From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6C5D2341666 for ; Wed, 20 Aug 2025 15:12:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755702725; cv=none; b=L4G1a5VFec+111C0Bbb2ejE5jpR6p/w6clQYam0/Y+ug9XPyOI+9yZW4/6bWY2/zqwU9/dqWYww/p5TU1VgNRO697GyN20MDUXFk/oR2HGY7Mg5z4kS+1scTe172PaDepN3hiVOjA+iOyrHoLcD4oQK0OnRg1ZeuBgEZUShbiL4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755702725; c=relaxed/simple; bh=bKySXmogrdywUpuJaQEVkaR1IVoL1YNv1ljg9g1gKVE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=MwESkoY0P4Oz/nI/zsXLcWkm7tOknn+ND63atfRJY3GwpD+3B/CBiRWv9yoRImu5qIOzwP8yvsUf0S9Ri9fEtVNG0fV55cJvP5w39PfD7MojaVDvEFb3WTuObUDlrYtVfS8sDmv6mrSMj2Z7plwayPXX7g9SHKDp39wVfq9Nc3o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C892F1D31; Wed, 20 Aug 2025 08:11:55 -0700 (PDT) Received: from e133380.arm.com (e133380.arm.com [10.1.197.68]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3AC2E3F738; Wed, 20 Aug 2025 08:12:00 -0700 (PDT) Date: Wed, 20 Aug 2025 16:11:57 +0100 From: Dave Martin To: Yeoreum Yun Cc: catalin.marinas@arm.com, will@kernel.org, broonie@kernel.org, oliver.upton@linux.dev, anshuman.khandual@arm.com, robh@kernel.org, james.morse@arm.com, mark.rutland@arm.com, joey.gouly@arm.com, ahmed.genidi@arm.com, kevin.brodsky@arm.com, scott@os.amperecomputing.com, mbenes@suse.cz, james.clark@linaro.org, frederic@kernel.org, rafael@kernel.org, pavel@kernel.org, ryan.roberts@arm.com, suzuki.poulose@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, kvmarm@lists.linux.dev Subject: Re: [PATCH v3 0/5] initialize SCTRL2_ELx Message-ID: References: <20250813120118.3953541-1-yeoreum.yun@arm.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20250813120118.3953541-1-yeoreum.yun@arm.com> Hi, On Wed, Aug 13, 2025 at 01:01:13PM +0100, Yeoreum Yun wrote: > This series introduces initial support for the SCTLR2_ELx registers in Linux. > The feature is optional starting from ARMv8.8/ARMv9.3, > and becomes mandatory from ARMv8.9/ARMv9.4. > > Currently, Linux has no strict need to modify SCTLR2_ELx— > at least assuming that firmware initializes > these registers to reasonable defaults. > > However, several upcoming architectural features will require configuring > control bits in these registers. > Notable examples include FEAT_PAuth_LR and FEAT_CPA2. This looks OK overall to me, apart from some confusion between SCTLR_ELx and SCTLR2_ELx in patch 2 (see my comments there). This code will need to be tested somehow. Do you have any thoughts on this? Hacking the bootwrapper, KVM and/or kvmtool may provide a way of checking what happens when the kernel is entered with "wrong" initial values in relevant bits (HRCX_EL2.SCTLR2En, SCTLR2_EL{1,2}). Regarding the patch history: > Patch History > ============== > from v2 to v3: > - rewrite commit messages. > - fix missing SCTLR2_EL2 synchonization at boot. > - https://lore.kernel.org/all/20250811163340.1561893-1-yeoreum.yun@arm.com/ > > from v1 to v2: > - rebase to v6.17-rc1 > - https://lore.kernel.org/all/20250804121724.3681531-1-yeoreum.yun@arm.com/ Going forwards, can you try to make sure that significant changes to the series are all mentioned here? I didn't have time to look at v2, and in the meantime half of the series disappeared and a chunk of code was moved from one patch to another. I saves reviewers some time and effort if they do not have to dig through previous review conversations in order to understand what changed between versions of a series. (No need to mention every trivial change, though.) Cheers ---Dave