From nobody Fri Apr 19 23:47:51 2024 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.zohomail.com; dkim=fail; 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; dmarc=fail(p=none dis=none) header.from=linaro.org Return-Path: Received: from lists.gnu.org (208.118.235.17 [208.118.235.17]) by mx.zohomail.com with SMTPS id 1523887507656647.4982613375109; Mon, 16 Apr 2018 07:05:07 -0700 (PDT) Received: from localhost ([::1]:48396 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f84kX-0000zx-OC for importer@patchew.org; Mon, 16 Apr 2018 10:04:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40373) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f84jI-0000Lc-QD for qemu-devel@nongnu.org; Mon, 16 Apr 2018 10:03:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f84jE-0004F0-Qd for qemu-devel@nongnu.org; Mon, 16 Apr 2018 10:03:36 -0400 Received: from mail-wr0-x243.google.com ([2a00:1450:400c:c0c::243]:39488) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1f84jE-0004EN-Hz for qemu-devel@nongnu.org; Mon, 16 Apr 2018 10:03:32 -0400 Received: by mail-wr0-x243.google.com with SMTP id q6so14293413wrd.6 for ; Mon, 16 Apr 2018 07:03:32 -0700 (PDT) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id x17sm2343829wmc.2.2018.04.16.07.03.30 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 16 Apr 2018 07:03:30 -0700 (PDT) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id 263933E01CA; Mon, 16 Apr 2018 15:03:30 +0100 (BST) 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=GxZK4GfDufua8AU59rd88gmnJwuYs4sjUeTh21YJVoY=; b=f4lxcBKUn3KedxrOCfX+/WJ/DLo+ffXpENoJ0w3ZMgoqldeS/40x4xAyA8vLNWIozT GBKPH9XVtYIVJyjNPMlcDr0K25h0mbzCWG2nrB8BWyaziPq52aHHfnSB4nqyXRR6IpNp g7cSG5ZGcA1kqmeCGfYFCieDL9BPnqiR3cnzk= 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=GxZK4GfDufua8AU59rd88gmnJwuYs4sjUeTh21YJVoY=; b=dPUfuWWFMj6o+yBkIiaP+MxBryYlzeZubA+QcVRJdL/jqVWUw8xMpjp4WL2pPadGsE MgkKCyXCPmowZV44whh2Gtkyf7QciWGB7ztER+KpRx7otbXcyyRG5wAGc7PicK7HpxFe B0xEXAFvHTSjEkdsBVA4mNbMmR+ZbqAOrRadsdWeDqI3J2d0lx18bJvp+jVABb1o1ne/ xwmCLIDwYhIY9WdFC7o/iS6V7fyPXNme/K0zkUzP37dHvhRlzQh7DYKEBXfRo6P1JW3l /1adVDl5hNS5j+AcIMH/CtYAWktd0Yos5HawsSeFY9wQ6mVGXAAIPijrgfUhl/H3SLPz R1GA== X-Gm-Message-State: ALQs6tD0wsRrXqml+nLA/9WTWBCQCjhc2OOmWosajau9+xRww/iD0LSY uGUaHKIAxSIWj39FTEgcVfsKrA== X-Google-Smtp-Source: AIpwx49rIisvkjL6uL/C8F52t6fzlAiQLhWprVKmeeSr1Y1vWcYdYuquntwtZNHumJjYzGaxndOwxQ== X-Received: by 10.223.150.139 with SMTP id u11mr1397741wrb.184.1523887411402; Mon, 16 Apr 2018 07:03:31 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= To: qemu-arm@nongnu.org Date: Mon, 16 Apr 2018 15:03:22 +0100 Message-Id: <20180416140322.904-1-alex.bennee@linaro.org> X-Mailer: git-send-email 2.17.0 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:400c:c0c::243 Subject: [Qemu-devel] [RFC PATCH] target/arm: support reading of CNTVCT_EL0 from user-space 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 , takeharu.kato@linaro.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= , qemu-devel@nongnu.org, renato.golin@linaro.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Since kernel commit a86bd139f2 (arm64: arch_timer: Enable CNTVCT_EL0 trap..) user-space has been able to read this system register. This patch enables access to that register although currently it always returns 0 as we don't yet have a mechanism for managing timers in linux-user mode. Signed-off-by: Alex Benn=C3=A9e --- target/arm/helper.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index b14fdab140..8244badd63 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -2121,11 +2121,25 @@ static const ARMCPRegInfo generic_timer_cp_reginfo[= ] =3D { }; =20 #else -/* In user-mode none of the generic timer registers are accessible, - * and their implementation depends on QEMU_CLOCK_VIRTUAL and qdev gpio ou= tputs, - * so instead just don't register any of them. + +/* In user-mode most of the generic timer registers are inaccessible + * however modern kernels (4.12+) allow access to cntvct_el0 */ + +static uint64_t gt_virt_cnt_read(CPUARMState *env, const ARMCPRegInfo *ri) +{ + /* Currently we have no support for QEMUTimer in linux-user so we + * can't call gt_get_countervalue(env). + */ + return 0; +} + static const ARMCPRegInfo generic_timer_cp_reginfo[] =3D { + { .name =3D "CNTVCT_EL0", .state =3D ARM_CP_STATE_AA64, + .opc0 =3D 3, .opc1 =3D 3, .crn =3D 14, .crm =3D 0, .opc2 =3D 2, + .access =3D PL0_R, .type =3D ARM_CP_NO_RAW | ARM_CP_IO, + .readfn =3D gt_virt_cnt_read, + }, REGINFO_SENTINEL }; =20 --=20 2.17.0