From mboxrd@z Thu Jan 1 00:00:00 1970 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 C82CAD3C935 for ; Mon, 21 Oct 2024 00:58:04 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t2gjK-0005f0-Sp; Sun, 20 Oct 2024 20:57:06 -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 1t2gjH-0005eX-NO; Sun, 20 Oct 2024 20:57:03 -0400 Received: from mail-vk1-xa29.google.com ([2607:f8b0:4864:20::a29]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1t2gjG-000339-1l; Sun, 20 Oct 2024 20:57:03 -0400 Received: by mail-vk1-xa29.google.com with SMTP id 71dfb90a1353d-50d3998923dso1227809e0c.2; Sun, 20 Oct 2024 17:57:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1729472220; x=1730077020; darn=nongnu.org; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=2mvEeq9NpxqfN3oL3affbuyazFTgTYYEvefC/JYTKrg=; b=B2I2hJgPa6sM9uRQeT92J2EfeGsn/rO8exeI6Y1bfxm0nhON8zTL9NnTDIQWEaKW4M DtsOp66G5WKA7A4XC74YMxH+ZHWgEc7gYNyjGiIx9Gf7o+N87vo9oc2HYI1l6SdQx9uv /EuB68hqKAqvJa7YEI08K4coXHTpVkW6vMI0v2ll4Xv+kEKA4uUCD5aGCgW1mqgb5qYW n/pmCtW0+7P21nJjF4vOLM/S7S7A3xpINQPSqQgOmcuy6YpGQJC9aUqE7i8xm7AWt58M M22yUB3eDwQTmGapHeMNKfpGadOZ6NSZbnMlIisZbgaC/ForWTvuN8V2EzmKnfsCsjw1 WrWg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1729472220; x=1730077020; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=2mvEeq9NpxqfN3oL3affbuyazFTgTYYEvefC/JYTKrg=; b=S85uSFY4QQjZSfKNu5OeaKYa/d4pAOShIoN3AdvpGhb8vKGq6RQ6FH/CpjDIEf1aPF SsKbWcNd5mxiamxBJA/Ir58L7niSHLK/893uZdaX7oQlvXN/z96o+X1EjpuUbxuLpfbN pepqItjBO+LoD4MMIHvUjXlj56aZPrNE1y+SN4Oj2px5QZc4gw239zwQemMe1h8Nzcif ZrXtN16TQkyyMU7YLl1pcdWe3gJ7DPsg1QqZp8NaKppNOH4xG7Sbhl1dEvNaRIDXaKy6 w1vHwXWSgrQkeYyOU44xA/UvS3Lb10c7wtCzkW8qIEdzKPwsDcznDu0yvZXGaDxRXv9F 5nDQ== X-Forwarded-Encrypted: i=1; AJvYcCWj7FvgXr4w4J6ktxd0m9TEM0PP5OjIXEhC3X33ywLBrTnb6woWjg8E2vNP6trgE/1pNs53mmPY2kJ4@nongnu.org X-Gm-Message-State: AOJu0YwAJZl0eWz55e26Zi+QbmExyE8blKumsvhdPvZqlpCAZS3DuJJ9 h7GEQL3RVnJ2Q6FnoSxw1QVjD9xyK74swDqNN+QEModj3Ey3NJXiQ+kKLZJdkFb9PQlMX+3bhwD BcAL5hWLFEr3JrCbhsWnWMx3GSxw= X-Google-Smtp-Source: AGHT+IHYpmnhj5zgZIoCi6TqO05wFN7RBZR5I6JDObltfKMcMuUqPewHAlzMIZMRNCJK2FdPlqmojeS4OVSF65S46sU= X-Received: by 2002:a05:6122:4584:b0:50c:eb10:9799 with SMTP id 71dfb90a1353d-50dda029213mr6277696e0c.1.1729472220680; Sun, 20 Oct 2024 17:57:00 -0700 (PDT) MIME-Version: 1.0 References: <20241017145226.365825-1-cleger@rivosinc.com> <20241017145226.365825-4-cleger@rivosinc.com> In-Reply-To: <20241017145226.365825-4-cleger@rivosinc.com> From: Alistair Francis Date: Mon, 21 Oct 2024 10:56:34 +1000 Message-ID: Subject: Re: [PATCH v4 3/9] target/riscv: Implement Ssdbltrp sret, mret and mnret behavior To: =?UTF-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= Cc: qemu-riscv@nongnu.org, Palmer Dabbelt , Alistair Francis , Bin Meng , Weiwei Li , Daniel Henrique Barboza , Liu Zhiwei , Ved Shanbhogue , Atish Patra , qemu-devel@nongnu.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass client-ip=2607:f8b0:4864:20::a29; envelope-from=alistair23@gmail.com; helo=mail-vk1-xa29.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 On Fri, Oct 18, 2024 at 12:53=E2=80=AFAM Cl=C3=A9ment L=C3=A9ger wrote: > > When the Ssdbltrp extension is enabled, SSTATUS.SDT field is cleared > when executing sret. When executing mret/mnret, SSTATUS.SDT is cleared > when returning to U, VS or VU and VSSTATUS.SDT is cleared when returning > to VU from HS. > > Signed-off-by: Cl=C3=A9ment L=C3=A9ger Reviewed-by: Alistair Francis Alistair > --- > target/riscv/op_helper.c | 35 ++++++++++++++++++++++++++++++++++- > 1 file changed, 34 insertions(+), 1 deletion(-) > > diff --git a/target/riscv/op_helper.c b/target/riscv/op_helper.c > index 180886f32a..dabc74de39 100644 > --- a/target/riscv/op_helper.c > +++ b/target/riscv/op_helper.c > @@ -287,6 +287,18 @@ target_ulong helper_sret(CPURISCVState *env) > get_field(mstatus, MSTATUS_SPIE)); > mstatus =3D set_field(mstatus, MSTATUS_SPIE, 1); > mstatus =3D set_field(mstatus, MSTATUS_SPP, PRV_U); > + > + if (riscv_cpu_cfg(env)->ext_ssdbltrp) { > + if (riscv_has_ext(env, RVH)) { > + target_ulong prev_vu =3D get_field(env->hstatus, HSTATUS_SPV= ) && > + prev_priv =3D=3D PRV_U; > + /* Returning to VU from HS, vsstatus.sdt =3D 0 */ > + if (!env->virt_enabled && prev_vu) { > + env->vsstatus =3D set_field(env->vsstatus, MSTATUS_SDT, = 0); > + } > + } > + mstatus =3D set_field(mstatus, MSTATUS_SDT, 0); > + } > if (env->priv_ver >=3D PRIV_VERSION_1_12_0) { > mstatus =3D set_field(mstatus, MSTATUS_MPRV, 0); > } > @@ -297,7 +309,6 @@ target_ulong helper_sret(CPURISCVState *env) > target_ulong hstatus =3D env->hstatus; > > prev_virt =3D get_field(hstatus, HSTATUS_SPV); > - > hstatus =3D set_field(hstatus, HSTATUS_SPV, 0); > > env->hstatus =3D hstatus; > @@ -328,6 +339,22 @@ static void check_ret_from_m_mode(CPURISCVState *env= , target_ulong retpc, > riscv_raise_exception(env, RISCV_EXCP_INST_ACCESS_FAULT, GETPC()= ); > } > } > +static target_ulong ssdbltrp_mxret(CPURISCVState *env, target_ulong msta= tus, > + target_ulong prev_priv, > + target_ulong prev_virt) > +{ > + /* If returning to U, VS or VU, sstatus.sdt =3D 0 */ > + if (prev_priv =3D=3D PRV_U || (prev_virt && > + (prev_priv =3D=3D PRV_S || prev_priv =3D=3D PRV_U))) { > + mstatus =3D set_field(mstatus, MSTATUS_SDT, 0); > + /* If returning to VU, vsstatus.sdt =3D 0 */ > + if (prev_virt && prev_priv =3D=3D PRV_U) { > + env->vsstatus =3D set_field(env->vsstatus, MSTATUS_SDT, 0); > + } > + } > + > + return mstatus; > +} > > target_ulong helper_mret(CPURISCVState *env) > { > @@ -345,6 +372,9 @@ target_ulong helper_mret(CPURISCVState *env) > mstatus =3D set_field(mstatus, MSTATUS_MPP, > riscv_has_ext(env, RVU) ? PRV_U : PRV_M); > mstatus =3D set_field(mstatus, MSTATUS_MPV, 0); > + if (riscv_cpu_cfg(env)->ext_ssdbltrp) { > + mstatus =3D ssdbltrp_mxret(env, mstatus, prev_priv, prev_virt); > + } > if ((env->priv_ver >=3D PRIV_VERSION_1_12_0) && (prev_priv !=3D PRV_= M)) { > mstatus =3D set_field(mstatus, MSTATUS_MPRV, 0); > } > @@ -378,6 +408,9 @@ target_ulong helper_mnret(CPURISCVState *env) > if (prev_priv < PRV_M) { > env->mstatus =3D set_field(env->mstatus, MSTATUS_MPRV, false); > } > + if (riscv_cpu_cfg(env)->ext_ssdbltrp) { > + env->mstatus =3D ssdbltrp_mxret(env, env->mstatus, prev_priv, pr= ev_virt); > + } > > if (riscv_has_ext(env, RVH) && prev_virt) { > riscv_cpu_swap_hypervisor_regs(env); > -- > 2.45.2 > >