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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 05C85C433EF for ; Mon, 15 Nov 2021 10:00:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C870063211 for ; Mon, 15 Nov 2021 10:00:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230452AbhKOKC4 (ORCPT ); Mon, 15 Nov 2021 05:02:56 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:60224 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236829AbhKOKCu (ORCPT ); Mon, 15 Nov 2021 05:02:50 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1636970394; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Lt8vnfwUf+2wRUuIIg/z1Tzh6iD0Hl2ryprO+vMM6Rc=; b=NHrTs38kq080Cs8h7xFjxeSjDuF1XLfM4yUiJdew+EcqUHjxbgmaG7VWVmoa34RBTd6MGO RQQ/MIgkSbvsbtKazNIlU4PBOflfRsjH32T4Vj0g2vKjHB6qr/81MSRq92lNoRWYS+Nczx B91U7waK5XW05aPNfX41MVM7TUtGd6c= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-209-RFb2WsybPVS5Xj97UJAfMw-1; Mon, 15 Nov 2021 04:59:51 -0500 X-MC-Unique: RFb2WsybPVS5Xj97UJAfMw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B0D1F1015DA0; Mon, 15 Nov 2021 09:59:49 +0000 (UTC) Received: from sirius.home.kraxel.org (unknown [10.39.193.245]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E2D2D60BE5; Mon, 15 Nov 2021 09:59:48 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id B3EE318000A9; Mon, 15 Nov 2021 10:59:46 +0100 (CET) Date: Mon, 15 Nov 2021 10:59:46 +0100 From: Gerd Hoffmann To: Lukas Wunner Cc: "Michael S. Tsirkin" , linux-pci@vger.kernel.org, Bjorn Helgaas , open list Subject: Re: [PATCH] pciehp: fast unplug for virtual machines Message-ID: <20211115095946.54tp5glmgfged3rz@sirius.home.kraxel.org> References: <20211111090225.946381-1-kraxel@redhat.com> <20211114163958.GA7211@wunner.de> <20211114122249-mutt-send-email-mst@kernel.org> <20211114180604.GA23907@wunner.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211114180604.GA23907@wunner.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Hi, > > This requires guest specific code though. Emulating the attention button > > works in a guest independent way. > > It sounds like you're using the Attention Button because it does > almost, but not quite what you want for your specific use case. Well, we want send a request to the guest to shutdown and poweroff the device. > Why don't you just trigger surprise-removal from outside the guest? To give the guest a chance to shutdown the device gracefully? Umount filesystems, flush data to disk. Also guest stability. Traditionally linux isn't very good at dealing with surprise removal, although the situation is improving. Emulating surprise-removal has been discussed too. More as fallback in case the guest doesn't respond to the attention button. Right now we don't have it but should be doable. For some kinds of devices it shouldn't be a problem to go straight to surprise-removal. I'll go experiment with that. take care, Gerd