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 50B35382F28; Thu, 25 Jun 2026 09:54:44 +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=1782381285; cv=none; b=DCktCI5T9AgI9KpUPTvKr02srRC+4qcBVEzRmnDx6gZP6LxwlbgUfIj4uwj7+OrAs5HViSBLuYc67l9ZE+e01FyRCQtFX03FkoEWSH6nd9dIyetTMdgdbOXetn+uX6okEmOjGLdWkEWuGK77bbWBnoN0oSupTAWXseQK6jZaPdQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782381285; c=relaxed/simple; bh=XdEUUc0LIH1CG4hWaGSpPsvbNYk3BgSi6lhZsxO0JP4=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=KMlX8hKZ9PEjx1AMpiNs7p0gG2iaAw4bO883mmthbJ4KpRsmsKyLbDGbujR3gFKpZfkOJUqZlgEd9sDA0IDZfYQf7Y/XEpsMQu4B9f84jq/PDyZb25/3suLZNYz8vhgLeLTfmbnK42Z5RSS6VHs2VuQ3NK1LTSwP+MRHu3o8SBw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=cW1YDz4i; 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="cW1YDz4i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DECA11F000E9; Thu, 25 Jun 2026 09:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782381283; bh=EQvzmhzhY00voWSBNdbfxNOmR53Cza+WLYkpg4Exsw8=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=cW1YDz4iq0eX1gwdCXa4sHqGm/2nXwLngx4dLAAamShH0CkGnA4LN1QTNU1VNP1Vk gbiNRfi2VcobYiBb9/4nqs1lJLwbJDRPbvd/xLAKtlG8jDQwNsqm0HanEa+sWn6aj/ FP4npsdEgKO98Ab3bKpqCdKS7sysAE5s2Hj08S7R19gdwEV70fFNQEd//xANPzfLjy qsGq5mC/vKyBsF/vKU0ip5KuaKWxZIYO6qzOsU1Zw19rTzjYqNnawjCkyOnaF9f/Ta nHo8iUkndGzQ1tk/mO0LZsKIxwbbcIy3btBGY2DMDbSU9ENzm+/pX5Scjc0iqKaxih scYE5jx11Azlg== 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 1wcgnB-0000000Fvck-0oXg; Thu, 25 Jun 2026 09:54:41 +0000 Date: Thu, 25 Jun 2026 10:54:40 +0100 Message-ID: <86h5mrq71b.wl-maz@kernel.org> From: Marc Zyngier To: Wei-Lin Chang Cc: Itaru Kitayama , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, Oliver Upton , Joey Gouly , Steffen Eiden , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon Subject: Re: [PATCH 0/3] KVM: arm64: nv: Shadow ptdump fixes In-Reply-To: References: <20260623142443.648972-1-weilin.chang@arm.com> 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: linux-kernel@vger.kernel.org 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: weilin.chang@arm.com, itaru.kitayama@fujitsu.com, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, oupton@kernel.org, joey.gouly@arm.com, seiden@linux.ibm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Thu, 25 Jun 2026 08:47:04 +0100, Wei-Lin Chang wrote: > > I don't see a way out with this per-mmu file scheme. The core issue is > mmus have a different lifetime than the VM's debugfs directory, and > both's removal can happen in parallel, i.e. the VM debugfs directory > can be removed anytime we are in mmu notifier release freeing the mmus > and their shadow ptdump files. Why isn't that a problem with the existing S2 ptdump code? M. -- Without deviation from the norm, progress is not possible.