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X-MS-Exchange-AntiSpam-MessageData: =?utf-8?B?Q3ZDZVBaY1VhdWxacnBOcStvK2dtSEtwNDlBYjF3Zm1kMTljSllrcEJ2NUxV?= =?utf-8?B?Sjd5dkdaWk1PZXdVTUlzdXZISVNENCtPWkNZcnMwZVRlVE11M2tQd09ORlFB?= =?utf-8?B?UXRMb3VzQVNrR1ZEcXdhek9pdkQ2bnJBd2xjZnFBcVM0YXFrQkNFSGpqTzVJ?= =?utf-8?B?ejRuYWxxM1pEVllEUm9nOVJmWkpYM0FSVyt3VmRodmh2Njg4OGhiVG1JaE5I?= =?utf-8?B?MExUVmcyUitxTDlmWXlERUtIRTdlVm13VTJ4RGRJTzJLbXVJckF6L3ZwK1M2?= =?utf-8?B?eHgrcEFFS1RISmpaRjJyeXM0biszWlVaZXhERU1yb09DWkhsQjRMbVU1Qmx4?= =?utf-8?B?c0lmSm9pcDYxV2QrUXFzR29YOVBQdXJjU3JFcVJsTExDb09Rb0YxZjNxdUpU?= =?utf-8?B?ZXNSaXQzR1FOdU9WNHpsQjVBQW13QXAvMGRiQjVSOEY1TEhkNTEwT1A0VWxC?= =?utf-8?B?emdBdVlwTldXSHZQVkdINDh6SVpMY3g0ZU4zb0RhSmhoK1RoRUFCK29zY3Rk?= =?utf-8?B?QzRkMC80NjJxV29aemNzNXlySUphN1BwbHJqdHBsNnFTTUFYdTRIem9uSVJC?= =?utf-8?B?TGkxV1BkZHJwVE9EZmhaK2lXMHR1ajVlbmxiVnJPRzRzUnd1UVhGOWozeThZ?= =?utf-8?B?Q0w2WkJzL2xiRUZXdXdCbWhLQkU3d1pVUnFSTE0xTkxSV2I3TExMQ2JRS0Iy?= =?utf-8?B?OTg4WDdIaXk1R3FQQ0R5UFJqeGtxMTdnNDhlMzF4R2ZBQzNrV0c0ajA0UnVJ?= =?utf-8?B?RG94LzZPS0pBUlNqSDZESFdmUDRCZzBLalVWVmNucVdTSEd5ZzRRdldldDV5?= =?utf-8?B?MGtoK1NZcXZBWW1pN1pPRGtNSkhDQXhsL05SL0pjRC9mTURUNzZudGJGQVRk?= =?utf-8?B?WHBYSnFKTi8vNDJUUnpKb0wzUmlFdlhqTldMNFY4TThMd3Ryb1g1Um0wdStU?= =?utf-8?B?b2lHZDh5Z1JFckNiNkVhM0RmU09pWlRROHhjWm4xSEdMb1VNNGdOd3ltNUFx?= =?utf-8?B?UkdzQnVyUDBveE1QS2N4cTJTa3RXWTQ0eDRhd2ZwelpPSUxJMExQcmZvVkM3?= =?utf-8?B?d2d4Ym12UllwcGROWGZnUitTWXM5NDJVSUFqZjJFeG9SSDhMSzRSQllIRlc3?= =?utf-8?B?V3hVTDVVMEdPSzQ2SEZSajY4SXNmb0hDYWFhRTNsTnJtTS9MNnZtVVpJUGNY?= =?utf-8?B?dG9BR3hvVnVqQUNGLyt3c3p2eDkwQXF6RnpaQTNaUC9pNE9sSkpDOWdnWUJP?= =?utf-8?B?MEtXN2VHR0xxUDZxSERyeTZFR2crcXQ1a29DN3RVYTFkd0wzV2RwRzFRWnJP?= =?utf-8?B?N214cXZCekhhaDM5d2Z3cmJqeFR1SGltMG50TFhuNUNqQ2kyMnBLSjcyazc0?= =?utf-8?B?ZVNkaGszWjcyMXZYUWgvUXg2a0tEeVEyWEQybjQzby9PRFdnQ2htREROdWo3?= =?utf-8?B?MDlpR2NQZzluZjByRG9rR2ExUG5qMHg3Z3JlNWhDYnhIS3FjZUVBSmhBMS9q?= =?utf-8?B?TEVGcTMyQjIzV21SZ0paTkczWTVraVFWMThVaDJzbFBKQk54TUxtN0FGZm82?= =?utf-8?B?MFh5M0pmaHlIZTJPZE5CRDhwc045Q1UrTkhkdmpwZG1uamJIQ3c2Wk1LTWJq?= =?utf-8?B?R2FOSzJ2OXQxR2lpUVFKbFVYM0NMSTVUNE1pMy93K3haR0lzaTUzNmdURE9y?= =?utf-8?B?Nmt1Rk5CeGJjdlZCRlpqT1lRMHNwVW9LZWIzL0NSTGdPd1ZTdTdhS1B5V3Jv?= =?utf-8?Q?cbIOTV7tanUcm0iUc7oTTjfH/MEmh94/h5Wh0SZ?= X-MS-Exchange-CrossTenant-Network-Message-Id: de3638c5-16e8-4c56-931c-08d905872ea4 X-MS-Exchange-CrossTenant-AuthSource: DS7PR03MB5608.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 22 Apr 2021 12:07:21.2838 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 335836de-42ef-43a2-b145-348c2ee9ca5b X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: dXQ1lfmzoXXhfGQmNDkqfJ6Mq5EGBfHY/3o7dSr6VleXUdKkq8ez0jghwnaJaeejFYcTlkptK70OX2ItywhPVQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR03MB5289 X-OriginatorOrg: citrix.com On Thu, Apr 22, 2021 at 01:42:45PM +0200, Jan Beulich wrote: > On 22.04.2021 13:37, Roger Pau Monné wrote: > > On Thu, Apr 22, 2021 at 01:05:23PM +0200, Jan Beulich wrote: > >> On 22.04.2021 12:56, Roger Pau Monné wrote: > >>> On Thu, Apr 22, 2021 at 12:48:36PM +0200, Jan Beulich wrote: > >>>> On 22.04.2021 12:34, Roger Pau Monné wrote: > >>>>> On Thu, Apr 22, 2021 at 11:58:45AM +0200, Jan Beulich wrote: > >>>>>> On 22.04.2021 11:42, Roger Pau Monné wrote: > >>>>>>> On Wed, Apr 14, 2021 at 03:49:02PM +0200, Jan Beulich wrote: > >>>>>>>> On 13.04.2021 16:01, Roger Pau Monne wrote: > >>>>>>>>> @@ -944,3 +945,130 @@ bool xc_cpu_policy_is_compatible(xc_interface *xch, const xc_cpu_policy_t host, > >>>>>>>>> > >>>>>>>>> return false; > >>>>>>>>> } > >>>>>>>>> + > >>>>>>>>> +static uint64_t level_msr(unsigned int index, uint64_t val1, uint64_t val2) > >>>>>>>>> +{ > >>>>>>>>> + uint64_t val = val1 & val2;; > >>>>>>>> > >>>>>>>> For arbitrary MSRs this isn't going to do any good. If only very > >>>>>>>> specific MSRs are assumed to make it here, I think this wants > >>>>>>>> commenting on. > >>>>>>> > >>>>>>> I've added: "MSRs passed to level_msr are expected to be bitmaps of > >>>>>>> features" > >>>>>> > >>>>>> How does such a comment help? I.e. how does the caller tell which MSRs > >>>>>> to pass here and which to deal with anyother way? > >>>>> > >>>>> All MSRs should be passed to level_msr, but it's handling logic would > >>>>> need to be expanded to support MSRs that are not feature bitmaps. > >>>>> > >>>>> It might be best to restore the previous switch and handle each MSR > >>>>> specifically? > >>>> > >>>> I think so, yes. We need to be very careful with what a possible > >>>> default case does there, though. > >>> > >>> Maybe it would be better to handle level_msr in a way similar to > >>> level_leaf: return true/false to notice whether the MSR should be > >>> added to the resulting compatible policy? > >>> > >>> And then make the default case in level_msr just return false in order > >>> to prevent adding MSRs not properly leveled to the policy? > >> > >> I'm afraid I'm not clear about the implications. What again is the > >> (planned?) final effect of an MSR not getting added there? > > > > Adding the MSR with a 0 value will zero out any previous value on the > > 'out' policy, while not adding it would leave the previous value > > there given the current code in xc_cpu_policy_calc_compatible added by > > this patch. > > > > I would expect callers of xc_cpu_policy_calc_compatible to pass a > > zeroed 'out' policy, so I think the end result should be the same. > > But we're not talking about actual MSR values here, as this is all > about policy. So in the end we'll have to see how things need to > be once we have the first non-feature-flag-like entries there. It > feels as if simply zeroing can't be generally the right thing in > such a case. It may e.g. be that min() is wanted instead. Maybe level_msr should return an error for MSRs not explicitly handled, that's propagated to the caller of xc_cpu_policy_calc_compatible. That way addition of new MSRs are not likely to miss adding the required handling in level_msr? Thanks, Roger.