From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-112.freemail.mail.aliyun.com (out30-112.freemail.mail.aliyun.com [115.124.30.112]) (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 1A3E4199AD for ; Mon, 11 Mar 2024 09:55:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.112 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710150909; cv=none; b=H94/0qFk9wZ7nmbXbZERsRKLJ1cWCxsIulbGqHr+OxtS8rwm7Kk+qyiLVko8y2nEmdkI8Tob+U9cCwZ2r3PRPzlgl077pk4pt0RNj5F6xI8W0B7EOZTcnQZqtZJpS9JgGvyLt1AfRtcXSXarFeicNGNJTplDXHeyyg7hac9S4iE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710150909; c=relaxed/simple; bh=5/qiiXwZTYdXODnxnJTgNllc8AomJcW2umJjIPgjH2U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=iKyNwFzu1VhcA1eaTAYO5Kn1Lw03oAs2GUKVv8joFjHyjfjbtxapX2y71L3yRcdLR4kEuUfarzrvLelT0FmW4YB/wuj8iTYJijEq/dR0sbed69+XH5tWwOh6w9JuWuNVu3ZcZU40yYHOBCQ7gBGBPBuHWArBL8Vay2Pi0CoTGFY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=kg8KKzce; arc=none smtp.client-ip=115.124.30.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="kg8KKzce" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1710150897; h=Date:From:To:Subject:Message-ID:MIME-Version:Content-Type; bh=5/qiiXwZTYdXODnxnJTgNllc8AomJcW2umJjIPgjH2U=; b=kg8KKzceM1XioczzNUXfI708VV2/l1OpccdorDnmT4KBJQkBpmFxdg4hEl52jBZcLnDqPl+nfmu3nDSWDiB/NnYnRXOwFuemJefCXpp3AnnesHEh/qDtv4CYelxXohi7XKgnoKNEPjZJHc1mrgnpioRHy2AwCxZzxIFe1umvIbE= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R111e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046059;MF=dust.li@linux.alibaba.com;NM=1;PH=DS;RN=5;SR=0;TI=SMTPD_---0W2F3SYm_1710150896; Received: from localhost(mailfrom:dust.li@linux.alibaba.com fp:SMTPD_---0W2F3SYm_1710150896) by smtp.aliyun-inc.com; Mon, 11 Mar 2024 17:54:57 +0800 Date: Mon, 11 Mar 2024 17:54:56 +0800 From: Dust Li To: Cong Wang Cc: lsf-pc@lists.linux-foundation.org, bpf , Xuan Zhuo , "a.mehrab@bytedance.com" Subject: Re: [LSF/MM/BPF TOPIC] Inter-VM Shared Memory Communications with eBPF Message-ID: <20240311095456.GA40084@linux.alibaba.com> Reply-To: dust.li@linux.alibaba.com References: <20240304095947.GB123222@linux.alibaba.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Thu, Mar 07, 2024 at 07:52:52PM -0800, Cong Wang wrote: >On Mon, Mar 4, 2024 at 1:59 AM Dust Li wrote: >> >> On Fri, Feb 23, 2024 at 03:05:59PM -0800, Cong Wang wrote: >> >> Hi Cong, >> >> This is a good topic ! >> We have proposed another solution to accelerate Inter-VM tcp/ip communication >> transparently within the same host based on SMC-D + virtio-ism >> https://lists.oasis-open.org/archives/virtio-comment/202212/msg00030.html >> >> I don't know, can we do better with your proposal ? > >We knew SMC and it _is_ actually why I have this eBPF based proposal. >Sorry for not providing more details here, since I just want to keep >this proposal >brief and will certain have all the details in our presentation if our >proposal gets >accepted. > >The main problem of SMC is it is not fully transparent, LD_PRELOAD could >work for most cases but not all. Therefore, I don't think introducing any new >socket family is in the right direction at all. Actually, this is not really true. We have introduce several ways to solve this. The best way I think is to support IPPROTO_SMC[1] in SMC and using the same eBPF infrastructure as MPTCP has already contributed[2]. [1] https://lore.kernel.org/netdev/20231113045758.GB121324@linux.alibaba.com [2] https://lore.kernel.org/all/cover.1692147782.git.geliang.tang@suse.com > >(There are some other problems with SMC too, for instance, it requires more >than a 3-way handshake.) Right, but I don't see much performance penalty because of the extra handshake, setting up the share memory is always the slowest part in a share memory communication model. > >And I don't think there is any conflict or overlap here at all. Our eBPF-based >solution relies on the existing inter-VM shared memory, no matter it is ivshmem >or virtio-ism. We don't propose any new way of sharing memory, what we >propose is merely using an existing one and building our solution on top. > >In fact, we believe our solution can be on top of your virtio-ism, >since it is just >another flat memory region from our point of view. > >Hope this helps. Don't get me wrong, I'm not against to your proposal at all, I like it. I just hope different solutions can be seen. Best regards, Dust > >Thanks.