From nobody Tue Nov 30 14:02:28 2021 X-Original-To: net@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 417C118B8C94 for ; Tue, 30 Nov 2021 14:02:32 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [IPv6:2610:1c1:1:606c::24b:4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4J3P6v6xS3z4XKh; Tue, 30 Nov 2021 14:02:31 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from [192.168.0.88] (unknown [195.64.148.76]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: avg/mail) by smtp.freebsd.org (Postfix) with ESMTPSA id 51E9B5F8F; Tue, 30 Nov 2021 14:02:31 +0000 (UTC) (envelope-from avg@FreeBSD.org) Message-ID: Date: Tue, 30 Nov 2021 16:02:28 +0200 List-Id: Networking and TCP/IP with FreeBSD List-Archive: https://lists.freebsd.org/archives/freebsd-net List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-net@freebsd.org MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.3.0 Subject: Re: vmxnet3: possible bug in vmxnet3_isc_rxd_pkt_get Content-Language: en-US From: Andriy Gapon To: "net@FreeBSD.org" Cc: Mark Johnston , Patrick Kelsey References: <0dbe63d0-3219-846d-4c58-0bf219f41634@FreeBSD.org> <65d72f7d-5096-07ec-4e21-c6356be7e06f@FreeBSD.org> In-Reply-To: <65d72f7d-5096-07ec-4e21-c6356be7e06f@FreeBSD.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1638280952; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=bhUdBO1NSbt3P2oUcmUz8yJd+sARByQWALlr+/ZVXqI=; b=g+gkoL/Nr+UwoRd6nHd9Qcq5h3o2ZRoiMnbEAS1wLIPANvh9c6lYja3SXCawu7JHLGUJsS vyqFtlNFKPHqxvGh+MxA9WkjwyVFtXubcANjd6kmlWcvh6p32Wn4Swc2h5/hsTDJPRTQke Kf0y0IBNbPM0dZim9dic58jqo3zkSe7ApzdBCd98wg6nfdikMWt5go3l1EXtEGHdrpzd6c RVe46J/DMnWmc0aqkzhsmxvGaM+cfayW4lGcxb6HJXC7pq4QjH2eIy72L8oPCI2Zy8nndF dzSC7X9cMC8CyeoZAyuMuYoSQVOEQN/gCiEwuSsgJzDbyMqr74VWcqdgaDKYSQ== ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1638280952; a=rsa-sha256; cv=none; b=yJYf0aV38hZQXsSE5+YeFZBHD/w8bf90Q3K5/d4Vh2rrdkgjZMKahHZCqU74SA+NLppqfm NA/LZYIdZIzM9YE0uUBuQnBKBacoKMT6zb8lWRilJcNTr0g6fWvBrJramCV3bWM8+GXofW fY4pwYsnYpY2d8TI/xFpZDutG121egZXZB5gq8hxI4GMuBN0SZ5rR5ZX18zYv9lOhIXDBz hhC7oR0Dg7NIDPcRVUZaXHmtd8tvZgTdsC9aAYvtj0MZ7kUy0EEP3xjwDQywei//mTeD2C DrJJ++4Y4hC0yacYY0tWXii3x2j+3vkiVnHbJ6DITa1arebbnn0SGKRI9qXyMw== ARC-Authentication-Results: i=1; mx1.freebsd.org; none X-ThisMailContainsUnwantedMimeParts: N On 19/11/2021 20:46, Andriy Gapon wrote: > I think that this was the case and that I was able to find the corresponding > descriptors in the completion ring. > > Please see https://people.freebsd.org/~avg/vmxnet3-fragment-overrun.txt > > $54 is the SOP, it has qid of 6. > It is followed by many fragments with qid 14 (there are 8 queues / queue sets) > and zero length. > But not all of them are zero length, some have length of 4096, e.g. $77, $86, etc. > $124 is the last fragment, its has eop = 1 and error = 1. > So, there are 71 fragments in total. > > So, it is clear that VMWare produced 71 segments for a single packet before > giving up on it. > > I wonder why it did that. > Perhaps it's a bug, perhaps it does not count zero-length segments against the > limit, maybe something else. > > In any case, it happens. This is what I am currently testing at work: https://reviews.freebsd.org/D33189 So far so good. > Finally, the packet looks interesting: udp = 0, tcp = 0, ipcsum_ok = 0, ipv6 = > 0, ipv4 = 0.  I wonder what kind of a packet it could be -- being rather large > and not an IP packet. -- Andriy Gapon