>-----Original Message----- >From: Tamas K Lengyel [mailto:tamas.k.leng...@gmail.com] >Sent: Thursday, May 12, 2016 8:54 AM >To: Wei Liu <wei.l...@citrix.com> >Cc: Big Strong <fangtu...@gmail.com>; Sahita, Ravi <ravi.sah...@intel.com>; >White, Edmund H <edmund.h.wh...@intel.com>; Jan Beulich ><jbeul...@suse.com>; Xen-devel <xen-devel@lists.xen.org> >Subject: Re: [Xen-devel] xc_altp2m_set_vcpu_enable_notify fail > >On Thu, May 12, 2016 at 9:17 AM, Wei Liu <wei.l...@citrix.com> wrote: >> On Thu, May 12, 2016 at 09:00:12PM +0800, Big Strong wrote: >>> I'm still not very clear why would do_altp2m_op change the domain to >>> current domain (which is dom0 in my case) when the cmd is >>> HVMOP_altp2m_vcpu_enable_notify >>> ><http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/hvm/hvm.c;hb >=743289d0296268fe6bad64531a24d8053afeb062#l6198>. >>> As to my case, it would prevent the dom0 to set the #ve info page for >>> other domUs because the check of is_hvm_domain would fail >>> <http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=xen/arch/x86/hvm/h >>> vm.c;hb=743289d0296268fe6bad64531a24d8053afeb062#l6204>and >>> the function will returns directly. >>> >> >> Maybe the intent of that HVMOP is to get called directly by the guest >> that is interested in such event? >> >> I looks like a natural restriction to me because the vcpu needs to set >> up handler for #ve AIUI. It's not likely that Dom0 can do this for >> arbitrary guest. >> > >That sounds like a reasonable explanation. When I wrote the libxc wrapper I >pretty much just exposed what was available based on the hypervisor side. As my >off-hand comment in the code states I did find it odd that this op works on >current vCPU. So if it's actually issued from the domain itself it would make >sense. >So with that we should probably remove the libxc wrapper for this hvmop as it >won't work/not designed to be issued from dom0 and should add some >comments in the header explaining its intended use.
Agree with that (and Wei's explanation is accurate). Ravi > >Tamas _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
