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X-Microsoft-Antispam-Message-Info: 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 X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(376014)(82310400026)(1800799024)(36860700016)(22082099003)(18002099003)(56012099003);DIR:OUT;SFP:1101; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: bUUMAh1dH4u+Sb5EpNwFzxmR0mfHAJ36DEm+PQVWrqNzpgm7oToK3oD/qgSb19O5bIUtT4vDWUiQbxeZYkXiMV9xbXSLoIOhXtme4y4eyHh6QULNVJegrZdHXet6J8JJtreAVWZR8RtESXqbbaX9KPYQsORG6hHdKSkEKsu8xiICBOU6BMiYCEuvb0aVSsbnZOKyqrFXOA7nqqw1Kgixm1llEiwfzB9x/eSuHqB9g2o6mUE4BbWXcI8o3Odo0S1RDifRzTejN+GoOWh6OdGBUTdmpAezHrxhJevE894w4oPyrldKpmfW6EaljtkWh2gd665xToA+SOMJ6z2zEq6r7pOLYUT5LJ0THBWpElUawij/19BukHkC8CKj7T7v7NlQk0FP+nzr+BhA/N192n59f65Kq4yVrry3e/r0QNEVP55e/vNRooJKWLMKLKIdPD46 X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 11 Mar 2026 09:46:49.1815 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 9d0a625f-3357-47af-1697-08de7f531dd5 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: CY4PEPF0000EE3A.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: PH7PR12MB8013 On Wed Mar 11, 2026 at 9:54 AM CET, Jan Beulich wrote: > On 13.02.2026 12:42, Alejandro Vallejo wrote: >> Alejandro Vallejo (4): >> x86: Reject CPU policies with vendors other than the host's >> x86/hvm: Disable cross-vendor handling in #UD handler >> x86/hvm: Remove cross-vendor checks from MSR handlers. >> x86/svm: Drop emulation of Intel's SYSENTER behaviour on AMD systems > > With this, do we actually want to keep emulation of SYS{ENTER,EXIT,CALL,R= ET} > in the insn emulator? Or at least gate that on e.g. VM_EVENT, to still al= low > its use by introspection? Whether to then also permit those with HVM_FEP= =3Dy > (but VM_EVENT=3Dn) would be a follow-on question. > > Jan I can force emulation of anything by writing an instruction to an xAPIC reg= ister followed by RET and then CALL-ing it that address. If we want a hypervisor capable of running such ridiculous cases the emulator must be complete. If = not, the question is what to do otherwise. Inject #UD? Crash the domain? Cheers, Alejandro