From patchwork Tue Feb 26 04:52:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: David Gibson X-Patchwork-Id: 1048089 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.b="YpSmx/ha"; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 447mmG0hz5z9s4V for ; Tue, 26 Feb 2019 15:58:22 +1100 (AEDT) Received: from localhost ([127.0.0.1]:48802 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyUou-0007xa-08 for incoming@patchwork.ozlabs.org; Mon, 25 Feb 2019 23:58:20 -0500 Received: from eggs.gnu.org ([209.51.188.92]:57580) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gyUkh-0004ss-MW for qemu-devel@nongnu.org; Mon, 25 Feb 2019 23:54:00 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gyUkd-000247-ER for qemu-devel@nongnu.org; Mon, 25 Feb 2019 23:53:57 -0500 Received: from ozlabs.org ([203.11.71.1]:59855) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gyUkY-0000g5-Vq; Mon, 25 Feb 2019 23:53:52 -0500 Received: by ozlabs.org (Postfix, from userid 1007) id 447mfG123Qz9sDL; Tue, 26 Feb 2019 15:53:09 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1551156790; bh=Zi/KKe+w9uDorpBew1Z7DPLRyrkhfPToW30Kpj0MC08=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YpSmx/havoUJnLz9rEKvKyDBWJ6uxSkMMLFrJrqBlu+X7LvzGYhZsjXtPd210Iy5H 2Pm6oyvCRIJot6M4cVjgErmppPAINP9BONACtcLSYmwYaI+fcIH4esnomddzrakaJG RdtGawLlLszlwoBqZ8sYrCyW1HZ8NYKC8nP1SlSA= From: David Gibson To: peter.maydell@linaro.org Date: Tue, 26 Feb 2019 15:52:21 +1100 Message-Id: <20190226045304.25618-8-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190226045304.25618-1-david@gibson.dropbear.id.au> References: <20190226045304.25618-1-david@gibson.dropbear.id.au> MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 203.11.71.1 Subject: [Qemu-devel] [PULL 07/50] 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: lvivier@redhat.com, gkurz@kaod.org, qemu-devel@nongnu.org, qemu-ppc@nongnu.org, clg@kaod.org, David Gibson Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" 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 Message-Id: <20190215161648.9600-8-clg@kaod.org> Signed-off-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 37546bb0f0..1a2f469a5f 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)