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 AC0F5C433EF for ; Fri, 22 Jul 2022 01:51:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229870AbiGVBvP (ORCPT ); Thu, 21 Jul 2022 21:51:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233680AbiGVBvN (ORCPT ); Thu, 21 Jul 2022 21:51:13 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2C77E9748F for ; Thu, 21 Jul 2022 18:51:11 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-31e65a848daso28851777b3.20 for ; Thu, 21 Jul 2022 18:51:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=cXHHG5JyJT6/zfSdYwcZ5hplI/Zwtw5pce4ngWT2RP0=; b=B/196tHwJZGxwdFpPDFtGgET20t1oaPOi+B7MforGvjteQqAubrBbnDQDcEDABfdFN 3DK9BLo4bXahlAM1Zsxz6zcxuz6ugGDvcoav9uuevoCJW5/jGeVxKgcMDWkvWNt+YlYE YGooogCFEZU+f/gGBwXExbBhTXJG7xpnwCN4d1QjLWLCX6p/euCGwNgqngATINfEafUZ vmxSUdXRy8210cbejvc/kzSbNqREBTwRlsnUJ3CeOb7E82yXcf7pGch9UX8WepzcpJGw gVDLrfHbXsI5qYh6TeA8MbgK6BZW4I+5FNvZUO3QAWxqrGa639qAV9IpgKC4MjSspDJg W3qQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=cXHHG5JyJT6/zfSdYwcZ5hplI/Zwtw5pce4ngWT2RP0=; b=5/uT7CIdw46moqnQSLENg/71EsFSA6RN+DagO4pRL26Oy8kiZlaH9SVkkK4+0ZxIJy tF/vkOG5DDNCc4fS0LLJ/5rcrtxBYyd3E+EC4U5Ho5QpRCqAlA3fZSZcGubQO8a86qfo PejyWt3DmYSRDV0qNDQXe53T7LOcnLf3UgiM5P37njkoOw+lgmBKu3exGAp4mTTy6s8f oOt/g28VH5YO/99doXY8vuhSM2NFkQJcduixlH6Hw8sX+PmZIB+PRG8JksSOxto1kgD+ 2ytSE5/Pn2N4wE5meh6xqQGuR8MA63xEZ1+Okqg9YFeF3Vzqv+A6CSAFZp8tnWB9ZIeg SDWQ== X-Gm-Message-State: AJIora+k9KIiftAfcvDaBs5Btnx6w8jqadA1b/QTIiaTjucw63iC9w3V mk30EiU3jy45BzwAk+JEyDClBm4= X-Google-Smtp-Source: AGRyM1uyeQgFMIiL2ECknr9YM3j6WFlHrejpaFbSL4QcZoqTrnLYKShMPao1gximyv/6/63IGwrd5rM= X-Received: from pcc-desktop.svl.corp.google.com ([2620:15c:2ce:200:7ed4:5864:d5e1:ffe1]) (user=pcc job=sendgmr) by 2002:a81:124b:0:b0:31c:fc99:d4de with SMTP id 72-20020a81124b000000b0031cfc99d4demr1273232yws.348.1658454670287; Thu, 21 Jul 2022 18:51:10 -0700 (PDT) Date: Thu, 21 Jul 2022 18:50:32 -0700 In-Reply-To: <20220722015034.809663-1-pcc@google.com> Message-Id: <20220722015034.809663-7-pcc@google.com> Mime-Version: 1.0 References: <20220722015034.809663-1-pcc@google.com> X-Mailer: git-send-email 2.37.1.359.gd136c6c3e2-goog Subject: [PATCH v2 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; } -- 2.37.1.359.gd136c6c3e2-goog