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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0A02C33CAF for ; Mon, 20 Jan 2020 00:32:42 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 7A8B120678 for ; Mon, 20 Jan 2020 00:32:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ejBObqip" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A8B120678 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:55726 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itKzh-0000v4-KD for qemu-devel@archiver.kernel.org; Sun, 19 Jan 2020 19:32:41 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:36060) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1itKz6-0000KP-4i for qemu-devel@nongnu.org; Sun, 19 Jan 2020 19:32:05 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1itKz4-0001XY-Ru for qemu-devel@nongnu.org; Sun, 19 Jan 2020 19:32:04 -0500 Received: from mail-lj1-x243.google.com ([2a00:1450:4864:20::243]:42332) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1itKz4-0001Wv-L4; Sun, 19 Jan 2020 19:32:02 -0500 Received: by mail-lj1-x243.google.com with SMTP id y4so31998236ljj.9; Sun, 19 Jan 2020 16:32:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RmMqJrBOHe/Q6dl3NvKH6ZqysU0tMXFP4wNB72lxUak=; b=ejBObqipHnJeBwVKO8A0Qxhj26xaDtSk5mllczuFxJ6bH8hy0n9z2CR0UGuO32RW8G cNR3Jrc/x3fgbkmgsq7LJuqUcrtdiGPkGT4Dk9ToVbNC/BSxa8TDKhhM0pjVUj/ttgEY WWEcl8ug6dspJl8aKC2Y6ppW2KELluqag+nayAW15Ywnk43iQixLZaRk2BlPf50+UmJP LIlsrTPBy77o1L/m772GTFufw6qeIt+4HWcWVLXjO/4Csk7bp3HWBZujyZQzd2xAWzmF 46SaZzvvOe7JgPcYKdATSJXWmYCVbwXhsnId+pdyKP0YzeRuSwMj2yyQ/gxuYk4WwnFw 3K4A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RmMqJrBOHe/Q6dl3NvKH6ZqysU0tMXFP4wNB72lxUak=; b=dQYc5nXXmFeHmscawf69k1kjkjW9MbohBq97/tQTPslr2d/bm43U8x7jkfcISn+Z5q JKumZ+rfiRp3DdHLJObiZ50DLlJIQeGGCTB/wDBwyvDDHQrWlJAhe6liJW2O6k+H5Hzb 5ks9ydT6EOZ9w2MEV0FMpHdFMdtEY77FaRlsJQZts9oq3ytMP/PkI2TaOIV4mGKiSmHw 5gqB0E5GGbqo9XNdJn3sa/2uEp8zar1u4PTMfpmEbd+bo7pHsE5CSr8FfgU1FWjs22xB YdOe8Qi80MSlke26xKV/bzIZrdEsD4T5xfjjFbnYc4jG00mwj915s22aXVnUolyzmNes Z03g== X-Gm-Message-State: APjAAAWCm9Tm6KNNIDUZgxBDSQ1SpvFgkmk7Pv8AWsTuijWHiWfFDzFg tvbHUqs4M1kSvjsQzw4Z8JQB3NHQYjD9FC0wez0= X-Google-Smtp-Source: APXvYqwdI2GF5LljLjWCzvIUotTwMq3HbLZBStbBeyL3q/4lLHDGeYTTRqUcKRgazawTEkJZWyOE7VBg4hTZ8T9nqW4= X-Received: by 2002:a2e:461a:: with SMTP id t26mr11762156lja.204.1579480320636; Sun, 19 Jan 2020 16:32:00 -0800 (PST) MIME-Version: 1.0 References: <5cc26abb98a9534720f09674b4b9caafb8f2cf0a.1566573576.git.alistair.francis@wdc.com> <20200105163640.GA1752551@aurel32.net> <20200105165916.GA1834646@aurel32.net> In-Reply-To: <20200105165916.GA1834646@aurel32.net> From: Alistair Francis Date: Mon, 20 Jan 2020 10:31:33 +1000 Message-ID: Subject: Re: [Qemu-devel] [PATCH v4 3/7] target/riscv: Create function to test if FP is enabled To: Aurelien Jarno Content-Type: text/plain; charset="UTF-8" X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2a00:1450:4864:20::243 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: "open list:RISC-V" , Palmer Dabbelt , Alistair Francis , "qemu-devel@nongnu.org Developers" , Bin Meng Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Jan 6, 2020 at 2:59 AM Aurelien Jarno wrote: > > On 2020-01-05 17:36, Aurelien Jarno wrote: > > > diff --git a/target/riscv/csr.c b/target/riscv/csr.c > > > index e0d4586760..2789215b5e 100644 > > > --- a/target/riscv/csr.c > > > +++ b/target/riscv/csr.c > > > > [ snip ] > > > > > @@ -307,6 +307,7 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val) > > > { > > > target_ulong mstatus = env->mstatus; > > > target_ulong mask = 0; > > > + int dirty; > > > > > > /* flush tlb on mstatus fields that affect VM */ > > > if (env->priv_ver <= PRIV_VERSION_1_09_1) { > > > @@ -340,8 +341,9 @@ static int write_mstatus(CPURISCVState *env, int csrno, target_ulong val) > > > > > > mstatus = (mstatus & ~mask) | (val & mask); > > > > > > - int dirty = ((mstatus & MSTATUS_FS) == MSTATUS_FS) | > > > - ((mstatus & MSTATUS_XS) == MSTATUS_XS); > > > + dirty = (riscv_cpu_fp_enabled(env) && > > > + ((mstatus & MSTATUS_FS) == MSTATUS_FS)) | > > > + ((mstatus & MSTATUS_XS) == MSTATUS_XS); > > > mstatus = set_field(mstatus, MSTATUS_SD, dirty); > > > env->mstatus = mstatus; > > > > This patch, and more precisely the above two hunks broke > > qemu-system-riscv64. More precisely, when running a Debian sid system > > inside QEMU, sshd hangs during key exchange. > > The problem is that at this stage, mstatus != env->status. Prior to that > patch, dirty was computed exclusively on the new mstatus status, after > the update by val. With this patch, riscv_cpu_fp_enabled() refers to the > old value of mstatus. Therefore when FS is changed from "Off" (FS = 00) > to "Dirty" (FS == 11), the SD bit is not set. Thanks for reporting this! Can you try this branch (it should be a PR to mainline QEMU soon) and let me know if that fixes the issue? https://github.com/palmer-dabbelt/qemu/commits/for-master Alistair > > -- > Aurelien Jarno GPG: 4096R/1DDD8C9B > aurelien@aurel32.net http://www.aurel32.net