On 13/06/18 12:20, Jan Beulich wrote: >>>> On 13.06.18 at 12:05, <jbeul...@suse.com> wrote: >>>>> On 13.06.18 at 11:58, <jgr...@suse.com> wrote: >>> Using privcmd_call() for a singleton multicall seems to be wrong, as >>> privcmd_call() is using stac()/clac() to enable hypervisor access to >>> Linux user space. >>> >>> Add a new xen_single_call() function to be use for that purpose. >>> >>> Reported-by: Jan Beulich <jbeul...@suse.com> >>> Signed-off-by: Juergen Gross <jgr...@suse.com> >> >> Reviewed-by: Jan Beulich <jbeul...@suse.com> > > Actually I've only now realized that this isn't a real problem right now: > PV can't use SMAP (we don't provide a virtualized version of it), and > HVM/PVH can't use multicalls (which may have to change for PVH Dom0, > so having the change in place is helpful anyway), so the whole > in-kernel logic to collect and issue batches should be unreachable there. > > But perhaps the commit message would benefit from a little bit of > re-wording.
Hmm, right. What about: "Using privcmd_call() for a singleton multicall seems to be wrong, as privcmd_call() is using stac()/clac() to enable hypervisor access to Linux user space. Even if currently not a problem (pv domains can't use SMAP while HVM and PVH domains can't use multicalls) things might change when PVH dom0 support is added to the kernel." Juergen
