From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BA3E5C433F5 for ; Thu, 16 Sep 2021 14:39:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 63FBC6120C for ; Thu, 16 Sep 2021 14:39:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 63FBC6120C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kaod.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:56032 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mQsYB-0007BZ-DY for qemu-devel@archiver.kernel.org; Thu, 16 Sep 2021 10:39:43 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57674) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQsVt-00053z-R8 for qemu-devel@nongnu.org; Thu, 16 Sep 2021 10:37:25 -0400 Received: from 10.mo548.mail-out.ovh.net ([46.105.77.235]:57393) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mQsVq-0007zg-Mr for qemu-devel@nongnu.org; Thu, 16 Sep 2021 10:37:21 -0400 Received: from mxplan5.mail.ovh.net (unknown [10.108.4.12]) by mo548.mail-out.ovh.net (Postfix) with ESMTPS id C99BE2139C; Thu, 16 Sep 2021 14:37:14 +0000 (UTC) Received: from kaod.org (37.59.142.103) by DAG4EX1.mxp5.local (172.16.2.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.14; Thu, 16 Sep 2021 16:37:13 +0200 Authentication-Results: garm.ovh; auth=pass (GARM-103G0057a029df9-6256-4e37-bab7-61dd4db912ae, 902CC554B2B666CF336F93082A9AEA4058B2700C) smtp.auth=clg@kaod.org X-OVh-ClientIp: 82.64.250.170 From: =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= To: David Gibson , Greg Kurz Subject: [PATCH v3] target/ppc: Fix 64-bit decrementer Date: Thu, 16 Sep 2021 16:37:10 +0200 Message-ID: <20210916143710.236489-1-clg@kaod.org> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-Originating-IP: [37.59.142.103] X-ClientProxiedBy: DAG7EX1.mxp5.local (172.16.2.61) To DAG4EX1.mxp5.local (172.16.2.31) X-Ovh-Tracer-GUID: 79084e6c-1616-4d48-a185-4de6b59b0c7d X-Ovh-Tracer-Id: 6240300237243714412 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvtddrudehgedgjeefucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhephffvufffkffogggtgfhisehtkeertdertdejnecuhfhrohhmpeevrogurhhitgcunfgvucfiohgrthgvrhcuoegtlhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepfedvuedtvdeikeekuefhkedujeejgffggffhtefglefgveevfeeghfdvgedtleevnecukfhppedtrddtrddtrddtpdefjedrheelrddugedvrddutdefnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepmhigphhlrghnhedrmhgrihhlrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpegtlhhgsehkrghougdrohhrghdprhgtphhtthhopegtlhhgsehkrghougdrohhrgh Received-SPF: pass client-ip=46.105.77.235; envelope-from=clg@kaod.org; helo=10.mo548.mail-out.ovh.net X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Richard Henderson , qemu-devel@nongnu.org, Luis Fernando Fujita Pires , qemu-ppc@nongnu.org, =?UTF-8?q?C=C3=A9dric=20Le=20Goater?= Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The current way the mask is built can overflow with a 64-bit decrementer. Use sextract64() to extract the signed values and remove the logic to handle negative values which has become useless. Cc: Luis Fernando Fujita Pires Fixes: a8dafa525181 ("target/ppc: Implement large decrementer support for TCG") Signed-off-by: Cédric Le Goater --- Tested on pSeries, PowerNV, MAC and MicroWatt (64bit dec) platforms. hw/ppc/ppc.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c index 7375bf4fa910..777e5756edfa 100644 --- a/hw/ppc/ppc.c +++ b/hw/ppc/ppc.c @@ -873,17 +873,15 @@ static void __cpu_ppc_store_decr(PowerPCCPU *cpu, uint64_t *nextp, CPUPPCState *env = &cpu->env; ppc_tb_t *tb_env = env->tb_env; uint64_t now, next; - bool negative; + target_long signed_value; + target_long signed_decr; /* Truncate value to decr_width and sign extend for simplicity */ - value &= ((1ULL << nr_bits) - 1); - negative = !!(value & (1ULL << (nr_bits - 1))); - if (negative) { - value |= (0xFFFFFFFFULL << nr_bits); - } + signed_value = sextract64(value, 0, nr_bits); + signed_decr = sextract64(decr, 0, nr_bits); LOG_TB("%s: " TARGET_FMT_lx " => " TARGET_FMT_lx "\n", __func__, - decr, value); + decr, signed_value); if (kvm_enabled()) { /* KVM handles decrementer exceptions, we don't need our own timer */ @@ -903,16 +901,16 @@ static void __cpu_ppc_store_decr(PowerPCCPU *cpu, uint64_t *nextp, * On MSB edge based DEC implementations the MSB going from 0 -> 1 triggers * an edge interrupt, so raise it here too. */ - if ((value < 3) || - ((tb_env->flags & PPC_DECR_UNDERFLOW_LEVEL) && negative) || - ((tb_env->flags & PPC_DECR_UNDERFLOW_TRIGGERED) && negative - && !(decr & (1ULL << (nr_bits - 1))))) { + if ((signed_value < 3) || + ((tb_env->flags & PPC_DECR_UNDERFLOW_LEVEL) && signed_value < 0) || + ((tb_env->flags & PPC_DECR_UNDERFLOW_TRIGGERED) && signed_value < 0 + && signed_decr >= 0)) { (*raise_excp)(cpu); return; } /* On MSB level based systems a 0 for the MSB stops interrupt delivery */ - if (!negative && (tb_env->flags & PPC_DECR_UNDERFLOW_LEVEL)) { + if (signed_value >= 0 && (tb_env->flags & PPC_DECR_UNDERFLOW_LEVEL)) { (*lower_excp)(cpu); } -- 2.31.1