From patchwork Wed Mar 29 14:49:34 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Ostrovsky X-Patchwork-Id: 9651777 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id CAE67602BE for ; Wed, 29 Mar 2017 14:52:30 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BD1E428491 for ; Wed, 29 Mar 2017 14:52:30 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B1CD9284BC; Wed, 29 Mar 2017 14:52:30 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RCVD_IN_SORBS_SPAM,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9FAD628491 for ; Wed, 29 Mar 2017 14:52:29 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ctEvX-00011s-U5; Wed, 29 Mar 2017 14:50:23 +0000 Received: from mail6.bemta6.messagelabs.com ([193.109.254.103]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1ctEvW-00011V-1E for xen-devel@lists.xen.org; Wed, 29 Mar 2017 14:50:22 +0000 Received: from [85.158.143.35] by server-4.bemta-6.messagelabs.com id F6/AB-03012-DA9CBD85; Wed, 29 Mar 2017 14:50:21 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFnrGLMWRWlGSWpSXmKPExsUyZ7p8oO6ak7c jDH7PtbZY8nExiwOjx9Hdv5kCGKNYM/OS8isSWDOuPvvAVLCWr2LqpGbWBsaZPF2MXBxCAh1M ErsmHGKFcH4wStxcvIYdwtnAKPH32QU2CGc3o8T6LcuAMpwcbAJGEmePTmcEsUUEpCWufb7MC FLELLCOUeL+6vNgCWGBYIlV7VtZQGwWAVWJ3m8gkzg5eAW8JPbMnsoMYksIyEncPNcJZRtL9M 3qY5nAyLOAkWEVo0ZxalFZapGuoYVeUlFmekZJbmJmjq6hgZlebmpxcWJ6ak5iUrFecn7uJka g/xmAYAfjzY0BhxglOZiURHlPGN6OEOJLyk+pzEgszogvKs1JLT7EKMPBoSTB+/gEUE6wKDU9 tSItMwcYiDBpCQ4eJRHeUJA0b3FBYm5xZjpE6hSjopQ4byJIQgAkkVGaB9cGC/5LjLJSwryMQ IcI8RSkFuVmlqDKv2IU52BUEuZ9CjKFJzOvBG76K6DFTECLxW1ugSwuSURISTUwcu9cZr5y0l qhd+s2HlinL2E7f7o926clb2OXHOF++8AwWcJYUnPr1gf7DG7ubXrrvrnXavOunjdJxcY+CSe 8zv/k6m8qaj79X+Vx4Ze89JmCPgtnlcdv913LGGL6VNvx7B+5bUaFHx7IRl9K38g7ryKkl+Fc uZa6fpzrgbPezJJt7OlpVpyySizFGYmGWsxFxYkARe2ySHkCAAA= X-Env-Sender: boris.ostrovsky@oracle.com X-Msg-Ref: server-16.tower-21.messagelabs.com!1490799019!56500930!1 X-Originating-IP: [156.151.31.81] X-SpamReason: No, hits=0.0 required=7.0 tests=sa_preprocessor: VHJ1c3RlZCBJUDogMTU2LjE1MS4zMS44MSA9PiAyODgzMzk=\n X-StarScan-Received: X-StarScan-Version: 9.2.3; banners=-,-,- X-VirusChecked: Checked Received: (qmail 23990 invoked from network); 29 Mar 2017 14:50:20 -0000 Received: from userp1040.oracle.com (HELO userp1040.oracle.com) (156.151.31.81) by server-16.tower-21.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 29 Mar 2017 14:50:20 -0000 Received: from aserv0021.oracle.com (aserv0021.oracle.com [141.146.126.233]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id v2TEo3Ro011221 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 29 Mar 2017 14:50:04 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by aserv0021.oracle.com (8.13.8/8.14.4) with ESMTP id v2TEo3p4004824 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Wed, 29 Mar 2017 14:50:03 GMT Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id v2TEo26u015571; Wed, 29 Mar 2017 14:50:02 GMT Received: from dhcp-burlington7-2nd-B-east-10-152-55-162.usdhcp.oraclecorp.com.com (/10.152.52.138) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 29 Mar 2017 07:50:02 -0700 From: Boris Ostrovsky To: xen-devel@lists.xen.org Date: Wed, 29 Mar 2017 10:49:34 -0400 Message-Id: <1490798974-24270-1-git-send-email-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 2.7.4 X-Source-IP: aserv0021.oracle.com [141.146.126.233] Cc: olaf@aepfle.de, wei.liu2@citrix.com, andrew.cooper3@citrix.com, ian.jackson@eu.citrix.com, jbeulich@suse.com, Boris Ostrovsky Subject: [Xen-devel] [PATCH] docs: Update xen-tscmode.pod.7 to reflect default TSC mode changes X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP A number of changes have been made to how we determine whether TSC is emulated (e.g. commit 4fc380ac0077 ("x86/time: don't use virtual TSC if host and guest frequencies are equal")). Update the man page to reflect those changes Signed-off-by: Boris Ostrovsky Suggested-by: Olaf Hering Acked-by: Wei Liu --- docs/man/xen-tscmode.pod.7 | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/docs/man/xen-tscmode.pod.7 b/docs/man/xen-tscmode.pod.7 index 0da57e5..0f93453 100644 --- a/docs/man/xen-tscmode.pod.7 +++ b/docs/man/xen-tscmode.pod.7 @@ -203,12 +203,12 @@ The default mode (tsc_mode==0) checks TSC-safeness of the underlying hardware on which the virtual machine is launched. If it is TSC-safe, rdtsc will execute at hardware speed; if it is not, rdtsc will be emulated. Once a virtual machine is save/restored or migrated, -however, there are two possibilities: For a paravirtualized (PV) domain, -TSC will always be emulated. For a fully-virtualized (HVM) domain, -TSC remains native IF the source physical machine and target physical machine -have the same TSC frequency; else TSC is emulated. Note that, though -emulated, the "apparent" TSC frequency will be the TSC frequency -of the initial physical machine, even after migration. +however, there are two possibilities: TSC remains native IF the source +physical machine and target physical machine have the same TSC frequency +(or, for HVM/PVH guests, if TSC scaling support is available); else TSC +is emulated. Note that, though emulated, the "apparent" TSC frequency +will be the TSC frequency of the initial physical machine, even after +migration. For environments where both TSC-safeness AND highest performance even across migration is a requirement, application code can be specially