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=-4.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 413E8C07E9C for ; Sat, 10 Jul 2021 04:29:22 +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 EC1F4613DC for ; Sat, 10 Jul 2021 04:29:21 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC1F4613DC 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]:49366 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m24cD-0007A2-2J for qemu-devel@archiver.kernel.org; Sat, 10 Jul 2021 00:29:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:48476) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m24ZB-0007sS-Rx for qemu-devel@nongnu.org; Sat, 10 Jul 2021 00:26:13 -0400 Received: from indium.canonical.com ([91.189.90.7]:45362) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m24Z8-0000Xw-GL for qemu-devel@nongnu.org; Sat, 10 Jul 2021 00:26:13 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by indium.canonical.com with esmtp (Exim 4.93 #5 (Debian)) id 1m24Z3-0003mP-F2 for ; Sat, 10 Jul 2021 04:26:05 +0000 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id 21DC82E81D0 for ; Sat, 10 Jul 2021 04:25:59 +0000 (UTC) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Sat, 10 Jul 2021 04:17:25 -0000 From: Launchpad Bug Tracker <1906516@bugs.launchpad.net> To: qemu-devel@nongnu.org X-Launchpad-Notification-Type: bug X-Launchpad-Bug: product=qemu; status=Expired; 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: janitor phantom1003 th-huth X-Launchpad-Bug-Reporter: jinyan (phantom1003) X-Launchpad-Bug-Modifier: Launchpad Janitor (janitor) References: <160691732836.26002.10346003915035160514.malonedeb@chaenomeles.canonical.com> Message-Id: <162589064525.5654.10912649859199189221.malone@loganberry.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="1b66c075b8638845e61f40eb9036fabeaa01f591"; Instance="production" X-Launchpad-Hash: 38ccd9bba79837a28168b079cdff9333e1d8b82d Received-SPF: none client-ip=91.189.90.7; envelope-from=bounces@canonical.com; helo=indium.canonical.com X-Spam_score_int: -68 X-Spam_score: -6.9 X-Spam_bar: ------ X-Spam_report: (-6.9 / 5.0 requ) BAYES_00=-1.9, HEADER_FROM_DIFFERENT_DOMAINS=0.001, RCVD_IN_DNSWL_HI=-5, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, 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" [Expired for QEMU because there has been no activity for 60 days.] ** Changed in: qemu Status: Incomplete =3D> Expired -- = 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: Expired 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