Public bug reported: IPI virtualization targets to make the processor emulate the write to APIC registers that would send IPIs in virtualized system. VMX provide new VM-execution control and VMCS field to support IPI virtualization which can eliminate APIC-Write VM-exit. The processor sets the bit corresponding to the vector in target vCPU's PIR and may send a notification (IPI) specified by NDST and NV fields in target vCPU's PID. It is similar to what IOMMU engine does when dealing with posted interrupt from devices.
IPI Virtualization is approved in SPR/EGS CCB and it is supposed to be enabled in C-step or later (perhaps D-step). Subject: Re: [PATCH v7 8/8] KVM: VMX: enable IPI virtualization https://lore.kernel.org/kvm/54df6da8-ad68-cc75-48db-d18fc8743...@intel.com/ Target Linux 5.18 ** Affects: kvm (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1967894 Title: KVM IPI Virtualization support for SPR To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/kvm/+bug/1967894/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
