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X-CSE-ConnectionGUID: hb3EI0SkS0u6iXVX0vSVrQ== X-CSE-MsgGUID: gPjeM5JBQdumRx6d3N8URA== X-IronPort-AV: E=McAfee;i="6800,10657,11586"; a="74514831" X-IronPort-AV: E=Sophos;i="6.19,249,1754982000"; d="scan'208";a="74514831" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by orvoesa105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Oct 2025 07:05:26 -0700 X-CSE-ConnectionGUID: rJ+Qrd/aTO6OKsETqqU0Xw== X-CSE-MsgGUID: BUwuqVcuQOOCsB2E9OqBhw== X-ExtLoop1: 1 Received: from tfalcon-desk.amr.corp.intel.com (HELO [10.125.108.251]) ([10.125.108.251]) by fmviesa003-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Oct 2025 07:05:24 -0700 Message-ID: <90047889-3b90-4c6a-90ed-f155c92f7ce1@intel.com> Date: Thu, 23 Oct 2025 07:05:24 -0700 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] x86/mm: Move _PAGE_BIT_NOPTISHADOW from bit 58 to bit 9 To: Usama Arif , dwmw@amazon.co.uk, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, ardb@kernel.org, hpa@zytor.com Cc: x86@kernel.org, apopple@nvidia.com, thuth@redhat.com, nik.borisov@suse.com, kas@kernel.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, kernel-team@meta.com, Michael van der Westhuizen , Tobias Fleig References: <20251022220755.1026144-1-usamaarif642@gmail.com> <20251022220755.1026144-4-usamaarif642@gmail.com> <98bc658f-2ec6-43f5-a7e1-e9424450a850@intel.com> <797c78f4-1a90-42da-9fed-e87682456a43@gmail.com> From: Dave Hansen Content-Language: en-US Autocrypt: addr=dave.hansen@intel.com; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/22/25 16:58, Usama Arif wrote: >> This isn't necessary once the previous 2 patches are applied, right? > In kexec if the target kernels have patch 1 and 2, then this patch > is not needed. Unfortunately, patches 1 and 2 are not livepatchable. > Also backporting patches 1 and 2 to all previous kernels running in > production in a large fleet is not very scalable. I don't think I've ever been asked to apply a patch to make livepatching easier. I'm not sure that's something we want to pollute mainline with.