From patchwork Mon Sep 13 13:15:09 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 510410 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=-19.1 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, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT 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 8C1C3C433F5 for ; Mon, 13 Sep 2021 14:40:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6FD4560F9F for ; Mon, 13 Sep 2021 14:40:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347263AbhIMOlg (ORCPT ); Mon, 13 Sep 2021 10:41:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:57712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346806AbhIMOjl (ORCPT ); Mon, 13 Sep 2021 10:39:41 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 94BB460698; Mon, 13 Sep 2021 13:55:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631541329; bh=m+rTPqoENtqtj2TZXeW4E1SejdlqGNQUDAe2NhIqw9o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lk5d38t4Q956uUyOKb977XqptOrxEbltThmNqkviF9YX3SFSLR1wI078k7whaVxWx DzB6RrJg4uxmtwa5o6lkD9k68NXGdNG7g5AeMCE608QzLpDomU6Uz9iBQf1al3WoQO hO7CHn+9vhFNJvZo+ljNfr1wvmQJnCttihb3xzpI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vitaly Kuznetsov , Michael Kelley , Wei Liu , Sasha Levin Subject: [PATCH 5.14 255/334] hv_utils: Set the maximum packet size for VSS driver to the length of the receive buffer Date: Mon, 13 Sep 2021 15:15:09 +0200 Message-Id: <20210913131122.031369469@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210913131113.390368911@linuxfoundation.org> References: <20210913131113.390368911@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Vitaly Kuznetsov [ Upstream commit 9d68cd9120e4e3af38f843e165631c323b86b4e4 ] Commit adae1e931acd ("Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer") introduced a notion of maximum packet size and for KVM and FCOPY drivers set it to the length of the receive buffer. VSS driver wasn't updated, this means that the maximum packet size is now VMBUS_DEFAULT_MAX_PKT_SIZE (4k). Apparently, this is not enough. I'm observing a packet of 6304 bytes which is being truncated to 4096. When VSS driver tries to read next packet from ring buffer it starts from the wrong offset and receives garbage. Set the maximum packet size to 'HV_HYP_PAGE_SIZE * 2' in VSS driver. This matches the length of the receive buffer and is in line with other utils drivers. Fixes: adae1e931acd ("Drivers: hv: vmbus: Copy packets sent by Hyper-V out of the ring buffer") Signed-off-by: Vitaly Kuznetsov Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20210825133857.847866-1-vkuznets@redhat.com Signed-off-by: Wei Liu Signed-off-by: Sasha Levin --- drivers/hv/hv_snapshot.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/hv/hv_snapshot.c b/drivers/hv/hv_snapshot.c index 2267bd4c3472..6018b9d1b1fb 100644 --- a/drivers/hv/hv_snapshot.c +++ b/drivers/hv/hv_snapshot.c @@ -375,6 +375,7 @@ hv_vss_init(struct hv_util_service *srv) } recv_buffer = srv->recv_buffer; vss_transaction.recv_channel = srv->channel; + vss_transaction.recv_channel->max_pkt_size = HV_HYP_PAGE_SIZE * 2; /* * When this driver loads, the user level daemon that