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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 11527E7717D for ; Wed, 11 Dec 2024 15:58:07 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1tLP5q-0005nl-C9; Wed, 11 Dec 2024 10:57:42 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1tLP5o-0005nb-TC for qemu-devel@nongnu.org; Wed, 11 Dec 2024 10:57:40 -0500 Received: from mail-pj1-x1036.google.com ([2607:f8b0:4864:20::1036]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1tLP5n-0004Mb-08 for qemu-devel@nongnu.org; Wed, 11 Dec 2024 10:57:40 -0500 Received: by mail-pj1-x1036.google.com with SMTP id 98e67ed59e1d1-2ef6af22ea8so4977960a91.0 for ; Wed, 11 Dec 2024 07:57:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1733932657; x=1734537457; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:from:to:cc:subject:date:message-id:reply-to; bh=VPNhkpkiR/2sp1sMgdrZpBZFaAENwx6+ttAeb6bfzKM=; b=Dx9sHTpUOyRKgAX9runwGRkbXSr+MaYhjjR2jumZosqmx+m9xcYlh2MyN3kivU2Ldv rV8G1P6Kc/YplT3wRwlhyoJRyvH9bpO0Hur/8+Hfeur/M5zFEOxA0kNKmtJ3UnANQoIB y1Z+AjCAPwChpjLL1h6nZQn/l7QBJhBfwEcnkIclpmxgsmZF1WBdqHRdc/msaImkPS6A by+c414LgQZtSnTG8+wTMFWbWBfurucr50Pz2fEW4BuJQ8QQoYVWYtXd43GjkNG4Ryrb msBeWUloYIAARXJkNyfqr5UueKOIZ7mhJ+rJWO+Y1M93bQgZl/Is2DH3WqlvX3PPJJNE KjXA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1733932657; x=1734537457; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=VPNhkpkiR/2sp1sMgdrZpBZFaAENwx6+ttAeb6bfzKM=; b=m5Tn2gS6zqzXI35R9Xp7ibyltNsIZgZlObHOQrZTpGL41Bf/z+lZ3ZwzCYyhkk7Ty/ B7AOnin9WVN3qvAxcfMV/Y+El1pM6dMgX7OmUjsUnZg/6b/4+0gfshHUG+Z48tTC8vHr 1jL4lquSYIbiUhH6zhRAyp0Fcl5TPQKMHENblY+YAgOi7710r1eoqKfpX10C60qKOZap u3X+2QSLiyiaszNrLHZjniVNszGadWnpYi15HRr6G8MIaq7PGY4AF7HXtgGlSTPC8RLu q3S20zifr3NZhEpLYd9z5T6ZuhB3k0ZSKiz0aBHTftb5T0jfKUj2ir4ArGnI8SFzumWL ioKA== X-Forwarded-Encrypted: i=1; AJvYcCUJMyrjLI+YfS6PfwhnzgwmkOH2Wbn6zhCDhJW08CMzPwJc/Aa8RHC3fwe5xc4HCIdlSuMI9o5CS2zJ@nongnu.org X-Gm-Message-State: AOJu0YxwV6w+SVckPE56yEOzRiXoRQQu87gWIGWt+IxAgYbx+Qr/trnV SiOw53tvZfXnAxXm03bSWpj8ivYPqO2Ts2F7qlay641IuMjDomRwgqSJrA== X-Gm-Gg: ASbGncsPTdsvbZIm0RdnZXVmD/PenCIS8mZkfn9IRqHPaHcJtSl4+1EqFxQecFGPPYx sCuvylzq2P5WGDu9/DaxJhAevznAn1cczOyGjZmSXsB8wnZQB5QcMPK7085rjlktuPQuc3fmmWh WA/j0tf8KXkAILGRpqPZcPHAxTYWIjujV/059kKUHPoBd5tJ9q6v8zCtY+zjMEErGccvv7Cd62v nabKSPFxbQEXlglotNhs1bX X-Google-Smtp-Source: AGHT+IF0SY5e/NdpHV0jEBEVwX01yqZckwH5oV0hvLdr/wj2p5HfpyMPJPmvsFr7oZj854NAFnxlRw== X-Received: by 2002:a17:90a:de98:b0:2ee:b4d4:69 with SMTP id 98e67ed59e1d1-2f128048ef7mr5173211a91.35.1733932656651; Wed, 11 Dec 2024 07:57:36 -0800 (PST) Received: from [192.168.1.18] ([223.233.86.194]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2ef67d6ea84sm11129071a91.47.2024.12.11.07.57.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 11 Dec 2024 07:57:36 -0800 (PST) Message-ID: Date: Wed, 11 Dec 2024 21:27:30 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC v4 0/5] Add packed virtqueue to shadow virtqueue To: Eugenio Perez Martin Cc: sgarzare@redhat.com, mst@redhat.com, qemu-devel@nongnu.org, Sahil Siddiq References: <20241205203430.76251-1-sahilcdq@proton.me> Content-Language: en-US From: Sahil Siddiq Autocrypt: addr=icegambit91@gmail.com; keydata= xsDNBGcgaYEBDADpKUSKbchLCMdCuZGkuF50/7BiraKc8Ch+mk4T+2+E2/6qXAkalvCkFoqx 3/sa35rconZAFzB/r19e7i3UajIQjATvENrGxqe/IFqcJxo2Jr1HQBwCrsmlQoUCilSC6nDi ejcEIAFytJORDkCcZwLXPjdf5/4pbqVAW5823LB5j5F0TqHAnGY1RhS2V1eBPdRqjAA3xecT zTmLHlkqAXgM2DOot1KbycedZSieCwEykTXMaLC0/3Gyo2Cp1WTWOIyD0hsXpLyFioV4FaX2 Lm+z45Zc4PoNXeC6+l4PdDxixs+saAbadknP+9omwlb+PkMd3esq2wkowTwTJVJK8FCCNTo5 2OArA/ddxcyXY25JHN7vzGooFNW6Bb9YV+lbX6y95ytE3KcAmid73tQrcjlebIpgNAvOMyyZ BgQJY0HSu3DGNZuKtbNM3iTl82TFj7MVgkEffgF83N6XyBqDztIz2lN47/q5wyRi3jda9NDt geI+Nv145HjulO7bI3NT048AEQEAAc0kU2FoaWwgU2lkZGlxIDxpY2VnYW1iaXQ5MUBnbWFp bC5jb20+wsENBBMBCAA3FiEERtYfQYWFu+uAZjYrrzGlXdb6f1cFAmcgaYEFCQWjmoACGwME CwkIBwUVCAkKCwUWAgMBAAAKCRCvMaVd1vp/V/nnC/9KnNIr4a3JW3E/snxv1+XIyUmHBDLn PKBmLDYxO9RJe1xKo/sNmLEno4c8G1F/y12TLV086cpBYGKkE8mPMBABqxuiPG8srwoKc2HW bvoC2Zfeu/WeQ0YqeI9ZEwRhsDGQZ7vc8PnKnEUaPZn6iWW4GeX7dXWeGNrK0wU2B04l2d+M FIKaoPHk8w5Ff++QNcn0YRkm//nYlukHUrMxhNcuc18jaLLftOh7BH/4EbKtTN75KAFePQBi I2CbuC41fchTt12QrPB3yz1GKfudsEMLFHBNeComJNnuolPOq0YSyuKdRO8Jubn5ZqWQeTwj XbG7wTonDc8xe46irOhz36VcjsjSY+PYhVZSeDWeDUZgpaJkBjQDDodIN2eoMwVEyUByos9H mKrqrpBMmylOspAZzqjb5FtOqM0BCxQINdKKiMwRelSb6pHYCrbS0XzpwDUEpp7RWCbHgg+6 Ot72kQCEFxj2LzX9VxF24GGQy9inlUfN51IV04klSibtBuuz/NbOwM0EZyBpgQEMAJelVX4k CtCxD4Ji3FQ8LZs22z7VoUvqIb7Gj2lNvhPeijlqqBkSMIgnSCLxlH4ahqKnEV58IrfVriV0 92zb94Az2nl0r+bZYfvev1qCcVIYxk+pYYcRl5qPXX8XGalrkcBBWmkgTSwzNK9rV4850iVI hsJNel49qen9JwiFYMSKa2MYgdYSbeuuwXwUp0ZHeVFc5RnPK2wxws1xcnsdb9hRXs2UeTEE 0klG3HuXqJ96DzKrCieKHLjs330h+16gDWAFZSEoT7Mh3HFGI2dscVuBstQNgnwUMnsJv8jx c005CfLCjCBnJEhMd2/QFuLwCZv4IdoghKwYw18e61UbX2bFovo9dduD527pD4sFqi7U7ofv aO3yf+ulL6jiKypGvnbiBP3KY3aKxx6pHHH3aDc9eOqCUgrtS3+xt1du4+qxrYqEnrywFoJy 5zqSzbnTTjFpdTbY5SS52fIOktLlAKzEg6V9hkg2r08hC3/L4NVj6I4tsGZlqb2neRlHFmCr bQARAQABwsD8BBgBCAAmFiEERtYfQYWFu+uAZjYrrzGlXdb6f1cFAmcgaYIFCQWjmoACGwwA CgkQrzGlXdb6f1fDIgwAmpB7eL3XNSx3F+gbmksOPMqCU5rEswRedjEt6tBzFTXhdNFfhZTb vCddUNePZnzddgxAnDBcTqI1jx6Go6Hkti/mxJqXSczMYBsImD/lEm47axsADvpnNaEM+tmu m/cMKfpILUpy2Ey7CKXUA1vpzYeUD29EQWi0fxM0arplrVt/uzUdFRFQRn2hCqeDLBLONX1F Adq+re6M0dhKl4a2+erzZRIXh3vIGiDmpJEGrajrhqEnMXFp6toSiMGian94m8H3NT6rB64E JmdHgyjXADFbn2G5Mb6Pwa8KnnK1kYcZ+Pwu9LfMXfgI01Sh/k01hjUVmnpYep4nHUfwXA8r kn6WekD80DYbAfKyFAXQCO/nclZ82RNmJbDRi3AeMFrxKi6KgdGCp1Izhj9USaMOVqcuV2p0 Rsoq+sFqWOKaHWnQHCM9RkynQVqrgUaSawEbGlCP1KIhVmjfjVsmsCaKkUb9T6VeO+ZNe+Pn rPgMe6IIvn24UuW2f6fIt0AaqOWq In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=2607:f8b0:4864:20::1036; envelope-from=icegambit91@gmail.com; helo=mail-pj1-x1036.google.com X-Spam_score_int: -17 X-Spam_score: -1.8 X-Spam_bar: - X-Spam_report: (-1.8 / 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, FREEMAIL_ENVFROM_END_DIGIT=0.25, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, 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: 2.1.29 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-bounces+qemu-devel=archiver.kernel.org@nongnu.org Hi, Thank you for your reply. On 12/10/24 2:57 PM, Eugenio Perez Martin wrote: > On Thu, Dec 5, 2024 at 9:34 PM Sahil Siddiq wrote: >> >> Hi, >> >> There are two issues that I found while trying to test >> my changes. I thought I would send the patch series >> as well in case that helps in troubleshooting. I haven't >> been able to find an issue in the implementation yet. >> Maybe I am missing something. >> >> I have been following the "Hands on vDPA: what do you do >> when you ain't got the hardware v2 (Part 2)" [1] blog to >> test my changes. To boot the L1 VM, I ran: >> >> [...] >> >> But if I boot L2 with x-svq=true as shown below, I am unable >> to ping the host machine. >> >> $ ./qemu/build/qemu-system-x86_64 \ >> -nographic \ >> -m 4G \ >> -enable-kvm \ >> -M q35 \ >> -drive file=//root/L2.qcow2,media=disk,if=virtio \ >> -netdev type=vhost-vdpa,vhostdev=/dev/vhost-vdpa-0,x-svq=true,id=vhost-vdpa0 \ >> -device virtio-net-pci,netdev=vhost-vdpa0,disable-legacy=on,disable-modern=off,ctrl_vq=on,ctrl_rx=on,event_idx=off,bus=pcie.0,addr=0x7 \ >> -smp 4 \ >> -cpu host \ >> 2>&1 | tee vm.log >> >> In L2: >> >> # ip addr add 111.1.1.2/24 dev eth0 >> # ip addr show eth0 >> 2: eth0: mtu 1500 qdisc fq_codel state UP group default qlen 1000 >> link/ether 52:54:00:12:34:57 brd ff:ff:ff:ff:ff:ff >> altname enp0s7 >> inet 111.1.1.2/24 scope global eth0 >> valid_lft forever preferred_lft forever >> inet6 fe80::9877:de30:5f17:35f9/64 scope link noprefixroute >> valid_lft forever preferred_lft forever >> >> # ip route >> 111.1.1.0/24 dev eth0 proto kernel scope link src 111.1.1.2 >> >> # ping 111.1.1.1 -w10 >> PING 111.1.1.1 (111.1.1.1) 56(84) bytes of data. >> From 111.1.1.2 icmp_seq=1 Destination Host Unreachable >> ping: sendmsg: No route to host >> From 111.1.1.2 icmp_seq=2 Destination Host Unreachable >> From 111.1.1.2 icmp_seq=3 Destination Host Unreachable >> >> --- 111.1.1.1 ping statistics --- >> 3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2076ms >> pipe 3 >> >> The other issue is related to booting L2 with "x-svq=true" >> and "packed=on". >> >> In L1: >> >> $ ./qemu/build/qemu-system-x86_64 \ >> -nographic \ >> -m 4G \ >> -enable-kvm \ >> -M q35 \ >> -drive file=//root/L2.qcow2,media=disk,if=virtio \ >> -netdev type=vhost-vdpa,vhostdev=/dev/vhost-vdpa-0,id=vhost-vdpa0,x-svq=true \ >> -device virtio-net-pci,netdev=vhost-vdpa0,disable-legacy=on,disable-modern=off,guest_uso4=off,guest_uso6=off,host_uso=off,guest_announce=off,ctrl_vq=on,ctrl_rx=on,event_idx=off,packed=on,bus=pcie.0,addr=0x7 \ >> -smp 4 \ >> -cpu host \ >> 2>&1 | tee vm.log >> >> The kernel throws "virtio_net virtio1: output.0:id 0 is not >> a head!" [4]. >> > > So this series implements the descriptor forwarding from the guest to > the device in packed vq. We also need to forward the descriptors from > the device to the guest. The device writes them in the SVQ ring. > > The functions responsible for that in QEMU are > hw/virtio/vhost-shadow-virtqueue.c:vhost_svq_flush, which is called by > the device when used descriptors are written to the SVQ, which calls > hw/virtio/vhost-shadow-virtqueue.c:vhost_svq_get_buf. We need to do > modifications similar to vhost_svq_add: Make them conditional if we're > in split or packed vq, and "copy" the code from Linux's > drivers/virtio/virtio_ring.c:virtqueue_get_buf. > > After these modifications you should be able to ping and forward > traffic. As always, It is totally ok if it needs more than one > iteration, and feel free to ask any question you have :). > Understood, I'll make these changes and will test it again. Thanks, Sahil