Re: [dpdk-dev] [PATCH 1/4] xen: allow choosing dom0 support at runtime

["Liu, Jijiang" <jijiang.liu@intel.com>]

> -----Original Message-----
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Sunday, February 15, 2015 10:28 PM
> To: Liu, Jijiang
> Cc: Stephen Hemminger; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 1/4] xen: allow choosing dom0 support at
> runtime
> 
> On Sun, 15 Feb 2015 04:07:21 +0000
> "Liu, Jijiang" <jijiang.liu@intel.com> wrote:
> 
> > Hi Stephen,
> >
> > What do you mean ' allow choosing dom0 support at runtime'?
> > If you mean user can choose DPDK  to run Xen Dom0 or not on DOM0 by a
> runtime flag, I don't think your change can achieve this goal.
> >
> > Thanks
> > Jijiang Liu
> 
> With the existing DPDK model if application is built with DOM0 support it will
> not work (it crashes) if the application is run in a non DOM0 environment (with
> real huge pages). And vice-versa if application is built without DOM0 support
> and it will crash if run in Xen Paravirt mode.
> 
> This patch allows the library to be built in such a way that only one version
> needs to be shipped which is important for distro's like RHEL who want to ship a
> shared library. And also important for users like Brocade/Vyatta who build one
> binary that needs to work on bare Linux and in Xen PV mode.
> 
Ok, thanks for the explanation.

Could you  replace 'internal_config.xen_dom0_support' with  'is_xen_dom0_supported()' in the function  rte_eal_hugepage_init()?

/* check if app runs on Xen Dom0 */
	if (internal_config.xen_dom0_support) {
#ifdef RTE_LIBRTE_XEN_DOM0
		/* use dom0_mm kernel driver to init memory */
		if (rte_xen_dom0_memory_init() < 0)
			return -1;
		else
			return 0;
#endif