Re: [PATCH 11/13] vmx: Use scaled host TSC to calculate TSC offset

["Jan Beulich" <JBeulich@suse.com>]

>>> On 28.09.15 at 09:13, <haozhong.zhang@intel.com> wrote:
> --- a/xen/arch/x86/hvm/vmx/vmx.c
> +++ b/xen/arch/x86/hvm/vmx/vmx.c
> @@ -1102,11 +1102,26 @@ static void vmx_handle_cd(struct vcpu *v, unsigned long value)
>  
>  static void vmx_set_tsc_offset(struct vcpu *v, u64 offset, u64 at_tsc)
>  {
> +    uint64_t host_tsc, guest_tsc;
> +    struct domain *d = v->domain;
> +
> +    guest_tsc = hvm_get_guest_tsc_fixed(v, at_tsc);
> +
> +    if ( cpu_has_vmx_tsc_scaling && !d->arch.vtsc )
> +    {
> +        host_tsc = at_tsc ? at_tsc : rdtsc();
> +        offset = guest_tsc - hvm_scale_tsc(v, host_tsc);
> +    }

Considering up to here this is basically the same as SVM's, this
should imo be factored out into a new hvm_set_tsc_offset(),
with the caller of hvm_funcs.set_tsc_offset() - lacking a proper
wrapper anyway - being converted to call that function.

>      vmx_vmcs_enter(v);
>  
> +    if ( !nestedhvm_enabled(d) )
> +        goto out;
> +
>      if ( nestedhvm_vcpu_in_guestmode(v) )
>          offset += nvmx_get_tsc_offset(v);
>  
> +out:

Instead of using goto and a malformed (coding style wise) label,
please simply extend the if() accordingly.

Jan