From nobody Wed Nov 5 14:59:51 2025 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; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1534777996473237.56013495924674; Mon, 20 Aug 2018 08:13:16 -0700 (PDT) Received: from localhost ([::1]:47658 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1frlrn-00024m-CZ for importer@patchew.org; Mon, 20 Aug 2018 11:13:15 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38179) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1frlnx-0006vj-5f for qemu-devel@nongnu.org; Mon, 20 Aug 2018 11:09:21 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1frlnt-0006BH-2g for qemu-devel@nongnu.org; Mon, 20 Aug 2018 11:09:15 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:48610 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1frlnp-00067q-9O for qemu-devel@nongnu.org; Mon, 20 Aug 2018 11:09:10 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id F3DA785775; Mon, 20 Aug 2018 15:09:07 +0000 (UTC) Received: from donizetti.mxp.redhat.com (unknown [10.32.181.140]) by smtp.corp.redhat.com (Postfix) with ESMTP id 745C110B7C98; Mon, 20 Aug 2018 15:09:07 +0000 (UTC) From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Mon, 20 Aug 2018 17:09:03 +0200 Message-Id: <20180820150903.1224-5-pbonzini@redhat.com> In-Reply-To: <20180820150903.1224-1-pbonzini@redhat.com> References: <20180820150903.1224-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 20 Aug 2018 15:09:08 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 20 Aug 2018 15:09:08 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'pbonzini@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PATCH 4/4] cpus: allow cpu_get_ticks out of BQL 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: "Emilio G . Cota" Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RDMRC_1 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Because of cpu_ticks_prev, we cannot use a seqlock. But then the conversion is even easier. :) Signed-off-by: Paolo Bonzini --- cpus.c | 35 ++++++++++++++++++++--------------- 1 file changed, 20 insertions(+), 15 deletions(-) diff --git a/cpus.c b/cpus.c index 63ddd4fd21..7786439362 100644 --- a/cpus.c +++ b/cpus.c @@ -316,11 +316,26 @@ int64_t cpu_icount_to_ns(int64_t icount) return icount << atomic_read(&timers_state.icount_time_shift); } =20 +static int64_t cpu_get_ticks_locked(void) +{ + int64_t ticks =3D timers_state.cpu_ticks_offset; + if (timers_state.cpu_ticks_enabled) { + ticks +=3D cpu_get_host_ticks(); + } + + if (timers_state.cpu_ticks_prev > ticks) { + /* Non increasing ticks may happen if the host uses software suspe= nd. */ + timers_state.cpu_ticks_offset +=3D timers_state.cpu_ticks_prev - t= icks; + ticks =3D timers_state.cpu_ticks_prev; + } + + timers_state.cpu_ticks_prev =3D ticks; + return ticks; +} + /* return the time elapsed in VM between vm_start and vm_stop. Unless * icount is active, cpu_get_ticks() uses units of the host CPU cycle * counter. - * - * Caller must hold the BQL */ int64_t cpu_get_ticks(void) { @@ -330,19 +345,9 @@ int64_t cpu_get_ticks(void) return cpu_get_icount(); } =20 - ticks =3D timers_state.cpu_ticks_offset; - if (timers_state.cpu_ticks_enabled) { - ticks +=3D cpu_get_host_ticks(); - } - - if (timers_state.cpu_ticks_prev > ticks) { - /* Note: non increasing ticks may happen if the host uses - software suspend */ - timers_state.cpu_ticks_offset +=3D timers_state.cpu_ticks_prev - t= icks; - ticks =3D timers_state.cpu_ticks_prev; - } - - timers_state.cpu_ticks_prev =3D ticks; + qemu_spin_lock(&timers_state.vm_clock_lock); + ticks =3D cpu_get_ticks_locked(); + qemu_spin_unlock(&timers_state.vm_clock_lock); return ticks; } =20 --=20 2.17.1