From patchwork Mon Jan 28 09:46:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?C=C3=A9dric_Le_Goater?= X-Patchwork-Id: 10783493 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E540691E for ; Mon, 28 Jan 2019 09:54:22 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D4B8D2A71B for ; Mon, 28 Jan 2019 09:54:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C8B732A71E; Mon, 28 Jan 2019 09:54:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 6EAD82932B for ; Mon, 28 Jan 2019 09:54:22 +0000 (UTC) Received: from localhost ([127.0.0.1]:56879 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1go3cT-00028h-LY for patchwork-qemu-devel@patchwork.kernel.org; Mon, 28 Jan 2019 04:54:21 -0500 Received: from eggs.gnu.org ([209.51.188.92]:38551) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1go3Vc-0005Nb-CV for qemu-devel@nongnu.org; Mon, 28 Jan 2019 04:47:17 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1go3VU-0003Al-IS for qemu-devel@nongnu.org; Mon, 28 Jan 2019 04:47:11 -0500 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:33652) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1go3VO-00030c-Pf for qemu-devel@nongnu.org; Mon, 28 Jan 2019 04:47:04 -0500 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x0S9i5Tu074217 for ; Mon, 28 Jan 2019 04:46:58 -0500 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0a-001b2d01.pphosted.com with ESMTP id 2q9vhk7aud-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 28 Jan 2019 04:46:58 -0500 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Mon, 28 Jan 2019 09:46:54 -0000 Received: from d06av26.portsmouth.uk.ibm.com (d06av26.portsmouth.uk.ibm.com [9.149.105.62]) by b06cxnps4076.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x0S9krq7197008 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 28 Jan 2019 09:46:54 GMT Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D9377AE051; Mon, 28 Jan 2019 09:46:53 +0000 (GMT) Received: from d06av26.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id BA3E3AE058; Mon, 28 Jan 2019 09:46:53 +0000 (GMT) Received: from smtp.lab.toulouse-stg.fr.ibm.com (unknown [9.101.4.1]) by d06av26.portsmouth.uk.ibm.com (Postfix) with ESMTP; Mon, 28 Jan 2019 09:46:53 +0000 (GMT) Received: from zorba.kaod.org.com (sig-9-145-15-166.uk.ibm.com [9.145.15.166]) by smtp.lab.toulouse-stg.fr.ibm.com (Postfix) with ESMTP id 26CDD220309; Mon, 28 Jan 2019 10:46:53 +0100 (CET) From: =?utf-8?q?C=C3=A9dric_Le_Goater?= To: David Gibson Date: Mon, 28 Jan 2019 10:46:21 +0100 X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190128094625.4428-1-clg@kaod.org> References: <20190128094625.4428-1-clg@kaod.org> MIME-Version: 1.0 X-TM-AS-GCONF: 00 x-cbid: 19012809-0028-0000-0000-0000033F0486 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19012809-0029-0000-0000-000023FC4F99 Message-Id: <20190128094625.4428-16-clg@kaod.org> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-01-28_07:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 phishscore=0 bulkscore=0 spamscore=0 clxscore=1034 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=352 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1901280080 X-MIME-Autoconverted: from 8bit to quoted-printable by mx0a-001b2d01.pphosted.com id x0S9i5Tu074217 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [generic] [fuzzy] X-Received-From: 148.163.156.1 Subject: [Qemu-devel] [PATCH 15/19] target/ppc: Detect erroneous condition in interrupt delivery 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: qemu-ppc@nongnu.org, qemu-devel@nongnu.org, =?utf-8?q?C=C3=A9dric_Le_Goa?= =?utf-8?q?ter?= Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Benjamin Herrenschmidt It's very easy for the CPU specific has_work() implementation and the logic in ppc_hw_interrupt() to be subtly out of sync. This can occasionally allow a CPU to wakeup from a PM state and resume executing past the PM instruction when it should resume at the 0x100 vector. This detects if it happens and aborts, making it a lot easier to catch such bugs when testing rather than chasing obscure guest misbehaviour. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson --- target/ppc/excp_helper.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c index 37546bb0f0fe..1a2f469a5fa2 100644 --- a/target/ppc/excp_helper.c +++ b/target/ppc/excp_helper.c @@ -878,6 +878,22 @@ static void ppc_hw_interrupt(CPUPPCState *env) return; } } + + if (env->resume_as_sreset) { + /* + * This is a bug ! It means that has_work took us out of halt without + * anything to deliver while in a PM state that requires getting + * out via a 0x100 + * + * This means we will incorrectly execute past the power management + * instruction instead of triggering a reset. + * + * It generally means a discrepancy between the wakup conditions in the + * processor has_work implementation and the logic in this function. + */ + cpu_abort(CPU(ppc_env_get_cpu(env)), + "Wakeup from PM state but interrupt Undelivered"); + } } void ppc_cpu_do_system_reset(CPUState *cs)