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=-17.3 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,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 3DC44C4360C for ; Tue, 2 Mar 2021 08:12:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 22F1964D9E for ; Tue, 2 Mar 2021 08:12:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1577419AbhCBGWJ (ORCPT ); Tue, 2 Mar 2021 01:22:09 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:29929 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238536AbhCBEMM (ORCPT ); Mon, 1 Mar 2021 23:12:12 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614658201; 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=AiqlnBbL124RbFr+ZWPEGMV28LDKcaWTVjjFw6NK3tk=; b=TQOZdzLifOpWklyQOjUJX1Q5EKxpvcxnbdflGoCRrYVDeIwzlxNsaX1GgPZuhh47rdQqa2 4aKcaTN7sjN0UIfTgHJ9nAhUsJ4NIhuRofOzRao3yGeB+XhkBERE9nOaZk0f1QvpVjLLXB cbrwSOa3nzoFHPHIDMC4L7OSTqn7TAM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-332-Z7l6R31lOImEgMGWxzuctg-1; Mon, 01 Mar 2021 23:05:43 -0500 X-MC-Unique: Z7l6R31lOImEgMGWxzuctg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8BCDC107ACE3; Tue, 2 Mar 2021 04:05:42 +0000 (UTC) Received: from wangxiaodeMacBook-Air.local (ovpn-13-215.pek2.redhat.com [10.72.13.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id A4F5E1A7D9; Tue, 2 Mar 2021 04:05:37 +0000 (UTC) Subject: Re: [RFC PATCH 10/10] vhost/vdpa: return configuration bytes read and written to user space To: Stefano Garzarella , virtualization@lists.linux-foundation.org Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" References: <20210216094454.82106-1-sgarzare@redhat.com> <20210216094454.82106-11-sgarzare@redhat.com> From: Jason Wang Message-ID: <4d682ff2-9663-d6ac-d5bf-616b2bf96e1a@redhat.com> Date: Tue, 2 Mar 2021 12:05:35 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210216094454.82106-11-sgarzare@redhat.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-GB X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/2/16 5:44 下午, Stefano Garzarella wrote: > vdpa_get_config() and vdpa_set_config() now return the amount > of bytes read and written, so let's return them to the user space. > > We also modify vhost_vdpa_config_validate() to return 0 (bytes read > or written) instead of an error, when the buffer length is 0. > > Signed-off-by: Stefano Garzarella > --- > drivers/vhost/vdpa.c | 26 +++++++++++++++----------- > 1 file changed, 15 insertions(+), 11 deletions(-) > > diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c > index 21eea2be5afa..b754c53171a7 100644 > --- a/drivers/vhost/vdpa.c > +++ b/drivers/vhost/vdpa.c > @@ -191,9 +191,6 @@ static ssize_t vhost_vdpa_config_validate(struct vhost_vdpa *v, > struct vdpa_device *vdpa = v->vdpa; > u32 size = vdpa->config->get_config_size(vdpa); > > - if (c->len == 0) > - return -EINVAL; > - > return min(c->len, size); > } > > @@ -204,6 +201,7 @@ static long vhost_vdpa_get_config(struct vhost_vdpa *v, > struct vhost_vdpa_config config; > unsigned long size = offsetof(struct vhost_vdpa_config, buf); > ssize_t config_size; > + long ret; > u8 *buf; > > if (copy_from_user(&config, c, size)) > @@ -217,15 +215,18 @@ static long vhost_vdpa_get_config(struct vhost_vdpa *v, > if (!buf) > return -ENOMEM; > > - vdpa_get_config(vdpa, config.off, buf, config_size); > - > - if (copy_to_user(c->buf, buf, config_size)) { > - kvfree(buf); > - return -EFAULT; > + ret = vdpa_get_config(vdpa, config.off, buf, config_size); > + if (ret < 0) { > + ret = -EFAULT; > + goto out; > } > > + if (copy_to_user(c->buf, buf, config_size)) > + ret = -EFAULT; > + > +out: > kvfree(buf); > - return 0; > + return ret; > } > > static long vhost_vdpa_set_config(struct vhost_vdpa *v, > @@ -235,6 +236,7 @@ static long vhost_vdpa_set_config(struct vhost_vdpa *v, > struct vhost_vdpa_config config; > unsigned long size = offsetof(struct vhost_vdpa_config, buf); > ssize_t config_size; > + long ret; > u8 *buf; > > if (copy_from_user(&config, c, size)) > @@ -248,10 +250,12 @@ static long vhost_vdpa_set_config(struct vhost_vdpa *v, > if (IS_ERR(buf)) > return PTR_ERR(buf); > > - vdpa_set_config(vdpa, config.off, buf, config_size); > + ret = vdpa_set_config(vdpa, config.off, buf, config_size); > + if (ret < 0) > + ret = -EFAULT; > > kvfree(buf); > - return 0; > + return ret; > } So I wonder whether it's worth to return the number of bytes since we can't propogate the result to driver or driver doesn't care about that. Thanks > > static long vhost_vdpa_get_features(struct vhost_vdpa *v, u64 __user *featurep) 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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 DD572C433DB for ; Tue, 2 Mar 2021 04:05:52 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4BEC1614A7 for ; Tue, 2 Mar 2021 04:05:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BEC1614A7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=virtualization-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id D555C42C27; Tue, 2 Mar 2021 04:05:51 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id BHI8Qt9irOc0; Tue, 2 Mar 2021 04:05:51 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp2.osuosl.org (Postfix) with ESMTP id 7FA7740025; Tue, 2 Mar 2021 04:05:50 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 6444EC000A; Tue, 2 Mar 2021 04:05:50 +0000 (UTC) Received: from smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) by lists.linuxfoundation.org (Postfix) with ESMTP id D8255C0001 for ; Tue, 2 Mar 2021 04:05:48 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id BBE6C4EF68 for ; Tue, 2 Mar 2021 04:05:48 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp4.osuosl.org (amavisd-new); dkim=pass (1024-bit key) header.d=redhat.com Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id kJ51eQhHDI-8 for ; Tue, 2 Mar 2021 04:05:47 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by smtp4.osuosl.org (Postfix) with ESMTPS id A02D54B33B for ; Tue, 2 Mar 2021 04:05:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1614657946; 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=AiqlnBbL124RbFr+ZWPEGMV28LDKcaWTVjjFw6NK3tk=; b=IcpbLi6pbx7tXg8V1zCZNZHg/VqgW0379ZAxGz1km3KG/Af3u5L7sE4vgY5jL3/vKXd7nR WJnG0gQfqhCI0e7zHGQ7cKO4iI8pmbZJsUFGZFCntMTzY+hLWmuBkgme1qWG0GnOfKlXqw LzmTyvgeDRuCkQVH3FqHH+vcem8QXWE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-332-Z7l6R31lOImEgMGWxzuctg-1; Mon, 01 Mar 2021 23:05:43 -0500 X-MC-Unique: Z7l6R31lOImEgMGWxzuctg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8BCDC107ACE3; Tue, 2 Mar 2021 04:05:42 +0000 (UTC) Received: from wangxiaodeMacBook-Air.local (ovpn-13-215.pek2.redhat.com [10.72.13.215]) by smtp.corp.redhat.com (Postfix) with ESMTP id A4F5E1A7D9; Tue, 2 Mar 2021 04:05:37 +0000 (UTC) Subject: Re: [RFC PATCH 10/10] vhost/vdpa: return configuration bytes read and written to user space To: Stefano Garzarella , virtualization@lists.linux-foundation.org References: <20210216094454.82106-1-sgarzare@redhat.com> <20210216094454.82106-11-sgarzare@redhat.com> From: Jason Wang Message-ID: <4d682ff2-9663-d6ac-d5bf-616b2bf96e1a@redhat.com> Date: Tue, 2 Mar 2021 12:05:35 +0800 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210216094454.82106-11-sgarzare@redhat.com> Content-Language: en-GB X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, "Michael S. Tsirkin" X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: base64 Content-Type: text/plain; charset="utf-8"; Format="flowed" Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" Ck9uIDIwMjEvMi8xNiA1OjQ0IOS4i+WNiCwgU3RlZmFubyBHYXJ6YXJlbGxhIHdyb3RlOgo+IHZk cGFfZ2V0X2NvbmZpZygpIGFuZCB2ZHBhX3NldF9jb25maWcoKSBub3cgcmV0dXJuIHRoZSBhbW91 bnQKPiBvZiBieXRlcyByZWFkIGFuZCB3cml0dGVuLCBzbyBsZXQncyByZXR1cm4gdGhlbSB0byB0 aGUgdXNlciBzcGFjZS4KPgo+IFdlIGFsc28gbW9kaWZ5IHZob3N0X3ZkcGFfY29uZmlnX3ZhbGlk YXRlKCkgdG8gcmV0dXJuIDAgKGJ5dGVzIHJlYWQKPiBvciB3cml0dGVuKSBpbnN0ZWFkIG9mIGFu IGVycm9yLCB3aGVuIHRoZSBidWZmZXIgbGVuZ3RoIGlzIDAuCj4KPiBTaWduZWQtb2ZmLWJ5OiBT dGVmYW5vIEdhcnphcmVsbGEgPHNnYXJ6YXJlQHJlZGhhdC5jb20+Cj4gLS0tCj4gICBkcml2ZXJz L3Zob3N0L3ZkcGEuYyB8IDI2ICsrKysrKysrKysrKysrKy0tLS0tLS0tLS0tCj4gICAxIGZpbGUg Y2hhbmdlZCwgMTUgaW5zZXJ0aW9ucygrKSwgMTEgZGVsZXRpb25zKC0pCj4KPiBkaWZmIC0tZ2l0 IGEvZHJpdmVycy92aG9zdC92ZHBhLmMgYi9kcml2ZXJzL3Zob3N0L3ZkcGEuYwo+IGluZGV4IDIx ZWVhMmJlNWFmYS4uYjc1NGM1MzE3MWE3IDEwMDY0NAo+IC0tLSBhL2RyaXZlcnMvdmhvc3QvdmRw YS5jCj4gKysrIGIvZHJpdmVycy92aG9zdC92ZHBhLmMKPiBAQCAtMTkxLDkgKzE5MSw2IEBAIHN0 YXRpYyBzc2l6ZV90IHZob3N0X3ZkcGFfY29uZmlnX3ZhbGlkYXRlKHN0cnVjdCB2aG9zdF92ZHBh ICp2LAo+ICAgCXN0cnVjdCB2ZHBhX2RldmljZSAqdmRwYSA9IHYtPnZkcGE7Cj4gICAJdTMyIHNp emUgPSB2ZHBhLT5jb25maWctPmdldF9jb25maWdfc2l6ZSh2ZHBhKTsKPiAgIAo+IC0JaWYgKGMt PmxlbiA9PSAwKQo+IC0JCXJldHVybiAtRUlOVkFMOwo+IC0KPiAgIAlyZXR1cm4gbWluKGMtPmxl biwgc2l6ZSk7Cj4gICB9Cj4gICAKPiBAQCAtMjA0LDYgKzIwMSw3IEBAIHN0YXRpYyBsb25nIHZo b3N0X3ZkcGFfZ2V0X2NvbmZpZyhzdHJ1Y3Qgdmhvc3RfdmRwYSAqdiwKPiAgIAlzdHJ1Y3Qgdmhv c3RfdmRwYV9jb25maWcgY29uZmlnOwo+ICAgCXVuc2lnbmVkIGxvbmcgc2l6ZSA9IG9mZnNldG9m KHN0cnVjdCB2aG9zdF92ZHBhX2NvbmZpZywgYnVmKTsKPiAgIAlzc2l6ZV90IGNvbmZpZ19zaXpl Owo+ICsJbG9uZyByZXQ7Cj4gICAJdTggKmJ1ZjsKPiAgIAo+ICAgCWlmIChjb3B5X2Zyb21fdXNl cigmY29uZmlnLCBjLCBzaXplKSkKPiBAQCAtMjE3LDE1ICsyMTUsMTggQEAgc3RhdGljIGxvbmcg dmhvc3RfdmRwYV9nZXRfY29uZmlnKHN0cnVjdCB2aG9zdF92ZHBhICp2LAo+ICAgCWlmICghYnVm KQo+ICAgCQlyZXR1cm4gLUVOT01FTTsKPiAgIAo+IC0JdmRwYV9nZXRfY29uZmlnKHZkcGEsIGNv bmZpZy5vZmYsIGJ1ZiwgY29uZmlnX3NpemUpOwo+IC0KPiAtCWlmIChjb3B5X3RvX3VzZXIoYy0+ YnVmLCBidWYsIGNvbmZpZ19zaXplKSkgewo+IC0JCWt2ZnJlZShidWYpOwo+IC0JCXJldHVybiAt RUZBVUxUOwo+ICsJcmV0ID0gdmRwYV9nZXRfY29uZmlnKHZkcGEsIGNvbmZpZy5vZmYsIGJ1Ziwg Y29uZmlnX3NpemUpOwo+ICsJaWYgKHJldCA8IDApIHsKPiArCQlyZXQgPSAtRUZBVUxUOwo+ICsJ CWdvdG8gb3V0Owo+ICAgCX0KPiAgIAo+ICsJaWYgKGNvcHlfdG9fdXNlcihjLT5idWYsIGJ1Ziwg Y29uZmlnX3NpemUpKQo+ICsJCXJldCA9IC1FRkFVTFQ7Cj4gKwo+ICtvdXQ6Cj4gICAJa3ZmcmVl KGJ1Zik7Cj4gLQlyZXR1cm4gMDsKPiArCXJldHVybiByZXQ7Cj4gICB9Cj4gICAKPiAgIHN0YXRp YyBsb25nIHZob3N0X3ZkcGFfc2V0X2NvbmZpZyhzdHJ1Y3Qgdmhvc3RfdmRwYSAqdiwKPiBAQCAt MjM1LDYgKzIzNiw3IEBAIHN0YXRpYyBsb25nIHZob3N0X3ZkcGFfc2V0X2NvbmZpZyhzdHJ1Y3Qg dmhvc3RfdmRwYSAqdiwKPiAgIAlzdHJ1Y3Qgdmhvc3RfdmRwYV9jb25maWcgY29uZmlnOwo+ICAg CXVuc2lnbmVkIGxvbmcgc2l6ZSA9IG9mZnNldG9mKHN0cnVjdCB2aG9zdF92ZHBhX2NvbmZpZywg YnVmKTsKPiAgIAlzc2l6ZV90IGNvbmZpZ19zaXplOwo+ICsJbG9uZyByZXQ7Cj4gICAJdTggKmJ1 ZjsKPiAgIAo+ICAgCWlmIChjb3B5X2Zyb21fdXNlcigmY29uZmlnLCBjLCBzaXplKSkKPiBAQCAt MjQ4LDEwICsyNTAsMTIgQEAgc3RhdGljIGxvbmcgdmhvc3RfdmRwYV9zZXRfY29uZmlnKHN0cnVj dCB2aG9zdF92ZHBhICp2LAo+ICAgCWlmIChJU19FUlIoYnVmKSkKPiAgIAkJcmV0dXJuIFBUUl9F UlIoYnVmKTsKPiAgIAo+IC0JdmRwYV9zZXRfY29uZmlnKHZkcGEsIGNvbmZpZy5vZmYsIGJ1Ziwg Y29uZmlnX3NpemUpOwo+ICsJcmV0ID0gdmRwYV9zZXRfY29uZmlnKHZkcGEsIGNvbmZpZy5vZmYs IGJ1ZiwgY29uZmlnX3NpemUpOwo+ICsJaWYgKHJldCA8IDApCj4gKwkJcmV0ID0gLUVGQVVMVDsK PiAgIAo+ICAgCWt2ZnJlZShidWYpOwo+IC0JcmV0dXJuIDA7Cj4gKwlyZXR1cm4gcmV0Owo+ICAg fQoKClNvIEkgd29uZGVyIHdoZXRoZXIgaXQncyB3b3J0aCB0byByZXR1cm4gdGhlIG51bWJlciBv ZiBieXRlcyBzaW5jZSB3ZSAKY2FuJ3QgcHJvcG9nYXRlIHRoZSByZXN1bHQgdG8gZHJpdmVyIG9y IGRyaXZlciBkb2Vzbid0IGNhcmUgYWJvdXQgdGhhdC4KClRoYW5rcwoKCj4gICAKPiAgIHN0YXRp YyBsb25nIHZob3N0X3ZkcGFfZ2V0X2ZlYXR1cmVzKHN0cnVjdCB2aG9zdF92ZHBhICp2LCB1NjQg X191c2VyICpmZWF0dXJlcCkKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fClZpcnR1YWxpemF0aW9uIG1haWxpbmcgbGlzdApWaXJ0dWFsaXphdGlvbkBsaXN0 cy5saW51eC1mb3VuZGF0aW9uLm9yZwpodHRwczovL2xpc3RzLmxpbnV4Zm91bmRhdGlvbi5vcmcv bWFpbG1hbi9saXN0aW5mby92aXJ0dWFsaXphdGlvbg==