From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: passt.top; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=FziKB4vB; dkim-atps=neutral Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by passt.top (Postfix) with ESMTPS id 66B3E5A0272 for ; Wed, 26 Nov 2025 09:04:37 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1764144276; 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:autocrypt:autocrypt; bh=EnWmjnhhemYeRAgxcTf+YO++Fvzxhr4HfazZlYKu7KI=; b=FziKB4vB6izHhn0KgE0LGyC2iW5J7jTMHzHRaK7T2qap7xqSvgNTwAXMZ34PHGQsHVgV4j tSUGw/UPhHNim+vtkGNCD/ZVRtrvRGGi3BJfDo4VOpF7JuUi5yiKyXVLFDEeSGAfz4pfms Muq5pyldrGuNmZ8bj6uoPFfuZvcKAPA= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-556-eBxVbTpONXmxD7l0TzqY9Q-1; Wed, 26 Nov 2025 03:04:33 -0500 X-MC-Unique: eBxVbTpONXmxD7l0TzqY9Q-1 X-Mimecast-MFC-AGG-ID: eBxVbTpONXmxD7l0TzqY9Q_1764144272 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-47775585257so46941875e9.1 for ; Wed, 26 Nov 2025 00:04:33 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764144272; x=1764749072; h=content-transfer-encoding:in-reply-to:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=EnWmjnhhemYeRAgxcTf+YO++Fvzxhr4HfazZlYKu7KI=; b=tn886WAtdqmVFGX+luJrb/5/3XRxR2h+NkSVt3rn117hCxMgMvT0x+GvMp4FptSik8 WVsQcmkmali6AQEsy0ATJOmMTZ69pH8bCAKowMXYuYTPpN493ojSnXsN4i0mzPGBPY8u dhfdcCD+i5vWC4/2ZyFlvu76Udzt+fUPsMAUW2drKH6l2UtfOzAtDapUR+SiGJnooKEl Gzoc92054hRDMp5daXRhlzN9RmbDvzTEhivOTxsHnKcDw8LE3DeeB8oCMOzPwSWnTkL2 eZZs/Fl45f8I47sz4inYiCdVWGPoYhKX+iqLd1RB1k3/dTUMnFXt9SgRdeVhsNLtjoJG EVxQ== X-Gm-Message-State: AOJu0YxmgI001xg6QtOkLZTH043AcXfXEWclrieghw+2CGO1RchK80Cz yx8/7PCMAiQj+7jkbusvgbOerFAoiM+y+/ZqAYDpF/kYyVPkoDNDcPtETja+m4TlF+qzjBmiVSH N2MvKc8qpYsdmyyAG1+wGEJx8vub1zD08Py9XT/sJ94+0zt32nhGzsA== X-Gm-Gg: ASbGncuzXAjbmFFdwhbxH6VFq4VBPMDSuAGzKwaxm3oXwSeMWYmnWaX5wMj9QhS+R/2 Ab8yVXfyj1f/sBvgxPl3cp54PJl9jEKZ8xkEEr4F6TbO6/3UHOjBMLnOX0fLo61mAnFczDP95XT Ifn6sr7gmfmzenRMZqX7KdxbGDfp/Nu04PyIn/HDxpJRk/xnAs5F0GfXtx5X7aA+/TTb4ILb/h7 K0XUyDvCodChJ3f0/C0j9EWfpwIpq19bsw3AWnV0vvrCi+/GWR6za1fjRZ43uWdZcJ9E+AlGqEn 3eRmBbKIE2SErsbwnevGL6oVtbneLp5AWVR0gd58xbA1+i2xTWp6eZ0aV60RkLFLpzwJPe+vlQd jmyMuxgms2prfS1nJTaA8ZzjdpJjDBPB9k5YfFIvl+oIRc7Ra X-Received: by 2002:a05:600c:1382:b0:477:a977:b8a7 with SMTP id 5b1f17b1804b1-477c1117956mr163258465e9.19.1764144272284; Wed, 26 Nov 2025 00:04:32 -0800 (PST) X-Google-Smtp-Source: AGHT+IGKRN0qTG4EM8qC7iRmvjtjlEIJxdzO/OLQYsxmNGSR5I1ZMfA48baHNdTqtM1bcc0/8XlXuA== X-Received: by 2002:a05:600c:1382:b0:477:a977:b8a7 with SMTP id 5b1f17b1804b1-477c1117956mr163257805e9.19.1764144271620; Wed, 26 Nov 2025 00:04:31 -0800 (PST) Received: from ?IPV6:2a01:e0a:e10:ef90:343a:68f:2e91:95c? ([2a01:e0a:e10:ef90:343a:68f:2e91:95c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4790addddf6sm28992865e9.8.2025.11.26.00.04.30 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 26 Nov 2025 00:04:31 -0800 (PST) Message-ID: Date: Wed, 26 Nov 2025 09:04:30 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2 2/6] vhost-user: Enable multiqueue To: David Gibson References: <20251121165902.1014964-1-lvivier@redhat.com> <20251121165902.1014964-3-lvivier@redhat.com> From: Laurent Vivier Autocrypt: addr=lvivier@redhat.com; keydata= xsFNBFYFJhkBEAC2me7w2+RizYOKZM+vZCx69GTewOwqzHrrHSG07MUAxJ6AY29/+HYf6EY2 WoeuLWDmXE7A3oJoIsRecD6BXHTb0OYS20lS608anr3B0xn5g0BX7es9Mw+hV/pL+63EOCVm SUVTEQwbGQN62guOKnJJJfphbbv82glIC/Ei4Ky8BwZkUuXd7d5NFJKC9/GDrbWdj75cDNQx UZ9XXbXEKY9MHX83Uy7JFoiFDMOVHn55HnncflUncO0zDzY7CxFeQFwYRbsCXOUL9yBtqLer Ky8/yjBskIlNrp0uQSt9LMoMsdSjYLYhvk1StsNPg74+s4u0Q6z45+l8RAsgLw5OLtTa+ePM JyS7OIGNYxAX6eZk1+91a6tnqfyPcMbduxyBaYXn94HUG162BeuyBkbNoIDkB7pCByed1A7q q9/FbuTDwgVGVLYthYSfTtN0Y60OgNkWCMtFwKxRaXt1WFA5ceqinN/XkgA+vf2Ch72zBkJL RBIhfOPFv5f2Hkkj0MvsUXpOWaOjatiu0fpPo6Hw14UEpywke1zN4NKubApQOlNKZZC4hu6/ 8pv2t4HRi7s0K88jQYBRPObjrN5+owtI51xMaYzvPitHQ2053LmgsOdN9EKOqZeHAYG2SmRW LOxYWKX14YkZI5j/TXfKlTpwSMvXho+efN4kgFvFmP6WT+tPnwARAQABzSNMYXVyZW50IFZp dmllciA8bHZpdmllckByZWRoYXQuY29tPsLBeAQTAQIAIgUCVgVQgAIbAwYLCQgHAwIGFQgC CQoLBBYCAwECHgECF4AACgkQ8ww4vT8vvjwpgg//fSGy0Rs/t8cPFuzoY1cex4limJQfReLr SJXCANg9NOWy/bFK5wunj+h/RCFxIFhZcyXveurkBwYikDPUrBoBRoOJY/BHK0iZo7/WQkur 6H5losVZtrotmKOGnP/lJYZ3H6OWvXzdz8LL5hb3TvGOP68K8Bn8UsIaZJoeiKhaNR0sOJyI YYbgFQPWMHfVwHD/U+/gqRhD7apVysxv5by/pKDln1I5v0cRRH6hd8M8oXgKhF2+rAOL7gvh jEHSSWKUlMjC7YwwjSZmUkL+TQyE18e2XBk85X8Da3FznrLiHZFHQ/NzETYxRjnOzD7/kOVy gKD/o7asyWQVU65mh/ECrtjfhtCBSYmIIVkopoLaVJ/kEbVJQegT2P6NgERC/31kmTF69vn8 uQyW11Hk8tyubicByL3/XVBrq4jZdJW3cePNJbTNaT0d/bjMg5zCWHbMErUib2Nellnbg6bc 2HLDe0NLVPuRZhHUHM9hO/JNnHfvgiRQDh6loNOUnm9Iw2YiVgZNnT4soUehMZ7au8PwSl4I KYE4ulJ8RRiydN7fES3IZWmOPlyskp1QMQBD/w16o+lEtY6HSFEzsK3o0vuBRBVp2WKnssVH qeeV01ZHw0bvWKjxVNOksP98eJfWLfV9l9e7s6TaAeySKRRubtJ+21PRuYAxKsaueBfUE7ZT 7zfOwU0EVgUmGQEQALxSQRbl/QOnmssVDxWhHM5TGxl7oLNJms2zmBpcmlrIsn8nNz0rRyxT 460k2niaTwowSRK8KWVDeAW6ZAaWiYjLlTunoKwvF8vP3JyWpBz0diTxL5o+xpvy/Q6YU3BN efdq8Vy3rFsxgW7mMSrI/CxJ667y8ot5DVugeS2NyHfmZlPGE0Nsy7hlebS4liisXOrN3jFz asKyUws3VXek4V65lHwB23BVzsnFMn/bw/rPliqXGcwl8CoJu8dSyrCcd1Ibs0/Inq9S9+t0 VmWiQWfQkz4rvEeTQkp/VfgZ6z98JRW7S6l6eophoWs0/ZyRfOm+QVSqRfFZdxdP2PlGeIFM C3fXJgygXJkFPyWkVElr76JTbtSHsGWbt6xUlYHKXWo+xf9WgtLeby3cfSkEchACrxDrQpj+ Jt/JFP+q997dybkyZ5IoHWuPkn7uZGBrKIHmBunTco1+cKSuRiSCYpBIXZMHCzPgVDjk4viP brV9NwRkmaOxVvye0vctJeWvJ6KA7NoAURplIGCqkCRwg0MmLrfoZnK/gRqVJ/f6adhU1oo6 z4p2/z3PemA0C0ANatgHgBb90cd16AUxpdEQmOCmdNnNJF/3Zt3inzF+NFzHoM5Vwq6rc1JP jfC3oqRLJzqAEHBDjQFlqNR3IFCIAo4SYQRBdAHBCzkM4rWyRhuVABEBAAHCwV8EGAECAAkF AlYFJhkCGwwACgkQ8ww4vT8vvjwg9w//VQrcnVg3TsjEybxDEUBm8dBmnKqcnTBFmxN5FFtI WlEuY8+YMiWRykd8Ln9RJ/98/ghABHz9TN8TRo2b6WimV64FmlVn17Ri6FgFU3xNt9TTEChq AcNg88eYryKsYpFwegGpwUlaUaaGh1m9OrTzcQy+klVfZWaVJ9Nw0keoGRGb8j4XjVpL8+2x OhXKrM1fzzb8JtAuSbuzZSQPDwQEI5CKKxp7zf76J21YeRrEW4WDznPyVcDTa+tz++q2S/Bp P4W98bXCBIuQgs2m+OflERv5c3Ojldp04/S4NEjXEYRWdiCxN7ca5iPml5gLtuvhJMSy36gl U6IW9kn30IWuSoBpTkgV7rLUEhh9Ms82VWW/h2TxL8enfx40PrfbDtWwqRID3WY8jLrjKfTd R3LW8BnUDNkG+c4FzvvGUs8AvuqxxyHbXAfDx9o/jXfPHVRmJVhSmd+hC3mcQ+4iX5bBPBPM oDqSoLt5w9GoQQ6gDVP2ZjTWqwSRMLzNr37rJjZ1pt0DCMMTbiYIUcrhX8eveCJtY7NGWNyx FCRkhxRuGcpwPmRVDwOl39MB3iTsRighiMnijkbLXiKoJ5CDVvX5yicNqYJPKh5MFXN1bvsB kmYiStMRbrD0HoY1kx5/VozBtc70OU0EB8Wrv9hZD+Ofp0T3KOr1RUHvCZoLURfFhSQ= In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: iIEKQJuCNXjXx_3O3QA2W-DF1nwcnZEeqmHpsanTbpQ_1764144272 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Message-ID-Hash: ABHBTG3Z2IHSALFRSFJUHZB4Q5O7MLMB X-Message-ID-Hash: ABHBTG3Z2IHSALFRSFJUHZB4Q5O7MLMB X-MailFrom: lvivier@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: On 11/26/25 03:20, David Gibson wrote: > On Fri, Nov 21, 2025 at 05:58:58PM +0100, Laurent Vivier wrote: >> Add the --max-queues parameter to specify the maximum number of >> queue > > Nit: you updated the option to be --max-qpairs, which I think is good, > but now the commit message is out of date. > > > One other query: what makes it "max qpairs" rather than just "qpairs" > - are there (now or in planned work) circumstances where you'd end up > with less qpairs than specified here? In fact, the number of qpairs is negociated by the guest. If you start passt with max-qpairs=16 but QEMU with queues=4, it will only use 4 qpairs. If you start QEMU with queues=17, it will fail. Perhaps we can remove the parameter and rely only on the hardcoded one (32 virtqueues = 16 qpairs)? I can add "--mq" parameter instead to enable multiqueue? > >> pairs supported in vhost-user mode. This enables multi-queue support >> by allowing configuration of up to 16 queue pairs (32 virtqueues). >> >> For the moment, only the first RX queue is used, the TX queue is >> selected by the guest kernel. > > IIUC, with this patch (but not the ones after) things will break if > the guest uses a qpair other than 0, right? AFAICT vu_kick_cb() isn't > updated so will ignore anything on the other qpairs. No, I think it should work. For the TX part (from guest) we add all the kick_fd to the epollfd, so all the TX queues are managed. But we we use only RX queue 0, that is not what is expected by the guest kernel as we should use the same queue pair but I think kernel will process them anyway. Thanks, Laurent