From nobody Mon Feb 9 16:34:34 2026 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.zoho.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 (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1488199684624890.9615831894571; Mon, 27 Feb 2017 04:48:04 -0800 (PST) Received: from localhost ([::1]:52230 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciKih-0005z1-Cr for importer@patchew.org; Mon, 27 Feb 2017 07:48:03 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35654) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ciKge-0004aU-R8 for qemu-devel@nongnu.org; Mon, 27 Feb 2017 07:45:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ciKgd-0000SB-K1 for qemu-devel@nongnu.org; Mon, 27 Feb 2017 07:45:56 -0500 Received: from mx1.redhat.com ([209.132.183.28]:39492) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ciKgd-0000Rw-8z for qemu-devel@nongnu.org; Mon, 27 Feb 2017 07:45:55 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 63591C04B326; Mon, 27 Feb 2017 12:45:55 +0000 (UTC) Received: from donizetti.redhat.com (ovpn-117-118.ams2.redhat.com [10.36.117.118]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1RCjpdv028718; Mon, 27 Feb 2017 07:45:54 -0500 From: Paolo Bonzini To: qemu-devel@nongnu.org Date: Mon, 27 Feb 2017 13:45:36 +0100 Message-Id: <20170227124551.8673-3-pbonzini@redhat.com> In-Reply-To: <20170227124551.8673-1-pbonzini@redhat.com> References: <20170227124551.8673-1-pbonzini@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Mon, 27 Feb 2017 12:45:55 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH 02/17] replay: check icount in cpu exec loop 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: Pavel Dovgalyuk , Pavel Dovgalyuk Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Pavel Dovgalyuk This patch adds check to break cpu loop when icount expires without setting the TB_EXIT_ICOUNT_EXPIRED flag. It happens when there is no available translated blocks and all instructions were executed. In icount replay mode unnecessary tb_find will be called (which may cause an exception) and execution will be non-deterministic. Because cpu_loop_exec_tb cannot longjmp anymore, we can remove the anticipated call to align_clocks in cpu_loop_exec_tb, as well as the SyncClocks *sc argument. Signed-off-by: Pavel Dovgalyuk Message-Id: <002801d2810f$18809c20$4981d460$@ru> Signed-off-by: Paolo Bonzini --- cpu-exec.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/cpu-exec.c b/cpu-exec.c index 6fd3f47..2a0dfb0 100644 --- a/cpu-exec.c +++ b/cpu-exec.c @@ -554,8 +554,9 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, qemu_mutex_unlock_iothread(); } =20 - - if (unlikely(atomic_read(&cpu->exit_request) || replay_has_interrupt()= )) { + /* Finally, check if we need to exit to the main loop. */ + if (unlikely(atomic_read(&cpu->exit_request) + || (use_icount && cpu->icount_decr.u16.low + cpu->icount_extra =3D= =3D 0))) { atomic_set(&cpu->exit_request, 0); cpu->exception_index =3D EXCP_INTERRUPT; return true; @@ -565,8 +566,7 @@ static inline bool cpu_handle_interrupt(CPUState *cpu, } =20 static inline void cpu_loop_exec_tb(CPUState *cpu, TranslationBlock *tb, - TranslationBlock **last_tb, int *tb_ex= it, - SyncClocks *sc) + TranslationBlock **last_tb, int *tb_ex= it) { uintptr_t ret; int32_t insns_left; @@ -615,10 +615,7 @@ static inline void cpu_loop_exec_tb(CPUState *cpu, Tra= nslationBlock *tb, */ if (insns_left > 0) { cpu_exec_nocache(cpu, insns_left, tb, false); - align_clocks(sc, cpu); } - cpu->exception_index =3D EXCP_INTERRUPT; - cpu_loop_exit(cpu); } #endif } @@ -593,7 +592,7 @@ int cpu_exec(CPUState *cpu) { CPUClass *cc =3D CPU_GET_CLASS(cpu); int ret; - SyncClocks sc; + SyncClocks sc =3D { 0 }; =20 /* replay_interrupt may need current_cpu */ current_cpu =3D cpu; @@ -677,7 +674,7 @@ int cpu_exec(CPUState *cpu) =20 while (!cpu_handle_interrupt(cpu, &last_tb)) { TranslationBlock *tb =3D tb_find(cpu, last_tb, tb_exit); - cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit, &sc); + cpu_loop_exec_tb(cpu, tb, &last_tb, &tb_exit); /* Try to align the host and virtual clocks if the guest is in advance */ align_clocks(&sc, cpu); --=20 2.9.3