From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f179.google.com (mail-qt1-f179.google.com [209.85.160.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4C092C198 for ; Fri, 8 Mar 2024 16:25:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.179 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709915137; cv=none; b=KZ1PdxQAr6q2Z7+KFM8eYr57ec6hCM5eYhrw8kJe/qpL0UbG13XE47iScW4jkqB7Zeg7n2Nu+DU14Q2O1uNBW1rrT4NCHywTSInNwtjEabn/NPIpZ7vbg9slyngdQW1XUk1Bou4kaz0JGBCgKB4vFcuqfH9A4ivsLDDxRiw3KSA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709915137; c=relaxed/simple; bh=bNKllj7mYvx/xxkLemA0fJHMcGlcVpU323BzoEH+uFQ=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=POW7jjfUBWpJniPqdcUI1Z8w/mcoCxCih0kGzrZNvjveuwi/Sco+F/F1SdvYriBXW4UR6H1YxKAq+4MTrb/AlEyQ9+/lGP/tQmhyuL66IMw+9gqVAQ5+fFOAntv2MbjQN5mb1uF51gL6h3NpuTF73lc9EY3AcPGGciZSxkQ8DGY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=26DMfhqy; arc=none smtp.client-ip=209.85.160.179 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="26DMfhqy" Received: by mail-qt1-f179.google.com with SMTP id d75a77b69052e-42ee0c326e8so285171cf.0 for ; Fri, 08 Mar 2024 08:25:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709915135; x=1710519935; darn=lists.linux.dev; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=bNKllj7mYvx/xxkLemA0fJHMcGlcVpU323BzoEH+uFQ=; b=26DMfhqyTxAEvZyUdFiKSChA04MggaBlMqQhLiAzfbqQKslZIdUNVj+Cj26CoNe73B m2bSEeKNNRqaLEE6wN/JaGQHKlWc22Lg2DB+k9TbUK4ZkkjUkjNfi2CcC/69RlB73Gr1 z/lKRnCkSC2lMJji0WIBiEYb1EDF3OHXYr2J0qOAsw1cZskXyuAz8MU5DrixwxJMM7mx sYYBpmUf8vp9af5vbBgemn4Lzvo91PhByZz+F0B/xw4yu3hfjo/XwCFmQBCNkeGqnJU+ nUPEQoqK2ooIjNK256B/TZBSiSQLS1/JS+vGaWkkR8VWzAH83+MjlkEdQnJxLrAb1dCy olFg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709915135; x=1710519935; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bNKllj7mYvx/xxkLemA0fJHMcGlcVpU323BzoEH+uFQ=; b=FcwVcZwYbX4xZn0btJW3qZIwryufe7zM9OgCM6pUjxQfLFQh3Fex0zfnnAfieiRvF9 vb5FBZ108cOvr1+APGGD+iSr0b+/uMnkK/ClyTjmHApsZyNu8UWzczfV5smFZwoPLdhT /ABHtVclZS3XGMsmQp8+ynJPJ8e8z0BAziO+5gcTSewimlNwYwwLuFK6nGcBjeUV+Ofc PJacezGmeY2Z+Sniegq52Dc1ImdAjPVtmmM+uMG9Uw9TXJuDa8NN8cCEISZk5wdgbHdp tmk/yMVNPTDpajHUKqtPzHZ4GNA5f+CXG+OgOYAU0gHOkrpNng/yXqH4E2Gy441eeEMA fxmw== X-Forwarded-Encrypted: i=1; AJvYcCXCNYkt3/Z3pczkAk09YNS1dldmZr669qILCBCuPKsSyy+909kN3im70EFMDEWHw55rwwCeL5DvkcQ/OpXmzxt/vRrsOOc6b/ti9A== X-Gm-Message-State: AOJu0YyjJp4QR1zdTenP+qbJ8MyQhLM0Y3CjZipA5W7R22YDt/8DMcV4 LT5gqMC9XJQahHAXJExG1m1uyuff3P8SNTkLczDn8mPCA1MD0d9avq8MFkrIdykFn0QNYXytFDQ cSf3XsnfDsUO5FfvBLdMIQmzX96hTuZKR89Bq X-Google-Smtp-Source: AGHT+IElQ3xjmycZ+6ORMpUoTkFmduy8rLaNpVKLnGA7x+Z+sC1aXJ1BEUZ5RKJmqqEgd0tD5BJWRtLMqwd9EMqbzds= X-Received: by 2002:ac8:7d41:0:b0:42f:a3c:2d53 with SMTP id h1-20020ac87d41000000b0042f0a3c2d53mr675497qtb.20.1709915134720; Fri, 08 Mar 2024 08:25:34 -0800 (PST) Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: In-Reply-To: From: Brendan Jackman Date: Fri, 8 Mar 2024 17:25:21 +0100 Message-ID: Subject: Re: Unmapping KVM Guest Memory from Host Kernel To: "Gowans, James" Cc: "seanjc@google.com" , "akpm@linux-foundation.org" , "Roy, Patrick" , "chao.p.peng@linux.intel.com" , "Manwaring, Derek" , "rppt@kernel.org" , "pbonzini@redhat.com" , "Woodhouse, David" , "Kalyazin, Nikita" , "lstoakes@gmail.com" , "Liam.Howlett@oracle.com" , "linux-mm@kvack.org" , "qemu-devel@nongnu.org" , "kirill.shutemov@linux.intel.com" , "vbabka@suse.cz" , "mst@redhat.com" , "somlo@cmu.edu" , "Graf (AWS), Alexander" , "kvm@vger.kernel.org" , "linux-coco@lists.linux.dev" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Hi James On Fri, 8 Mar 2024 at 16:50, Gowans, James wrote: > Our goal is to more completely address the class of issues whose leak > origin is categorized as "Mapped memory" [1]. Did you forget a link below? I'm interested in hearing about that categorisation. > ... what=E2=80=99s the best way to solve getting guest RAM out of > the direct map? It's perhaps a bigger hammer than you are looking for, but the solution we're working on at Google is "Address Space Isolation" (ASI) - the latest posting about that is [2]. The sense in which it's a bigger hammer is that it doesn't only support removing guest memory from the direct map, but rather arbitrary data from arbitrary kernel mappings. [2] https://lore.kernel.org/linux-mm/CA+i-1C169s8pyqZDx+iSnFmftmGfssdQA29+p= Ym-gqySAYWgpg@mail.gmail.com/