Re: [Xen-devel] [PATCH v3 03/13] x86/hvm: Scale host TSC when setting/getting guest TSC

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 31.12.15 at 04:03, <haozhong.zhang@xxxxxxxxx> wrote:
> --- a/xen/arch/x86/hvm/svm/svm.c
> +++ b/xen/arch/x86/hvm/svm/svm.c
> @@ -804,6 +804,16 @@ static uint64_t scale_tsc(uint64_t host_tsc, uint64_t 
> ratio)
>      return scaled_host_tsc;
>  }
>  
> +static uint64_t svm_scale_tsc(struct vcpu *v, uint64_t tsc)
> +{
> +    struct domain *d = v->domain;
> +
> +    if ( !cpu_has_tsc_ratio || d->arch.vtsc )

The left side of this check is redundant with those at both call sites.
It should either be removed altogether, or converted to an ASSERT().
Perhaps the right side should move into the callers too (as being
vendor independent), or if not at least the pointless local variable
should be eliminated.

Further I suppose this new hook really could/should have its
first argument const qualified (the hook isn't supposed to fiddle
with the vCPU).

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel