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 mm01.cs.columbia.edu (mm01.cs.columbia.edu [128.59.11.253]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6404BC433EF for ; Fri, 22 Jul 2022 01:50:59 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D1B444C83D; Thu, 21 Jul 2022 21:50:58 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Authentication-Results: mm01.cs.columbia.edu (amavisd-new); dkim=softfail (fail, message has been altered) header.i=@google.com Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vq2FTrYPdaCZ; Thu, 21 Jul 2022 21:50:57 -0400 (EDT) Received: from mm01.cs.columbia.edu (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 9EA694C70C; Thu, 21 Jul 2022 21:50:57 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 1FBD04C6CD for ; Thu, 21 Jul 2022 21:50:56 -0400 (EDT) X-Virus-Scanned: at lists.cs.columbia.edu Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HkUvSgOa8STA for ; Thu, 21 Jul 2022 21:50:54 -0400 (EDT) Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) by mm01.cs.columbia.edu (Postfix) with ESMTPS id CDD4D4C6C7 for ; Thu, 21 Jul 2022 21:50:54 -0400 (EDT) Received: by mail-yb1-f201.google.com with SMTP id x8-20020a5b0948000000b006707a126318so2622961ybq.1 for ; Thu, 21 Jul 2022 18:50:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=Rhs+4jBfg1QM5n7eWG2/LdEIc5IyIGfWAsCL7NyPRwQ=; b=EPu9cfSmX3DAmdVD3SXg5Chipd7twxc2aYzKZWGdt9qqZYcXxOhVbYsm2Q4w3Keblq iOOY371rfBqvXTY6NybNQWreMp53L+rUZ1LTcNZne4JJDGcvaPks3Ru8OFBCCz30Qmwx 4WD270XRYhRv/GvT+dVV1awsfHaNxwtD37r68MFhp9ELCmrImgLiyWRhaKkWDXkBoZnH s78qnShu3Azqth50MftuCULbQDS0/sGtGm8g1LRAArzgephpOZ9rxfyCLFfTxD4ZvsHo W0x7N5i+Yoy5MqKgYCuj6TnY2HyvX9xkkG6z1rNzJUm68C/cjwlYxsZY/ACE2sHzBlDO jhcQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=Rhs+4jBfg1QM5n7eWG2/LdEIc5IyIGfWAsCL7NyPRwQ=; b=3GeqjUzIUw85zcg2PPm4wWxTC2uTVrUaKa3FfZ0OLoG2/7zmg11/8V/XoX6mpdfTf2 Q/EpSSY08tRDg6WnXb91Y0IFgNBbvc4cVNhTY5r+tUYhByzFNSz66DSeeHiHpHONvkkM 7p7ejYVyAy4pTQuEQnpU6VNMtb1WYXeOhcNI5oWul/uTiR6L8XAOUF5Fl+FbdB5ppQJB ynSe6uDg7a8/eOodzYY6ZYuNmJDnrx/Rnb3tnZmTv2LS5+7/13aC/CCf9VTb4I82pbyQ SDOeeJAzcDayghoKXNTI23glf1NLvmAQgKW4GQBY8aR6NOx/SFLQfhmPZQ38jCjtwRSa Wa+Q== X-Gm-Message-State: AJIora+q4M1zoFv9Y5rZ2OXP0gRJsqYkGKKL8K+WVb7x/sTJCHqPB33a 4599XuPDeRTxjr25aLPSI1ddzqQ= X-Google-Smtp-Source: AGRyM1s/pmWLb7/RVeSHgBd1PqQYRVoHVPsujzJ6L2UtPXkGfO1tJ3J+fcjlJoTgQYjpaF7llAnRI+U= X-Received: from pcc-desktop.svl.corp.google.com ([2620:15c:2ce:200:7ed4:5864:d5e1:ffe1]) (user=pcc job=sendgmr) by 2002:a5b:890:0:b0:670:8312:a52f with SMTP id e16-20020a5b0890000000b006708312a52fmr1197181ybq.139.1658454654329; Thu, 21 Jul 2022 18:50:54 -0700 (PDT) Date: Thu, 21 Jul 2022 18:50:26 -0700 Message-Id: <20220722015034.809663-1-pcc@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.37.1.359.gd136c6c3e2-goog Subject: [PATCH v2 0/7] KVM: arm64: permit MAP_SHARED mappings with MTE enabled From: Peter Collingbourne To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: kvm@vger.kernel.org, Will Deacon , Catalin Marinas , Cornelia Huck , Steven Price , Marc Zyngier , Vincenzo Frascino , Peter Collingbourne , Evgenii Stepanov X-BeenThere: kvmarm@lists.cs.columbia.edu X-Mailman-Version: 2.1.14 Precedence: list List-Id: Where KVM/ARM decisions are made List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu Hi, This patch series allows VMMs to use shared mappings in MTE enabled guests. The first four patches are based on the series that Catalin sent out, whose cover letter [1] I quote from below: > This series aims to fix the races between initialising the tags on a > page and setting the PG_mte_tagged flag. Currently the flag is set > either before or after that tag initialisation and this can lead to CoW > copying stale tags. The first patch moves the flag setting after the > tags have been initialised, solving the CoW issue. However, concurrent > mprotect() on a shared mapping may (very rarely) lead to valid tags > being zeroed. > > The second skips the sanitise_mte_tags() call in kvm_set_spte_gfn(), > deferring it to user_mem_abort(). The outcome is that no > sanitise_mte_tags() can be simplified to skip the pfn_to_online_page() > check and only rely on VM_MTE_ALLOWED vma flag that can be checked in > user_mem_abort(). > > The third and fourth patches use PG_arch_3 as a lock for page tagging, > based on Peter Collingbourne's idea of a two-bit lock. > > I think the first patch can be queued but the rest needs some in depth > review and test. With this series (if correct) we could allos MAP_SHARED > on KVM guest memory but this is to be discussed separately as there are > some KVM ABI implications. I rebased Catalin's series onto -next, addressed the issues that I identified in the review and added the proposed userspace enablement patches after the series. [1] https://lore.kernel.org/all/20220705142619.4135905-1-catalin.marinas@arm.com/ Catalin Marinas (3): arm64: mte: Fix/clarify the PG_mte_tagged semantics KVM: arm64: Simplify the sanitise_mte_tags() logic arm64: mte: Lock a page for MTE tag initialisation Peter Collingbourne (4): mm: Add PG_arch_3 page flag KVM: arm64: unify the tests for VMAs in memslots when MTE is enabled KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled Documentation: document the ABI changes for KVM_CAP_ARM_MTE Documentation/virt/kvm/api.rst | 5 +-- arch/arm64/include/asm/mte.h | 62 ++++++++++++++++++++++++++++++++ arch/arm64/include/asm/pgtable.h | 3 +- arch/arm64/kernel/cpufeature.c | 4 ++- arch/arm64/kernel/elfcore.c | 2 +- arch/arm64/kernel/hibernate.c | 2 +- arch/arm64/kernel/mte.c | 17 +++++---- arch/arm64/kvm/guest.c | 18 ++++++---- arch/arm64/kvm/mmu.c | 55 ++++++++++++---------------- arch/arm64/mm/copypage.c | 6 ++-- arch/arm64/mm/fault.c | 4 ++- arch/arm64/mm/mteswap.c | 5 ++- fs/proc/page.c | 1 + include/linux/page-flags.h | 1 + include/trace/events/mmflags.h | 7 ++-- mm/huge_memory.c | 1 + 16 files changed, 134 insertions(+), 59 deletions(-) -- 2.37.1.359.gd136c6c3e2-goog _______________________________________________ kvmarm mailing list kvmarm@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/kvmarm