From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3649C39D6EC for ; Fri, 26 Jun 2026 16:03:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782489799; cv=none; b=rQk6SkwNxvmYHuTvzFoclCPs11cKujGq/Dv2Nsa3IwmDezcasHrOxS7g78+kTczsQHJbfbpwX65Vef14uj9Gkn/slHDvh5fyxh+8yih1AWZg1dRoVmFjcMGvsXGuBXjShqi3leWK4GmUKmiUlObPwDlilOzFqxj/R2vUMLkSRyQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782489799; c=relaxed/simple; bh=Xm9jrP1P4FpykHMiNyDjQelK7tMBFaT/4WfCZq/z/gA=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=i5VNMpwOwW6dQlt6EeYaEf9PVxHYyGT7IagYtvwB1yEbdLkMN1PD5OV+Hv525uZO43+693AH1DINfFEMhQ50jl+uoq4sKv0Pp9zRg5EPXiGDhjSczVdBL+yX83iVJJFcgyCRF+99ege8Ct6YLuCnEmL5RYtW9P85dcRe9yhSHlA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=l/nJsgTz; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="l/nJsgTz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EF15C1F000E9; Fri, 26 Jun 2026 16:03:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782489798; bh=o4FGdJk2fpboGhU8yqtKhsBcTKTVw5l3qmsX4ieyTt8=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=l/nJsgTzIEnZcXmOT8aMO9DRqnEx00lTqtVvTWwc06U7eYF1T6yshLAbTkXV3DpYO AFzbaGHOrKoCD3G5EBjyU4n7F+j65nS52LhM13whGAOguvlxxb0x2m6+ZuaGzIVrj8 ALFAHeKK2K7BPzkW0KxXgbw3GYR5uTGH+V9XBq2Yi0UNYXZIlQozSQXZiiqPuqBmdZ xGLYM36/p/FRLkQG7nh+2aHs49xDTRPszgYIR5VvKRClZTykhV2dsmNRwVmQfkZHp0 cSCWSmmZtpBHkq1SQbruJDQHxQWvkEkIPWifUkubjNhCaEbqv7bq+sA+HjRN3Bk1kG 3rgnyUzfv3meg== 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 1wd91Q-0000000GOqA-0gHQ; Fri, 26 Jun 2026 16:03:16 +0000 Date: Fri, 26 Jun 2026 17:03:15 +0100 Message-ID: <864iipqofw.wl-maz@kernel.org> From: Marc Zyngier To: Leonardo Bras Cc: Oliver Upton , kvmarm@lists.linux.dev, Joey Gouly , Suzuki K Poulose , Zenghui Yu , Wei-Lin Chang , Steffen Eiden Subject: Re: [PATCH 13/22] KVM: arm64: Set dirty state at stage-1 In-Reply-To: References: <20260623184201.1518871-1-oupton@kernel.org> <20260623184201.1518871-14-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: leo.bras@arm.com, oupton@kernel.org, kvmarm@lists.linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, weilin.chang@arm.com, seiden@linux.ibm.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Fri, 26 Jun 2026 16:49:36 +0100, Leonardo Bras wrote: > > On Tue, Jun 23, 2026 at 11:41:52AM -0700, Oliver Upton wrote: > > Mark the descriptor as dirty if the permissions are sufficient to grant > > write access. Note that compute_s1_direct_permissions() already > > considers the DBM bit as writable. > > IIUC the idea here is to avoid having a write fault when we first write to > that page. Is that correct? No. This is about *stage-1*, as indicated in $SUBJECT, and updating stage-1 when we take a fault that would indeed require a S1 update to be visible to the guest. A VNCR_EL2 fault, for example. M. -- Without deviation from the norm, progress is not possible.