From patchwork Thu Oct 31 03:52:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alistair Francis X-Patchwork-Id: 13857465 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 E9E03E68950 for ; Thu, 31 Oct 2024 03:57:09 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t6MGe-0000FV-BT; Wed, 30 Oct 2024 23:54:40 -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 1t6MGc-0000Cy-RH for qemu-devel@nongnu.org; Wed, 30 Oct 2024 23:54:38 -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 1t6MGb-0003yr-64 for qemu-devel@nongnu.org; Wed, 30 Oct 2024 23:54:38 -0400 Received: by mail-pl1-x62d.google.com with SMTP id d9443c01a7336-20cbcd71012so5966865ad.3 for ; Wed, 30 Oct 2024 20:54:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1730346876; x=1730951676; 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=3Gfe6gVM/+/x7palaXttLCrMDqCuFk1to10UEThqdZw=; b=DHWCR8iW+b9GKPReoyIUp6vzQy7LUVXOnaCi36RBA/nyls26gDdn1h12Q7jeCByjED s7axk4lu05n8c2ymhRO/AjsPmIq90Ad6gdCwnlhPm/zikk6T7AHBV65w9CJ/KabP0d+Y WLqQBSnAnGvuJZUay2hz9lvf1BxOi5tlhNYQh3HUvQljIICQL9bnEXzfDnZsNzkr5sdo KOcV4t4c8njWppJXQonFI0f/EDsgSDk6ssUkOSCRu4UGOmCk6U4drQbPMJJlPBSjvldm MrsQY8WvppaBlYK/DVI6TkQObnXhB1bykh4d72rRLJjcU3/zruKE3sqxNXC6jAcR8QLv u+hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730346876; x=1730951676; 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=3Gfe6gVM/+/x7palaXttLCrMDqCuFk1to10UEThqdZw=; b=WA/CKtcekfk5iaYcEEyfdWsa3cGML9m2NzwMArCRxuz5ySBDLPbIOqDzqtkzKTtIVi 5H0RfiaOruRDIZK6OZSlo1B8hGH8jOL2U2qkoJ6CIL3kPPo1BRQR6AddES8QW5OGcoFz kLcxz1tJlzamDe0V3TH+uNpFco0lSZ+v0M+Z+ljkRVXSOGcHXqs1c+vJ0kRwScNpIOGX rgfyg4evaYYrab62EoGUCYez5F7Fq+IqLQnGK1JjXYIupu1K4ok/qWDLnxru6jyy81gY iXhV1iiG9/0nClkzxEPGetXS71QCpURmHmrjXAZENRGHMlW2S/2gyE/WlP9I73biKLFr txFA== X-Gm-Message-State: AOJu0YwJ8zLLOBzvYWJuUA90eCq3Z9O/jyiyQoYkVUtD5rZgmYzIgeqE fIwC4NxfVcMJ9rbUpmGRGjaaxnZO0CHgLf3lNHfOEzAhEguGw7fgN4r7pX7V X-Google-Smtp-Source: AGHT+IGbimdxsMvu2j4QqOYMRYFf/wQFpQ/zYg9L27nz8ip80FfEIpBlFF8P2QGKSxI6Gqn9WsFE/g== X-Received: by 2002:a17:903:1106:b0:20c:a498:1e4d with SMTP id d9443c01a7336-210c6cd644dmr210998675ad.60.1730346875607; Wed, 30 Oct 2024 20:54:35 -0700 (PDT) Received: from toolbox.alistair23.me (2403-580b-97e8-0-82ce-f179-8a79-69f4.ip6.aussiebb.net. [2403:580b:97e8:0:82ce:f179:8a79:69f4]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-21105707064sm3022795ad.70.2024.10.30.20.54.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Oct 2024 20:54:35 -0700 (PDT) From: Alistair Francis X-Google-Original-From: Alistair Francis To: qemu-devel@nongnu.org Cc: alistair23@gmail.com, Deepak Gupta , Jim Shu , Andy Chiu , Richard Henderson , Alistair Francis Subject: [PULL 22/50] target/riscv: zicfilp `lpad` impl and branch tracking Date: Thu, 31 Oct 2024 13:52:50 +1000 Message-ID: <20241031035319.731906-23-alistair.francis@wdc.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241031035319.731906-1-alistair.francis@wdc.com> References: <20241031035319.731906-1-alistair.francis@wdc.com> MIME-Version: 1.0 Received-SPF: pass client-ip=2607:f8b0:4864:20::62d; envelope-from=alistair23@gmail.com; helo=mail-pl1-x62d.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 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, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, 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 From: Deepak Gupta Implements setting lp expected when `jalr` is encountered and implements `lpad` instruction of zicfilp. `lpad` instruction is taken out of auipc x0, . This is an existing HINTNOP space. If `lpad` is target of an indirect branch, cpu checks for 20 bit value in x7 upper with 20 bit value embedded in `lpad`. If they don't match, cpu raises a sw check exception with tval = 2. Signed-off-by: Deepak Gupta Co-developed-by: Jim Shu Co-developed-by: Andy Chiu Reviewed-by: Richard Henderson Reviewed-by: Alistair Francis Message-ID: <20241008225010.1861630-8-debug@rivosinc.com> Signed-off-by: Alistair Francis --- target/riscv/cpu_user.h | 1 + target/riscv/insn32.decode | 5 ++- target/riscv/insn_trans/trans_rvi.c.inc | 55 +++++++++++++++++++++++++ 3 files changed, 60 insertions(+), 1 deletion(-) diff --git a/target/riscv/cpu_user.h b/target/riscv/cpu_user.h index 02afad608b..e6927ff847 100644 --- a/target/riscv/cpu_user.h +++ b/target/riscv/cpu_user.h @@ -15,5 +15,6 @@ #define xA6 16 #define xA7 17 /* syscall number for RVI ABI */ #define xT0 5 /* syscall number for RVE ABI */ +#define xT2 7 #endif diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode index c45b8fa1d8..27108b992b 100644 --- a/target/riscv/insn32.decode +++ b/target/riscv/insn32.decode @@ -123,7 +123,10 @@ sfence_vm 0001000 00100 ..... 000 00000 1110011 @sfence_vm # *** RV32I Base Instruction Set *** lui .................... ..... 0110111 @u -auipc .................... ..... 0010111 @u +{ + lpad label:20 00000 0010111 + auipc .................... ..... 0010111 @u +} jal .................... ..... 1101111 @j jalr ............ ..... 000 ..... 1100111 @i beq ....... ..... ..... 000 ..... 1100011 @b diff --git a/target/riscv/insn_trans/trans_rvi.c.inc b/target/riscv/insn_trans/trans_rvi.c.inc index fab5c06719..638fc0fb7b 100644 --- a/target/riscv/insn_trans/trans_rvi.c.inc +++ b/target/riscv/insn_trans/trans_rvi.c.inc @@ -36,6 +36,49 @@ static bool trans_lui(DisasContext *ctx, arg_lui *a) return true; } +static bool trans_lpad(DisasContext *ctx, arg_lpad *a) +{ + /* + * fcfi_lp_expected can set only if fcfi was eanbled. + * translate further only if fcfi_lp_expected set. + * lpad comes from NOP space anyways, so return true if + * fcfi_lp_expected is false. + */ + if (!ctx->fcfi_lp_expected) { + return true; + } + + ctx->fcfi_lp_expected = false; + if ((ctx->base.pc_next) & 0x3) { + /* + * misaligned, according to spec we should raise sw check exception + */ + tcg_gen_st_tl(tcg_constant_tl(RISCV_EXCP_SW_CHECK_FCFI_TVAL), + tcg_env, offsetof(CPURISCVState, sw_check_code)); + gen_helper_raise_exception(tcg_env, + tcg_constant_i32(RISCV_EXCP_SW_CHECK)); + return true; + } + + /* per spec, label check performed only when embedded label non-zero */ + if (a->label != 0) { + TCGLabel *skip = gen_new_label(); + TCGv tmp = tcg_temp_new(); + tcg_gen_extract_tl(tmp, get_gpr(ctx, xT2, EXT_NONE), 12, 20); + tcg_gen_brcondi_tl(TCG_COND_EQ, tmp, a->label, skip); + tcg_gen_st_tl(tcg_constant_tl(RISCV_EXCP_SW_CHECK_FCFI_TVAL), + tcg_env, offsetof(CPURISCVState, sw_check_code)); + gen_helper_raise_exception(tcg_env, + tcg_constant_i32(RISCV_EXCP_SW_CHECK)); + gen_set_label(skip); + } + + tcg_gen_st8_tl(tcg_constant_tl(0), tcg_env, + offsetof(CPURISCVState, elp)); + + return true; +} + static bool trans_auipc(DisasContext *ctx, arg_auipc *a) { TCGv target_pc = dest_gpr(ctx, a->rd); @@ -75,6 +118,18 @@ static bool trans_jalr(DisasContext *ctx, arg_jalr *a) gen_set_gpr(ctx, a->rd, succ_pc); tcg_gen_mov_tl(cpu_pc, target_pc); + if (ctx->fcfi_enabled) { + /* + * return from functions (i.e. rs1 == xRA || rs1 == xT0) are not + * tracked. zicfilp introduces sw guarded branch as well. sw guarded + * branch are not tracked. rs1 == xT2 is a sw guarded branch. + */ + if (a->rs1 != xRA && a->rs1 != xT0 && a->rs1 != xT2) { + tcg_gen_st8_tl(tcg_constant_tl(1), + tcg_env, offsetof(CPURISCVState, elp)); + } + } + lookup_and_goto_ptr(ctx); if (misaligned) {