setup_syscalls_segments() calls get_segment() and than overwrites all
but one of the structure fields and this one should also be overwritten
anyway, so we can drop call to get_segment() and avoid a couple of vmreads
on vmx. Also drop zeroing ss/cs structures since most of the fields are
set anyway. Just set those that were not set explicitly.
Signed-off-by: NGleb Natapov <gleb@redhat.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>