KVM notify VM Exit

[Paul Lai]

A VMM can enable notification VM exits to occur if no interrupt windows occur
in VMX non-root operation for a specified amount of time (notify window).

KVM Enabling:
1.enable bit 31 of secondary processor-based excution control.
2.enable notification VM exit (exit reason 75) handler.
3.expose a module param to configure notify window.

Platform: Xeon Sapphire Rapids

Linux 5.20
Notify VM Exit(Still requires qemu patches to enable it):
2f4073e08f4c KVM: VMX: Enable Notify VM exit
938c8745bcf2 KVM: x86: Introduce "struct kvm_caps" to track misc caps/settings
30267b43c5b0 KVM: selftests: Add a test to get/set triple fault event
ed2351174e38 KVM: x86: Extend KVM_{G,S}ET_VCPU_EVENTS to support pending triple fault

[Paul Lai (pclai)]

qemu 7.2
e2e69f6bb9 i386: add notify VM exit support
5f8a6bce1f kvm: expose struct KVMState
3dba0a335c kvm: allow target-specific accelerator properties

[Paul Lai (pclai)]

qemu 7.2
* e2e69f6bb9 i386: add notify VM exit support
* 5f8a6bce1f kvm: expose struct KVMState
* 3dba0a335c kvm: allow target-specific accelerator properties
* d525f73f91 Update linux headers to v6.0-rc4

[Christian Ehrhardt  (paelzer)]

I can confirm that those changes are in qemu 7.2 and Ubuntu Lunar (23.04) has picked them up via qemu having qemu 7.2.