From patchwork Mon Mar 17 11:16:25 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Akihiko Odaki X-Patchwork-Id: 14018982 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C4862C28B28 for ; Mon, 17 Mar 2025 11:17:54 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tu8Sm-0003IJ-5y; Mon, 17 Mar 2025 07:16:56 -0400 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 1tu8Sf-0003Fu-Sx for qemu-devel@nongnu.org; Mon, 17 Mar 2025 07:16:49 -0400 Received: from mail-pl1-x62d.google.com ([2607:f8b0:4864:20::62d]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tu8Sd-0003me-K8 for qemu-devel@nongnu.org; Mon, 17 Mar 2025 07:16:49 -0400 Received: by mail-pl1-x62d.google.com with SMTP id d9443c01a7336-225e3002dffso36793855ad.1 for ; Mon, 17 Mar 2025 04:16:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=daynix-com.20230601.gappssmtp.com; s=20230601; t=1742210204; x=1742815004; darn=nongnu.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=6CHlSa6FesbaE//XoscZHu5Gz170/KWdbmIiQDcVlS8=; b=tPuzlP2XHWLjIcg+F2raYgEejs0fSOWQF2FLYdymcQA0TskIq73A4JNo6SxEIR0R3k UiX4jUyQOdd3bOkBHlK5b5QkGqT2vpt3fU3LnBtCQRfKnZVXPpOZ3wo0lha3eHA8Gm9s 1cFMdky/DQ0S0dghkuc2WypSLLABr9XbYjFd4Ab1Eju4YON7rv2QF4AXC4yQNt3I4BHq bE4lzu8qshl2vM/Qnrhfs06tU7S9hYNcgJBpDCkThDPwgdFOuJhc5LplTbhu0SNLsf+u pselVTz56BWvsnqcP6/UlegEEy2D1E9pg91xN5p+r6NF+SQmT6qDOgBSAtmpuW+FlYXx gqFQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1742210204; x=1742815004; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=6CHlSa6FesbaE//XoscZHu5Gz170/KWdbmIiQDcVlS8=; b=I8RBMEjcAwcNUGLdASFkPk5cEeyCnHg6X5bcYRNWMjX7kcjx0XJJds2rfhjvd/Yei2 W6R9Ih9kst7sLkC9rG9SJTdgkHsR6QZ8A9RxJ1ZCOVSI044asXK044Y1pUsMURvTuwU8 pY4GzfIR2T2YmvI44JVrn9DQEgM40BVW8QzTWnETlOEBmGggQ2RC/F882TOVE3A3sb5e Cq/S5u4WLQrjS3okeLkD9lzIrnJzlNjVEhDZwdbUE2dm8x1Fncllxv1mAKjkEg5C4qTw +E3tk8cxXwyS4gBP231k12VMIcVpq4woLzQ8x6ZvewczR4OWQzWiF1QG8Km5CY24qUJa 0RwA== X-Gm-Message-State: AOJu0Yyd9AUMccCWKGRHnM5Ltnh88FwePrhwPaMFwUUK3WwWfRryWrn+ J79seANefi898XIzCzJtZwLFyZquyQn0danGW8nIrhn7pf6geiDchbhQds0x00k= X-Gm-Gg: ASbGncsOWATaDrzcCADhDzHjBb9GVxEvWwi6O/EGnKgqyL+1CS3/7f4r/lrG13SZzCJ ntjrALBkvKpiV31FrdQc4jYbZ1XMbh4dK7sFtlEQghnybVHt2E2ecp2ZfKhrsC2MDseC2vXMixc JrhjJHZc2XiKAPR+nibpIAPdGtaWWAw0TyBzZZxJw4IgxH1Ic5sfk23Ys+PiZzxr1cIDfKNX5f2 gNWg+hgltpU+GW+iK33uLhiJtzkNo0WzpHAcsYEsRMiNYg+X7RhkdNQ0C8zv2S45w3ixp2JPZwh jS4n2LDAfjDU7bPeoiVxKbUTSNJWkcIcbDnZFwGnka+yUD58NlKaiGJ3+TQ= X-Google-Smtp-Source: AGHT+IGPbCrjEnD4bLL+I84IN2slw0WD1tr12zA9gmKelzScq0fwZo5lKGnn/4mv5BSlopaEnZDWKQ== X-Received: by 2002:a17:902:ce8f:b0:224:1074:63a7 with SMTP id d9443c01a7336-225e0b0998emr139821925ad.47.1742210204486; Mon, 17 Mar 2025 04:16:44 -0700 (PDT) Received: from localhost ([157.82.207.107]) by smtp.gmail.com with UTF8SMTPSA id d9443c01a7336-225c6bd4d6csm72288065ad.238.2025.03.17.04.16.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 17 Mar 2025 04:16:44 -0700 (PDT) From: Akihiko Odaki Date: Mon, 17 Mar 2025 20:16:25 +0900 Subject: [PATCH 4/4] target/arm: Flag PMCNTENCLR with ARM_CP_NO_RAW MIME-Version: 1.0 Message-Id: <20250317-raw-v1-4-09e2dfff0e90@daynix.com> References: <20250317-raw-v1-0-09e2dfff0e90@daynix.com> In-Reply-To: <20250317-raw-v1-0-09e2dfff0e90@daynix.com> To: qemu-devel@nongnu.org Cc: Peter Maydell , qemu-arm@nongnu.org, devel@daynix.com, Akihiko Odaki X-Mailer: b4 0.15-dev-edae6 Received-SPF: pass client-ip=2607:f8b0:4864:20::62d; envelope-from=akihiko.odaki@daynix.com; helo=mail-pl1-x62d.google.com X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org A normal write to PMCNTENCLR clears written bits so it is not appropriate for writing a raw value. This kind of situation is usually handled by setting a raw write function, but flag the register with ARM_CP_NO_RAW instead to workaround a problem with KVM. KVM also has the same problem with PMINTENSET so add a comment to note that. This register is already flagged with ARM_CP_NO_RAW. Signed-off-by: Akihiko Odaki --- target/arm/helper.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/target/arm/helper.c b/target/arm/helper.c index 2dd8f4d56a1e..ee15132aadea 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -1901,12 +1901,21 @@ static const ARMCPRegInfo v7_cp_reginfo[] = { .accessfn = pmreg_access, .fgt = FGT_PMCNTEN, .writefn = pmcntenclr_write, - .type = ARM_CP_ALIAS | ARM_CP_IO }, + /* + * Flag PMCNTENCLR with ARM_CP_NO_RAW instead of implementing raw + * access to workaround a problem with KVM; KVM applies bit operations + * that prevents writing back raw values since Linux 6.7: + * https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a45f41d754e0b37de4b7dc1fb3c6b7a1285882fc + * + * It is fine to lack raw access with PMCNTENCLR because KVM still + * exposes PMCNTENSET, which shares the underlying state. + */ + .type = ARM_CP_ALIAS | ARM_CP_IO | ARM_CP_NO_RAW }, { .name = "PMCNTENCLR_EL0", .state = ARM_CP_STATE_AA64, .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 2, .access = PL0_RW, .accessfn = pmreg_access, .fgt = FGT_PMCNTEN, - .type = ARM_CP_ALIAS | ARM_CP_IO, + .type = ARM_CP_ALIAS | ARM_CP_IO | ARM_CP_NO_RAW, .fieldoffset = offsetof(CPUARMState, cp15.c9_pmcnten), .writefn = pmcntenclr_write }, { .name = "PMOVSR", .cp = 15, .crn = 9, .crm = 12, .opc1 = 0, .opc2 = 3, @@ -2025,6 +2034,7 @@ static const ARMCPRegInfo v7_cp_reginfo[] = { { .name = "PMINTENCLR", .cp = 15, .crn = 9, .crm = 14, .opc1 = 0, .opc2 = 2, .access = PL1_RW, .accessfn = access_tpm, .fgt = FGT_PMINTEN, + /* Flag PMINTENCLR with ARM_CP_NO_RAW, as with PMCNTENCLR. */ .type = ARM_CP_ALIAS | ARM_CP_IO | ARM_CP_NO_RAW, .fieldoffset = offsetof(CPUARMState, cp15.c9_pminten), .writefn = pmintenclr_write, },