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Peter Anvin" , "Peter Zijlstra (Intel)" , "Kirill A. Shutemov" , "Xin Li (Intel)" , Rik van Riel , "Ahmed S. Darwish" , "open list:KVM PARAVIRT (KVM/paravirt)" , "open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)" Content-Type: text/plain; charset="us-ascii" On Fri, Jul 18, 2025, Chao Gao wrote: > >> >> >> From: Jason Wang > >If xAPIC vs. x2APIC is stable when > >kvm_setup_pv_ipi() runs, maybe key off of that? > > But the guest doesn't know if APICv is enabled or even IPI virtualization > is enabled. Oh yeah, duh. Given that KVM emulates x2APIC irrespective of hardware support, and that Linux leans heavily towards x2APIC (thanks MMIO stale data!), my vote is to leave things as they are.