From patchwork Thu Mar 26 09:45:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juergen Gross X-Patchwork-Id: 11459761 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 49BBB17EA for ; Thu, 26 Mar 2020 09:47:43 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3096D2070A for ; Thu, 26 Mar 2020 09:47:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3096D2070A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHP5P-000182-UD; Thu, 26 Mar 2020 09:46:03 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.89) (envelope-from ) id 1jHP5O-00017V-BT for xen-devel@lists.xenproject.org; Thu, 26 Mar 2020 09:46:02 +0000 X-Inumbo-ID: 99bd6db2-6f46-11ea-8790-12813bfff9fa Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 99bd6db2-6f46-11ea-8790-12813bfff9fa; Thu, 26 Mar 2020 09:46:01 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id E1159AD1E; Thu, 26 Mar 2020 09:45:59 +0000 (UTC) From: Juergen Gross To: xen-devel@lists.xenproject.org Date: Thu, 26 Mar 2020 10:45:57 +0100 Message-Id: <20200326094557.13822-1-jgross@suse.com> X-Mailer: git-send-email 2.16.4 Subject: [Xen-devel] [PATCH] tools/libxl: make default of max event channels dependant on vcpus X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Juergen Gross , Anthony PERARD , Ian Jackson , Wei Liu Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Today the maximum number of event channels for a guest is defaulting to 1023. For large guests with lots of vcpus this is not enough, as e.g. the Linux kernel uses 7 event channels per vcpu, limiting the guest to about 140 vcpus. Instead of requiring to specify the allowed number of event channels via the "event_channels" domain config option, make the default depend on the maximum number of vcpus of the guest. In order not to regress current configs use 1023 as the minimum default setting. Signed-off-by: Juergen Gross --- tools/libxl/libxl_create.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c index e7cb2dbc2b..eddd0e98e5 100644 --- a/tools/libxl/libxl_create.c +++ b/tools/libxl/libxl_create.c @@ -226,7 +226,7 @@ int libxl__domain_build_info_setdefault(libxl__gc *gc, b_info->iomem[i].gfn = b_info->iomem[i].start; if (!b_info->event_channels) - b_info->event_channels = 1023; + b_info->event_channels = min(1023, b_info->max_vcpus * 8 + 255); libxl__arch_domain_build_info_setdefault(gc, b_info); libxl_defbool_setdefault(&b_info->dm_restrict, false);