From patchwork Thu Jun 23 16:53:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Dr. David Alan Gilbert" X-Patchwork-Id: 12892960 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F259BCCA47C for ; Thu, 23 Jun 2022 16:56:14 +0000 (UTC) Received: from localhost ([::1]:49248 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1o4Q7p-0000Me-Rf for qemu-devel@archiver.kernel.org; Thu, 23 Jun 2022 12:56:13 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:60188) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4Q5n-0005mq-8B for qemu-devel@nongnu.org; Thu, 23 Jun 2022 12:54:07 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:40987) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1o4Q5l-0005vt-P0 for qemu-devel@nongnu.org; Thu, 23 Jun 2022 12:54:07 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656003244; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=rdC8wzK3qRlsTGe76YoR1juFzydDpgy+3C0yW+4L/1Q=; b=HKOLTU7o7l3DgZb0BBUP191jf8j6KsnS4G8Veua8AnZiu5z908qPZMX9NCRXIX9EbozRBt QTtSOqPv79tbCMnaxi4yQ951pDYZIQbK2uDedWaxVY2Hhhfhp+JOStbamiDJaqj7wnqsPV yzqeazlIdrvtNGXZ4VWP9Oz2r+kq1Ww= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-197-PV9-Y_uLOMiBFjo35S9tCw-1; Thu, 23 Jun 2022 12:54:03 -0400 X-MC-Unique: PV9-Y_uLOMiBFjo35S9tCw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id D0C42801E80; Thu, 23 Jun 2022 16:54:02 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.33.36.159]) by smtp.corp.redhat.com (Postfix) with ESMTP id D6E342026D64; Thu, 23 Jun 2022 16:54:01 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, berrange@redhat.com, huangy81@chinatelecom.cn, quintela@redhat.com, leobras@redhat.com, peterx@redhat.com Cc: jdenemar@redhat.com Subject: [PULL 02/25] QIOChannelSocket: Introduce assert and reduce ifdefs to improve readability Date: Thu, 23 Jun 2022 17:53:31 +0100 Message-Id: <20220623165354.197792-3-dgilbert@redhat.com> In-Reply-To: <20220623165354.197792-1-dgilbert@redhat.com> References: <20220623165354.197792-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 Received-SPF: pass client-ip=170.10.129.124; envelope-from=dgilbert@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -28 X-Spam_score: -2.9 X-Spam_bar: -- X-Spam_report: (-2.9 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.082, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Leonardo Bras During implementation of MSG_ZEROCOPY feature, a lot of #ifdefs were introduced, particularly at qio_channel_socket_writev(). Rewrite some of those changes so it's easier to read. Also, introduce an assert to help detect incorrect zero-copy usage is when it's disabled on build. Signed-off-by: Leonardo Bras Reviewed-by: Daniel P. Berrangé Reviewed-by: Juan Quintela Reviewed-by: Peter Xu Signed-off-by: Juan Quintela Signed-off-by: Dr. David Alan Gilbert dgilbert: Fixed up thinko'd g_assert_unreachable->g_assert_not_reached --- io/channel-socket.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/io/channel-socket.c b/io/channel-socket.c index dc9c165de1..b8c13dba7c 100644 --- a/io/channel-socket.c +++ b/io/channel-socket.c @@ -578,11 +578,17 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, memcpy(CMSG_DATA(cmsg), fds, fdsize); } -#ifdef QEMU_MSG_ZEROCOPY if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) { +#ifdef QEMU_MSG_ZEROCOPY sflags = MSG_ZEROCOPY; - } +#else + /* + * We expect QIOChannel class entry point to have + * blocked this code path already + */ + g_assert_not_reached(); #endif + } retry: ret = sendmsg(sioc->fd, &msg, sflags); @@ -592,15 +598,13 @@ static ssize_t qio_channel_socket_writev(QIOChannel *ioc, return QIO_CHANNEL_ERR_BLOCK; case EINTR: goto retry; -#ifdef QEMU_MSG_ZEROCOPY case ENOBUFS: - if (sflags & MSG_ZEROCOPY) { + if (flags & QIO_CHANNEL_WRITE_FLAG_ZERO_COPY) { error_setg_errno(errp, errno, "Process can't lock enough memory for using MSG_ZEROCOPY"); return -1; } break; -#endif } error_setg_errno(errp, errno,