From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.rulkc.org (mail.rulkc.org [155.212.184.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5CCF824DD15; Sun, 14 Jun 2026 17:48:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=155.212.184.193 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781459305; cv=none; b=jC0F/VXGTf9VOJ7yXDWoHJ6tkQ7Czd1JAtwZ8fzJ8GnUBQWrZidFACtU2sm1r7SMUq/zxi4XrK4xvgLUqSo6bJ8oeFKZJCaHbhLSEzuNU3K3L7CkhsqsFijPnMMUKqjiCqTSHf4e8EG1x7C2Mb/Jb571b4bjFgchD+O8pF0LZrQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781459305; c=relaxed/simple; bh=cV9X6iCjeGCGGaKnmc9UIteri4enJNH7S++iuTX7mBA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=KXq9OLuzcJLtpMt21DFgZkmn+kG5HmKEC48e5ksRmV0g/H8GqkxjnuxCqFCPfBghG0o55aPqnD9H598cdeF6P/7OTDk06H+vza0ncKpre0pDAsmfBH05CHq5xjk862qc3JddC4pi4mY6TAsZsP73WjJeVl4Jc5CvPTv2YP26Ask= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=rulkc.org; spf=pass smtp.mailfrom=rulkc.org; dkim=pass (2048-bit key) header.d=rulkc.org header.i=@rulkc.org header.b=PBGgk4Ny; arc=none smtp.client-ip=155.212.184.193 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=rulkc.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rulkc.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=rulkc.org header.i=@rulkc.org header.b="PBGgk4Ny" Received: from [127.0.0.1] (localhost [127.0.0.1]) by localhost (Mailerdaemon) with ESMTPSA id 013341009EF; Sun, 14 Jun 2026 20:48:03 +0300 (MSK) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rulkc.org; s=dkim; t=1781459293; h=from:subject:date:message-id:to:cc:mime-version: content-transfer-encoding; bh=qbU7FTOSPWekRxEa6SP3qr2Gku8x/AVx3Rh/8yrUUPA=; b=PBGgk4NyA5KZFn0TglHZbVh4O6NdVI6L/LTJmst0TsjZClYaJGEcef5laOZdUeRTgJsnwZ Q3YWxYUFaUHxkrUmlfSF9mlFJScSOZOX17yMQKu+gw+36iWYIG7h5R6ZTi2ZhyqZR1uwDU YtzfWkp0yXFNiDLXRlWuKPJUJM7veyMyMgr2ZZ7SjZwt9g3cZ98+XUcqWLBYAN6H/0oCsw rV581gno9JxOOZlEBUq8xI8l9mntQ6Zod461a92ppO/UhYTBRmAnNqy+N9XVd3/nhHoqE3 dQYgUvoaBok8yBXBzg7DJ8Ev1njL7YbkCOuKAps7v4dG2qEU3Qyosj+ZtV3+IQ== From: Arseniy Krasnov To: Stefan Hajnoczi , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Jason Wang , Bobby Eshleman , Xuan Zhuo , =?UTF-8?q?Eugenio=20P=C3=A9rez?= , Simon Horman Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, oxffffaa@gmail.com, rulkc@linuxtesting.org, Arseniy Krasnov Subject: [PATCH v2] vsock/virtio: rework MSG_ZEROCOPY flag handling Date: Sun, 14 Jun 2026 20:47:56 +0300 Message-ID: <20260614174756.170631-1-avkrasnov@rulkc.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Last-TLS-Session-Version: TLSv1.3 Logically it was based on TCP implementation, so make further support easier, rewrite it in the TCP way. Signed-off-by: Arseniy Krasnov --- Changelog v1->v2: * Rebase on last 'net-next'. Don't need 'skb_zcopy_set()' now - it was already added. net/vmw_vsock/virtio_transport_common.c | 48 ++++++++++++------------- 1 file changed, 23 insertions(+), 25 deletions(-) diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index 09475007165b..787524b8cb44 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -328,38 +328,36 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk, if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW) return pkt_len; - if (info->msg) { - /* If zerocopy is not enabled by 'setsockopt()', we behave as - * there is no MSG_ZEROCOPY flag set. + if (info->msg && (info->msg->msg_flags & MSG_ZEROCOPY)) { + /* If 'info->msg' is not NULL, this is only VIRTIO_VSOCK_OP_RW. + * 'MSG_ZEROCOPY' flag handling here is based on the same flag + * handling from 'tcp_sendmsg_locked()'. */ - if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY)) - info->msg->msg_flags &= ~MSG_ZEROCOPY; + if (info->msg->msg_ubuf) { + uarg = info->msg->msg_ubuf; + can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len); + } else if (sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY)) { + uarg = msg_zerocopy_realloc(sk_vsock(vsk), pkt_len, + NULL, false); + if (!uarg) { + virtio_transport_put_credit(vvs, pkt_len); + return -ENOMEM; + } - if (info->msg->msg_flags & MSG_ZEROCOPY) can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len); + if (!can_zcopy) + uarg_to_msgzc(uarg)->zerocopy = 0; + + have_uref = true; + } + + /* 'can_zcopy' means that this transmission will be + * in zerocopy way (e.g. using 'frags' array). + */ if (can_zcopy) max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE, (MAX_SKB_FRAGS * PAGE_SIZE)); - - if (info->msg->msg_flags & MSG_ZEROCOPY && - info->op == VIRTIO_VSOCK_OP_RW) { - uarg = info->msg->msg_ubuf; - - if (!uarg) { - uarg = msg_zerocopy_realloc(sk_vsock(vsk), - pkt_len, NULL, false); - if (!uarg) { - virtio_transport_put_credit(vvs, pkt_len); - return -ENOMEM; - } - - if (!can_zcopy) - uarg_to_msgzc(uarg)->zerocopy = 0; - - have_uref = true; - } - } } rest_len = pkt_len; -- 2.25.1