From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754211AbdBETyk (ORCPT + 2 others); Sun, 5 Feb 2017 14:54:40 -0500 Received: from wtarreau.pck.nerim.net ([62.212.114.60]:28165 "EHLO 1wt.eu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754111AbdBETZt (ORCPT ); Sun, 5 Feb 2017 14:25:49 -0500 From: Willy Tarreau To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, linux@roeck-us.net Cc: David Vrabel , Konrad Rzeszutek Wilk , Willy Tarreau Subject: [PATCH 3.10 034/319] xen-netback: don't use last request to determine minimum Tx credit Date: Sun, 5 Feb 2017 20:20:21 +0100 Message-Id: <1486322486-8024-5-git-send-email-w@1wt.eu> X-Mailer: git-send-email 2.8.0.rc2.1.gbe9624a In-Reply-To: <1486322486-8024-1-git-send-email-w@1wt.eu> References: <1486322486-8024-1-git-send-email-w@1wt.eu> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: From: David Vrabel commit 0f589967a73f1f30ab4ac4dd9ce0bb399b4d6357 upstream. The last from guest transmitted request gives no indication about the minimum amount of credit that the guest might need to send a packet since the last packet might have been a small one. Instead allow for the worst case 128 KiB packet. This is part of XSA155. Reviewed-by: Wei Liu Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Willy Tarreau --- drivers/net/xen-netback/netback.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 1595f81..3e0907a 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -928,9 +928,7 @@ static void tx_add_credit(struct xenvif *vif) * Allow a burst big enough to transmit a jumbo packet of up to 128kB. * Otherwise the interface can seize up due to insufficient credit. */ - max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size; - max_burst = min(max_burst, 131072UL); - max_burst = max(max_burst, vif->credit_bytes); + max_burst = max(131072UL, vif->credit_bytes); /* Take care that adding a new chunk of credit doesn't wrap to zero. */ max_credit = vif->remaining_credit + vif->credit_bytes; -- 2.8.0.rc2.1.gbe9624a