From nobody Sat Nov 1 22:28:31 2025 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 (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1526644003981117.53263047101348; Fri, 18 May 2018 04:46:43 -0700 (PDT) Received: from localhost ([::1]:38179 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJdqJ-0007wz-Ew for importer@patchew.org; Fri, 18 May 2018 07:46:39 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38317) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fJdoE-0006hd-FB for qemu-devel@nongnu.org; Fri, 18 May 2018 07:44:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fJdoB-00080j-PW for qemu-devel@nongnu.org; Fri, 18 May 2018 07:44:30 -0400 Received: from mail-wr0-x244.google.com ([2a00:1450:400c:c0c::244]:45074) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1fJdoB-0007z8-H0 for qemu-devel@nongnu.org; Fri, 18 May 2018 07:44:27 -0400 Received: by mail-wr0-x244.google.com with SMTP id w3-v6so1185299wrl.12 for ; Fri, 18 May 2018 04:44:27 -0700 (PDT) Received: from zen.linaro.local ([81.128.185.34]) by smtp.gmail.com with ESMTPSA id d83-v6sm9959996wmh.16.2018.05.18.04.44.24 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 18 May 2018 04:44:24 -0700 (PDT) Received: from zen.linaroharston (localhost [127.0.0.1]) by zen.linaro.local (Postfix) with ESMTP id 389E23E0260; Fri, 18 May 2018 12:44:24 +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:in-reply-to:references :mime-version:content-transfer-encoding; bh=dELcojVFJWt7A2v6t7CFtT+0hLIdSVJNso/IcORbe2g=; b=CeTig8jZJAtlkWEkzpo0qdEcqpuGXzaV8LkYbaYKIprgF+/SYCka4fsWOJkRoT1tCO aHv0LijegnyJEV3dKnZ9RiZAQfInT+GZAZpBEh/22Vi9zuVNbqRNh7gimQGyJfFSOWb1 rU5c9Mdoj5J6KGSV/AnYSNT58vMiKTmlNVlGM= 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:in-reply-to :references:mime-version:content-transfer-encoding; bh=dELcojVFJWt7A2v6t7CFtT+0hLIdSVJNso/IcORbe2g=; b=Kq9LOIWwkq6vIYlHO9BVyQxcCAHATeDKS/sY0+LJVaJS085HUSlRu5YCSZR01RaWtX D2smmTwwvwNwZ4EkJoQXtDlNpIwmnCTNwC/imOe6TAnmgsNhcsz5YCyfIuHebZJ2TJWM DmsU6RG4O/hsTBHRoFHU4Y9CY1X/N0Izq7iKHssmVKmhm4ZjszlsfucUnAyxhcv9NbZR W2K7AehY0+FBNtKi9hq7OrY+l0P6oeuzsXf4H/QDsj6IxVOwCVXRftZDO5XnAhz2jl5h 0taTY7RWzlQt+78Udu0W77XIqTO8XEThDGhn8hhU2p/rS2iv5BSJVK6fcE+9wr37AQXq 1XiQ== X-Gm-Message-State: ALKqPweb0q48EjChN4N8hS9Mz4H3gD5fxvSXJLQanF43UBeXYv0ansFj XK64lCTZfgj83DhfDH/a9s+93A== X-Google-Smtp-Source: AB8JxZpMyYIXZRMjIqafrzTqR0TbQq5+6wF4jQr1jmLt0AfzkbSgM2vYSXxoGMdxxNyN0tbTPVXmFQ== X-Received: by 2002:adf:afce:: with SMTP id y14-v6mr7833436wrd.249.1526643866258; Fri, 18 May 2018 04:44:26 -0700 (PDT) From: =?UTF-8?q?Alex=20Benn=C3=A9e?= To: peter.maydell@linaro.org Date: Fri, 18 May 2018 12:44:23 +0100 Message-Id: <20180518114424.18054-2-alex.bennee@linaro.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180518114424.18054-1-alex.bennee@linaro.org> References: <20180518114424.18054-1-alex.bennee@linaro.org> 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::244 Subject: [Qemu-devel] [PATCH v2 1/2] target/arm: support reading of CNT[VCT|FRQ]_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: qemu-arm@nongnu.org, =?UTF-8?q?Alex=20Benn=C3=A9e?= , qemu-devel@nongnu.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 these system registers. As we can't use QEMUTimer's in linux-user mode we just directly call cpu_get_clock(). Signed-off-by: Alex Benn=C3=A9e --- v2 - include CNTFRQ_EL0 for PL0_R only --- target/arm/helper.c | 27 ++++++++++++++++++++++++--- 1 file changed, 24 insertions(+), 3 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index db8bbe52a6..39098a15bf 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -2135,11 +2135,32 @@ 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), instead we directly + * call the lower level functions. + */ + return cpu_get_clock() / GTIMER_SCALE; +} + static const ARMCPRegInfo generic_timer_cp_reginfo[] =3D { + { .name =3D "CNTFRQ_EL0", .state =3D ARM_CP_STATE_AA64, + .opc0 =3D 3, .opc1 =3D 3, .crn =3D 14, .crm =3D 0, .opc2 =3D 0, + .access =3D PL0_R /* no PL1_RW in linux-user */, + .fieldoffset =3D offsetof(CPUARMState, cp15.c14_cntfrq), + .resetvalue =3D (1000 * 1000 * 1000) / GTIMER_SCALE, + }, + { .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