From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 4137D46895 for ; Fri, 6 Jun 2025 16:20:36 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 16B7B40263; Fri, 6 Jun 2025 16:20:36 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by mails.dpdk.org (Postfix) with ESMTP id 196D340263 for ; Fri, 6 Jun 2025 16:20:34 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1749219633; 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=bf2jNE7MQKBTu/5aYhfW2Fd9g3GPdA+tPXNJT1+S71A=; b=XKw38X/r5cUOyu+h/Ee21/hBEYncCmTbHC+HG8BXqYbi/o2fHw2b0ar/vHJfErenYHN31/ n6U4h+L2OlQDBOTfbl4rWmjHYpGn9qGcn7t8t6l6Lm2p7WnyMMS+MLYWAcUU7/wO5TZG06 aA+woYkQUSO6ckVq/+QwnfPgiJqfNfg= Received: from mail-lf1-f72.google.com (mail-lf1-f72.google.com [209.85.167.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-90-dm9sBA_bM0uIUyQ7YHSyPg-1; Fri, 06 Jun 2025 10:20:32 -0400 X-MC-Unique: dm9sBA_bM0uIUyQ7YHSyPg-1 X-Mimecast-MFC-AGG-ID: dm9sBA_bM0uIUyQ7YHSyPg_1749219631 Received: by mail-lf1-f72.google.com with SMTP id 2adb3069b0e04-55324bc26dcso1126781e87.1 for ; Fri, 06 Jun 2025 07:20:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749219631; x=1749824431; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=bf2jNE7MQKBTu/5aYhfW2Fd9g3GPdA+tPXNJT1+S71A=; b=RZb7iQy7VSj2nrU7ffXagMtkT9Y1i61Jrnpu0g0+7Ute1hdVOvKCFZQ7GVpa7aQovP /i1XXC/YK0s2t7iGlNq3xhtSRUA/r5kyIYHG9yaxr4rzXPlJU7CSYG3+biLV3uOZO2lQ HvwcR1gUIxi4WRQu8/Pry/sCSR63h3xYuqt/e/EVCJy+rw7HoB5fIWtOKb5hNnQfFHew 0NzvQbgWBf4R6S/OQBvKw0ycADgAbJIRUEtI5hUifvFdlsOOMj0rhu6WOvYjAE3cDcxk mi77hyzolK03AFWBL2EuASdhBxTB7SU6MReJu88WyQ+jlyLusqUMBpYaVyERETS5km6+ Xdwg== X-Forwarded-Encrypted: i=1; AJvYcCWNn1N9F5QTvmroZTeweLnb538ItvJ0HydJgimZLok9e9TmDGVzwHtMboaEafuUcIO+3ugqffo=@dpdk.org X-Gm-Message-State: AOJu0YyZ2mJRVI4GCnAGp+iCyflp4x4zkH0WmldGfdLxpsmYOh1arKbm PUhPBijXoUpsBcp7GTu6Q2o2dESUZm4vnbZ5Ro0GJ90TpPnyCFQHD61CXlIiaxI6cg7c6XqYRsC 8rsLMyLOb7xuW+CgXSZrWceRAG0pRZ4aIBClAfGauf29Dg9mLikvWHzYZA4nfj1LD0+aFlRFC3v GGAOv21fBzRletquUd5c7yijU= X-Gm-Gg: ASbGncsUYasX0YiYb++HUJ6hFkbAb5WA8p/MAMzdK4AkhHl7e6S1EvTm3qKutNj9Mlt U9v3NsF0mQ9tOVXP/lKYh0qcXhLIKSxu8zUYbJCWqtDHGEjk4yq4jXFmV8s+zjXYiP0Hl1FxJ67 KfJZQGug== X-Received: by 2002:a05:6512:2c09:b0:553:2308:1ac5 with SMTP id 2adb3069b0e04-55366bd9a1cmr946590e87.4.1749219630733; Fri, 06 Jun 2025 07:20:30 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGu5zWQeVqwD7uo2EZ3VDL0T2lp7vtuIkB3UZ+rI2nBCgQrtkd8gw+u7By37ikqOj+kt5rQfj5sbLxJUFBKHv4= X-Received: by 2002:a05:6512:2c09:b0:553:2308:1ac5 with SMTP id 2adb3069b0e04-55366bd9a1cmr946582e87.4.1749219630313; Fri, 06 Jun 2025 07:20:30 -0700 (PDT) MIME-Version: 1.0 References: <20250605113552.918120-1-eperezma@redhat.com> In-Reply-To: From: David Marchand Date: Fri, 6 Jun 2025 16:20:17 +0200 X-Gm-Features: AX0GCFujhci4ANrxwGrxqDiVFLNutZjtNOHR8QKIYK_JRWf93VpUzdnZVMqxv2w Message-ID: Subject: Re: [PATCH 0/2] Search the split vq desc and avail in RO areas To: Eugenio Perez Martin Cc: dev@dpdk.org, Chenbo Xia , stable@dpdk.org, Maxime Coquelin X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: uV1cR8dYfrG22uvtM4zpI3biUPQq-psQZvGznvSejbs_1749219631 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: stable-bounces@dpdk.org On Thu, Jun 5, 2025 at 4:55=E2=80=AFPM Eugenio Perez Martin wrote: > > On Thu, Jun 5, 2025 at 1:50=E2=80=AFPM David Marchand wrote: > > > > On Thu, Jun 5, 2025 at 1:36=E2=80=AFPM Eugenio P=C3=A9rez wrote: > > > > > > QEMU's shadow virtqueue and VDUSE exposes these areas as read-only. I= f > > > we don't change it, vhost_iova_to_vva do not consider them as valid a= nd > > > returns that they're not found. > > > > > > Eugenio P=C3=A9rez (2): > > > vhost: search the split vq desc and avail in RO areas > > > vhost: search the packed vq driver area in RO areas > > > > > > lib/vhost/vhost.c | 6 +++--- > > > 1 file changed, 3 insertions(+), 3 deletions(-) > > > > At a quick glance, no need for two patches. > > > > Sure I can respin with both squashed. > > > Sorry, the implication of this issue is not clear to me. > > What is the impact from a user pov? > > > > QEMU maps the CVQ descriptors and avail vring through as read only > maps in the case of vDPA. But DPDK is looking for them with RW > permissions, so the vhost_iova_to_vva function never selects the right > one as valid. > > Looking for them with RO still picks the map if it is mapped as RW, > but the reverse is not true. Ok, thanks. Well, it's better, but still hard to tell how this impacts existing usecases :-). After discussing with Maxime, I understand that the shadow CVQ just can't work =3D> blocking multi queue support with vduse for example. This is the type of high level impact I was looking for. > Let me know if you want me to respin the series with this comment too! Ideally yes, but maybe Maxime can do it when applying. --=20 David Marchand