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 ws5-mx01.kavi.com (ws5-mx01.kavi.com [34.193.7.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5F3DAC64EC4 for ; Thu, 9 Mar 2023 13:55:28 +0000 (UTC) Received: from lists.oasis-open.org (oasis.ws5.connectedcommunity.org [10.110.1.242]) by ws5-mx01.kavi.com (Postfix) with ESMTP id 908562AC51 for ; Thu, 9 Mar 2023 13:55:27 +0000 (UTC) Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 89DD0986702 for ; Thu, 9 Mar 2023 13:55:27 +0000 (UTC) Received: from host09.ws5.connectedcommunity.org (host09.ws5.connectedcommunity.org [10.110.1.97]) by lists.oasis-open.org (Postfix) with QMQP id 7F0929866F6; Thu, 9 Mar 2023 13:55:27 +0000 (UTC) Mailing-List: contact virtio-dev-help@lists.oasis-open.org; run by ezmlm List-ID: Sender: Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [10.110.1.242]) by lists.oasis-open.org (Postfix) with ESMTP id 68FE69866FC for ; Thu, 9 Mar 2023 13:55:24 +0000 (UTC) X-Virus-Scanned: amavisd-new at kavi.com X-MC-Unique: kWK7xp6MNvWgN0jh6PIWKA-1 X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678370121; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=ypWQ3MqWDxaGQlJbf1BaO9jqW6vlCO7UiRw+dgYV524=; b=i/MErzh/3Gw8GxgwbXzcFSBnHy6N+lHQryCSX7vXn0vFM4bwHOUHxGNkFEgcIuzGUh XWQQbOe3x9qSNOYysTKf9uA112HRCGk+Egu+4Dy9hAnXO8utzZOQy5UBqQMNCShWQwRI X7EbfRK8E4vIzkxdrA+rPxOZCx0AXNMXd/6cZsoNNujHsqSKyp0XIQ0PlYGSK0jmsSqM q58xP+KoceIKrbVeJavn2CN25hcabyZeiqpkrnCj91KqcJYZ4KMvoG1tre49p9DkCaTQ 3V9zif30pWsCaDMpy7kqDBMBcnEAS2KO5HOAdyb0FHE3ysocnXkUehw8IH7yEVcaKVXJ g8kQ== X-Gm-Message-State: AO0yUKVz7OtUiz4EDsU82lkoM1BESidsTvNH9dJoBiDhSNIXBtLSxiW8 TgLyqeZItnuoKFwgWRPWaXlYGDMmeR2Cv77Uc9zUbuFcgCXYBXjDzDJCKs0qRDXXRIGncjW+eI8 gZEjnYRfHh0iYgV/U/mnCKjx4lWWV X-Received: by 2002:a17:907:a094:b0:8aa:c143:ffe1 with SMTP id hu20-20020a170907a09400b008aac143ffe1mr22985584ejc.48.1678370121610; Thu, 09 Mar 2023 05:55:21 -0800 (PST) X-Google-Smtp-Source: AK7set/uRSmgg4uTO7E+ffkuc6kjQ0pieg3LE/QGTM1EXcmtJeEsjrPyoveQbgsQF9aUeVR2xLBZfA== X-Received: by 2002:a17:907:a094:b0:8aa:c143:ffe1 with SMTP id hu20-20020a170907a09400b008aac143ffe1mr22985516ejc.48.1678370120394; Thu, 09 Mar 2023 05:55:20 -0800 (PST) Date: Thu, 9 Mar 2023 08:55:15 -0500 From: "Michael S. Tsirkin" To: Stefan Hajnoczi Cc: Max Gurtovoy , Jason Wang , Zhu Lingshan , virtio-comment@lists.oasis-open.org, virtio-dev@lists.oasis-open.org, cohuck@redhat.com, sgarzare@redhat.com, nrupal.jani@intel.com, Piotr.Uminski@intel.com, hang.yuan@intel.com, virtio@lists.oasis-open.org, pasic@linux.ibm.com, Shahaf Shuler , Parav Pandit Message-ID: <20230309085432-mutt-send-email-mst@kernel.org> References: <7f63fa0a-7deb-5875-6c6b-bfc651681653@redhat.com> <20230306112030.GB35392@fedora> <853c78d0-f752-05e9-d79d-811e82801627@nvidia.com> <20230306162538.GA56760@fedora> <20230308141317.GC299426@fedora> <18ddbf69-19a6-3c6b-9e42-aaae66e20bcf@nvidia.com> <20230308171523.GA320810@fedora> <20230308122017-mutt-send-email-mst@kernel.org> <20230309123542.GC370169@fedora> MIME-Version: 1.0 In-Reply-To: <20230309123542.GC370169@fedora> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Subject: [virtio-dev] Re: [virtio-comment] Re: [virtio] Re: [PATCH v10 04/10] admin: introduce virtio admin virtqueues On Thu, Mar 09, 2023 at 07:35:42AM -0500, Stefan Hajnoczi wrote: > On Wed, Mar 08, 2023 at 12:21:46PM -0500, Michael S. Tsirkin wrote: > > On Wed, Mar 08, 2023 at 12:15:23PM -0500, Stefan Hajnoczi wrote: > > > > > > > Or we could say that admin commands must complete within bounded time, > > > > > > > but I'm not sure that is implementable for some device types like > > > > > > > virtio-blk, virtio-scsi, and virtiofs. > > > > > > > > > > > > No we can't. > > > > > > Some commands, for example FW upgrade can take 10 minutes and it's perfectly > > > > > > fine. Other commands like setting feature bit will take 1 millisec. > > > > > > Each device implements commands in a different internal logic so we can't > > > > > > expect to complete after X time. > > > > > > > > > > When I say bounded time, I mean that it finishes in a finite amount of > > > > > time. I'm not saying there is a specific time X that all device > > > > > implementations must satisfy. Unbounded means it might never finish. > > > > > > > > There might be a chance that any command for any virtio device type will > > > > never finish. Nothing new here in the adminq. > > > > > > > > what one can do is to set a timeout for himself and if this timeout expire - > > > > check the device status. If it needs_reset - do a reset. if status is ok, > > > > then wait some more time. > > > > After X retries, unmap buffers or reset the adminq. > > > > > > Michael: What effect does resetting the group owner device have on group > > > member devices? > > > > virtio level reset? It's a good question. I'd expect them all to be > > reset no? > > > > > I'm concerned that this approach disrupts all group member devices. For > > > example, you try to add a new device but the command hangs. In order to > > > recover you now have to reset the group owner device and this breaks all > > > the group member devices. > > > > > > I agree. How about a VQ level reset though? Seems like exactly > > what's needed here? > > Yes, a new virtqueue-level reset feature would take care of this case. > > Stefan Why would we need a new one? We already have VIRTIO_F_RING_RESET. -- MST --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org