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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?6IDmUmFmDG0Ag1JqJ166NgVXA+ux8HIfhzr+Ffaw/4mCyk43f0Wd4sN0DUhZ?= =?us-ascii?Q?uk/mj0SeJP18Pa/yhKmEqX4IUYe399iw1a3YsxnK6OzCMbWbFSUg54Esj3GA?= =?us-ascii?Q?36XmvVdOOSXcm3CGI0F8nmBjEqZrRXXAyafRs+9FCTFHYDUbcdgQhXYL2Kde?= =?us-ascii?Q?5udDFaD+khtrFUyTlQgbLR3lHvw9FyXalZKnaC2PmaOA6z7oAhPemM7t41cv?= =?us-ascii?Q?uPQFnbv4EL4dVqjIRrjt9ChnOOpe822iPR5mz7mgESGfPM8lLeUZ6bJzqv/e?= =?us-ascii?Q?jjMwzzlUixv3RgMbXPkiYuyquIvw9PP75XkrvEpPaRNCg1eKFQxrhylQKkks?= =?us-ascii?Q?rIabXTA+u3yUxoKBKPDD/e/WyujY62BsnVn1sOfrNGY1efu8oykfvIc6hDAR?= =?us-ascii?Q?kZDM/zy4ZlhdaY813kgDL1GE1k7sIYeBpkl/rkz9WWhv2J+NmtsXkE2IRtxu?= =?us-ascii?Q?cj1BwXIE+tVTZoTuf9H3mtDHAX2NL3wlAZarac8JUFIYrOM2xblJymWoJIJd?= =?us-ascii?Q?EcUMCuhrEnNEhwV0eKocJ2VNuyu/PdmmyD0XtDeGpi4BYu1Spp6rDDOWsSEu?= =?us-ascii?Q?/cqiJarQnf2vin6A7B7xaAIeAt/RgXUeXkZUASmACWPgYHv/csMcUgIWOYgU?= =?us-ascii?Q?Ekx8d++1HhLgXKi2t/hv7a+AgjW4kcFHJMHPMVdj+bO0QDsCfoqtw/3XlHbI?= =?us-ascii?Q?s9tWPO70baMVFTJgrk8WaLp5XRotIHpBzzA6Mhc+I1+Cnx2l6McW+P4dBQ4/?= =?us-ascii?Q?b22RJrVM+5nthYzuXoUZ9BWZ3lhCvrqiZwrtH3LvatJtdrPpHgWO7PJ01nWF?= =?us-ascii?Q?NAp7ilF+q8U6POm5ux+pMm4NpOzj7gFC7D3Vb7HXSacfqmQAX4EAmhqTgHWb?= =?us-ascii?Q?AHTWcBwW3njYhJarTWg9d/3sNREQKYMaS8QEk1y6j2n9t8DzuphKhWsOG8tc?= =?us-ascii?Q?dMWhRfFASNUZb/gOU3POW//OcGlkoUCBpRRwMs9ggWDwnT8W8BlM+IgJWb/g?= =?us-ascii?Q?YCSK/8MBIpIzQtaWMr7tn6xiaRuqzHsoSH05urfLNgyzB1uXos1bFAbBIaIs?= =?us-ascii?Q?uqkFf1eihWn5UE0yHCjF6AVDcKGWNNDrkOhEQSEdY6icf3zNP16vG59AgW/6?= =?us-ascii?Q?Dp+EOep6hH1f58qj1n9b0NpyIYLf56/th2wBBTGLJE0Knq5YKXtGwewY1BFm?= =?us-ascii?Q?blsHZfJ1ptyapF+N+CSVF0hjKYyooiOpwCGuAJ9KvKOBvz9LkmWN9g+GXfKH?= =?us-ascii?Q?TmfafxSINBO9llEdkeEgYuTzdVoj51/8fCR5wu2cEpPy3NQEoJd0zz1/raNL?= =?us-ascii?Q?sXqRiJnx1IzOfdYujdsQ25Y44ZKzEFHk4XHzmlQnlPNyXPuKXciinja2jqdH?= =?us-ascii?Q?HnOWlvItXwzR2a8BG7CEOok+/fIMD89p04HUl8l0DjS5uUIwKNrLDNSoN+mh?= =?us-ascii?Q?Jb9IZYWkoVoqP81Pxn4I9FVlxwg7zZ4jNDYBWi/Lgy92dus0Bpfk/Ugdwpay?= =?us-ascii?Q?0VSzCTd2DcriTX6XdXO0Gp8g6K9+DQ6Zmfa6UEld2mRS7SyQhHx9Ntnsh+wW?= =?us-ascii?Q?6txo5zCrJYqouX2oNeTW1850kC2swLu//5jtttkz?= X-MS-Exchange-CrossTenant-Network-Message-Id: e3aca568-cbea-4aec-7512-08daa14027b0 X-MS-Exchange-CrossTenant-AuthSource: MWHPR1101MB2221.namprd11.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 28 Sep 2022 10:56:54.4075 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 46c98d88-e344-4ed4-8496-4ed7712e255d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: oy1KPTJcf+dfOIXxWjJ/hmFZjEs1e6eMpmp/bCg3mLu6+p3qR+tl4192EudVdJIMhrGV57CWig+FFCZJN+0OVA== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR11MB6687 X-OriginatorOrg: intel.com Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org >> Changes in v2 (addressed comments from Kevin): >> - measure/estimate the impact to non-IPC-intensive cases >> - don't tie PID.SN to vcpu->mode. Instead, clear PID.SN >> right before VM-entry and set it after VM-exit. > >One correction here. My comment in v1 [1] was actually close to Sean's >suggestion, i.e. opposite to above description: Hi Kevin, Yes. The changelog is misleading. You suggested using a dedicate hook. And I indeed agreed to follow the suggestion. But as you said, what v2 does is the complete opposite of the suggestion. The reason is when I started v2 recently, the idea of clearing SN right before VM-entry came to my mind. Since it could also solve some problems of v1 without a hook (hence, more self-contained), I thought it was slightly better. But I missed that clearing SN right before VM-entry can cause unnecessary SN toggling to VM-exit fast-path.