From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 62E762DAFA5 for ; Fri, 9 Jan 2026 11:31:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767958298; cv=none; b=U0t68H0YXuc4KydVsCj1bw5BHGtTDcKTVuzjRjCExR934xiGjIvFJ4SsCBYr49dThNQfWALui2H3sTllaimxxoS9HGojorihhi6kjGUmw2VEg+tYRnBhCGmkfZ7sZDjSt0ldk4zBtTXAAq/hS99cxYWwZKH3PIFBKhMMqx3XS7Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767958298; c=relaxed/simple; bh=zwrlSX5MFGfZn0wZHiNMh9qTBLPxncAZSIbxeMyXplc=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=udIiYC+moNa6Dkahw4uFQWZNMqQ2RfSHcSjbFQ9Y5y8A9ByDouciovRcdgxvmr5a27O6jYsKALzZ0i8+d34As9vsElEzxVm4Br18RFShqxaoJZfTX6Hwdn8KcGmJFrpDaBJ2Cga9+YwmhCEPMgRxAuhfdxKv3PomY1bgtaJ54cM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DrYnDpcf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DrYnDpcf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 095FCC4CEF1; Fri, 9 Jan 2026 11:31:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767958298; bh=zwrlSX5MFGfZn0wZHiNMh9qTBLPxncAZSIbxeMyXplc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=DrYnDpcfbwZ+Adm6XpW/BpIkuWVUmBOwffDY6lgRkh9o+LKKk0fddjis2ObXFR5xH QXJMjoojQTyFGVnJU2rgMdOUVaPnVhQotEIlhA2kfJJ/msakHRtaect5DisU+6UQpm F/BXqDe5UNUsVplRSmqG8C5lvy8Z2R2OnUz0jypCH8ExLNJaNNBIrphXtKQhEhS2yk OaS72QPHMRKhDqsz+dVtfMm8VMjF3vHeyM5HuqNKUNG+ybet6sM8PQTFfSqiThL0m9 ZfV79MgtoOud4My8/BiQjbrqATeS86vn+qsWsyfN1FsjOAmIt32J/HYHClRRbR3YRL oS8iXe79gsmBQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) 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 1veAiN-00000000lUj-3L45; Fri, 09 Jan 2026 11:31:35 +0000 Date: Fri, 09 Jan 2026 11:31:35 +0000 Message-ID: <86y0m7koo8.wl-maz@kernel.org> From: Marc Zyngier To: Oliver Upton Cc: kvmarm@lists.linux.dev, Joey Gouly , Suzuki K Poulose , Zenghui Yu Subject: Re: [PATCH] KVM: arm64: nv: Respect stage-2 write permssion when setting stage-1 AF In-Reply-To: <20260108204230.677172-1-oupton@kernel.org> References: <20260108204230.677172-1-oupton@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: oupton@kernel.org, kvmarm@lists.linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Thu, 08 Jan 2026 20:42:30 +0000, Oliver Upton wrote: > > Naturally, updating the Access Flag in a stage-1 descriptor requires > write permission at stage-2, although this isn't actually enforced in > KVM's software PTW. > > Generate a stage-2 permission fault if the stage-1 walk attempts to > update the descriptor and its corresponding stage-2 translation lacks > write permission. > > Fixes: bff8aa213dee ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW") > Signed-off-by: Oliver Upton Reviewed-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.