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 193EB46895; Fri, 6 Jun 2025 16:20:37 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 3D2624068E; 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 1E49C40283 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-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-90-l_79zp51PqCcQg8N2m1PhQ-1; Fri, 06 Jun 2025 10:20:32 -0400 X-MC-Unique: l_79zp51PqCcQg8N2m1PhQ-1 X-Mimecast-MFC-AGG-ID: l_79zp51PqCcQg8N2m1PhQ_1749219631 Received: by mail-lf1-f69.google.com with SMTP id 2adb3069b0e04-55324bc26dcso1126783e87.1 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=ONw98GfAUYxf2rPi7h8bjeMAHDymrRcNCYrGA8S0I0ZNW+LLMFPszqogYv1iYbktnE UZQ1IJKfya7pMS5MBWH/rTa2aMAmhSFNg30Hzx71IjxaCpNjG4ZtX3QDCcsuhAwIuNHQ 09XTfQdi9bg2CqpKRIq4XPvs15gqtPn9k8atc6P/beI2RXK+tcOGxHsvAqDl7gu8nyrq 0aRI1AsEJG3TkoNcOS/BhmwCQgbn7hsa2hIYIHXJds14AOGNON77ji60PD5XL3WCD8D9 kIhPjbb6Wk4pJI5Xm8gu7hIWUW66HK+JJrRPz1SPpY1M4AVxPOxGwfKveExAVNvt9VER vFMA== X-Gm-Message-State: AOJu0YwaQk5dumiN6ZoL/YPXa6OrJOIjE8hZneEubEdJ7IlEIpq8bc9h QD1UwjhLyejWU2OjNTgA2r9Jmfmoxnx1EDZkMkbjTMEtfqmo3OTGGkbVbB8u9Cf+4lZBkXH/qIv n2JuI25Db4tvT8jhIca9FkPB3NINABDfyEKs1zPuZHokGOkZKCW8TmUn997AZXV2yI1WiTSFVQg 5uzJGX2eLyF0LTovp6V7U= X-Gm-Gg: ASbGnctKKYyy4rZ58pZZ5L2zS8cQgpBnmdcF1z+ylEK2dNfyVWBi6Ae698e9pMMpFVI gr6nmEAo6PuRutdCCiM0lGG26sY+s9Il+vVE6IeJmngEWWybU+zIvbKZIomYaAwEdpw5EddzPo9 mIbFCJwQ== X-Received: by 2002:a05:6512:2c09:b0:553:2308:1ac5 with SMTP id 2adb3069b0e04-55366bd9a1cmr946592e87.4.1749219630734; 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: jXqftwYxzqOq97_IFwTicetCbhVLxugSbP2CkVMsrFY_1749219631 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-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