On Thu, Sep 28, 2023 at 09:16:48AM +0200, Jan Beulich wrote: > The registration by virtual/linear address has downsides: At least on > x86 the access is expensive for HVM/PVH domains. Furthermore for 64-bit > PV domains the areas are inaccessible (and hence cannot be updated by > Xen) when in guest-user mode, and for HVM guests they may be > inaccessible when Meltdown mitigations are in place. (There are yet > more issues.) > > In preparation of the introduction of new vCPU operations allowing to > register the respective areas (one of the two is x86-specific) by > guest-physical address, flesh out the map/unmap functions. > > Noteworthy differences from map_vcpu_info(): > - areas can be registered more than once (and de-registered), > - remote vCPU-s are paused rather than checked for being down (which in > principle can change right after the check), > - the domain lock is taken for a much smaller region. > > Signed-off-by: Jan Beulich <jbeul...@suse.com>
Acked-by: Roger Pau Monné <roger....@citrix.com> Thanks, Roger.
