NASM 2.05 based x86 Instruction Reference[ch131]
A.5.111 FXRSTOR: Restore FP, MMX and SSE State FXRSTOR memory ; 0F AE /1 [P6,SSE,FPU] The FXRSTOR instruction reloads the FPU, MMX and SSE state (environment and registers), from the 512 byte memory area defined by the source operand. This data should have been written by a previous FXSAVE.