From nobody Fri May 17 07:55:51 2024 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 1695571908508330.28417218336836; Sun, 24 Sep 2023 09:11:48 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qkRhT-0003gV-Hs; Sun, 24 Sep 2023 12:11:15 -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 1qkRhQ-0003fa-5X; Sun, 24 Sep 2023 12:11:12 -0400 Received: from 60-248-80-70.hinet-ip.hinet.net ([60.248.80.70] helo=Atcsqr.andestech.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qkRhK-00042T-Sv; Sun, 24 Sep 2023 12:11:11 -0400 Received: from mail.andestech.com (ATCPCS16.andestech.com [10.0.1.222]) by Atcsqr.andestech.com with ESMTP id 38OGArGE070012; Mon, 25 Sep 2023 00:10:53 +0800 (+08) (envelope-from alvinga@andestech.com) Received: from alvinga-VirtualBox.andestech.com (10.0.13.76) by ATCPCS16.andestech.com (10.0.1.222) with Microsoft SMTP Server id 14.3.498.0; Mon, 25 Sep 2023 00:10:51 +0800 From: Alvin Chang To: , CC: , , Alvin Chang Subject: [PATCH v4] target/riscv: update checks on writing pmpcfg for Smepmp to version 1.0 Date: Mon, 25 Sep 2023 00:10:44 +0800 Message-ID: <20230924161044.1859672-1-alvinga@andestech.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.0.13.76] X-DNSRBL: X-SPAM-SOURCE-CHECK: pass X-MAIL: Atcsqr.andestech.com 38OGArGE070012 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=60.248.80.70; envelope-from=alvinga@andestech.com; helo=Atcsqr.andestech.com X-Spam_score_int: -8 X-Spam_score: -0.9 X-Spam_bar: / X-Spam_report: (-0.9 / 5.0 requ) BAYES_00=-1.9, RDNS_DYNAMIC=0.982, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, TVD_RCVD_IP=0.001 autolearn=no 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1695571910231100001 Content-Type: text/plain; charset="utf-8" Current checks on writing pmpcfg for Smepmp follows Smepmp version 0.9.1. However, Smepmp specification has already been ratified, and there are some differences between version 0.9.1 and 1.0. In this commit we update the checks of writing pmpcfg to follow Smepmp version 1.0. When mseccfg.MML is set, the constraints to modify PMP rules are: 1. Locked rules cannot be removed or modified until a PMP reset, unless mseccfg.RLB is set. 2. From Smepmp specification version 1.0, chapter 2 section 4b: Adding a rule with executable privileges that either is M-mode-only or a locked Shared-Region is not possible and such pmpcfg writes are ignored, leaving pmpcfg unchanged. The commit transfers the value of pmpcfg into the index of the Smepmp truth table, and checks the rules by aforementioned specification changes. Signed-off-by: Alvin Chang --- Changes from v3: Modify "epmp_operation" to "smepmp_operation". Changes from v2: Adopt switch case ranges and numerical order. Changes from v1: Convert ePMP over to Smepmp. target/riscv/pmp.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index a08cd95658..2ebf18c941 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -99,16 +99,40 @@ static void pmp_write_cfg(CPURISCVState *env, uint32_t = pmp_index, uint8_t val) locked =3D false; } =20 - /* mseccfg.MML is set */ - if (MSECCFG_MML_ISSET(env)) { - /* not adding execute bit */ - if ((val & PMP_LOCK) !=3D 0 && (val & PMP_EXEC) !=3D PMP_E= XEC) { + /* + * mseccfg.MML is set. Locked rules cannot be removed or modif= ied + * until a PMP reset. Besides, from Smepmp specification versi= on 1.0 + * , chapter 2 section 4b says: + * Adding a rule with executable privileges that either is + * M-mode-only or a locked Shared-Region is not possible and s= uch + * pmpcfg writes are ignored, leaving pmpcfg unchanged. + */ + if (MSECCFG_MML_ISSET(env) && !pmp_is_locked(env, pmp_index)) { + /* + * Convert the PMP permissions to match the truth table in= the + * Smepmp spec. + */ + const uint8_t smepmp_operation =3D + ((val & PMP_LOCK) >> 4) | ((val & PMP_READ) << 2) | + (val & PMP_WRITE) | ((val & PMP_EXEC) >> 2); + + switch (smepmp_operation) { + case 0 ... 8: locked =3D false; - } - /* shared region and not adding X bit */ - if ((val & PMP_LOCK) !=3D PMP_LOCK && - (val & 0x7) !=3D (PMP_WRITE | PMP_EXEC)) { + break; + case 9 ... 11: + break; + case 12: + locked =3D false; + break; + case 13: + break; + case 14: + case 15: locked =3D false; + break; + default: + g_assert_not_reached(); } } } else { --=20 2.34.1