From patchwork Wed Aug 7 00:06:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Deepak Gupta X-Patchwork-Id: 13755527 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 B08C0C49EA1 for ; Wed, 7 Aug 2024 00:09:31 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sbUDA-0003KL-I7; Tue, 06 Aug 2024 20:07:28 -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 1sbUCn-0002YV-5C for qemu-devel@nongnu.org; Tue, 06 Aug 2024 20:07:06 -0400 Received: from mail-pl1-x629.google.com ([2607:f8b0:4864:20::629]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sbUCl-00017z-1e for qemu-devel@nongnu.org; Tue, 06 Aug 2024 20:07:04 -0400 Received: by mail-pl1-x629.google.com with SMTP id d9443c01a7336-1fd90c2fc68so11856625ad.1 for ; Tue, 06 Aug 2024 17:07:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1722989221; x=1723594021; darn=nongnu.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=svo4LPG7r850nEYgZiVRG+jHhd5cukzMD7ExuHKhohU=; b=Wgpvq1xz7qAZ+af1ovAzY5X0c5l4zrQ2Byroqh6J2FdWVtvSeO3urqWEb4mZnC7oq3 jP6mvzftc0av5b3x3GwtjI/nwi/CnHD6bINvA82aNK9CRou/5OHqHzeWPb+DzaEfl2wO uwo8KcDvygfQwZaLQonDac5Ja/FF+PGU+0NMRrZo1YdMOt1ZDd7qj13ynN7YcQl9q6sV yMDYzocqnKZRbbFsJDDYKftsn1NWz7PJHlV/0xSHG6ZAU0My2k83WevrZFLHGFoJ6tPp tY2gmwn2aUK6ILTWOf3xNTMdJ7Vxydi/QBJ0GA+LySVgKkZm6OnJXBPmnghYhBNy4GXq SiTg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1722989221; x=1723594021; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=svo4LPG7r850nEYgZiVRG+jHhd5cukzMD7ExuHKhohU=; b=HKAmibgtjaOAB/RFBk+oqcnjdhW5XcmE6qcaO+u8g5tDnY4+yNi21POao8bHe/HJH+ cGhSwhVqZUvz3qfnMG3/hp9b7+cXGortwhqNLZDLJq642X8K5IsXWNNCvJzpoYVMxNEr k9XWV+wlZ3xtquPp1L6xS9GP9rB6/bqE4jrjV61ccGWLCwKkFS7W2ic74RqZ2JVOt2e7 Ts7wop9AchZoE+hJBbUVyuJlcbBBBEImqcW/Ag1uHPTY1C/bN3/FwIOgWc7mnXdSD4e4 u6K6mK/VJwMIXAIlr/n1zj/pZWb+QZjg760ujM2Iz0YmerD/d/TLWSPb6DTqY06cpohi Y/gg== X-Gm-Message-State: AOJu0Yxvu0YEXcCIAA7kpjBbydNcCR41Eo/2VXI3L135o+zCozfyAekg B5ixHUBPDgPTFH/exGMBNm6aUPGsaseuOljxs2/6yKMguTZBaYo67jOtfWeJHoy+MkRh/HHvJPf w X-Google-Smtp-Source: AGHT+IF03lP5QJ41skWd759etF1SIbqvcnJHu7CDz4o1hqof9i+UAPVNcU/dGlfRbtE5Ix3cIesANQ== X-Received: by 2002:a17:903:32ce:b0:1fb:8cab:ccc9 with SMTP id d9443c01a7336-1ff573cca00mr160609285ad.45.1722989221321; Tue, 06 Aug 2024 17:07:01 -0700 (PDT) Received: from debug.ba.rivosinc.com ([64.71.180.162]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1ff58f59cc2sm93381845ad.92.2024.08.06.17.07.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Aug 2024 17:07:01 -0700 (PDT) From: Deepak Gupta To: qemu-devel@nongnu.org, qemu-riscv@nongnu.org Cc: richard.henderson@linaro.org, pbonzini@redhat.com, palmer@dabbelt.com, Alistair.Francis@wdc.com, laurent@vivier.eu, bmeng.cn@gmail.com, liwei1518@gmail.com, dbarboza@ventanamicro.com, zhiwei_liu@linux.alibaba.com, Deepak Gupta , Jim Shu , Andy Chiu Subject: [PATCH v3 04/20] target/riscv: save and restore elp state on priv transitions Date: Tue, 6 Aug 2024 17:06:35 -0700 Message-ID: <20240807000652.1417776-5-debug@rivosinc.com> X-Mailer: git-send-email 2.45.0 In-Reply-To: <20240807000652.1417776-1-debug@rivosinc.com> References: <20240807000652.1417776-1-debug@rivosinc.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::629; envelope-from=debug@rivosinc.com; helo=mail-pl1-x629.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=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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org elp state is recorded in *status on trap entry (less privilege to higher privilege) and restored in elp from *status on trap exit (higher to less privilege). Additionally this patch introduces a forward cfi helper function to determine if current privilege has forward cfi is enabled or not based on *envcfg (for U, VU, S, VU, HS) or mseccfg csr (for M). For qemu-user, a new field `ufcfien` is introduced which is by default set to false and helper function returns value deposited in `ufcfien` for qemu-user. Signed-off-by: Deepak Gupta Co-developed-by: Jim Shu Co-developed-by: Andy Chiu --- target/riscv/cpu.c | 5 ++++ target/riscv/cpu.h | 2 ++ target/riscv/cpu_helper.c | 58 +++++++++++++++++++++++++++++++++++++++ target/riscv/op_helper.c | 18 ++++++++++++ 4 files changed, 83 insertions(+) diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c index 82fa85a8d6..e1526c7ab5 100644 --- a/target/riscv/cpu.c +++ b/target/riscv/cpu.c @@ -1022,6 +1022,11 @@ static void riscv_cpu_reset_hold(Object *obj, ResetType type) env->load_res = -1; set_default_nan_mode(1, &env->fp_status); +#ifdef CONFIG_USER_ONLY + /* qemu-user for riscv, fcfi is off by default */ + env->ufcfien = false; +#endif + #ifndef CONFIG_USER_ONLY if (cpu->cfg.debug) { riscv_trigger_reset_hold(env); diff --git a/target/riscv/cpu.h b/target/riscv/cpu.h index ae436a3179..8c7841fc08 100644 --- a/target/riscv/cpu.h +++ b/target/riscv/cpu.h @@ -226,6 +226,7 @@ struct CPUArchState { cfi_elp elp; #ifdef CONFIG_USER_ONLY uint32_t elf_flags; + bool ufcfien; #endif #ifndef CONFIG_USER_ONLY @@ -530,6 +531,7 @@ void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen); bool riscv_cpu_vector_enabled(CPURISCVState *env); void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable); int riscv_env_mmu_index(CPURISCVState *env, bool ifetch); +bool cpu_get_fcfien(CPURISCVState *env); G_NORETURN void riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr, MMUAccessType access_type, int mmu_idx, uintptr_t retaddr); diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 6709622dd3..8c69c55576 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -33,6 +33,7 @@ #include "cpu_bits.h" #include "debug.h" #include "tcg/oversized-guest.h" +#include "pmp.h" int riscv_env_mmu_index(CPURISCVState *env, bool ifetch) { @@ -63,6 +64,35 @@ int riscv_env_mmu_index(CPURISCVState *env, bool ifetch) #endif } +bool cpu_get_fcfien(CPURISCVState *env) +{ +#ifdef CONFIG_USER_ONLY + return env->ufcfien; +#else + /* no cfi extension, return false */ + if (!env_archcpu(env)->cfg.ext_zicfilp) { + return false; + } + + switch (env->priv) { + case PRV_U: + if (riscv_has_ext(env, RVS)) { + return env->senvcfg & MENVCFG_LPE; + } + return env->menvcfg & MENVCFG_LPE; + case PRV_S: + if (env->virt_enabled) { + return env->henvcfg & HENVCFG_LPE; + } + return env->menvcfg & MENVCFG_LPE; + case PRV_M: + return env->mseccfg & MSECCFG_MLPE; + default: + g_assert_not_reached(); + } +#endif +} + void cpu_get_tb_cpu_state(CPURISCVState *env, vaddr *pc, uint64_t *cs_base, uint32_t *pflags) { @@ -546,6 +576,15 @@ void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env) } bool current_virt = env->virt_enabled; + /* + * If zicfilp extension available and henvcfg.LPE = 1, + * then apply SPELP mask on mstatus + */ + if (env_archcpu(env)->cfg.ext_zicfilp && + get_field(env->henvcfg, HENVCFG_LPE)) { + mstatus_mask |= SSTATUS_SPELP; + } + g_assert(riscv_has_ext(env, RVH)); if (current_virt) { @@ -1754,6 +1793,11 @@ void riscv_cpu_do_interrupt(CPUState *cs) if (env->priv <= PRV_S && cause < 64 && (((deleg >> cause) & 1) || s_injected || vs_injected)) { /* handle the trap in S-mode */ + /* save elp status */ + if (cpu_get_fcfien(env)) { + env->mstatus = set_field(env->mstatus, MSTATUS_SPELP, env->elp); + } + if (riscv_has_ext(env, RVH)) { uint64_t hdeleg = async ? env->hideleg : env->hedeleg; @@ -1802,6 +1846,11 @@ void riscv_cpu_do_interrupt(CPUState *cs) riscv_cpu_set_mode(env, PRV_S); } else { /* handle the trap in M-mode */ + /* save elp status */ + if (cpu_get_fcfien(env)) { + env->mstatus = set_field(env->mstatus, MSTATUS_MPELP, env->elp); + } + if (riscv_has_ext(env, RVH)) { if (env->virt_enabled) { riscv_cpu_swap_hypervisor_regs(env); @@ -1833,6 +1882,15 @@ void riscv_cpu_do_interrupt(CPUState *cs) riscv_cpu_set_mode(env, PRV_M); } + /* + * Interrupt/exception/trap delivery is asynchronous event and as per + * Zisslpcfi spec CPU should clear up the ELP state. If cfi extension is + * available, clear ELP state. + */ + + if (cpu->cfg.ext_zicfilp) { + env->elp = NO_LP_EXPECTED; + } /* * NOTE: it is not necessary to yield load reservations here. It is only * necessary for an SC from "another hart" to cause a load reservation diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c index 2baf5bc3ca..488116cc2e 100644 --- a/target/riscv/op_helper.c +++ b/target/riscv/op_helper.c @@ -313,6 +313,15 @@ target_ulong helper_sret(CPURISCVState *env) riscv_cpu_set_mode(env, prev_priv); + /* + * If forward cfi enabled for new priv, restore elp status + * and clear spelp in mstatus + */ + if (cpu_get_fcfien(env)) { + env->elp = get_field(env->mstatus, MSTATUS_SPELP); + env->mstatus = set_field(env->mstatus, MSTATUS_SPELP, 0); + } + return retpc; } @@ -357,6 +366,15 @@ target_ulong helper_mret(CPURISCVState *env) riscv_cpu_set_virt_enabled(env, prev_virt); } + /* + * If forward cfi enabled for new priv, restore elp status + * and clear mpelp in mstatus + */ + if (cpu_get_fcfien(env)) { + env->elp = get_field(env->mstatus, MSTATUS_MPELP); + env->mstatus = set_field(env->mstatus, MSTATUS_MPELP, 0); + } + return retpc; }