On Sat, Oct 06, 2018 at 12:19:45PM +0300, Raz wrote: > Hey > How does HVSC works ? > I looked in the code and LoPAR documentation. It looks like there is > vector called > system_call_pSeries ( at 0xc00 ) that is supposed to be called when we > invoke HVSC from kernel > mode. > Now, I wrote a NULL call HSVC and patched the exceptions-64s.S to > return RFID immediately. > This does not work. > Would you be so kind to explain how HVSC works ? > thank you
If your kernel is not running in hypervisor mode, sc 1 does not call the kernel (but the hypervisor, instead). If your kernel _is_ running in hypervisor mode, sc 1 does the same as sc 0, a normal system call. I don't know which it is for you; you didn't say. I have no idea what "a NULL call HSVC" means. If you make exception c00 return immediately (as you suggest) then you have made all system calls non-functional, which indeed is unlikely to work as you want. Segher
