The nested_svm_exit_handled_msr() function maps only one
page of the guests msr permission bitmap. This patch changes
the code to use kvm_read_guest to fix the bug.

Cc: stable@kernel.org
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NAvi Kivity <avi@redhat.com>