From patchwork Tue Nov 21 07:17:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ivan Klokov X-Patchwork-Id: 1866499 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=syntacore.com header.i=@syntacore.com header.a=rsa-sha256 header.s=mta-04 header.b=MplioIrU; dkim=pass (2048-bit key; unprotected) header.d=syntacore.com header.i=@syntacore.com header.a=rsa-sha256 header.s=mta-03 header.b=TYtB53R4; dkim-atps=neutral Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=patchwork.ozlabs.org) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4SZG2t4bJbz1ySS for ; Tue, 21 Nov 2023 18:19:18 +1100 (AEDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1r5L1W-0007Hw-Ud; Tue, 21 Nov 2023 02:18:18 -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 1r5L1S-0007F8-S4; Tue, 21 Nov 2023 02:18:15 -0500 Received: from mta-04.yadro.com ([89.207.88.248]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1r5L1Q-0003jI-BB; Tue, 21 Nov 2023 02:18:14 -0500 DKIM-Filter: OpenDKIM Filter v2.11.0 mta-04.yadro.com 5071AC0002 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=syntacore.com; s=mta-04; t=1700551089; bh=+tm80IOxtZrRk6/aiCijbvq3pGsJG2aqKhn9wVIaYIA=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:From; b=MplioIrU+h2ybygkNrUDiC16SM3ADAy8kFIT74EpEu9cQoceXpqPnvjOM8aTcImOx cFpNaOGWvWYGXv96nio8bmpBOtOB5lAmHmM3g4UK5+CRtZjhgDGxXsh9cjhm83WM13 YZkBIqKpxDWfOd2SqqjgpsvgLjyQKwtmoO/YPd6CXpLwHXCAH7irhCNxY+DCnonWsK ef8GcZDJVekaCg8SX7QMyRuDkhJ4IZKVCMnnukV6JuzzCtMkijPzYX0FcxZz5TIGER S8rl84+IXrXGFXiftYStFDYJLjJ4/eyo3oPBZsmwYWHe9uN92aa+8YGOpQ4Ofc0+V1 /d5SCEXOjJwnA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=syntacore.com; s=mta-03; t=1700551089; bh=+tm80IOxtZrRk6/aiCijbvq3pGsJG2aqKhn9wVIaYIA=; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type:From; b=TYtB53R47hfsRGHGNbdbb0ND+Se2uWrOW31vgfaB+QdxTA/Aaz5GAulOzk6YtuwEr bQtFEin48C4gY7nCfgF9zCiYEDaMJofteFPHc6y8XKa5YhRSghjmj4NuuqUVWlTiDs La0LA4ggsdACqPdK4tHUZ8eUttgPUy2nJ5xK3GQiGsVNNRvPf3/X7LrmAnv7zlxl12 U0TaLS03x7PjcPg8gQOnJnIy0oWqoAy4Bwdamp3ea9hiRBt1cK4h22fj0bHOjyVhsE CMBOclstyGuBAPQjy+Pta3y3ijdEKWStF7DDz8RUmKUuh07td8aclRcr1O6ncwsbvL 6mLLP6e1vD3CA== From: Ivan Klokov To: CC: , , , , , , , Ivan Klokov Subject: [PATCH v2 2/2] target/riscv/cpu_helper.c: Fix mxr bit behavior Date: Tue, 21 Nov 2023 10:17:57 +0300 Message-ID: <20231121071757.7178-3-ivan.klokov@syntacore.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231121071757.7178-1-ivan.klokov@syntacore.com> References: <20231121071757.7178-1-ivan.klokov@syntacore.com> MIME-Version: 1.0 X-ClientProxiedBy: T-EXCH-08.corp.yadro.com (172.17.11.58) To S-Exch-01.corp.yadro.com (10.78.5.241) Received-SPF: permerror client-ip=89.207.88.248; envelope-from=ivan.klokov@syntacore.com; helo=mta-04.yadro.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, T_SCC_BODY_TEXT_LINE=-0.01, T_SPF_PERMERROR=0.01 autolearn=ham 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+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org According to RISCV Specification sect 9.5 on two stage translation when V=1 the vsstatus(mstatus in QEMU's terms) field MXR, which makes execute-only pages readable, only overrides VS-stage page protection. Setting MXR at HS-level(mstatus_hs), however, overrides both VS-stage and G-stage execute-only permissions. The hypervisor extension changes the behavior of MXR\MPV\MPRV bits. Due to RISCV Specification sect. 9.4.1 when MPRV=1, explicit memory accesses are translated and protected, and endianness is applied, as though the current virtualization mode were set to MPV and the current nominal privilege mode were set to MPP. vsstatus.MXR makes readable those pages marked executable at the VS translation stage. Fixes: 36a18664ba ("target/riscv: Implement second stage MMU") Signed-off-by: Ivan Klokov Reviewed-by: Daniel Henrique Barboza Reviewed-by: Alistair Francis --- target/riscv/cpu_helper.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 9ff0952e46..e7e23b34f4 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -1032,13 +1032,29 @@ restart: prot |= PAGE_WRITE; } if (pte & PTE_X) { - bool mxr; + bool mxr = false; - if (first_stage == true) { + /* + * Use mstatus for first stage or for the second stage without + * virt_enabled (MPRV+MPV) + */ + if (first_stage || !env->virt_enabled) { mxr = get_field(env->mstatus, MSTATUS_MXR); - } else { - mxr = get_field(env->vsstatus, MSTATUS_MXR); } + + /* MPRV+MPV case, check VSSTATUS */ + if (first_stage && two_stage && !env->virt_enabled) { + mxr |= get_field(env->vsstatus, MSTATUS_MXR); + } + + /* + * Setting MXR at HS-level overrides both VS-stage and G-stage + * execute-only permissions + */ + if (env->virt_enabled) { + mxr |= get_field(env->mstatus_hs, MSTATUS_MXR); + } + if (mxr) { prot |= PAGE_READ; }