Re: [Xen-devel] [PATCH 2/2] x86/HVM: Use fixed TSC value when saving or restoring domain

["Tian, Kevin" <kevin.tian@xxxxxxxxx>]

> From: Boris Ostrovsky [mailto:boris.ostrovsky@xxxxxxxxxx]
> Sent: Monday, March 31, 2014 10:01 PM
> 
> On 03/31/2014 05:51 AM, Jan Beulich wrote:
> >
> >> --- a/xen/arch/x86/hvm/save.c
> >> +++ b/xen/arch/x86/hvm/save.c
> >> @@ -24,7 +24,7 @@
> >>   #include <asm/hvm/support.h>
> >>   #include <public/hvm/save.h>
> >>
> >> -void arch_hvm_save(struct domain *d, struct hvm_save_header *hdr)
> >> +void arch_hvm_save(struct domain *dom, struct hvm_save_header *hdr)
> > The change is unmotivated (afaict) and inconsistent with most other
> > code - we conventionally use "d" for struct domain * variables. Please
> > drop the change here and use "d" throughout the rest of the patch,
> > at once resulting in less churn and hence making it easier to review.
> 
> The reason for this change is subsequent
>      rdtscll(dom->arch.chkpt_tsc);
> 
> which will not work as
>      rdtscll(d->arch.chkpt_tsc);
> 
> The alternatives as I see are
> * Declare a temporary variable for use with rdtscll
> * Change rdtscll's definition to use something else instead of variable
> 'd'. Say, eax and edx (hopefully this won't clash with something else)
> 

use temp variable at least for now, which is cleaner regarding to the
purpose of this patch. rdtscll() should be a separate patch, however
imo it is not worthy of doing that.

Thanks
Kevin

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