CR4_PGE
(CR4_PSE|CR4_PAE|CR4_PGE|CR4_PCIDE|CR4_SMEP)
CR4_PGE | \
(CR4_PSE|CR4_PAE|CR4_PGE|CR4_PCIDE|CR4_SMEP)
load_cr4(cr4 & ~CR4_PGE);
load_cr4(rcr4() | CR4_PGE | CR4_PSE);
load_cr4(cr4 & ~CR4_PGE);