Re: [PATCH 02/24] KVM: Provide callback to get/set control registers in emulator ops.

[Avi Kivity <avi@redhat.com>]

On 03/09/2010 04:09 PM, Gleb Natapov wrote:
> Use this callback instead of directly call kvm function. Also rename
> realmode_(set|get)_cr to emulator_(set|get)_cr since function has nothing
> to do with real mode.
>
>
> +	ulong (*get_cr)(int cr, struct kvm_vcpu *vcpu);
> +	void (*set_cr)(int cr, ulong val, struct kvm_vcpu *vcpu);
>   };
>    

Note, passing a vcpu means we are still tightly coupled to kvm.  Can be 
fixed later.

> +static unsigned long emulator_get_cr(int cr, struct kvm_vcpu *vcpu)
> +{
> +	unsigned long value;
> +
> +	switch (cr) {
> +	case 0:
> +		value = kvm_read_cr0(vcpu);
> +		break;
> +	case 2:
> +		value = vcpu->arch.cr2;
> +		break;
> +	case 3:
> +		value = vcpu->arch.cr3;
> +		break;
> +	case 4:
> +		value = kvm_read_cr4(vcpu);
> +		break;
> +	case 8:
> +		value = kvm_get_cr8(vcpu);
> +		break;
> +	default:
> +		vcpu_printf(vcpu, "%s: unexpected cr %u\n", __func__, cr);
> +		return 0;
>    

This printk is triggerable by guest code (as the patch didn't introduce 
this, it can be fixed later).

The emulator should #UD on unrecognised control registers.

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