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 A0FCFC433EF for ; Tue, 5 Oct 2021 12:10:00 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 31AB761166 for ; Tue, 5 Oct 2021 12:10:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 31AB761166 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=crudebyte.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:37268 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mXjGh-0008Is-6S for qemu-devel@archiver.kernel.org; Tue, 05 Oct 2021 08:09:59 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:41418) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXj8F-0000GD-Cr; Tue, 05 Oct 2021 08:01:22 -0400 Received: from kylie.crudebyte.com ([5.189.157.229]:49907) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mXj8C-0003nN-53; Tue, 05 Oct 2021 08:01:15 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=kylie; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=oReEq7Yo56DFtHntIV6d5KmDT6OgjuS82n4nCjQNi8U=; b=oMlAqIAaW90Iv4PJ5eCPyC9Dvp w9Uly/n8xSkO5kWhjEilimFdvL9Uvss7JxkDpfdIneox3t9oaA5dWcetKUEBfYZ424fktxRIzAOmp DW/1aX5izX4gyViUA15NDwzKZ/E0eKYlM/5fwy9hxHbeH8nHzDIgFoVNO1KZUAqwcGAtx1d+I7/H0 TLK4f3I5cUJUWHHlPiftBswh272KJujAwNIYN/JzPJUoa8VHijqpOZcrT98seurG2y/SnyPK8VE3Y anUSIuXafsmZil83WVeP1lzL3mRT5pLqG3FFAGeRkwqyJ9CTfnP/Ku43gx2IxYrsr83wIbNLiPnRn aj1yMaawGPbHtg01pfP6g1dqclLdLML9H/lEVHwSXILQs2mf/86KLn2xORE8c/qepzFp6vfaIO5VF k+ZcbXFIo51yJ3uRJL8OaP7D+NDw8QPLmIXD17OE4JM1m2JGsjXe7/m2OM2JXLNhTteskxzV+b0Zh PSGiTd/48oamd+grBEbNhzdxQLYFNnTAOekt7rWf1rYZ3rs3NvkEhA7P8NvMiFLThfjRhVjXaA5dj nNDV7soxy/BcNGsbwbhncZA289zIly9X5SBy66z1NhsAlWlnuCLfFx0PFHrUrQBO05yEuoH1HBh67 JS4ua0mhbh/5lH5BXxJVBBukVtIwYsp6ogHf9PDAk=; From: Christian Schoenebeck To: qemu-devel@nongnu.org Cc: "Michael S. Tsirkin" , Kevin Wolf , Laurent Vivier , qemu-block@nongnu.org, Amit Shah , Jason Wang , David Hildenbrand , Raphael Norwitz , virtio-fs@redhat.com, Eric Auger , Hanna Reitz , "Gonglei (Arei)" , Gerd Hoffmann , Stefan Hajnoczi , Paolo Bonzini , =?ISO-8859-1?Q?Marc=2DAndr=E9?= Lureau , Fam Zheng , "Dr. David Alan Gilbert" , Greg Kurz Subject: Re: [PATCH v2 2/3] virtio: increase VIRTQUEUE_MAX_SIZE to 32k Date: Tue, 05 Oct 2021 14:01:00 +0200 Message-ID: <3198295.vc1OghKV7D@silver> In-Reply-To: <20211005072243-mutt-send-email-mst@kernel.org> References: <2365616.UHP9OR3mgr@silver> <20211005072243-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Received-SPF: pass client-ip=5.189.157.229; envelope-from=qemu_oss@crudebyte.com; helo=kylie.crudebyte.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Dienstag, 5. Oktober 2021 13:24:36 CEST Michael S. Tsirkin wrote: > On Tue, Oct 05, 2021 at 01:17:59PM +0200, Christian Schoenebeck wrote: > > On Dienstag, 5. Oktober 2021 09:16:07 CEST Michael S. Tsirkin wrote: > > > On Mon, Oct 04, 2021 at 09:38:08PM +0200, Christian Schoenebeck wrote: > > > > Raise the maximum possible virtio transfer size to 128M > > > > (more precisely: 32k * PAGE_SIZE). See previous commit for a > > > > more detailed explanation for the reasons of this change. > > > > > > > > For not breaking any virtio user, all virtio users transition > > > > to using the new macro VIRTQUEUE_LEGACY_MAX_SIZE instead of > > > > VIRTQUEUE_MAX_SIZE, so they are all still using the old value > > > > of 1k with this commit. > > > > > > > > On the long-term, each virtio user should subsequently either > > > > switch from VIRTQUEUE_LEGACY_MAX_SIZE to VIRTQUEUE_MAX_SIZE > > > > after checking that they support the new value of 32k, or > > > > otherwise they should replace the VIRTQUEUE_LEGACY_MAX_SIZE > > > > macro by an appropriate value supported by them. > > > > > > > > Signed-off-by: Christian Schoenebeck > > > > > > I don't think we need this. Legacy isn't descriptive either. Just leave > > > VIRTQUEUE_MAX_SIZE alone, and come up with a new name for 32k. > > > > Does this mean you disagree that on the long-term all virtio users should > > transition either to the new upper limit of 32k max queue size or > > introduce > > their own limit at their end? > > depends. if 9pfs is the only one unhappy, we can keep 4k as > the default. it's sure a safe one. > > > Independent of the name, and I would appreciate for suggestions for an > > adequate macro name here, I still think this new limit should be placed in > > the shared virtio.h file. Because this value is not something invented on > > virtio user side. It rather reflects the theoretical upper limited > > possible with the virtio protocol, which is and will be common for all > > virtio users. > We can add this to the linux uapi headers, sure. Well, then I wait for few days, and if nobody else cares about this issue, then I just hard code 32k on 9pfs side exclusively in v3 for now and that's it. Best regards, Christian Schoenebeck From mboxrd@z Thu Jan 1 00:00:00 1970 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=crudebyte.com; s=kylie; h=Content-Type:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:Cc:To:From: Content-ID:Content-Description; bh=oReEq7Yo56DFtHntIV6d5KmDT6OgjuS82n4nCjQNi8U=; b=oMlAqIAaW90Iv4PJ5eCPyC9Dvp w9Uly/n8xSkO5kWhjEilimFdvL9Uvss7JxkDpfdIneox3t9oaA5dWcetKUEBfYZ424fktxRIzAOmp DW/1aX5izX4gyViUA15NDwzKZ/E0eKYlM/5fwy9hxHbeH8nHzDIgFoVNO1KZUAqwcGAtx1d+I7/H0 TLK4f3I5cUJUWHHlPiftBswh272KJujAwNIYN/JzPJUoa8VHijqpOZcrT98seurG2y/SnyPK8VE3Y anUSIuXafsmZil83WVeP1lzL3mRT5pLqG3FFAGeRkwqyJ9CTfnP/Ku43gx2IxYrsr83wIbNLiPnRn aj1yMaawGPbHtg01pfP6g1dqclLdLML9H/lEVHwSXILQs2mf/86KLn2xORE8c/qepzFp6vfaIO5VF k+ZcbXFIo51yJ3uRJL8OaP7D+NDw8QPLmIXD17OE4JM1m2JGsjXe7/m2OM2JXLNhTteskxzV+b0Zh PSGiTd/48oamd+grBEbNhzdxQLYFNnTAOekt7rWf1rYZ3rs3NvkEhA7P8NvMiFLThfjRhVjXaA5dj nNDV7soxy/BcNGsbwbhncZA289zIly9X5SBy66z1NhsAlWlnuCLfFx0PFHrUrQBO05yEuoH1HBh67 JS4ua0mhbh/5lH5BXxJVBBukVtIwYsp6ogHf9PDAk= From: Christian Schoenebeck Date: Tue, 05 Oct 2021 14:01:00 +0200 Message-ID: <3198295.vc1OghKV7D@silver> In-Reply-To: <20211005072243-mutt-send-email-mst@kernel.org> References: <2365616.UHP9OR3mgr@silver> <20211005072243-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Subject: Re: [Virtio-fs] [PATCH v2 2/3] virtio: increase VIRTQUEUE_MAX_SIZE to 32k List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Kevin Wolf , Laurent Vivier , qemu-block@nongnu.org, Amit Shah , Jason Wang , "Michael S. Tsirkin" , David Hildenbrand , Raphael Norwitz , virtio-fs@redhat.com, Eric Auger , Hanna Reitz , "Gonglei (Arei)" , Gerd Hoffmann , =?ISO-8859-1?Q?Marc=2DAndr=E9?= Lureau , Paolo Bonzini , Fam Zheng On Dienstag, 5. Oktober 2021 13:24:36 CEST Michael S. Tsirkin wrote: > On Tue, Oct 05, 2021 at 01:17:59PM +0200, Christian Schoenebeck wrote: > > On Dienstag, 5. Oktober 2021 09:16:07 CEST Michael S. Tsirkin wrote: > > > On Mon, Oct 04, 2021 at 09:38:08PM +0200, Christian Schoenebeck wrote: > > > > Raise the maximum possible virtio transfer size to 128M > > > > (more precisely: 32k * PAGE_SIZE). See previous commit for a > > > > more detailed explanation for the reasons of this change. > > > > > > > > For not breaking any virtio user, all virtio users transition > > > > to using the new macro VIRTQUEUE_LEGACY_MAX_SIZE instead of > > > > VIRTQUEUE_MAX_SIZE, so they are all still using the old value > > > > of 1k with this commit. > > > > > > > > On the long-term, each virtio user should subsequently either > > > > switch from VIRTQUEUE_LEGACY_MAX_SIZE to VIRTQUEUE_MAX_SIZE > > > > after checking that they support the new value of 32k, or > > > > otherwise they should replace the VIRTQUEUE_LEGACY_MAX_SIZE > > > > macro by an appropriate value supported by them. > > > > > > > > Signed-off-by: Christian Schoenebeck > > > > > > I don't think we need this. Legacy isn't descriptive either. Just leave > > > VIRTQUEUE_MAX_SIZE alone, and come up with a new name for 32k. > > > > Does this mean you disagree that on the long-term all virtio users should > > transition either to the new upper limit of 32k max queue size or > > introduce > > their own limit at their end? > > depends. if 9pfs is the only one unhappy, we can keep 4k as > the default. it's sure a safe one. > > > Independent of the name, and I would appreciate for suggestions for an > > adequate macro name here, I still think this new limit should be placed in > > the shared virtio.h file. Because this value is not something invented on > > virtio user side. It rather reflects the theoretical upper limited > > possible with the virtio protocol, which is and will be common for all > > virtio users. > We can add this to the linux uapi headers, sure. Well, then I wait for few days, and if nobody else cares about this issue, then I just hard code 32k on 9pfs side exclusively in v3 for now and that's it. Best regards, Christian Schoenebeck