From nobody Mon May 6 20:47:41 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1513764269815946.2224247206826; Wed, 20 Dec 2017 02:04:29 -0800 (PST) Received: from localhost ([::1]:43730 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eRbET-0003i8-CV for importer@patchew.org; Wed, 20 Dec 2017 05:04:13 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33470) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eRbCU-0002Z7-B2 for qemu-devel@nongnu.org; Wed, 20 Dec 2017 05:02:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eRbCQ-0007Nm-11 for qemu-devel@nongnu.org; Wed, 20 Dec 2017 05:02:10 -0500 Received: from mail.ispras.ru ([83.149.199.45]:57688) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eRbCP-0007N6-P9 for qemu-devel@nongnu.org; Wed, 20 Dec 2017 05:02:05 -0500 Received: from [127.0.1.1] (unknown [85.142.117.226]) by mail.ispras.ru (Postfix) with ESMTPSA id 4DF3D54006A; Wed, 20 Dec 2017 13:02:04 +0300 (MSK) From: Pavel Dovgalyuk To: qemu-devel@nongnu.org Date: Wed, 20 Dec 2017 13:02:05 +0300 Message-ID: <20171220100205.16625.84632.stgit@pasha-VirtualBox> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 83.149.199.45 Subject: [Qemu-devel] [PATCH v2] hpet: recover timer offset correctly X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mst@redhat.com, quintela@redhat.com, dgilbert@redhat.com, maria.klimushenkova@ispras.ru, dovgaluk@ispras.ru, pavel.dovgaluk@ispras.ru, pbonzini@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 HPET saves its state by calculating the current time and recovers timer offset using this calculated value. But these calculations include divisions and multiplications. Therefore the timer state cannot be recovered precise enough. This patch introduces saving of the original value of the offset to preserve the determinism of the timer. Signed-off-by: Maria Klimushenkova Signed-off-by: Pavel Dovgalyuk Reviewed-by: Juan Quintela --- hw/timer/hpet.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/hw/timer/hpet.c b/hw/timer/hpet.c index 577371b..4904a60 100644 --- a/hw/timer/hpet.c +++ b/hw/timer/hpet.c @@ -70,6 +70,7 @@ typedef struct HPETState { =20 MemoryRegion iomem; uint64_t hpet_offset; + bool hpet_offset_loaded; qemu_irq irqs[HPET_NUM_IRQ_ROUTES]; uint32_t flags; uint8_t rtc_irq_level; @@ -221,7 +222,9 @@ static int hpet_pre_save(void *opaque) HPETState *s =3D opaque; =20 /* save current counter value */ - s->hpet_counter =3D hpet_get_ticks(s); + if (hpet_enabled(s)) { + s->hpet_counter =3D hpet_get_ticks(s); + } =20 return 0; } @@ -232,6 +235,8 @@ static int hpet_pre_load(void *opaque) =20 /* version 1 only supports 3, later versions will load the actual valu= e */ s->num_timers =3D HPET_MIN_TIMERS; + /* for checking whether the hpet_offset section is loaded */ + s->hpet_offset_loaded =3D false; return 0; } =20 @@ -252,7 +257,10 @@ static int hpet_post_load(void *opaque, int version_id) HPETState *s =3D opaque; =20 /* Recalculate the offset between the main counter and guest time */ - s->hpet_offset =3D ticks_to_ns(s->hpet_counter) - qemu_clock_get_ns(QE= MU_CLOCK_VIRTUAL); + if (!s->hpet_offset_loaded) { + s->hpet_offset =3D ticks_to_ns(s->hpet_counter) + - qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + } =20 /* Push number of timers into capability returned via HPET_ID */ s->capability &=3D ~HPET_ID_NUM_TIM_MASK; @@ -267,6 +275,14 @@ static int hpet_post_load(void *opaque, int version_id) return 0; } =20 +static int hpet_offset_post_load(void *opaque, int version_id) +{ + HPETState *s =3D opaque; + + s->hpet_offset_loaded =3D true; + return 0; +} + static bool hpet_rtc_irq_level_needed(void *opaque) { HPETState *s =3D opaque; @@ -285,6 +301,17 @@ static const VMStateDescription vmstate_hpet_rtc_irq_l= evel =3D { } }; =20 +static const VMStateDescription vmstate_hpet_offset =3D { + .name =3D "hpet/offset", + .version_id =3D 1, + .minimum_version_id =3D 1, + .post_load =3D hpet_offset_post_load, + .fields =3D (VMStateField[]) { + VMSTATE_UINT64(hpet_offset, HPETState), + VMSTATE_END_OF_LIST() + } +}; + static const VMStateDescription vmstate_hpet_timer =3D { .name =3D "hpet_timer", .version_id =3D 1, @@ -320,6 +347,7 @@ static const VMStateDescription vmstate_hpet =3D { }, .subsections =3D (const VMStateDescription*[]) { &vmstate_hpet_rtc_irq_level, + &vmstate_hpet_offset, NULL } };