From nobody Sat Nov 30 00:41:14 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) client-ip=192.237.175.120; envelope-from=xen-devel-bounces@lists.xenproject.org; helo=lists.xenproject.org; Authentication-Results: mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass(p=quarantine dis=none) header.from=suse.com ARC-Seal: i=1; a=rsa-sha256; t=1620900228; cv=none; d=zohomail.com; s=zohoarc; b=lLg+B9JWZhE17VDnY13Gwvwf7SAifXSbo5OjshNEtdHwk28fV2AfPHUVbvrvyOUjbb+iNyYQyUhib4mPY5ZtNW2zUnB4L2uA7hi3NlF0gensCuZijqzXqKb1Bti4U4ZVcnXmcmyAHVGCUaFnyWadMqysJV9V3KpepexqAujZPmM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1620900228; h=Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=ygDKbDhfDMlj04vAZT1nQUuD2Bsz2E2EX2ert/+Sldc=; b=At8v1gifPQ9wxH4c7xvV93Wff5PwliBzPbO9Xx6oxvk2cC0Qs9cu3zCkLUF9/VYgcMP9TQDdT+MJiRzzKYII9U1sBoeQsCLSVF1iqWwFgt92q6ulxROOrkRA+SEDKK+HPOnuTxVxQNI7tmfEV/9LI1IF7DeDf0I8bduz8fcF0rg= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass; spf=pass (zohomail.com: domain of lists.xenproject.org designates 192.237.175.120 as permitted sender) smtp.mailfrom=xen-devel-bounces@lists.xenproject.org; dmarc=pass header.from= (p=quarantine dis=none) header.from= Return-Path: Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) by mx.zohomail.com with SMTPS id 1620900228177876.7214082971051; Thu, 13 May 2021 03:03:48 -0700 (PDT) Received: from list by lists.xenproject.org with outflank-mailman.126814.238357 (Exim 4.92) (envelope-from ) id 1lh8Bk-0006XQ-Rf; Thu, 13 May 2021 10:03:28 +0000 Received: by outflank-mailman (output) from mailman id 126814.238357; Thu, 13 May 2021 10:03:28 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lh8Bk-0006X1-LP; Thu, 13 May 2021 10:03:28 +0000 Received: by outflank-mailman (input) for mailman id 126814; Thu, 13 May 2021 10:03:27 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lh8Bj-0003vg-3n for xen-devel@lists.xenproject.org; Thu, 13 May 2021 10:03:27 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id e15c491b-d62f-4b73-aa93-74a38cbc588f; Thu, 13 May 2021 10:03:07 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 68AE3B062; Thu, 13 May 2021 10:03:06 +0000 (UTC) X-Outflank-Mailman: Message body and most headers restored to incoming version X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: e15c491b-d62f-4b73-aa93-74a38cbc588f X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1620900186; h=from:from:reply-to: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=ygDKbDhfDMlj04vAZT1nQUuD2Bsz2E2EX2ert/+Sldc=; b=iGbXPTsViBTDLv+bdZJGVl+oV4HRm0TVz4r6wDci4iCRCW2Hm5WIIRHkHZxUc0LEd1sO1H vwqUv4y3NiJHJBX0idWsuTAMxSTOznt4q/IRhurE8VkFp4pjlCxdnjec6RwkyKSaTT5CBc PnbZFESlVi1Q5KeT0sJ2wcfmvqVNRzk= From: Juergen Gross To: xen-devel@lists.xenproject.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Juergen Gross , Boris Ostrovsky , Stefano Stabellini , "David S. Miller" , Jakub Kicinski Subject: [PATCH 5/8] xen/netfront: read response from backend only once Date: Thu, 13 May 2021 12:02:59 +0200 Message-Id: <20210513100302.22027-6-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210513100302.22027-1-jgross@suse.com> References: <20210513100302.22027-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMail-DKIM: pass (identity @suse.com) Content-Type: text/plain; charset="utf-8" In order to avoid problems in case the backend is modifying a response on the ring page while the frontend has already seen it, just read the response into a local buffer in one go and then operate on that buffer only. Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich --- drivers/net/xen-netfront.c | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index 44275908d61a..f91e41ece554 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -399,13 +399,13 @@ static void xennet_tx_buf_gc(struct netfront_queue *q= ueue) rmb(); /* Ensure we see responses up to 'rp'. */ =20 for (cons =3D queue->tx.rsp_cons; cons !=3D prod; cons++) { - struct xen_netif_tx_response *txrsp; + struct xen_netif_tx_response txrsp; =20 - txrsp =3D RING_GET_RESPONSE(&queue->tx, cons); - if (txrsp->status =3D=3D XEN_NETIF_RSP_NULL) + RING_COPY_RESPONSE(&queue->tx, cons, &txrsp); + if (txrsp.status =3D=3D XEN_NETIF_RSP_NULL) continue; =20 - id =3D txrsp->id; + id =3D txrsp.id; skb =3D queue->tx_skbs[id].skb; if (unlikely(gnttab_query_foreign_access( queue->grant_tx_ref[id]) !=3D 0)) { @@ -814,7 +814,7 @@ static int xennet_get_extras(struct netfront_queue *que= ue, RING_IDX rp) =20 { - struct xen_netif_extra_info *extra; + struct xen_netif_extra_info extra; struct device *dev =3D &queue->info->netdev->dev; RING_IDX cons =3D queue->rx.rsp_cons; int err =3D 0; @@ -830,24 +830,22 @@ static int xennet_get_extras(struct netfront_queue *q= ueue, break; } =20 - extra =3D (struct xen_netif_extra_info *) - RING_GET_RESPONSE(&queue->rx, ++cons); + RING_COPY_RESPONSE(&queue->rx, ++cons, &extra); =20 - if (unlikely(!extra->type || - extra->type >=3D XEN_NETIF_EXTRA_TYPE_MAX)) { + if (unlikely(!extra.type || + extra.type >=3D XEN_NETIF_EXTRA_TYPE_MAX)) { if (net_ratelimit()) dev_warn(dev, "Invalid extra type: %d\n", - extra->type); + extra.type); err =3D -EINVAL; } else { - memcpy(&extras[extra->type - 1], extra, - sizeof(*extra)); + memcpy(&extras[extra.type - 1], &extra, sizeof(extra)); } =20 skb =3D xennet_get_rx_skb(queue, cons); ref =3D xennet_get_rx_ref(queue, cons); xennet_move_rx_slot(queue, skb, ref); - } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE); + } while (extra.flags & XEN_NETIF_EXTRA_FLAG_MORE); =20 queue->rx.rsp_cons =3D cons; return err; @@ -905,7 +903,7 @@ static int xennet_get_responses(struct netfront_queue *= queue, struct sk_buff_head *list, bool *need_xdp_flush) { - struct xen_netif_rx_response *rx =3D &rinfo->rx; + struct xen_netif_rx_response *rx =3D &rinfo->rx, rx_local; int max =3D XEN_NETIF_NR_SLOTS_MIN + (rx->status <=3D RX_COPY_THRESHOLD); RING_IDX cons =3D queue->rx.rsp_cons; struct sk_buff *skb =3D xennet_get_rx_skb(queue, cons); @@ -989,7 +987,8 @@ static int xennet_get_responses(struct netfront_queue *= queue, break; } =20 - rx =3D RING_GET_RESPONSE(&queue->rx, cons + slots); + RING_COPY_RESPONSE(&queue->rx, cons + slots, &rx_local); + rx =3D &rx_local; skb =3D xennet_get_rx_skb(queue, cons + slots); ref =3D xennet_get_rx_ref(queue, cons + slots); slots++; @@ -1044,10 +1043,11 @@ static int xennet_fill_frags(struct netfront_queue = *queue, struct sk_buff *nskb; =20 while ((nskb =3D __skb_dequeue(list))) { - struct xen_netif_rx_response *rx =3D - RING_GET_RESPONSE(&queue->rx, ++cons); + struct xen_netif_rx_response rx; skb_frag_t *nfrag =3D &skb_shinfo(nskb)->frags[0]; =20 + RING_COPY_RESPONSE(&queue->rx, ++cons, &rx); + if (skb_shinfo(skb)->nr_frags =3D=3D MAX_SKB_FRAGS) { unsigned int pull_to =3D NETFRONT_SKB_CB(skb)->pull_to; =20 @@ -1062,7 +1062,7 @@ static int xennet_fill_frags(struct netfront_queue *q= ueue, =20 skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, skb_frag_page(nfrag), - rx->offset, rx->status, PAGE_SIZE); + rx.offset, rx.status, PAGE_SIZE); =20 skb_shinfo(nskb)->nr_frags =3D 0; kfree_skb(nskb); @@ -1161,7 +1161,7 @@ static int xennet_poll(struct napi_struct *napi, int = budget) i =3D queue->rx.rsp_cons; work_done =3D 0; while ((i !=3D rp) && (work_done < budget)) { - memcpy(rx, RING_GET_RESPONSE(&queue->rx, i), sizeof(*rx)); + RING_COPY_RESPONSE(&queue->rx, i, rx); memset(extras, 0, sizeof(rinfo.extras)); =20 err =3D xennet_get_responses(queue, &rinfo, rp, &tmpq, --=20 2.26.2