From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ulrich Obergfell Subject: [PATCH v5 4/5] hpet 'driftfix': add code in update_irq() to detect coalesced interrupts (x86 apic only) Date: Fri, 20 May 2011 09:13:22 +0200 Message-ID: <1305875603-3104-5-git-send-email-uobergfe@redhat.com> References: <1305875603-3104-1-git-send-email-uobergfe@redhat.com> Cc: kvm@vger.kernel.org, uobergfe@redhat.com, gcosta@redhat.com, avi@redhat.com, mtosatti@redhat.com, zamsden@redhat.com, aliguori@us.ibm.com, jan.kiszka@siemens.com To: qemu-devel@nongnu.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:30851 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933731Ab1ETHNR (ORCPT ); Fri, 20 May 2011 03:13:17 -0400 In-Reply-To: <1305875603-3104-1-git-send-email-uobergfe@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: 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 | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/hw/hpet.c b/hw/hpet.c index dba9370..0428290 100644 --- a/hw/hpet.c +++ b/hw/hpet.c @@ -184,11 +184,12 @@ 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 @@ -213,8 +214,16 @@ 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_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) -- 1.6.2.5 From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:59043) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNJtc-000214-0B for qemu-devel@nongnu.org; Fri, 20 May 2011 03:13:16 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QNJtb-0005RC-3S for qemu-devel@nongnu.org; Fri, 20 May 2011 03:13:15 -0400 Received: from mx1.redhat.com ([209.132.183.28]:23404) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QNJta-0005R6-RR for qemu-devel@nongnu.org; Fri, 20 May 2011 03:13:15 -0400 From: Ulrich Obergfell Date: Fri, 20 May 2011 09:13:22 +0200 Message-Id: <1305875603-3104-5-git-send-email-uobergfe@redhat.com> In-Reply-To: <1305875603-3104-1-git-send-email-uobergfe@redhat.com> References: <1305875603-3104-1-git-send-email-uobergfe@redhat.com> Subject: [Qemu-devel] [PATCH v5 4/5] hpet 'driftfix': add code in update_irq() to detect coalesced interrupts (x86 apic only) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: aliguori@us.ibm.com, mtosatti@redhat.com, kvm@vger.kernel.org, jan.kiszka@siemens.com, zamsden@redhat.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 | 13 +++++++++++-- 1 files changed, 11 insertions(+), 2 deletions(-) diff --git a/hw/hpet.c b/hw/hpet.c index dba9370..0428290 100644 --- a/hw/hpet.c +++ b/hw/hpet.c @@ -184,11 +184,12 @@ 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 @@ -213,8 +214,16 @@ 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_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) -- 1.6.2.5