x86/ept: fix shattering of special pages
The current logic in epte_get_entry_emt() will split any page marked
as special with order greater than zero, without checking whether the
super page is all special.
Fix this by only splitting the page only if it's not all marked as
special, in order to prevent unneeded super page shuttering.
The unconditional special super page shattering has caused a
performance regression on some XenServer GPU pass through workloads.
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
projects / xen.git / commit