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=-8.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 30297C433B4 for ; Mon, 10 May 2021 04:56:54 +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 D89D5613CE for ; Mon, 10 May 2021 04:56:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D89D5613CE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bugs.launchpad.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58806 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lfxyO-0004yk-Se for qemu-devel@archiver.kernel.org; Mon, 10 May 2021 00:56:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:44384) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lfxxK-0003c8-VQ for qemu-devel@nongnu.org; Mon, 10 May 2021 00:55:46 -0400 Received: from indium.canonical.com ([91.189.90.7]:52468) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lfxxH-00066E-Iv for qemu-devel@nongnu.org; Mon, 10 May 2021 00:55:46 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.93 #5 (Debian)) id 1lfxxF-0001dL-W9 for ; Mon, 10 May 2021 04:55:42 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id F08BB2E8187 for ; Mon, 10 May 2021 04:55:41 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Mon, 10 May 2021 04:46:15 -0000 From: Thomas Huth <1906516@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Incomplete; importance=Undecided; assignee=None; X-Launchpad-Bug-Tags: tcg X-Launchpad-Bug-Information-Type: Public X-Launchpad-Bug-Private: no X-Launchpad-Bug-Security-Vulnerability: no X-Launchpad-Bug-Commenters: phantom1003 th-huth X-Launchpad-Bug-Reporter: jinyan (phantom1003) X-Launchpad-Bug-Modifier: Thomas Huth (th-huth) References: <160691732836.26002.10346003915035160514.malonedeb@chaenomeles.canonical.com> Message-Id: <162062197517.10300.11316562518570049938.malone@chaenomeles.canonical.com> Subject: [Bug 1906516] Re: [RISCV] sfence.vma need to end the translation block X-Launchpad-Message-Rationale: Subscriber (QEMU) @qemu-devel-ml X-Launchpad-Message-For: qemu-devel-ml Precedence: bulk X-Generated-By: Launchpad (canonical.com); Revision="dccd804998035922efb3da0a725ecc923e2255f3"; Instance="production" X-Launchpad-Hash: 004dbe7e47c89bb73e186fb459a9dc06da52dc6b Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -66 X-Spam_score: -6.7 X-Spam_bar: ------ X-Spam_report: (-6.7 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.249, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Bug 1906516 <1906516@bugs.launchpad.net> Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The QEMU project is currently moving its bug tracking to another system. For this we need to know which bugs are still valid and which could be closed already. Thus we are setting the bug state to "Incomplete" now. If the bug has already been fixed in the latest upstream version of QEMU, then please close this ticket as "Fix released". If it is not fixed yet and you think that this bug report here is still valid, then you have two options: 1) If you already have an account on gitlab.com, please open a new ticket for this problem in our new tracker here: https://gitlab.com/qemu-project/qemu/-/issues and then close this ticket here on Launchpad (or let it expire auto- matically after 60 days). Please mention the URL of this bug ticket on Launchpad in the new ticket on GitLab. 2) If you don't have an account on gitlab.com and don't intend to get one, but still would like to keep this ticket opened, then please switch the state back to "New" or "Confirmed" within the next 60 days (other- wise it will get closed as "Expired"). We will then eventually migrate the ticket automatically to the new system (but you won't be the reporter of the bug in the new system and thus you won't get notified on changes anymore). Thank you and sorry for the inconvenience. ** Tags added: tcg ** Changed in: qemu Status: New =3D> Incomplete -- = You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1906516 Title: [RISCV] sfence.vma need to end the translation block Status in QEMU: Incomplete Bug description: QEMU emulator version 5.0.0 sfence.vma will flush the tlb, so after this instruction, the translation= block should be end. The following code will only work in single step mode: ``` relocate: =C2=A0li a0, OFFSET =C2=A0la t0, 1f =C2=A0add t0, t0, a0 =C2=A0csrw stvec, t0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0la t0, early_pgtbl =C2=A0srl t0, t0, PAGE_SHIFT =C2=A0li t1, SATP_SV39 =C2=A0or t0, t1, t0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0csrw satp, t0 1: =C2=A0sfence.vma =C2=A0la t0, trap_s =C2=A0csrw stvec, t0 =C2=A0ret ``` In this code, I want to relocate pc to virtual address with the OFFSET prefix. Before writing to satp, pc run at physic address, stvec has been set to label 1 with a virtual prefix and virtual address has been mapping in early_pgtbl, after writing satp, qemu will throw a page fault, and pc will set to virtual address of label 1. The problem is that, in this situation, the translation block will not end after sfence.vma, and stvec will be set to trap_s, ``` ---------------- IN: Priv: 1; Virt: 0 0x00000000800000dc: 00a080b3 add ra,ra,a0 0x00000000800000e0: 00007297 auipc t0,28672 # = 0x800070e0 0x00000000800000e4: f2028293 addi t0,t0,-224 0x00000000800000e8: 00c2d293 srli t0,t0,12 0x00000000800000ec: fff0031b addiw t1,zero,-1 0x00000000800000f0: 03f31313 slli t1,t1,63 0x00000000800000f4: 005362b3 or t0,t1,t0 0x00000000800000f8: 18029073 csrrw zero,satp,t0 ---------------- IN: Priv: 1; Virt: 0 0x00000000800000fc: 12000073 sfence.vma zero,zero 0x0000000080000100: 00000297 auipc t0,0 # = 0x80000100 0x0000000080000104: 1c828293 addi t0,t0,456 0x0000000080000108: 10529073 csrrw zero,stvec,t0 riscv_raise_exception: 12 riscv_raise_exception: 12 riscv_raise_exception: 12 riscv_raise_exception: 12 ... ``` So, the program will crash, and the program will work in single step mode: ``` ---------------- IN: Priv: 1; Virt: 0 0x00000000800000f8: 18029073 csrrw zero,satp,t0 ---------------- IN: Priv: 1; Virt: 0 0x00000000800000fc: 12000073 sfence.vma zero,zero riscv_raise_exception: 12 ---------------- IN: Priv: 1; Virt: 0 0xffffffff800000fc: 12000073 sfence.vma zero,zero ---------------- IN: Priv: 1; Virt: 0 0xffffffff80000100: 00000297 auipc t0,0 # = 0xffffffff80000100 ``` The pc will set to label 1, instead of trap_s. I try to patch the code in fence.i in trans_rvi.inc.c to sfence.vma: ``` =C2=A0=C2=A0=C2=A0=C2=A0tcg_gen_movi_tl(cpu_pc, ctx->pc_succ_insn); =C2=A0=C2=A0=C2=A0=C2=A0exit_tb(ctx); =C2=A0=C2=A0=C2=A0=C2=A0ctx->base.is_jmp =3D DISAS_NORETURN; ``` This codes can help to end the tranlate block, since I'm not a qemu guy, = I'm not sure if this is a corret method. To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1906516/+subscriptions