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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 346B4C433FE for ; Fri, 11 Nov 2022 07:57:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232890AbiKKH5V (ORCPT ); Fri, 11 Nov 2022 02:57:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232540AbiKKH5U (ORCPT ); Fri, 11 Nov 2022 02:57:20 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5A7A263CE2 for ; Thu, 10 Nov 2022 23:56:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1668153388; 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=UnTFHda/akjWgwzpX/PE2gG9WoMnoW6YdEZHH3/oXhA=; b=b0kFjco/D3tiDcc1NeN4LN+tj9tWIWlnItUIrlMz822T3Gm1VFEeHwmXYG/he/dS4EalP7 xUsh6ITAwC2CMP/IkjLZ0/5w0kEOS0sWc48XicDwC6e5h1q96i4LAo1F0MFExQ+YCQ1LjY fTkcfvAa2fbunhe8Dw6wPqajPC0h9Bc= Received: from mail-pf1-f199.google.com (mail-pf1-f199.google.com [209.85.210.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-237-B6d_fBQ-MU2HmgvI5440dQ-1; Fri, 11 Nov 2022 02:56:25 -0500 X-MC-Unique: B6d_fBQ-MU2HmgvI5440dQ-1 Received: by mail-pf1-f199.google.com with SMTP id x8-20020aa79568000000b0056dd717e051so2395782pfq.11 for ; Thu, 10 Nov 2022 23:56:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=UnTFHda/akjWgwzpX/PE2gG9WoMnoW6YdEZHH3/oXhA=; b=tqWVCWRkv/V+CMLVTM0K+slXP/74gb2VXcs1IZumzCu0boWcAr+wMfo8nHFB7VQbF1 UDH9mjQitbMexB2Moseq7+apYKt1avgnfzL3hzNKiFq8Q+BFHhjIgWrFJRBfQkZKJF+x iUEQw+yfUyd+hiwO6u/vLCj5J4hF6/oYBfhWngWDIHxXxr6InLyEue6LnxcOss1Nchz4 VjwD9GlbR3jY1yNgucSJkthMqRSa22vtVTz4KvKKOzNYmpm4O6z+l7P1EuPZ+q8TPC+V 3SMerYLJgjqxVmDGYD/2R3eABNY4JgSSZIQBZDsRJCJ+q8kyBiIkXHBC1bs8eMKubeJ4 6nfw== X-Gm-Message-State: ANoB5pnRBndEa3i0vblAbaae8MjeWF3EzX9H9ZezIcFB8O9MXRD0YSQf 444uhW5jBM2qtgL0wVya7xkIuknGFbTSaxE+YLKXEZ47KzqLCIcHGr7ZCEVHCqNLKfC0aeOZrFu sWYCZ7D9DVSTpvdc0/4KRcbI3aEQk X-Received: by 2002:a63:535e:0:b0:46f:98cf:3bb6 with SMTP id t30-20020a63535e000000b0046f98cf3bb6mr666998pgl.332.1668153384466; Thu, 10 Nov 2022 23:56:24 -0800 (PST) X-Google-Smtp-Source: AA0mqf6zj1smmqmQGSImMBVUk1UvMmcC8P5xYJwYwpl7RXo60Jkv/KNrmV2ZAEYOYogj39nEjkRMlN4zw6vJdgQTQH4= X-Received: by 2002:a63:535e:0:b0:46f:98cf:3bb6 with SMTP id t30-20020a63535e000000b0046f98cf3bb6mr666975pgl.332.1668153384152; Thu, 10 Nov 2022 23:56:24 -0800 (PST) MIME-Version: 1.0 References: <20221108170755.92768-1-eperezma@redhat.com> <20221108170755.92768-6-eperezma@redhat.com> <56bfad97-74d2-8570-c391-83ecf9965cfd@redhat.com> In-Reply-To: From: Eugenio Perez Martin Date: Fri, 11 Nov 2022 08:55:48 +0100 Message-ID: Subject: Re: [PATCH v6 05/10] vdpa: move SVQ vring features check to net/ To: Jason Wang Cc: qemu-devel@nongnu.org, Parav Pandit , Stefan Hajnoczi , Si-Wei Liu , Laurent Vivier , Harpreet Singh Anand , "Michael S. Tsirkin" , Gautam Dawar , Liuxiangdong , Stefano Garzarella , Cindy Lu , Eli Cohen , Cornelia Huck , Zhu Lingshan , kvm@vger.kernel.org, "Gonglei (Arei)" , Paolo Bonzini Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Fri, Nov 11, 2022 at 8:34 AM Jason Wang wrote: > > > =E5=9C=A8 2022/11/10 21:09, Eugenio Perez Martin =E5=86=99=E9=81=93: > > On Thu, Nov 10, 2022 at 6:40 AM Jason Wang wrote: > >> > >> =E5=9C=A8 2022/11/9 01:07, Eugenio P=C3=A9rez =E5=86=99=E9=81=93: > >>> The next patches will start control SVQ if possible. However, we don'= t > >>> know if that will be possible at qemu boot anymore. > >> > >> If I was not wrong, there's no device specific feature that is checked > >> in the function. So it should be general enough to be used by devices > >> other than net. Then I don't see any advantage of doing this. > >> > > Because vhost_vdpa_init_svq is called at qemu boot, failing if it is > > not possible to shadow the Virtqueue. > > > > Now the CVQ will be shadowed if possible, so we need to check this at > > device start, not at initialization. > > > Any reason we can't check this at device start? We don't need > driver_features and we can do any probing to make sure cvq has an unique > group during initialization time. > We need the CVQ index to check if it has an independent group. CVQ index depends on the features the guest's ack: * If it acks _F_MQ, it is the last one. * If it doesn't, CVQ idx is 2. We cannot have acked features at initialization, and they could change: It is valid for a guest to ack _F_MQ, then reset the device, then not ack it. > > > To store this information at boot > > time is not valid anymore, because v->shadow_vqs_enabled is not valid > > at this time anymore. > > > Ok, but this doesn't explain why it is net specific but vhost-vdpa specif= ic. > We can try to move it to a vhost op, but we have the same problem as the svq array allocation: We don't have the right place in vhost ops to check this. Maybe vhost_set_features is the right one here? Thanks! > Thanks > > > > > > Thanks! > > > >> Thanks > >> > >> > >>> Since the moved checks will be already evaluated at net/ to know if i= t > >>> is ok to shadow CVQ, move them. > >>> > >>> Signed-off-by: Eugenio P=C3=A9rez > >>> --- > >>> hw/virtio/vhost-vdpa.c | 33 ++------------------------------- > >>> net/vhost-vdpa.c | 3 ++- > >>> 2 files changed, 4 insertions(+), 32 deletions(-) > >>> > >>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c > >>> index 3df2775760..146f0dcb40 100644 > >>> --- a/hw/virtio/vhost-vdpa.c > >>> +++ b/hw/virtio/vhost-vdpa.c > >>> @@ -402,29 +402,9 @@ static int vhost_vdpa_get_dev_features(struct vh= ost_dev *dev, > >>> return ret; > >>> } > >>> > >>> -static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_= vdpa *v, > >>> - Error **errp) > >>> +static void vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost= _vdpa *v) > >>> { > >>> g_autoptr(GPtrArray) shadow_vqs =3D NULL; > >>> - uint64_t dev_features, svq_features; > >>> - int r; > >>> - bool ok; > >>> - > >>> - if (!v->shadow_vqs_enabled) { > >>> - return 0; > >>> - } > >>> - > >>> - r =3D vhost_vdpa_get_dev_features(hdev, &dev_features); > >>> - if (r !=3D 0) { > >>> - error_setg_errno(errp, -r, "Can't get vdpa device features")= ; > >>> - return r; > >>> - } > >>> - > >>> - svq_features =3D dev_features; > >>> - ok =3D vhost_svq_valid_features(svq_features, errp); > >>> - if (unlikely(!ok)) { > >>> - return -1; > >>> - } > >>> > >>> shadow_vqs =3D g_ptr_array_new_full(hdev->nvqs, vhost_svq_free= ); > >>> for (unsigned n =3D 0; n < hdev->nvqs; ++n) { > >>> @@ -436,7 +416,6 @@ static int vhost_vdpa_init_svq(struct vhost_dev *= hdev, struct vhost_vdpa *v, > >>> } > >>> > >>> v->shadow_vqs =3D g_steal_pointer(&shadow_vqs); > >>> - return 0; > >>> } > >>> > >>> static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Er= ror **errp) > >>> @@ -461,11 +440,7 @@ static int vhost_vdpa_init(struct vhost_dev *dev= , void *opaque, Error **errp) > >>> dev->opaque =3D opaque ; > >>> v->listener =3D vhost_vdpa_memory_listener; > >>> v->msg_type =3D VHOST_IOTLB_MSG_V2; > >>> - ret =3D vhost_vdpa_init_svq(dev, v, errp); > >>> - if (ret) { > >>> - goto err; > >>> - } > >>> - > >>> + vhost_vdpa_init_svq(dev, v); > >>> vhost_vdpa_get_iova_range(v); > >>> > >>> if (!vhost_vdpa_first_dev(dev)) { > >>> @@ -476,10 +451,6 @@ static int vhost_vdpa_init(struct vhost_dev *dev= , void *opaque, Error **errp) > >>> VIRTIO_CONFIG_S_DRIVER); > >>> > >>> return 0; > >>> - > >>> -err: > >>> - ram_block_discard_disable(false); > >>> - return ret; > >>> } > >>> > >>> static void vhost_vdpa_host_notifier_uninit(struct vhost_dev *dev, > >>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > >>> index d3b1de481b..fb35b17ab4 100644 > >>> --- a/net/vhost-vdpa.c > >>> +++ b/net/vhost-vdpa.c > >>> @@ -117,9 +117,10 @@ static bool vhost_vdpa_net_valid_svq_features(ui= nt64_t features, Error **errp) > >>> if (invalid_dev_features) { > >>> error_setg(errp, "vdpa svq does not work with features 0x%= " PRIx64, > >>> invalid_dev_features); > >>> + return false; > >>> } > >>> > >>> - return !invalid_dev_features; > >>> + return vhost_svq_valid_features(features, errp); > >>> } > >>> > >>> static int vhost_vdpa_net_check_device_id(struct vhost_net *net) >