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 X-Spam-Level: X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B32ABC433FE for ; Tue, 14 Sep 2021 12:58:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9A38A610CE for ; Tue, 14 Sep 2021 12:58:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233187AbhINM7z (ORCPT ); Tue, 14 Sep 2021 08:59:55 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49288 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233145AbhINM7x (ORCPT ); Tue, 14 Sep 2021 08:59:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1631624314; 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: in-reply-to:in-reply-to:references:references; bh=+i8tXrYj4yDnCoPDe/Tv3/7/5YA9BMLPa/F1k7LioJM=; b=EMTRTFVfIvGlHQ404ZTrJT6w8JHsyOGWPXbrZ4ci4RBDzd1vCRQ65jhoDY3Z6F3Gn8Ro18 A/qDYt33ykXW5B9UWzWu7Z+SviVLnfxB4sAoSCMuuKufYjrJ4gAQKK1pbm8v1mi69aT2ij 4nJhRzzj+0cTmRJJ+LpIltH/hNfDQHI= Received: from mail-wm1-f70.google.com (mail-wm1-f70.google.com [209.85.128.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-319-jkbUNOPOP--9NcU-if7uug-1; Tue, 14 Sep 2021 08:58:33 -0400 X-MC-Unique: jkbUNOPOP--9NcU-if7uug-1 Received: by mail-wm1-f70.google.com with SMTP id g70-20020a1c2049000000b00303d06c20b2so1168936wmg.0 for ; Tue, 14 Sep 2021 05:58:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=+i8tXrYj4yDnCoPDe/Tv3/7/5YA9BMLPa/F1k7LioJM=; b=AQ2sEeDkzrAMlIUU+nBpLuzKWK+0nLrzo6EyWY/oX0RmH+1YHa3coivnhKGK5BeHQy +Uw1yEKodC1VhzmXbcU2EccJfkSwwFTAIBWGDU1dyW84+vQMLRj9T8goPwh1A06hxvre LUTK2twMvev360gWWL/PsMWzryWMMn/KwX1nvQzrXY/UxAehWt93H65YpAvOYvIClCPO 36J7WUjMeGoWdjVodKyPBNxIjkqurgQq4XLwfX6X6+RscDjqKIDRw3pw96Ef6OYZ0PGI G78p2ziGA6/ODkAE6RmqxP0PQ+KY/xQScl+Hs0O6ckgx3BtUnIp4mbONEsNWRemVOf2O oYvg== X-Gm-Message-State: AOAM530Sjl8ZoTLVtzrmXLsV1B0wrYhIQM+06+yOFtTA3qlDMtLmq0I6 Zv0bxtNmpiUk9E4R2nJUO1FuG5i/3MdrCtIz+I+NLQQOtQhHo0XlXN6BAgc3TCaUvRF7Q11r3PD MYxE0uT2zdjXKwhqN3iB11ND5 X-Received: by 2002:a1c:cc03:: with SMTP id h3mr2044632wmb.73.1631624312219; Tue, 14 Sep 2021 05:58:32 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyHtbUQhdNaZzLMjWktMr/Fa0pUFCfp6kfBfoBbJYkI/xrFMVITu+svlOkLkMY+p+sXXK31Tw== X-Received: by 2002:a1c:cc03:: with SMTP id h3mr2044619wmb.73.1631624312047; Tue, 14 Sep 2021 05:58:32 -0700 (PDT) Received: from redhat.com ([2.55.151.134]) by smtp.gmail.com with ESMTPSA id c9sm11063685wrf.77.2021.09.14.05.58.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Sep 2021 05:58:31 -0700 (PDT) Date: Tue, 14 Sep 2021 08:58:28 -0400 From: "Michael S. Tsirkin" To: Wu Zongyong Cc: jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, wei.yang1@linux.alibaba.com Subject: Re: [PATCH v2 4/5] vdpa: add new vdpa attribute VDPA_ATTR_DEV_F_VERSION_1 Message-ID: <20210914085711-mutt-send-email-mst@kernel.org> References: <834528d24c839080215b2e077f100e9ed5073edc.1631621507.git.wuzongyong@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <834528d24c839080215b2e077f100e9ed5073edc.1631621507.git.wuzongyong@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 14, 2021 at 08:24:51PM +0800, Wu Zongyong wrote: > This new attribute advertises whether the vdpa device is legacy or not. > Users can pick right virtqueue size if the vdpa device is legacy which > doesn't support to change virtqueue size. > > Signed-off-by: Wu Zongyong So if we are bothering with legacy, I think there are several things to do when building the interface - support transitional devices, that is allow userspace to tell device it's in legacy mode - support reporting/setting supporting endian-ness > --- > drivers/vdpa/vdpa.c | 6 ++++++ > drivers/virtio/virtio_vdpa.c | 7 ++++++- > include/uapi/linux/vdpa.h | 1 + > 3 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/drivers/vdpa/vdpa.c b/drivers/vdpa/vdpa.c > index 1dc121a07a93..533d7f589eee 100644 > --- a/drivers/vdpa/vdpa.c > +++ b/drivers/vdpa/vdpa.c > @@ -12,6 +12,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -494,6 +495,7 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq > u16 max_vq_size; > u32 device_id; > u32 vendor_id; > + u64 features; > void *hdr; > int err; > > @@ -508,6 +510,7 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq > device_id = vdev->config->get_device_id(vdev); > vendor_id = vdev->config->get_vendor_id(vdev); > max_vq_size = vdev->config->get_vq_num_max(vdev); > + features = vdev->config->get_features(vdev); > > err = -EMSGSIZE; > if (nla_put_string(msg, VDPA_ATTR_DEV_NAME, dev_name(&vdev->dev))) > @@ -520,6 +523,9 @@ vdpa_dev_fill(struct vdpa_device *vdev, struct sk_buff *msg, u32 portid, u32 seq > goto msg_err; > if (nla_put_u16(msg, VDPA_ATTR_DEV_MAX_VQ_SIZE, max_vq_size)) > goto msg_err; > + if (features & BIT_ULL(VIRTIO_F_VERSION_1) && > + nla_put_flag(msg, VDPA_ATTR_DEV_VERSION_1)) > + goto msg_err; > > genlmsg_end(msg, hdr); > return 0; > diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c > index 72eaef2caeb1..1cba957c4cdc 100644 > --- a/drivers/virtio/virtio_vdpa.c > +++ b/drivers/virtio/virtio_vdpa.c > @@ -7,6 +7,7 @@ > * > */ > > +#include "linux/virtio_config.h" > #include > #include > #include > @@ -145,6 +146,7 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, > /* Assume split virtqueue, switch to packed if necessary */ > struct vdpa_vq_state state = {0}; > unsigned long flags; > + bool may_reduce_num = false; > u32 align, num; > int err; > > @@ -169,10 +171,13 @@ virtio_vdpa_setup_vq(struct virtio_device *vdev, unsigned int index, > goto error_new_virtqueue; > } > > + if (ops->get_features(vdpa) & BIT_ULL(VIRTIO_F_VERSION_1)) > + may_reduce_num = true; > + > /* Create the vring */ > align = ops->get_vq_align(vdpa); > vq = vring_create_virtqueue(index, num, align, vdev, > - true, true, ctx, > + true, may_reduce_num, ctx, > virtio_vdpa_notify, callback, name); > if (!vq) { > err = -ENOMEM; > diff --git a/include/uapi/linux/vdpa.h b/include/uapi/linux/vdpa.h > index 66a41e4ec163..ce0b74276a5b 100644 > --- a/include/uapi/linux/vdpa.h > +++ b/include/uapi/linux/vdpa.h > @@ -32,6 +32,7 @@ enum vdpa_attr { > VDPA_ATTR_DEV_VENDOR_ID, /* u32 */ > VDPA_ATTR_DEV_MAX_VQS, /* u32 */ > VDPA_ATTR_DEV_MAX_VQ_SIZE, /* u16 */ > + VDPA_ATTR_DEV_VERSION_1, /* flag */ > > /* new attributes must be added above here */ > VDPA_ATTR_MAX, > -- > 2.31.1