From patchwork Fri May 16 15:00:39 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: fred.konrad@greensocs.com X-Patchwork-Id: 349626 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id A4621140082 for ; Sat, 17 May 2014 01:03:49 +1000 (EST) Received: from localhost ([::1]:36129 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlJfn-00028k-Af for incoming@patchwork.ozlabs.org; Fri, 16 May 2014 11:03:47 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:46737) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlJda-0006XI-Hp for qemu-devel@nongnu.org; Fri, 16 May 2014 11:01:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WlJdT-0003NC-G3 for qemu-devel@nongnu.org; Fri, 16 May 2014 11:01:30 -0400 Received: from [2001:41d0:8:2b42::1] (port=49820 helo=greensocs.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WlJdT-0003Dr-6F for qemu-devel@nongnu.org; Fri, 16 May 2014 11:01:23 -0400 Received: from localhost (localhost.localdomain [127.0.0.1]) by greensocs.com (Postfix) with ESMTP id 4AFB627A5F; Fri, 16 May 2014 17:01:04 +0200 (CEST) X-Virus-Scanned: Debian amavisd-new at Received: from greensocs.com ([127.0.0.1]) by localhost (greensocs.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id GIny99wOJjUX; Fri, 16 May 2014 17:01:04 +0200 (CEST) Received: by greensocs.com (Postfix, from userid 998) id 1DC6427A3D; Fri, 16 May 2014 17:01:04 +0200 (CEST) Received: from localhost.localdomain (lan31-11-83-155-143-136.fbx.proxad.net [83.155.143.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: fred.konrad@greensocs.com) by greensocs.com (Postfix) with ESMTPSA id C5C14278FB; Fri, 16 May 2014 17:01:03 +0200 (CEST) From: fred.konrad@greensocs.com To: qemu-devel@nongnu.org Date: Fri, 16 May 2014 17:00:39 +0200 Message-Id: <1400252448-13347-5-git-send-email-fred.konrad@greensocs.com> X-Mailer: git-send-email 1.9.0 In-Reply-To: <1400252448-13347-1-git-send-email-fred.konrad@greensocs.com> References: <1400252448-13347-1-git-send-email-fred.konrad@greensocs.com> X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2001:41d0:8:2b42::1 Cc: pbonzini@redhat.com, mark.burton@greensocs.com, vilanova@ac.upc.edu, fred.konrad@greensocs.com Subject: [Qemu-devel] [RFC PATCH v3 04/13] icount: introduce icount timer. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: KONRAD Frederic This introduces a new timer based only on instruction counter and without any compensation. Signed-off-by: KONRAD Frederic --- cpus.c | 19 ++++++++++++------- include/qemu/timer.h | 9 ++++++++- qemu-timer.c | 8 +++++++- stubs/cpu-get-icount.c | 2 +- 4 files changed, 28 insertions(+), 10 deletions(-) diff --git a/cpus.c b/cpus.c index 89f4b26..e646bac 100644 --- a/cpus.c +++ b/cpus.c @@ -132,7 +132,7 @@ typedef struct TimersState { static TimersState timers_state; /* Return the virtual CPU time, based on the instruction counter. */ -static int64_t cpu_get_icount_locked(void) +static int64_t cpu_get_icount_locked(int with_bias) { int64_t icount; CPUState *cpu = current_cpu; @@ -144,17 +144,22 @@ static int64_t cpu_get_icount_locked(void) } icount -= (cpu->icount_decr.u16.low + cpu->icount_extra); } - return timers_state.qemu_icount_bias + (icount << icount_time_shift); + + if (with_bias) { + return timers_state.qemu_icount_bias + (icount << icount_time_shift); + } else { + return icount << icount_time_shift; + } } -int64_t cpu_get_icount(void) +int64_t cpu_get_icount(int with_bias) { int64_t icount; unsigned start; do { start = seqlock_read_begin(&timers_state.vm_clock_seqlock); - icount = cpu_get_icount_locked(); + icount = cpu_get_icount_locked(with_bias); } while (seqlock_read_retry(&timers_state.vm_clock_seqlock, start)); return icount; @@ -167,7 +172,7 @@ int64_t cpu_get_ticks(void) int64_t ticks; if (use_icount) { - return cpu_get_icount(); + return cpu_get_icount(true); } ticks = timers_state.cpu_ticks_offset; @@ -265,7 +270,7 @@ static void icount_adjust(void) seqlock_write_lock(&timers_state.vm_clock_seqlock); cur_time = cpu_get_clock_locked(); - cur_icount = cpu_get_icount_locked(); + cur_icount = cpu_get_icount_locked(true); delta = cur_icount - cur_time; /* FIXME: This is a very crude algorithm, somewhat prone to oscillation. */ @@ -328,7 +333,7 @@ static void icount_warp_rt(void *opaque) * far ahead of real time. */ int64_t cur_time = cpu_get_clock_locked(); - int64_t cur_icount = cpu_get_icount_locked(); + int64_t cur_icount = cpu_get_icount_locked(true); int64_t delta = cur_time - cur_icount; warp_delta = MIN(warp_delta, delta); } diff --git a/include/qemu/timer.h b/include/qemu/timer.h index 7f9a074..6204cab 100644 --- a/include/qemu/timer.h +++ b/include/qemu/timer.h @@ -36,12 +36,19 @@ * is suspended, and it will reflect system time changes the host may * undergo (e.g. due to NTP). The host clock has the same precision as * the virtual clock. + * + * @QEMU_CLOCK_ICOUNT: icount clock + * + * The icount clock is based on instruction counter without any compensation for + * speed. It will run only when instruction are executed and make only sense in + * icount mode. */ typedef enum { QEMU_CLOCK_REALTIME = 0, QEMU_CLOCK_VIRTUAL = 1, QEMU_CLOCK_HOST = 2, + QEMU_CLOCK_ICOUNT = 3, QEMU_CLOCK_MAX } QEMUClockType; @@ -743,7 +750,7 @@ static inline int64_t get_clock(void) #endif /* icount */ -int64_t cpu_get_icount(void); +int64_t cpu_get_icount(int with_bias); int64_t cpu_get_clock(void); /*******************************************/ diff --git a/qemu-timer.c b/qemu-timer.c index e15ce47..9b0223f 100644 --- a/qemu-timer.c +++ b/qemu-timer.c @@ -551,7 +551,7 @@ int64_t qemu_clock_get_ns(QEMUClockType type) default: case QEMU_CLOCK_VIRTUAL: if (use_icount) { - return cpu_get_icount(); + return cpu_get_icount(true); } else { return cpu_get_clock(); } @@ -563,6 +563,12 @@ int64_t qemu_clock_get_ns(QEMUClockType type) notifier_list_notify(&clock->reset_notifiers, &now); } return now; + case QEMU_CLOCK_ICOUNT: + if (use_icount) { + return cpu_get_icount(false); + } else { + return -1; + } } } diff --git a/stubs/cpu-get-icount.c b/stubs/cpu-get-icount.c index d685859..1968de7 100644 --- a/stubs/cpu-get-icount.c +++ b/stubs/cpu-get-icount.c @@ -3,7 +3,7 @@ int use_icount; -int64_t cpu_get_icount(void) +int64_t cpu_get_icount(int with_bias) { abort(); }