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X-CSE-ConnectionGUID: khlGXOlkTwKr1U9JjdnP3w== X-CSE-MsgGUID: yLxhqetFTP2koLO8avucCw== X-IronPort-AV: E=McAfee;i="6800,10657,11469"; a="52437980" X-IronPort-AV: E=Sophos;i="6.16,252,1744095600"; d="scan'208";a="52437980" Received: from orviesa010.jf.intel.com ([10.64.159.150]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jun 2025 15:46:17 -0700 X-CSE-ConnectionGUID: k7JyIxXjSziBo8N29UjCyA== X-CSE-MsgGUID: yrg8bu1wRT23ayQDfi8v0Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,252,1744095600"; d="scan'208";a="150463429" Received: from aschofie-mobl2.amr.corp.intel.com (HELO [10.125.108.136]) ([10.125.108.136]) by orviesa010-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jun 2025 15:46:13 -0700 Message-ID: Date: Fri, 20 Jun 2025 15:46:11 -0700 Precedence: bulk X-Mailing-List: linux-efi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCHv6 00/16] x86: Enable Linear Address Space Separation support To: Andrew Cooper Cc: acme@redhat.com, aik@amd.com, akpm@linux-foundation.org, alexander.shishkin@linux.intel.com, ardb@kernel.org, ast@kernel.org, bp@alien8.de, brijesh.singh@amd.com, changbin.du@huawei.com, christophe.leroy@csgroup.eu, corbet@lwn.net, daniel.sneddon@linux.intel.com, dave.hansen@linux.intel.com, ebiggers@google.com, geert+renesas@glider.be, houtao1@huawei.com, hpa@zytor.com, jgg@ziepe.ca, jgross@suse.com, jpoimboe@kernel.org, kai.huang@intel.com, kees@kernel.org, kirill.shutemov@linux.intel.com, leitao@debian.org, linux-doc@vger.kernel.org, linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux@rasmusvillemoes.dk, luto@kernel.org, mcgrof@kernel.org, mhiramat@kernel.org, michael.roth@amd.com, mingo@kernel.org, mingo@redhat.com, namhyung@kernel.org, paulmck@kernel.org, pawan.kumar.gupta@linux.intel.com, peterz@infradead.org, rick.p.edgecombe@intel.com, rppt@kernel.org, sandipan.das@amd.com, shijie@os.amperecomputing.com, sohil.mehta@intel.com, tglx@linutronix.de, tj@kernel.org, tony.luck@intel.com, vegard.nossum@oracle.com, x86@kernel.org, xin3.li@intel.com, xiongwei.song@windriver.com, ytcoode@gmail.com References: <61af62d9-4cd0-485f-8f0c-2da981f52695@intel.com> <1aa5fb31-ce23-4c9f-ba1b-d5dc93402209@citrix.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 8bit On 6/20/25 15:04, Andrew Cooper wrote: >> Most of the cover letter here reads like an Intel whitepaper. That's not >> the worst thing in the world, but I think it glosses over one very >> important point: >> >> Had it been available, LASS alone would have mitigated Meltdown. >> >> Could we say this up front in a prominent place, please? > > I'm going to nitpick. :) > > Yes, LASS would have made Meltdown a far less major problem than it was, > but I don't think that phrasing is fair.  As I recall, LASS was > literally invented as a "what would have been useful?" exercise in the > wake of Meltdown. While being concise, I was also trying to convey that LASS is pretty powerful, rather than it being some uniquely genius move by the CPU designers. It was absolutely conceived of in hindsight. Do you feel like the changelog is sufficient as-is? Or do you think we can beef the changelog up a bit? I just want to make sure folks reading it have a clear understanding that it's not fixing purely theoretical issues.