nongnu.org Cc: aliguori@us.ibm.com, kvm@vger.kernel.org, jan.kiszka@siemens.com, uobergfe@redhat.com, gcosta@redhat.com, avi@redhat.com update_irq() uses a similar method as in 'rtc_td_hack' to detect coalesced interrupts. The function entry addresses are retrieved from 'target_get_irq_delivered' and 'target_reset_irq_delivered'. This change can be replaced if a generic feedback infrastructure to track coalesced IRQs for periodic, clock providing devices becomes available. Signed-off-by: Ulrich Obergfell --- hw/hpet.c | 15 +++++++++++++-- 1 files changed, 13 insertions(+), 2 deletions(-) diff --git a/hw/hpet.c b/hw/hpet.c index 7ab6e62..35466ae 100644 --- a/hw/hpet.c +++ b/hw/hpet.c @@ -31,6 +31,7 @@ #include "hpet_emul.h" #include "sysbus.h" #include "mc146818rtc.h" +#include "sysemu.h" //#define HPET_DEBUG #ifdef HPET_DEBUG @@ -175,11 +176,12 @@ static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current) } } -static void update_irq(struct HPETTimer *timer, int set) +static int update_irq(struct HPETTimer *timer, int set) { uint64_t mask; HPETState *s; int route; + int irq_delivered = 1; if (timer->tn <= 1 && hpet_in_legacy_mode(timer->state)) { /* if LegacyReplacementRoute bit is set, HPET specification requires @@ -204,8 +206,17 @@ static void update_irq(struct HPETTimer *timer, int set) qemu_irq_raise(s->irqs[route]); } else { s->isr &= ~mask; - qemu_irq_pulse(s->irqs[route]); + if (s->driftfix && target_get_irq_delivered + && target_reset_irq_delivered) { + target_reset_irq_delivered(); + qemu_irq_raise(s->irqs[route]); + irq_delivered = target_get_irq_delivered(); + qemu_irq_lower(s->irqs[route]); + } else { + qemu_irq_pulse(s->irqs[route]); + } } + return irq_delivered; } static void hpet_pre_save(void *opaque)