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 3CBC0C00140 for ; Wed, 10 Aug 2022 19:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232835AbiHJTa6 (ORCPT ); Wed, 10 Aug 2022 15:30:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33390 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233118AbiHJTa5 (ORCPT ); Wed, 10 Aug 2022 15:30:57 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B331F76958 for ; Wed, 10 Aug 2022 12:30:53 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id u44-20020a25ab2f000000b0067c1b3e9fceso5227057ybi.17 for ; Wed, 10 Aug 2022 12:30:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc; bh=+yNPE0YtwokNPZdowqkCFFxMTcHqUO1hXxky5MuupRY=; b=oZ5EETOvVLFNFJcFvJs5CUWFZV2YZx1lZtCVYg3Xpam3/6hJePg2ArdHUJxsspg7R5 kYnk9btdizwNCjiWTgj6vhaG+Ln/haQoW/pUsdjAvXGRUtwyTKhYaNbVGIqa4N0knmX5 Y6Bf8Sp0myosiRXqgzgjzzrxNgMTvUamymRKjYhHFjm5HuDY7N2HLKT82K2ZR3tI6a2I TkfL2xlNiTx9SHZbWxe0/jGZ8EVR0bP+e7g+tySRt7UNKn82GSElS85ZLEZQitwkkwIT z43wgykSu9Orgytw+Yk5q/JCadYNjdaFTKqRIDXR1Haw0of7kw8Io57Gij0cmraUd7F0 vpZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc; bh=+yNPE0YtwokNPZdowqkCFFxMTcHqUO1hXxky5MuupRY=; b=ICJHgsgKuvygMWmsDfE0cnWO4OnvTj5x2nUp5Te1uNNO8Dl12O/NzWFnZJSQsNDqwM hWAuNajwyhrE5cICPnKcSjuxxMsLXLrMF3srA9MtAJ9pfiTKe6th+wiznc2SAF9dc+DG DMy+fOEOC2OxvF/UMV9BHykSSInRvH5Rm7komklv2IkVQ2vwFxJzjZygV58mM1pr86Hn RcZUXKrOh9YNkrtecmsNPFCUnAzkLBfKp0oRc+ZibddtBfO5ZYNkC/lOlPdgOK79mxKx pD95c4rJtvZjqcQEWCGVxslYJE4B1AEVQNLv0AVwnrqeBS0xjBosTTJXT/T8k80UgT+o j5qA== X-Gm-Message-State: ACgBeo3hzUSZ52ERbrzKKgD8X0gpE7rqhhUDcaWA5wZqVdr/8utxZo8S 0zSxoKcsSSpFrC7WTqIjbQ7Z+6k= X-Google-Smtp-Source: AA6agR6moG62zPERwU4Dk26hNOp5DcD21DJAex4OmPFxWG3fnAGG1z1V+i1T2gQ2yJV0LxVv859Fqu0= X-Received: from pcc-desktop.svl.corp.google.com ([2620:15c:2ce:200:4d8b:fb2a:2ecb:c2bb]) (user=pcc job=sendgmr) by 2002:a25:b951:0:b0:67b:93e9:1ff9 with SMTP id s17-20020a25b951000000b0067b93e91ff9mr21338230ybm.101.1660159852914; Wed, 10 Aug 2022 12:30:52 -0700 (PDT) Date: Wed, 10 Aug 2022 12:30:32 -0700 In-Reply-To: <20220810193033.1090251-1-pcc@google.com> Message-Id: <20220810193033.1090251-7-pcc@google.com> Mime-Version: 1.0 References: <20220810193033.1090251-1-pcc@google.com> X-Mailer: git-send-email 2.37.1.559.g78731f0fdb-goog Subject: [PATCH v3 6/7] KVM: arm64: permit all VM_MTE_ALLOWED mappings with MTE enabled From: Peter Collingbourne To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu Cc: Peter Collingbourne , Cornelia Huck , Catalin Marinas , Will Deacon , Marc Zyngier , Evgenii Stepanov , kvm@vger.kernel.org, Steven Price , Vincenzo Frascino Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Certain VMMs such as crosvm have features (e.g. sandboxing) that depend on being able to map guest memory as MAP_SHARED. The current restriction on sharing MAP_SHARED pages with the guest is preventing the use of those features with MTE. Now that the races between tasks concurrently clearing tags on the same page have been fixed, remove this restriction. Signed-off-by: Peter Collingbourne --- arch/arm64/kvm/mmu.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index d54be80e31dd..fc65dc20655d 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -1075,14 +1075,6 @@ static void sanitise_mte_tags(struct kvm *kvm, kvm_pfn_t pfn, static bool kvm_vma_mte_allowed(struct vm_area_struct *vma) { - /* - * VM_SHARED mappings are not allowed with MTE to avoid races - * when updating the PG_mte_tagged page flag, see - * sanitise_mte_tags for more details. - */ - if (vma->vm_flags & VM_SHARED) - return false; - return vma->vm_flags & VM_MTE_ALLOWED; } -- 2.37.1.559.g78731f0fdb-goog