Re: RFC: proposal for VM reset & shutdown hcall (v3)

[Scott Wood <scottwood@freescale.com>]

On 07/02/2013 05:08:02 PM, Yoder Stuart-B08248 wrote:
> ------------------------------------------------------------------------
> 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[].   As per the ePAPR hcall ABI, the return value
> should be returned to the guest in R3 and output return values
> in R4 - R10.

Should we specify that KVM fills in upper half of each value with zero  
if the target is not in 64-bit mode?

-Scott