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Peter Anvin" , Joerg Roedel , Borislav Petkov , Tom Lendacky , X86 ML , KVM list , LKML , Sean Christopherson , Venu Busireddy , Brijesh Singh Subject: Re: [PATCH v11 10/13] KVM: x86: Introduce new KVM_FEATURE_SEV_LIVE_MIGRATION feature & Custom MSR. 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X-MS-Exchange-AntiSpam-MessageData: =?us-ascii?Q?+DXz0yVHOlm5kr6NmebgHoGquIfPP/6ZcNJjr7RtmzkcZeoOMDnipKmGJMKP?= =?us-ascii?Q?hcyhTbHKvRWwkT439vDmyjTjJWwgv1dbx7c6Vpi6z3TEqkFF/fE8RPf3EBVS?= =?us-ascii?Q?B3eVXEupbO60fPLnGld0Q0AFt+0KTGXXH/hARSEHYv0pNpop6VckCoVYZStv?= =?us-ascii?Q?GS9l9J3xtu0CpdT+S8PKc+idCo+pf0oNxCMuDwKmTgLrNxyHqGJt+RSsGco4?= =?us-ascii?Q?f7hu2QTTjMbowMB+FJ20mnj9Fg9UOl5T9Gm7a4OapDkwzswB8g4oQQlqE8Go?= =?us-ascii?Q?bxb0a6ZHBRLNLtNW5B1XUVWSLXIgq8rtwg0u6gVyi56rNxut3yAO7/fEavMW?= =?us-ascii?Q?i/8wgimF3m+JViZPLTyl3VThX8LLMJ5cjUlTj6p/GtZS+WJ29cOpmpm5Is/Q?= =?us-ascii?Q?EWuGEOkdx3rbY9ByWHncKxCdG5btT29qlhBvuwEFgIEt8TSfGwr6jA9CxPz6?= =?us-ascii?Q?TuZGARzB9n9f03ABaWLZTQuSGoRM+HtKHvBtKEzECS5L+RBV98t9bl2tChDq?= =?us-ascii?Q?5+upPLhRya33mTJlALJcKmGZK7k+wcholepjpZ0trN3n1DLHPrcds11m7qQV?= =?us-ascii?Q?u/AFUhYVG1tisNO4dO9g0G7oc+iXusLSQVa0JUeFCT9WQz2CV25252RcdACk?= =?us-ascii?Q?T4/lHFIjEuCVc9RskTnFK/jipSPzclj9cUF2TcHja4fts1Ur6s0CKF4tQHNf?= =?us-ascii?Q?OyDrPOvnWF1BrpVakmgiKH6GlIXEnwM989HEy0M7P9ZSlcVOl9hG59JpXR1k?= =?us-ascii?Q?+ldf5wfi2eD3Yfd8vmIHSEuaGCJfVdrPV4JiK21qhphS0D7uMbUGH65qC5OJ?= =?us-ascii?Q?QlDEH3QhcG3zcg964t+N8ISFkJ6+rYuYrQJ6+OscBZWQtW91Vr4hm9DKKQDY?= =?us-ascii?Q?ZOyNTfFHm3//SUulLvb+fyjviHBNv/Tn0hXU53VEGwdelcZtIez4TDWyvo4f?= =?us-ascii?Q?D3o07hPu8zIRJjwatoii3aJcvwBiP3YVQP25kAOjJalMBvKqOfhlxHKmiBBR?= =?us-ascii?Q?VurbKRMJ8O23FPF2nedxVwoq8xHq9ed0frt5oabWMLCWH+7SKckBL9BPUqZv?= =?us-ascii?Q?nBqx52w9SjJ/p4lozNOyPDL49Y71OAMovUB9GLO3uGXUB6xYxZjnA0Vukgrl?= =?us-ascii?Q?XSeeoDXxHwhRZlQDw8tgl+8BmsmEEtwvSybzIdLieMZNC3xBOdGkmUeIjHxR?= =?us-ascii?Q?3N5+uDr6421Zp9pf0w9C7IJtSs3+OxftSY/sU9Ci+8KTZB2KkPk5tHZtrNu+?= =?us-ascii?Q?bPV26+p3C7UYtJYdAWl1Jd4nukazklquhgbL3moNFpqOsCK23r+ANvG2S5q9?= =?us-ascii?Q?JsILpEXg3KirTrPJuouAc4Ow?= X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-Network-Message-Id: 1505c07b-fa49-4ad0-818f-08d8f9044268 X-MS-Exchange-CrossTenant-AuthSource: SN6PR12MB2767.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Apr 2021 13:59:56.3195 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: YVAoL4e2Hnhckc3d2mru52HGMVKiDLyvWoFqL4eTYASEckctXGvOlmP+ZWadg0m1hamB2YFMHv5v+eFqePEd9Q== X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN6PR12MB2719 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Paolo, On Tue, Apr 06, 2021 at 03:47:59PM +0200, Paolo Bonzini wrote: > On 06/04/21 15:26, Ashish Kalra wrote: > > > It's a little unintuitive to see KVM_MSR_RET_FILTERED here, since > > > userspace can make this happen on its own without having an entry in > > > this switch statement (by setting it in the msr filter bitmaps). When > > > using MSR filters, I would only expect to get MSR filter exits for > > > MSRs I specifically asked for. > > > > > > Not a huge deal, just a little unintuitive. I'm not sure other options > > > are much better (you could put KVM_MSR_RET_INVALID, or you could just > > > not have these entries in svm_{get,set}_msr). > > > > > Actually KVM_MSR_RET_FILTERED seems more logical to use, especially in > > comparison with KVM_MSR_RET_INVALID. > > > > Also, hooking this msr in svm_{get,set}_msr allows some in-kernel error > > pre-processsing before doing the pass-through to userspace. > > I agree that it should be up to userspace to set up the filter since we now > have that functionality. > The userspace is still setting up the filter and handling this MSR, it is only some basic error pre-processing being done in-kernel here. Thanks, Ashish > Let me read the whole threads for the past versions to see what the > objections were... > > Paolo >