Version 4 changes -clarified that KVM zeros the upper half of the struct fields if the VM is not in 64-bit mode ------------------------------------------------------------------------ KVM_CAP_EXIT_EPAPR_HCALL Capability A new capability KVM_CAP_EXIT_EPAPR_HCALL is defined to advertise the new KVM_EXIT_EPAPR_HCALL exit . ------------------------------------------------------------------------ KVM_EXIT_EPAPR_HCALL exit definition /* KVM_EXIT_EPAPR_HCALL */ struct { __u64 nr; __u64 ret; __u64 args[8]; } epapr_hcall; This is used on Power/PowerPC platforms that support ePAPR hcalls. It occurs when a guest does a hypercall (as defined in the ePAPR 1.1) and the hcall is not handled by the kernel. The 'nr' field contains the hypercall number (from the guest R11), and 'args' contains the arguments (from the guest R3 - R10). Userspace should put the return code in 'ret' and any extra returned values in args[]. If the VM is not in 64-bit mode KVM zeros the upper half of each field in the struct. As per the ePAPR hcall ABI, the return value is returned to the guest in R3 and output return values in R4 - R10. ------------------------------------------------------------------------ Advertising reset and shutdown in device tree. A virtual machine can detect the availability of the reset and shutdown hcalls by looking at properties on the /hypervisor node in the device tree passed to the VM. Property name: kvm,has-reset Value type: <none> Definition: If the property is present the hypervisor supports the KVM_HC_VM_RESET hcall. Property name: kvm,has-shutdown Value type: <none> Definition: If the property is present the hypervisor supports the KVM_HC_VM_SHUTDOWN hcall. ------------------------------------------------------------------------ Hypercall: KVM_HC_VM_RESET Description: Requests that the virtual machine be reset. The hcall takes no arguments. If successful the hcall does not return. Arguments: r11 hcall-token KVM_HC_VM_RESET Return values r3 status Status of the hcall. If the hcall succeeds it does not return. If an error occurs EV_INTERNAL is returned. ------------------------------------------------------------------------ Hypercall: KVM_HC_VM_SHUTDOWN Description: Requests that the virtual machine be powered-off/halted. The hcall takes no arguments. If successful the hcall does not return. Arguments: r11 hcall-token KVM_HC_VM_SHUTDOWN Return values r3 status Status of the hcall. If the hcall succeeds it does not return. If an error occurs EV_INTERNAL is returned. Regards, Stuart -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html