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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DBF2C433EF for ; Thu, 20 Jan 2022 10:06:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359722AbiATKGF (ORCPT ); Thu, 20 Jan 2022 05:06:05 -0500 Received: from smtp-relay-internal-0.canonical.com ([185.125.188.122]:40074 "EHLO smtp-relay-internal-0.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238429AbiATKGD (ORCPT ); Thu, 20 Jan 2022 05:06:03 -0500 Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-0.canonical.com (Postfix) with ESMTPS id C96F140049 for ; Thu, 20 Jan 2022 10:05:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1642673157; bh=w26SyRlRb1I1H6K/gmJqzdX3K4fWh5zNRWtuBCu0Vhg=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=e6hXJ0IeM+a3TZvnftPzACQUC/BTo148mKyEaRzmMMatFoA204htx69CQOI3YB5OO sriUGwnpfgmuijm7iGKzVu9gsZXNszndfh7JcmME+dZHAkCqlJjY+s2SY/j8b0RfAM y5tigLyYcUgxXDLPupnKq/7rUCSt/dWuGzLB/VgcvHVAkGEV50ulXl+qUPlZvTqVW7 Yih4CcfKH1m9RXvM5LhOQkubPZDw5xfyLw3jI+jFlwKAhqXqrlZZoPWTIIrs+REZVe y1OsmlSegpYeq51n6Z86bERKNT0XGQUqnsLme9MAbJtafug0lyRkA6CjzJjACCXmtq W6twBPcAijYVA== Received: by mail-ed1-f72.google.com with SMTP id p17-20020aa7c891000000b004052d1936a5so1088701eds.7 for ; Thu, 20 Jan 2022 02:05:57 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=w26SyRlRb1I1H6K/gmJqzdX3K4fWh5zNRWtuBCu0Vhg=; b=ku44nzDbg9NxfX7Yx2Udt6voXANUdVYuITgskhNXMya6tPxUVt0n6vSUSYiRrD0/kD WjPGLGWgJy/E0kwvYr/+3DhdETguWXBZ17iTX+XKpB3lJtXA4vXWrl1iuAXNxVmGjcgT eiFxg3LrU965PndIn7piCJG8uzL3NAKXUDK/ypy8tWqcCMEu4F3cfP0TqwUn6AsQtT+i 3NGCIbfmNfc7Pt4PUjf4/+X5bAu3Scqx889AkLxlJ9wmZeiQWFT7KjFrD79cF1GJZAs3 lU0ZcyMSy7irPA3Z9bRcxHDjXjUlu5SE9IHXIccZv0U2gooZWJnf6ayOi38xDqUgtRAv oRIg== X-Gm-Message-State: AOAM530bVA/6EAGDpZKF7KI970H4WkNXHdsHBQ1iAr3oIV0jTpv8QCpG G54/d1fb5LkWvYtWDA4U/qB6IGAr/1RGXsh4KF7mv19OZ9iVc05eF+dOXZhd8gsprpvLK1nXjna Bc2OKr6wElhZwKBqeYJjK5oecMTBsv5yyjfkNHgyms05tJm5LwzhBm+funw== X-Received: by 2002:a05:6402:b33:: with SMTP id bo19mr7643840edb.70.1642673157480; Thu, 20 Jan 2022 02:05:57 -0800 (PST) X-Google-Smtp-Source: ABdhPJynv0ocn7NF6vgUdF1oJY52IvmBizAszTcAGapgjCakCzI58Vihpn2W5C5OjIWMX2LmXdeXWqskyns8624yTaM= X-Received: by 2002:a05:6402:b33:: with SMTP id bo19mr7643811edb.70.1642673157166; Thu, 20 Jan 2022 02:05:57 -0800 (PST) MIME-Version: 1.0 References: <20211206104657.433304-1-alexandre.ghiti@canonical.com> In-Reply-To: From: Alexandre Ghiti Date: Thu, 20 Jan 2022 11:05:46 +0100 Message-ID: Subject: Re: [PATCH v3 00/13] Introduce sv48 support without relocatable kernel To: Palmer Dabbelt Cc: corbet@lwn.net, Paul Walmsley , aou@eecs.berkeley.edu, zong.li@sifive.com, anup@brainfault.org, Atish.Patra@rivosinc.com, Christoph Hellwig , ryabinin.a.a@gmail.com, glider@google.com, andreyknvl@gmail.com, dvyukov@google.com, ardb@kernel.org, Arnd Bergmann , keescook@chromium.org, guoren@linux.alibaba.com, heinrich.schuchardt@canonical.com, mchitale@ventanamicro.com, panqinglin2020@iscas.ac.cn, linux-doc@vger.kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-efi@vger.kernel.org, linux-arch@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 20, 2022 at 8:30 AM Alexandre Ghiti wrote: > > On Thu, Jan 20, 2022 at 5:18 AM Palmer Dabbelt wrote: > > > > On Mon, 06 Dec 2021 02:46:44 PST (-0800), alexandre.ghiti@canonical.com wrote: > > > * Please note notable changes in memory layouts and kasan population * > > > > > > This patchset allows to have a single kernel for sv39 and sv48 without > > > being relocatable. > > > > > > The idea comes from Arnd Bergmann who suggested to do the same as x86, > > > that is mapping the kernel to the end of the address space, which allows > > > the kernel to be linked at the same address for both sv39 and sv48 and > > > then does not require to be relocated at runtime. > > > > > > This implements sv48 support at runtime. The kernel will try to > > > boot with 4-level page table and will fallback to 3-level if the HW does not > > > support it. Folding the 4th level into a 3-level page table has almost no > > > cost at runtime. > > > > > > Note that kasan region had to be moved to the end of the address space > > > since its location must be known at compile-time and then be valid for > > > both sv39 and sv48 (and sv57 that is coming). > > > > > > Tested on: > > > - qemu rv64 sv39: OK > > > - qemu rv64 sv48: OK > > > - qemu rv64 sv39 + kasan: OK > > > - qemu rv64 sv48 + kasan: OK > > > - qemu rv32: OK > > > > > > Changes in v3: > > > - Fix SZ_1T, thanks to Atish > > > - Fix warning create_pud_mapping, thanks to Atish > > > - Fix k210 nommu build, thanks to Atish > > > - Fix wrong rebase as noted by Samuel > > > - * Downgrade to sv39 is only possible if !KASAN (see commit changelog) * > > > - * Move KASAN next to the kernel: virtual layouts changed and kasan population * > > > > > > Changes in v2: > > > - Rebase onto for-next > > > - Fix KASAN > > > - Fix stack canary > > > - Get completely rid of MAXPHYSMEM configs > > > - Add documentation > > > > > > Alexandre Ghiti (13): > > > riscv: Move KASAN mapping next to the kernel mapping > > > riscv: Split early kasan mapping to prepare sv48 introduction > > > riscv: Introduce functions to switch pt_ops > > > riscv: Allow to dynamically define VA_BITS > > > riscv: Get rid of MAXPHYSMEM configs > > > asm-generic: Prepare for riscv use of pud_alloc_one and pud_free > > > riscv: Implement sv48 support > > > riscv: Use pgtable_l4_enabled to output mmu_type in cpuinfo > > > riscv: Explicit comment about user virtual address space size > > > riscv: Improve virtual kernel memory layout dump > > > Documentation: riscv: Add sv48 description to VM layout > > > riscv: Initialize thread pointer before calling C functions > > > riscv: Allow user to downgrade to sv39 when hw supports sv48 if !KASAN > > > > > > Documentation/riscv/vm-layout.rst | 48 ++- > > > arch/riscv/Kconfig | 37 +- > > > arch/riscv/configs/nommu_k210_defconfig | 1 - > > > .../riscv/configs/nommu_k210_sdcard_defconfig | 1 - > > > arch/riscv/configs/nommu_virt_defconfig | 1 - > > > arch/riscv/include/asm/csr.h | 3 +- > > > arch/riscv/include/asm/fixmap.h | 1 > > > arch/riscv/include/asm/kasan.h | 11 +- > > > arch/riscv/include/asm/page.h | 20 +- > > > arch/riscv/include/asm/pgalloc.h | 40 ++ > > > arch/riscv/include/asm/pgtable-64.h | 108 ++++- > > > arch/riscv/include/asm/pgtable.h | 47 +- > > > arch/riscv/include/asm/sparsemem.h | 6 +- > > > arch/riscv/kernel/cpu.c | 23 +- > > > arch/riscv/kernel/head.S | 4 +- > > > arch/riscv/mm/context.c | 4 +- > > > arch/riscv/mm/init.c | 408 ++++++++++++++---- > > > arch/riscv/mm/kasan_init.c | 250 ++++++++--- > > > drivers/firmware/efi/libstub/efi-stub.c | 2 > > > drivers/pci/controller/pci-xgene.c | 2 +- > > > include/asm-generic/pgalloc.h | 24 +- > > > include/linux/sizes.h | 1 > > > 22 files changed, 833 insertions(+), 209 deletions(-) > > > > Sorry this took a while. This is on for-next, with a bit of juggling: a > > handful of trivial fixes for configs that were failing to build/boot and > > some merge issues. I also pulled out that MAXPHYSMEM fix to the top, so > > it'd be easier to backport. This is bigger than something I'd normally like to > > take late in the cycle, but given there's a lot of cleanups, likely some fixes, > > and it looks like folks have been testing this I'm just going to go with it. > > > > Yes yes yes! That's fantastic news :) > > > Let me know if there's any issues with the merge, it was a bit hairy. > > Probably best to just send along a fixup patch at this point. > > I'm going to take a look at that now, and I'll fix anything that comes > up quickly :) I see in for-next that you did not take the following patches: riscv: Improve virtual kernel memory layout dump Documentation: riscv: Add sv48 description to VM layout riscv: Initialize thread pointer before calling C functions riscv: Allow user to downgrade to sv39 when hw supports sv48 if !KASAN I'm not sure this was your intention. If it was, I believe that at least the first 2 patches are needed in this series, the 3rd one is a useful fix and we can discuss the 4th if that's an issue for you. I tested for-next on both sv39 and sv48 successfully, I took a glance at the code and noticed you fixed the PTRS_PER_PGD error, thanks for that. Otherwise nothing obvious has popped. Thanks again, Alex > > Thanks! > > Alex > > > > > Thanks!