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Shutemov" Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Zijlstra , Ard Biesheuvel , "Paul E. McKenney" , Josh Poimboeuf , Xiongwei Song , Xin Li , "Mike Rapoport (IBM)" , Brijesh Singh , Michael Roth , Tony Luck , Alexey Kardashevskiy , Alexander Shishkin , Jonathan Corbet , Sohil Mehta , Ingo Molnar , Pawan Gupta , Daniel Sneddon , Kai Huang , Sandipan Das , Breno Leitao , Rick Edgecombe , Alexei Starovoitov , Hou Tao , Juergen Gross , Vegard Nossum , Kees Cook , Eric Biggers , Jason Gunthorpe , "Masami Hiramatsu (Google)" , Andrew Morton , Luis Chamberlain , Yuntao Wang , Rasmus Villemoes , Christophe Leroy , Tejun Heo , Changbin Du , Huang Shijie , Geert Uytterhoeven , Namhyung Kim , Arnaldo Carvalho de Melo , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, linux-mm@kvack.org, Yian Chen Subject: Re: [PATCHv6 01/16] x86/cpu: Enumerate the LASS feature bits Message-ID: <20250626151837.GFaF1kzfLtesXLqaAQ@fat_crate.local> References: <20250620135325.3300848-1-kirill.shutemov@linux.intel.com> <20250620135325.3300848-2-kirill.shutemov@linux.intel.com> <20250620163504.GCaFWNuI-8QFqAM0yI@fat_crate.local> <6y2iqv6c2idn7yebaec7tyhzl5zcsrwqq4lcsokumlqeophzaf@ljnmxorblgcj> <20250620182943.GDaFWolxhwogB2tTxb@fat_crate.local> <20250623102105.GCaFkqkatFSbyl1YeN@fat_crate.local> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Rspam-User: X-Stat-Signature: cy3d9rmnpq6js8ccutrrshursi9bxzpo X-Rspamd-Queue-Id: 3CF4040008 X-Rspamd-Server: rspam08 X-HE-Tag: 1750951184-402245 X-HE-Meta: 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 da73yvP2 i+DYBW2U4Qnm1ifTsXDA0jFRWbS91Sdh++qdGj5xaWRRqcdCz+RKMgl19H68ifwHOPvkBMYq2LMrKnxmFrCshBCSUl/Q7SIeLzjzBHXzqdwR4i3dGuo0QEvmhKH/j7c+cXXnuPoAi3RH2Se7zMX6TrAHDJ9n/v+rKFGTGDk63sThxYjmFJE5T85gBYAA0JBY96Ct+cjVwMUY49FD0f7VRwZUlIdw+SCKrwpSA3XShfnQtabgRPnyDS3NdfNPgo1ouJF9TzAl9LSlPM+xvTCsruqjZ8DSSLHttUH9fVRgibdHUz8dR7xZkPTDAaxfzyYmOM0h/sVKT5shJICuAAchF9KqxE2x9T0S60C8cTQ0WR/NWeUykFFBARBCJAg== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Jun 23, 2025 at 04:42:41PM +0300, Kirill A. Shutemov wrote: > Due to SLAM, we decided to postpone LAM enabling, until LASS is landed. > > I am not sure if we want to add static > /sys/devices/system/cpu/vulnerabilities/slam with "Mitigation: LASS". > > There might be other yet-to-be-discovered speculative attacks that LASS > mitigates. Security features have to visible to userspace independently of > known vulnerabilities. ... and the fact that a vuln is being mitigated by stating that in /sys/devices/system/cpu/vulnerabilities/ needs to happen too. I'm not talking about LAM enablement - I'm talking about adding a SPECTRE_V1_MITIGATION_LASS and setting that when X86_FEATURE_LASS is set so that luserspace gets told that "Spectre V1 : Mitigation: LASS" or so. Makes more sense? -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette