On Thu, Oct 17, 2013 at 2:07 PM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On 16/10/13 18:02, Anup Patel wrote: >> The PSCI SYSTEM_OFF and SYSTEM_RESET functions are VM or Guest level >> functions hence cannot be emulated by the in-kernel PSCI emulation code. > > Why can't we implement system-wide functionality in the kernel? I fail > to see the issue here. > >> To tackle this, we forward PSCI SYSTEM_OFF and SYSTEM_RESET function >> calls from Guest to user space (i.e. QEMU or KVMTOOL) via KVM run >> structure with KVM_EXIT_PSCI exit reason. > > I'm really not keen on this approach. Having part of the PSCI > implementation offloaded to userspace means we don't have a complete > implementation in KVM anymore, and we end-up duplicating functionality > all over the place. > > Also, OFF and RESET are not PSCI specific concepts, and could be > implemented in various ways. I'm more inclined to return a > *standardized* exit code that the various platforms can interpret. Please refer to the documentation of SYSTEM_OFF and SYSTEM_RESET functions in the PSCI specifications. (More preciesly section 5.10 and 5.11 of http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0022b/index.html) -- Anup > > M. > -- > Jazz is not dead. It just smells funny... > > > _______________________________________________ > kvmarm mailing list > kvmarm@xxxxxxxxxxxxxxxxxxxxx > https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/cucslists/listinfo/kvmarm
