Re: [PATCH] tools/libxc: Improve efficiency of xc_cpuid_apply_policy()

[Ian Campbell <ian.campbell@citrix.com>]

On Tue, 2015-10-06 at 10:14 +0100, Wei Liu wrote:
> On Mon, Oct 05, 2015 at 02:12:17PM +0100, Andrew Cooper wrote:
> > Having the internals of xc_cpuid_policy() make hypercalls to collect
> > domain
> > information causes xc_cpuid_apply_policy() to be very inefficient.
> > 
> > Re-order operations to collect all information at once at the outermost
> > layer,
> > and pass a structure in to all cpuid policy generation functions.
> > 
> > This removes several hypercalls (4 from HVM, 3 from PV) for each of the
> > up-to 108 leaves processed.
> > 
> > No change in the eventual policy provided, although all the information
> > gathering how has (or has correct) error checking.
> > 
> > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
> > ---
> > CC: Ian Campbell <Ian.Campbell@citrix.com>
> > CC: Ian Jackson <Ian.Jackson@eu.citrix.com>
> > CC: Wei Liu <wei.liu2@citrix.com>
> 
> Acked-by: Wei Liu <wei.liu2@citrix.com>

Applied.

> > +    /* PV-only information. */
> > +    bool pv64;
> > +
> > +    /* HVM-only infomation. */

Typo fixed


> > +    bool pae;
> > +    bool nestedhvm;
> 
> I would have used union for these fields. But I don't want to bikeshed
> too much on this. Definitely not a blocker for this patch. :-)

Indeed.

Ian.