test self-ipi working, sending vector 226 to guest
pv works. in guest, enable posted IPI interrupt, but EOI is trapped, vINT is used when vm is in guest mode
a working version with EOI on/off at virtual INT injection
Only network using IPI (hardcore to vector 81), pass iperf 200 sec, rx: 7.6G, see __apic_accept_irq
single vector IPI, pass iperf2000s, rx11G
merge the temp-branch into the master