From nobody Tue Feb 10 13:17:36 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1763779315223372.6727827648341; Fri, 21 Nov 2025 18:41:55 -0800 (PST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1vMcs0-0006ls-5F; Fri, 21 Nov 2025 20:57:01 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vMbmL-00017J-Lr; Fri, 21 Nov 2025 19:47:05 -0500 Received: from isrv.corpit.ru ([212.248.84.144]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1vMbm8-00084D-RB; Fri, 21 Nov 2025 19:47:01 -0500 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 36ED816CA3F; Fri, 21 Nov 2025 21:44:20 +0300 (MSK) Received: from think4mjt.tls.msk.ru (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id E7A9D321C7B; Fri, 21 Nov 2025 21:44:28 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Peter Maydell , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Richard Henderson , Michael Tokarev Subject: [Stable-10.0.7 04/81] target/arm: Fix reads of CNTFRQ_EL0 in linux-user mode Date: Fri, 21 Nov 2025 21:43:03 +0300 Message-ID: <20251121184424.1137669-4-mjt@tls.msk.ru> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=212.248.84.144; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1763779317054018900 From: Peter Maydell In commit bd8e9ddf6f6 ("target/arm: Refactor default generic timer frequency handling") we changed how we initialized the generic timer frequency as reported in the CNTFRQ_EL0 register. As part of that, we chanegd the linux-user version of the CNTFRQ_EL0 sysreg from having a constant value set at compile time through the .resetvalue field to having a reset value which we compute in a .resetfn. This accidentally broke the reading of CNTFRQ_EL0 in linux-user mode, because the cpreg is marked as ARM_CP_CONST, which means we translate it as a read of the compile-time constant value in the .resetvalue field. This is now zero, so userspace sees a 0 frequency value. Fix the bug by dropping the ARM_CP_CONST marking. This will cause us to translate the read as a load of the value from the CPU state struct cp15.c14_cntfrq field, which is where the real frequency value now lives. Cc: qemu-stable@nongnu.org Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3159 Fixes: bd8e9ddf6f6 ("target/arm: Refactor default generic timer frequency h= andling") Signed-off-by: Peter Maydell Reviewed-by: Philippe Mathieu-Daud=C3=A9 Reviewed-by: Richard Henderson Message-id: 20251013161040.216819-1-peter.maydell@linaro.org (cherry picked from commit 3f462d79a080060e54e39d31ce10fdf1a20317ef) Signed-off-by: Michael Tokarev diff --git a/target/arm/helper.c b/target/arm/helper.c index b3ca49a6de..f694b266d9 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -3420,7 +3420,7 @@ static uint64_t gt_virt_cnt_read(CPUARMState *env, co= nst ARMCPRegInfo *ri) 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, - .type =3D ARM_CP_CONST, .access =3D PL0_R /* no PL1_RW in linux-user= */, + .access =3D PL0_R /* no PL1_RW in linux-user */, .fieldoffset =3D offsetof(CPUARMState, cp15.c14_cntfrq), .resetfn =3D arm_gt_cntfrq_reset, }, --=20 2.47.3