Re: [PATCH 3/3] KVM - add hypercall nr to kvm_run

[Avi Kivity <avi@qumranet.com>]

Jeff Dike wrote:
> Add the hypercall number to kvm_run and initialize it.  This might be
> considered API-changing, so I kept it separate.
>
> Signed-off-by: Jeff Dike <jdike@linux.intel.com>
> --
>  drivers/kvm/kvm_main.c |    1 +
>  include/linux/kvm.h    |    1 +
>  2 files changed, 2 insertions(+)
>
> Index: kvm/drivers/kvm/kvm_main.c
> ===================================================================
> --- kvm.orig/drivers/kvm/kvm_main.c
> +++ kvm/drivers/kvm/kvm_main.c
> @@ -1361,6 +1361,7 @@ int kvm_hypercall(struct kvm_vcpu *vcpu,
>  	}
>  	switch (nr) {
>  	default:
> +		run->hypercall.nr = nr;
>  		run->hypercall.args[0] = a0;
>  		run->hypercall.args[1] = a1;
>  		run->hypercall.args[2] = a2;
> Index: kvm/include/linux/kvm.h
> ===================================================================
> --- kvm.orig/include/linux/kvm.h
> +++ kvm/include/linux/kvm.h
> @@ -106,6 +106,7 @@ struct kvm_run {
>  		} mmio;
>  		/* KVM_EXIT_HYPERCALL */
>  		struct {
> +			__u64 nr;
>  			__u64 args[6];
>  			__u64 ret;
>  			__u32 longmode;
>   

It isn't API changing as the API could not be (and has not been) used.  
We do need to add a padding element to the union to make sure additional 
union members don't cause its size to change.

Quite sad that we got this far with such brokenness.

-- 
error compiling committee.c: too many arguments to function