From patchwork Thu Sep 21 11:06:25 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Alex_Benn=C3=A9e?= X-Patchwork-Id: 113218 Delivered-To: patch@linaro.org Received: by 10.140.106.117 with SMTP id d108csp1877218qgf; Thu, 21 Sep 2017 04:06:57 -0700 (PDT) X-Received: by 10.55.68.77 with SMTP id r74mr2375363qka.125.1505992017136; Thu, 21 Sep 2017 04:06:57 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1505992017; cv=none; d=google.com; s=arc-20160816; b=xEDd36tLoEjrBb5Obv+Q/lusRZn2INCosX7L2cjjMUESOik9Gl/v67nVg7732dlge2 Llqg5PinpO7TmZ0W4KXb45+BVnB9MKxPT13pW5msZNHBjwHokAkTW6SHdqyG0NIGTcTr hwsAK37VOe0PbRhiDeharv3spXpnm7Jo7mIze2X5v74MrWKYepnYSD/KsKapEgmWaH6p zH9naHLIvnJW/aiLECcHUARSaDyqK4WqSftWyVlkXlRRefqMk10mrgEaHgw6geoCPCaH gfciyyelF0Mf80YNG6FSjPLUjm2xbRQEx2u/Q8loP3Tq2ZzH3t6dW6gkFcKrFBtgh/hC Kv7Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:cc:list-subscribe:list-help:list-post:list-archive :list-unsubscribe:list-id:precedence:subject :content-transfer-encoding:mime-version:message-id:date:to:from :dkim-signature:arc-authentication-results; bh=nHmZOEOf8b+ucbApdE9LO6cI3c40nr7UWJ1w+zWvhoc=; b=twY4wJ1O28WEPLZ+2vpobz21sDyGiqgwralMZpH8PcmE1XIGdJH/GcZ6Ax45kf0TN3 g1HU34t2j4VYOro3AADj/dsMyrJAOKqwPJPTw5oBSQUvfXtv349gfvCKbXiDjw0uuKdj ujhgdWbMqD+0xLMSRFbhCexJJGHxcB0FbQ/enxyT8J/8GBmg4qpJgb1aaCQen3UvpT73 lsk0OiZ2Y/XBIglRprfUzuTBpRSO0sNuH8I/bmL3SYTJjOKiPmdGDlP1Lu9GVjIMt9aw /AMSmAXJ3szYFhj1OK4nPS15oEv2ZEPjXUzc0CjZCyclCEnTI7YNoel9AC818dWOkkn7 EtrQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=ZIGx2NF4; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from lists.gnu.org (lists.gnu.org. [2001:4830:134:3::11]) by mx.google.com with ESMTPS id a55si937425qta.363.2017.09.21.04.06.56 for (version=TLS1 cipher=AES128-SHA bits=128/128); Thu, 21 Sep 2017 04:06:57 -0700 (PDT) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=ZIGx2NF4; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-devel-bounces+patch=linaro.org@nongnu.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:52917 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1duzJn-0001NV-4i for patch@linaro.org; Thu, 21 Sep 2017 07:06:55 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53226) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1duzJa-0001NL-CW for qemu-devel@nongnu.org; Thu, 21 Sep 2017 07:06:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1duzJW-0002Gj-HG for qemu-devel@nongnu.org; Thu, 21 Sep 2017 07:06:42 -0400 Received: from mail-wm0-x22b.google.com ([2a00:1450:400c:c09::22b]:50464) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1duzJW-0002CS-BD for qemu-devel@nongnu.org; Thu, 21 Sep 2017 07:06:38 -0400 Received: by mail-wm0-x22b.google.com with SMTP id b195so701739wmb.5 for ; Thu, 21 Sep 2017 04:06:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nHmZOEOf8b+ucbApdE9LO6cI3c40nr7UWJ1w+zWvhoc=; b=ZIGx2NF4z5+TZRmCePl1f3sKSnSxNpnYVKb/x+I5bWVlVCTiLfjVypUaXO3e6EdLqj NQUgvHfTqS5y6YuOUJd4es743g7BiF54oDepVUzgqfzlP6YyEgBrBnIKfbNxmmuHd0Sj 1Hng1ggeo5gEWOoSYAEeUhHkLTUe4Jx4ekmh8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=nHmZOEOf8b+ucbApdE9LO6cI3c40nr7UWJ1w+zWvhoc=; b=fj85oWq7fTwhhFITufYQ16tArLfj2pWujytfot/mZrcbnS9hp7bOwH3VeS+ux3mZIZ kAnmGJeaelvKKWl5nwYqOe8FLX1YVlaz97RhRMKw/WmgbrakirRxcGO7tlouGUG1GM7I KBK4iH7YMdgJBTrUjTfvgwHacnEehFEzgBCUKzbVYj9w+MzfiyWTKYehMJExySHGEu42 4hsdrhk7nyaERjMrmH2VNR8zXMz9i0W4dTQymvhgUGDeK884mCA/pvsrxUsUDuUKzeX4 n9SmiC4Rddy+H2sopCZNrldB84HFlhNAFEb0NHMzUMmjSp8TPN/HDouM7P/9Y7SPaEUy kEqQ== X-Gm-Message-State: AHPjjUjh3NZ1dtb4AH4ET9vCSmHSYKn1UcYdBnfQi1uYk/wb37q6lJHD nv5cdgbg+6RJhCn7Eroeo8jttw== X-Google-Smtp-Source: AOwi7QB7MXhpGSFYKPYZ1RpGBLa3yTimZoC8fhHwx9g8Ejse/gtJ+0kWPj0RoxU3trR1AMstgggwtw== X-Received: by 10.28.152.70 with SMTP id a67mr628193wme.132.1505991994635; Thu, 21 Sep 2017 04:06:34 -0700 (PDT) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id 11sm1136272wmj.14.2017.09.21.04.06.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 21 Sep 2017 04:06:33 -0700 (PDT) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id C59323E05A7; Thu, 21 Sep 2017 12:06:36 +0100 (BST) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: qemu-devel@nongnu.org Date: Thu, 21 Sep 2017 12:06:25 +0100 Message-Id: <20170921110625.9500-1-alex.bennee@linaro.org> X-Mailer: git-send-email 2.14.1 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:400c:c09::22b Subject: [Qemu-devel] [PATCH] accel/tcg/cputlb: avoid recursive BQL (fixes #1706296) 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: peter.maydell@linaro.org, Paolo Bonzini , Peter Crosthwaite , Richard Jones , Paolo Bonzini , =?utf-8?q?A?= =?utf-8?q?lex_Benn=C3=A9e?= , Richard Henderson Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" The mmio path (see exec.c:prepare_mmio_access) already protects itself against recursive locking and it makes sense to do the same for io_readx/writex. Otherwise any helper running in the BQL context will assert when it attempts to write to device memory as in the case of the bug report. Signed-off-by: Alex Bennée CC: Richard Jones CC: Paolo Bonzini --- accel/tcg/cputlb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.14.1 Reviewed-by: Peter Maydell Reviewed-by: Richard Henderson diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c index e72415a882..bcbcc4db6c 100644 --- a/accel/tcg/cputlb.c +++ b/accel/tcg/cputlb.c @@ -765,7 +765,7 @@ static uint64_t io_readx(CPUArchState *env, CPUIOTLBEntry *iotlbentry, cpu->mem_io_vaddr = addr; - if (mr->global_locking) { + if (mr->global_locking && !qemu_mutex_iothread_locked()) { qemu_mutex_lock_iothread(); locked = true; } @@ -800,7 +800,7 @@ static void io_writex(CPUArchState *env, CPUIOTLBEntry *iotlbentry, cpu->mem_io_vaddr = addr; cpu->mem_io_pc = retaddr; - if (mr->global_locking) { + if (mr->global_locking && !qemu_mutex_iothread_locked()) { qemu_mutex_lock_iothread(); locked = true; }