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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 E9542C48BF6 for ; Thu, 29 Feb 2024 09:40:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:References:Cc:To :From:Date:Subject:Message-ID:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=F4AGC6LhQ8Etbmz/AgXkeOLKjk+I82HAP2LPRb2GsOc=; b=Eajbq18MGterNnoFqFdwk+IudH gCWuxnUvty0Wvvl0PVX1sK22pcsjwHtCtobST+eNtBmAgzvJTq7CWH0r/pX2oudbjM8wBVYv5L5jW A0bX6LiEL8wDVp1lKN/VTWhZI7NtT0Rn4yyEu6t9xwVNWk6pUrrSqHrXuLiWYt2YhkCi1PAktiwkm SLGyRtmxsHNJK+n8q+GTCHTro2Gj0RCZ1BtZQ4IjucpCzNf6NJfTljzsF3mmEDOy4p4Hh7HeUdz5R B/nHw2aVpBA2CJURu+JH66VtYtZBIQuDLN5yNmtX/SrTp8WE2bYuPVA38ihbUzyOCCjpbMbogIyHU ADFRciNg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfctr-0000000Cxjo-0hoP; Thu, 29 Feb 2024 09:40:23 +0000 Received: from out30-101.freemail.mail.aliyun.com ([115.124.30.101]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rfcto-0000000Cxi4-1jTn for linux-um@lists.infradead.org; Thu, 29 Feb 2024 09:40:22 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1709199618; h=Message-ID:Subject:Date:From:To; bh=F4AGC6LhQ8Etbmz/AgXkeOLKjk+I82HAP2LPRb2GsOc=; b=FnJ22vVnlDVDoASdcCs5twMlelDjQjNou7UDNW7Ur8lJzk/dosj7/dE7qt0EgOKp0WLluOMiBzR/7YROcAYvTH3R3B7SbFsMvKERhMSHZRjd/ql9o9t9E6sJzp5zuUGrg2+vEzSOleEQjflkfLpHE6VJ+b4Dl0p4xdjfkursPHA= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=34;SR=0;TI=SMTPD_---0W1SfgPr_1709199614; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0W1SfgPr_1709199614) by smtp.aliyun-inc.com; Thu, 29 Feb 2024 17:40:15 +0800 Message-ID: <1709199386.9824007-2-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH vhost v3 00/19] virtio: drivers maintain dma info for premapped vq Date: Thu, 29 Feb 2024 17:36:26 +0800 From: Xuan Zhuo To: "Michael S. Tsirkin" Cc: virtualization@lists.linux.dev, Richard Weinberger , Anton Ivanov , Johannes Berg , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Hans de Goede , =?utf-8?q?Ilpo_J=C3=A4rvinen?= , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Eric Farman , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , linux-um@lists.infradead.org, netdev@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, bpf@vger.kernel.org References: <20240229072044.77388-1-xuanzhuo@linux.alibaba.com> <20240229031755-mutt-send-email-mst@kernel.org> <1709197357.626784-1-xuanzhuo@linux.alibaba.com> <20240229043238-mutt-send-email-mst@kernel.org> In-Reply-To: <20240229043238-mutt-send-email-mst@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240229_014020_787806_5AE56AF2 X-CRM114-Status: GOOD ( 36.78 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Thu, 29 Feb 2024 04:34:20 -0500, "Michael S. Tsirkin" wrote: > On Thu, Feb 29, 2024 at 05:02:37PM +0800, Xuan Zhuo wrote: > > On Thu, 29 Feb 2024 03:21:14 -0500, "Michael S. Tsirkin" wrote: > > > On Thu, Feb 29, 2024 at 03:20:25PM +0800, Xuan Zhuo wrote: > > > > As discussed: > > > > http://lore.kernel.org/all/CACGkMEvq0No8QGC46U4mGsMtuD44fD_cfLcPaVmJ3rHYqRZxYg@mail.gmail.com > > > > > > > > If the virtio is premapped mode, the driver should manage the dma info by self. > > > > So the virtio core should not store the dma info. > > > > So we can release the memory used to store the dma info. > > > > > > > > But if the desc_extra has not dma info, we face a new question, > > > > it is hard to get the dma info of the desc with indirect flag. > > > > For split mode, that is easy from desc, but for the packed mode, > > > > it is hard to get the dma info from the desc. And for hardening > > > > the dma unmap is saft, we should store the dma info of indirect > > > > descs. > > > > > > > > So I introduce the "structure the indirect desc table" to > > > > allocate space to store dma info with the desc table. > > > > > > > > On the other side, we mix the descs with indirect flag > > > > with other descs together to share the unmap api. That > > > > is complex. I found if we we distinguish the descs with > > > > VRING_DESC_F_INDIRECT before unmap, thing will be clearer. > > > > > > > > Because of the dma array is allocated in the find_vqs(), > > > > so I introduce a new parameter to find_vqs(). > > > > > > > > Note: > > > > this is on the top of > > > > [PATCH vhost v1] virtio: packed: fix unmap leak for indirect desc table > > > > http://lore.kernel.org/all/20240223071833.26095-1-xuanzhuo@linux.alibaba.com > > > > > > > > Please review. > > > > > > > > Thanks > > > > > > > > v3: > > > > 1. fix the conflict with the vp_modern_create_avq(). > > > > > > Okay but are you going to address huge memory waste all this is causing for > > > - people who never do zero copy > > > - systems where dma unmap is a nop > > > > > > ? > > > > > > You should address all comments when you post a new version, not just > > > what was expedient, or alternatively tag patch as RFC and explain > > > in commit log that you plan to do it later. > > > > > > Do you miss this one? > > http://lore.kernel.org/all/1708997579.5613105-1-xuanzhuo@linux.alibaba.com > > > I did. The answer is that no, you don't get to regress memory usage > for lots of people then fix it up. > So the patchset is big, I guess it will take a couple of cycles to > merge gradually. I see. But I hope we can review the other part of this patch set. @Jason @Michael I don't want us to give up on this plan for some other reason after I've done so much work. Thanks. > > > I asked you. But I didnot recv your answer. > > > > Thanks. > > > > > > > > > > > v2: > > > > 1. change the dma item of virtio-net, every item have MAX_SKB_FRAGS + 2 > > > > addr + len pairs. > > > > 2. introduce virtnet_sq_free_stats for __free_old_xmit > > > > > > > > v1: > > > > 1. rename transport_vq_config to vq_transport_config > > > > 2. virtio-net set dma meta number to (ring-size + 1)(MAX_SKB_FRGAS +2) > > > > 3. introduce virtqueue_dma_map_sg_attrs > > > > 4. separate vring_create_virtqueue to an independent commit > > > > > > > > > > > > > > > > Xuan Zhuo (19): > > > > virtio_ring: introduce vring_need_unmap_buffer > > > > virtio_ring: packed: remove double check of the unmap ops > > > > virtio_ring: packed: structure the indirect desc table > > > > virtio_ring: split: remove double check of the unmap ops > > > > virtio_ring: split: structure the indirect desc table > > > > virtio_ring: no store dma info when unmap is not needed > > > > virtio: find_vqs: pass struct instead of multi parameters > > > > virtio: vring_create_virtqueue: pass struct instead of multi > > > > parameters > > > > virtio: vring_new_virtqueue(): pass struct instead of multi parameters > > > > virtio_ring: simplify the parameters of the funcs related to > > > > vring_create/new_virtqueue() > > > > virtio: find_vqs: add new parameter premapped > > > > virtio_ring: export premapped to driver by struct virtqueue > > > > virtio_net: set premapped mode by find_vqs() > > > > virtio_ring: remove api of setting vq premapped > > > > virtio_ring: introduce dma map api for page > > > > virtio_ring: introduce virtqueue_dma_map_sg_attrs > > > > virtio_net: unify the code for recycling the xmit ptr > > > > virtio_net: rename free_old_xmit_skbs to free_old_xmit > > > > virtio_net: sq support premapped mode > > > > > > > > arch/um/drivers/virtio_uml.c | 31 +- > > > > drivers/net/virtio_net.c | 283 ++++++--- > > > > drivers/platform/mellanox/mlxbf-tmfifo.c | 24 +- > > > > drivers/remoteproc/remoteproc_virtio.c | 31 +- > > > > drivers/s390/virtio/virtio_ccw.c | 33 +- > > > > drivers/virtio/virtio_mmio.c | 30 +- > > > > drivers/virtio/virtio_pci_common.c | 59 +- > > > > drivers/virtio/virtio_pci_common.h | 9 +- > > > > drivers/virtio/virtio_pci_legacy.c | 16 +- > > > > drivers/virtio/virtio_pci_modern.c | 38 +- > > > > drivers/virtio/virtio_ring.c | 698 ++++++++++++----------- > > > > drivers/virtio/virtio_vdpa.c | 45 +- > > > > include/linux/virtio.h | 13 +- > > > > include/linux/virtio_config.h | 48 +- > > > > include/linux/virtio_ring.h | 82 +-- > > > > tools/virtio/virtio_test.c | 4 +- > > > > tools/virtio/vringh_test.c | 28 +- > > > > 17 files changed, 847 insertions(+), 625 deletions(-) > > > > > > > > -- > > > > 2.32.0.3.g01195cf9f > > > >