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=-13.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 02B03C433DB for ; Thu, 28 Jan 2021 14:42:32 +0000 (UTC) Received: from whitealder.osuosl.org (smtp1.osuosl.org [140.211.166.138]) (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 63CC064DE0 for ; Thu, 28 Jan 2021 14:42:31 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 63CC064DE0 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 whitealder.osuosl.org (Postfix) with ESMTP id EA05186DBE; Thu, 28 Jan 2021 14:42:30 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from whitealder.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id mxRDZYXXuW-w; Thu, 28 Jan 2021 14:42:30 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by whitealder.osuosl.org (Postfix) with ESMTP id 5E7F286DAE; Thu, 28 Jan 2021 14:42:30 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 48BAFC0FA8; Thu, 28 Jan 2021 14:42:30 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 020A8C08A1 for ; Thu, 28 Jan 2021 14:42:29 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id E4B2487253 for ; Thu, 28 Jan 2021 14:42:28 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Fj8QAAo9R4b3 for ; Thu, 28 Jan 2021 14:42:28 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) by hemlock.osuosl.org (Postfix) with ESMTPS id 10D2085BA1 for ; Thu, 28 Jan 2021 14:42:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611844946; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=dMfBbPjDPZ4dIyXQtS0tJU0Oae1keECk1ejt9iIRqJg=; b=U/7lAwf5Hx6ghL0gZW9GJv+d4/iOvzNp4sLtd6436+BNTwD7Yxgzu2fjKriBL0IjeVbNV2 tGLHcVkHc8n35ERuZcvxiJgbE9yQwwE8lmLH1Pt8ZpjiZOi6er6TJSA+hO8TcO5qisNYrB z2iYpps3TdnDpghD24iFVoqXGf4x448= 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-524-UzL0ZiMJPbiRkiCf77zeAA-1; Thu, 28 Jan 2021 09:42:25 -0500 X-MC-Unique: UzL0ZiMJPbiRkiCf77zeAA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CA868801B2E; Thu, 28 Jan 2021 14:42:23 +0000 (UTC) Received: from steredhat.redhat.com (ovpn-113-219.ams2.redhat.com [10.36.113.219]) by smtp.corp.redhat.com (Postfix) with ESMTP id A0F9E19443; Thu, 28 Jan 2021 14:42:05 +0000 (UTC) From: Stefano Garzarella To: virtualization@lists.linux-foundation.org Subject: [PATCH RFC v2 04/10] vringh: implement vringh_kiov_advance() Date: Thu, 28 Jan 2021 15:41:21 +0100 Message-Id: <20210128144127.113245-5-sgarzare@redhat.com> In-Reply-To: <20210128144127.113245-1-sgarzare@redhat.com> References: <20210128144127.113245-1-sgarzare@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Cc: Laurent Vivier , Max Gurtovoy , kvm@vger.kernel.org, "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, Xie Yongji , Stefan Hajnoczi 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" In some cases, it may be useful to provide a way to skip a number of bytes in a vringh_kiov. Let's implement vringh_kiov_advance() for this purpose, reusing the code from vringh_iov_xfer(). We replace that code calling the new vringh_kiov_advance(). Signed-off-by: Stefano Garzarella --- include/linux/vringh.h | 2 ++ drivers/vhost/vringh.c | 41 +++++++++++++++++++++++++++++------------ 2 files changed, 31 insertions(+), 12 deletions(-) diff --git a/include/linux/vringh.h b/include/linux/vringh.h index 9c077863c8f6..755211ebd195 100644 --- a/include/linux/vringh.h +++ b/include/linux/vringh.h @@ -199,6 +199,8 @@ static inline void vringh_kiov_cleanup(struct vringh_kiov *kiov) kiov->iov = NULL; } +void vringh_kiov_advance(struct vringh_kiov *kiov, size_t len); + int vringh_getdesc_kern(struct vringh *vrh, struct vringh_kiov *riov, struct vringh_kiov *wiov, diff --git a/drivers/vhost/vringh.c b/drivers/vhost/vringh.c index bee63d68201a..4d800e4f31ca 100644 --- a/drivers/vhost/vringh.c +++ b/drivers/vhost/vringh.c @@ -75,6 +75,34 @@ static inline int __vringh_get_head(const struct vringh *vrh, return head; } +/** + * vringh_kiov_advance - skip bytes from vring_kiov + * @iov: an iov passed to vringh_getdesc_*() (updated as we consume) + * @len: the maximum length to advance + */ +void vringh_kiov_advance(struct vringh_kiov *iov, size_t len) +{ + while (len && iov->i < iov->used) { + size_t partlen = min(iov->iov[iov->i].iov_len, len); + + iov->consumed += partlen; + iov->iov[iov->i].iov_len -= partlen; + iov->iov[iov->i].iov_base += partlen; + + if (!iov->iov[iov->i].iov_len) { + /* Fix up old iov element then increment. */ + iov->iov[iov->i].iov_len = iov->consumed; + iov->iov[iov->i].iov_base -= iov->consumed; + + iov->consumed = 0; + iov->i++; + } + + len -= partlen; + } +} +EXPORT_SYMBOL(vringh_kiov_advance); + /* Copy some bytes to/from the iovec. Returns num copied. */ static inline ssize_t vringh_iov_xfer(struct vringh *vrh, struct vringh_kiov *iov, @@ -95,19 +123,8 @@ static inline ssize_t vringh_iov_xfer(struct vringh *vrh, done += partlen; len -= partlen; ptr += partlen; - iov->consumed += partlen; - iov->iov[iov->i].iov_len -= partlen; - iov->iov[iov->i].iov_base += partlen; - if (!iov->iov[iov->i].iov_len) { - /* Fix up old iov element then increment. */ - iov->iov[iov->i].iov_len = iov->consumed; - iov->iov[iov->i].iov_base -= iov->consumed; - - - iov->consumed = 0; - iov->i++; - } + vringh_kiov_advance(iov, partlen); } return done; } -- 2.29.2 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization