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X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 13 Oct 2025 10:01:50.9990 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 246091f4-df1e-4af9-13e3-08de0a3f87cf 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: DS2PEPF00003439.namprd02.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: DM6PR12MB4418 On Wed Oct 8, 2025 at 6:04 PM CEST, Jan Beulich wrote: > On 30.09.2025 14:52, Grygorii Strashko wrote: >> --- a/xen/arch/x86/hvm/Kconfig >> +++ b/xen/arch/x86/hvm/Kconfig >> @@ -62,6 +62,16 @@ config ALTP2M >> =20 >> If unsure, stay with defaults. >> =20 >> +config VIRIDIAN >> + bool "Hyper-V enlightenments for guests" if EXPERT >> + default y >> + help >> + Support optimizations for Hyper-V guests such as faster hypercalls, >> + efficient timer and interrupt handling, and enhanced paravirtualized >> + I/O. This is to improve performance and compatibility of Windows VMs= . > > What is "paravirtualized I/O" about in this context? Hypervisor-assisted IPIs, TLB flushes, etc. Or so I understood back when I = said that looked ok. I see there could be confusion with Xen PV device protocols= , but as far as the user of the help message is concerned it makes no differe= nce. One could even remove the examples and leave it as "... for Hyper-V guests.= This is to...". They are truly inconsequential. All that matters is that (modern) Windows won't run without it, and that it provides some indeterminate hypervisor-provided assists to try to reduce so= me virtualization overheads. Cheers, Alejandro