From nobody Sat Nov 15 19:43:36 2025 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 1748175045666292.37328161270455; Sun, 25 May 2025 05:10:45 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uJAB7-0005yD-Qk; Sun, 25 May 2025 08:10:10 -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 1uJA9i-0004Vo-F2; Sun, 25 May 2025 08:08:43 -0400 Received: from isrv.corpit.ru ([86.62.121.231]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uJA9f-0003Db-8k; Sun, 25 May 2025 08:08:40 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id 5DCE0124E4F; Sun, 25 May 2025 15:08:17 +0300 (MSK) Received: from think4mjt.origo (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id 6A73B215FB6; Sun, 25 May 2025 15:08:18 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, =?UTF-8?q?Lo=C3=AFc=20Lefort?= , Daniel Henrique Barboza , LIU Zhiwei , Alistair Francis , Michael Tokarev Subject: [Stable-10.0.1 29/59] target/riscv: pmp: fix checks on writes to pmpcfg in Smepmp MML mode Date: Sun, 25 May 2025 15:07:46 +0300 Message-Id: <20250525120818.273372-6-mjt@tls.msk.ru> X-Mailer: git-send-email 2.39.5 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=86.62.121.231; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_HI=-5, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 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+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1748175047037116600 From: Lo=C3=AFc Lefort With Machine Mode Lockdown (mseccfg.MML) set and RLB not set, checks on pmp= cfg writes would match the wrong cases of Smepmp truth table. The existing code allows writes for the following cases: - L=3D1, X=3D0: cases 8, 10, 12, 14 - L=3D0, RWX!=3DWX: cases 0-2, 4-6 This leaves cases 3, 7, 9, 11, 13, 15 for which writes are ignored. From the Smepmp specification: "Adding a rule with executable privileges th= at either is M-mode-only or a locked Shared-Region is not possible (...)" This description matches cases 9-11, 13 of the truth table. This commit implements an explicit check for these cases by using pmp_get_epmp_operation to convert between PMP configuration and Smepmp truth table cases. Signed-off-by: Lo=C3=AFc Lefort Reviewed-by: Daniel Henrique Barboza Reviewed-by: LIU Zhiwei Message-ID: <20250313193011.720075-4-loic@rivosinc.com> Signed-off-by: Alistair Francis Cc: qemu-stable@nongnu.org (cherry picked from commit 19cf1a7d9e59b71bf8d6571d4747e5c82667c3d1) Signed-off-by: Michael Tokarev diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index 7d65dc24a5..c5f6cdaccb 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -75,6 +75,44 @@ static int pmp_is_readonly(CPURISCVState *env, uint32_t = pmp_index) return pmp_is_locked(env, pmp_index) && !MSECCFG_RLB_ISSET(env); } =20 +/* + * Check whether `val` is an invalid Smepmp config value + */ +static int pmp_is_invalid_smepmp_cfg(CPURISCVState *env, uint8_t val) +{ + /* No check if mseccfg.MML is not set or if mseccfg.RLB is set */ + if (!MSECCFG_MML_ISSET(env) || MSECCFG_RLB_ISSET(env)) { + return 0; + } + + /* + * Adding a rule with executable privileges that either is M-mode-only + * or a locked Shared-Region is not possible + */ + switch (pmp_get_smepmp_operation(val)) { + case 0: + case 1: + case 2: + case 3: + case 4: + case 5: + case 6: + case 7: + case 8: + case 12: + case 14: + case 15: + return 0; + case 9: + case 10: + case 11: + case 13: + return 1; + default: + g_assert_not_reached(); + } +} + /* * Count the number of active rules. */ @@ -103,44 +141,13 @@ static inline uint8_t pmp_read_cfg(CPURISCVState *env= , uint32_t pmp_index) static bool pmp_write_cfg(CPURISCVState *env, uint32_t pmp_index, uint8_t = val) { if (pmp_index < MAX_RISCV_PMPS) { - bool readonly =3D true; - - if (riscv_cpu_cfg(env)->ext_smepmp) { - /* mseccfg.RLB is set */ - if (MSECCFG_RLB_ISSET(env)) { - readonly =3D false; - } - - /* mseccfg.MML is not set */ - if (!MSECCFG_MML_ISSET(env) && !pmp_is_readonly(env, pmp_index= )) { - readonly =3D false; - } - - /* 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) { - readonly =3D false; - } - /* shared region and not adding X bit */ - if ((val & PMP_LOCK) !=3D PMP_LOCK && - (val & 0x7) !=3D (PMP_WRITE | PMP_EXEC)) { - readonly =3D false; - } - } - } else { - readonly =3D pmp_is_readonly(env, pmp_index); - } - - if (readonly) { + if (pmp_is_readonly(env, pmp_index)) { qemu_log_mask(LOG_GUEST_ERROR, "ignoring pmpcfg write - read only\n"); - } else if (env->pmp_state.pmp[pmp_index].cfg_reg !=3D val) { - /* If !mseccfg.MML then ignore writes with encoding RW=3D01 */ - if ((val & PMP_WRITE) && !(val & PMP_READ) && - !MSECCFG_MML_ISSET(env)) { - return false; - } + } else if (pmp_is_invalid_smepmp_cfg(env, val)) { + qemu_log_mask(LOG_GUEST_ERROR, + "ignoring pmpcfg write - invalid\n"); + } else { env->pmp_state.pmp[pmp_index].cfg_reg =3D val; pmp_update_rule_addr(env, pmp_index); return true; --=20 2.39.5