From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 545DBCCD18E for ; Tue, 14 Oct 2025 08:49:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc: To:From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=8yF5an8vPwKISsVSZz7CHZXrwqqq4VnMfISpZHg7iVk=; b=4RYbsIGe+k2QruIUdf/eWPwCwg 6joED1sU93ohJAPEwaQUODtk/NLZf9R0oUR3Z9yxIHO5z3Jy5nTzBJU88G8Ld5VpRnLRK60bqbQZc 37HalpmmyO01utd2yci3c8HQZgQ8MgbWlLhEbS8W/R2V0MSqOVTJTV8r4ZNZZCCjQRb/HsSNwOOlt GUpywvDygNxXT9jjIC5fdMAWEVDW0PYjO6QvYgYSSpWMqZiM1IoMYIE2HLTi9rb8g901n6ZHjjIpx A7L8IlPsxioRRwjJP0e+YrzbobxXPLUX9n8inEeXiW9x9p9rWUpQdYiXA3xpuhPf/KT7kv5n6Sge6 MsBZpl2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1v8ain-0000000FfP5-00LK; Tue, 14 Oct 2025 08:49:29 +0000 Received: from tor.source.kernel.org ([2600:3c04:e001:324:0:1991:8:25]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1v8ail-0000000FfOs-3k28 for linux-arm-kernel@lists.infradead.org; Tue, 14 Oct 2025 08:49:27 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id F1CC762227; Tue, 14 Oct 2025 08:49:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AF8DC4CEF9; Tue, 14 Oct 2025 08:49:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760431766; bh=C7JuaamqYjTY8yKNBk8DAaYNefNASMvcLoZIKSBAuJ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PLqbpLL1+Oo1r/vYSggD+Gynz+O1HTnN3Ih9MriG3qxEBLKsfdJJ4YpwUiF4m7fzs 5ukz4smjDbUyHkGXfQGCg/mNL7AvE74QgnpsDidNa2YbM/ygwNuunF0OB2Je3tHEBn O+WOimzFFYMKdcDYTC7YFX2ajKyn2Rswue4pcWxWgOvjaFPgk5PjaxL4W7nPck3hUs TFbZoa4LKe8DLGtnrwntVo7EJByt1La91uB7pPTljp4zR5k1ehOoLNTcoy+eBzH5yI fxB1o5SrAczaPGjIgISdKP+kdqp8Csr8ifmjh7KXWO1HEAf8Rddz27iIFp6gk5G5JN K9MVoU9KZAVVQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=valley-girl.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1v8aii-0000000Dms5-1mLR; Tue, 14 Oct 2025 08:49:24 +0000 From: Marc Zyngier To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, Marc Zyngier Cc: Joey Gouly , Suzuki K Poulose , Oliver Upton , Zenghui Yu , Will Deacon , Catalin Marinas , Mark Rutland , Jan Kotas Subject: Re: [PATCH] arm64: Revamp HCR_EL2.E2H RES1 detection Date: Tue, 14 Oct 2025 09:49:20 +0100 Message-ID: <176043175100.977560.12584294473093983228.b4-ty@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251009121239.29370-1-maz@kernel.org> References: <20251009121239.29370-1-maz@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, maz@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, oliver.upton@linux.dev, yuzenghui@huawei.com, will@kernel.org, catalin.marinas@arm.com, mark.rutland@arm.com, jank@cadence.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 09 Oct 2025 13:12:39 +0100, Marc Zyngier wrote: > We currently have two ways to identify CPUs that only implement FEAT_VHE > and not FEAT_E2H0: > > - either they advertise it via ID_AA64MMFR4_EL1.E2H0, > - or the HCR_EL2.E2H bit is RAO/WI > > However, there is a third category of "cpus" that fall between these > two cases: on CPUs that do not implement FEAT_FGT, it is IMPDEF whether > an access to ID_AA64MMFR4_EL1 can trap to EL2 when the register value > is zero. > > [...] Applied to fixes, thanks! [1/1] arm64: Revamp HCR_EL2.E2H RES1 detection commit: ca88ecdce5f51874a7c151809bd2c936ee0d3805 Cheers, M. -- Without deviation from the norm, progress is not possible.