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 A1D0C48A8C6; Tue, 13 Oct 2026 09:44:59 +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=1791884700; cv=none; b=jCT1UiZcxoEMFZvZUp68yx9v+3hCxQYZHf91o93vlrINtNxhmtQNSUjsX2xxvlSzGXVU3IMws33exc2nuKMoozx9wa9kJhbOK59QtJ6Ji3TSf8H2IU42hI23gFZWJlxjENoWWf7ZKTIYO+Y5kJPJAg1gEpqwrKa1JETSjFr7dZY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791884700; c=relaxed/simple; bh=baI/Z7T0bwwNIrODzYKxBTCIfUH5WsrcaSPxkQXMS38=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=tCLnpmouZdyTkGY0TmfR4XT1Ofz8G3aJyYFQbMeZk/QznA9YNrQAyHqAX6iH7cgd4YOdTpxMRCW1TMVb1kPk4OaAUMcWqPYdzBVCg0L2W0+fWbEbTDJooIDINkLYow6P7T7enRZBTfmIHPC52QZN6+wQf92hjfzg3tQaJW/LXGs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y4gYy5/t; 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="Y4gYy5/t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A9D51F000FF; Tue, 13 Oct 2026 09:44:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791884699; bh=baI/Z7T0bwwNIrODzYKxBTCIfUH5WsrcaSPxkQXMS38=; h=From:To:Cc:Subject:In-Reply-To:References:Date; b=Y4gYy5/t16IBoLeQuvOgguyRav6A1B9TBV4bcQm+19mdAtrEG20QomQxeN4NJurKQ 2kdlNv3V9sMjRN+RGyMEa0dEiaWGXIqI33qJOk3EyTFm49QD0mzts6pdNKHnDgtd6E icdJsF/XEgs6xGK5unA0dSAIKfn39Vkalw32aqOSIdmXGNe6VRVbpi5Lc9X6T1ZTjF sCvY7ILOliqI9BujkF/cIQkYsjs6bSHc/pu6u6qJPErvnDX1+v5XIniLkEGKkl95qZ XkFkfyBOtjhb/LhzJixL9tpI87Z7pMb3MwxSB1ayFfcoGoWPd98dJ++WLp6x3J/Thb tYidCCc5Asgjw== X-Mailer: emacs 31.1 (via feedmail 11-beta-1 I) From: Aneesh Kumar K.V To: Jason Gunthorpe Cc: sashiko-reviews@lists.linux.dev, iommu@lists.linux.dev, linux-coco@lists.linux.dev Subject: Re: [PATCH v7 16/16] PCI/TSM: wait for vdevice contexts before removing a DSM In-Reply-To: <20261012130739.GM13920@nvidia.com> References: <20261008055955.4014342-1-aneesh.kumar@kernel.org> <20261008055955.4014342-17-aneesh.kumar@kernel.org> <20261012130739.GM13920@nvidia.com> Date: Tue, 13 Oct 2026 15:14:54 +0530 Message-ID: Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain Jason Gunthorpe writes: > On Mon, Oct 12, 2026 at 03:31:17PM +0530, Aneesh Kumar K.V wrote: > >> With this series, vdevices hold a reference to their parent vIOMMU, >> which pins arm-cca-host. sysfs unbind is disabled, and the SMCCC >> provider device has no hot-unplug path. > > It probably needs some logic like vfio has to prevent unregister from > completing if there are active users. The module pin should prevent it > from ever triggering, but as a safety precaution. > Are you suggesting that tsm_unregister() should return an error or wait, as device removal does? Returning an error would be much easier to implement by adding an unregistering flag to tsm_dev, set under pci_tsm_rwsem after checking all pf0->context_users counters. -aneesh