1. Checkpointing for Virtual Platforms and SystemC-TLM-2.0 Màrius Montón Directors: Dr. Mark Burton Dr. Jordi Carrabina December 2010 Univ. Autònoma Barcelona

3. Objectives

4. Virtual Platforms and SystemC

5. Checkpointing for SystemC

6. Conclusions

8. Objectives

9. Virtual Platforms and SystemC

10. Checkpointing for SystemC

11. Conclusions Introduction

13. Target SW unable to distinguish virtual platform from real HW

14. Run SW or OS on Virtual HW

15. Develop SW for non-existing HW

16. Simulate complex system interconnectivity

17. Introduction – Virtual Platforms

18. Introduction – Virtual Platforms

19. Introduction – Virtual Platforms

20. Introduction – Virtual Platforms

21. Virtual Platform Design Hardware Software Integration & Test time Engineering Resources © WindRiver (Virtutech)

22. Virtual Platform Design Hardware Software Integration & Test time Engineering Resources time Engineering Resources Resources Time to Market Hardware Software Integration & Test © WindRiver (Virtutech)

23. Generic Virtual Platform Diagram Virtual Platform ISS ISS VP Back-end functions Devices Devices Memories Target Drivers Boot code Target Operating System User User User

25. OSCI simulator

28. Retrieve the execution from a disk

30. bug fixing (modify a simulation value & continue)

31. reverse execution

32. multi-site development teams

34. HW engineers know (or should) SystemC, not other languages

35. Different VP -> Rewrite own models

36. No interoperability

38. Objectives

39. Virtual Platforms and SystemC

40. Checkpointing for SystemC

41. Conclusions Objectives

43. Objectives

44. Virtual Platforms and SystemC

45. Checkpointing for SystemC

46. Conclusions Objectives

49. Overcome limitations

50. Generic Virtual Platform Diagram Virtual Platform ISS ISS VP Back-end functions Devices Devices Memories Target Drivers Boot code Target Operating System User User User SystemC SystemC Devices Sync

52. Objectives

53. Virtual Platforms and SystemC

54. Checkpointing for SystemC

55. Conclusions Virtual Platforms and SystemC

57. Objectives

58. Virtual Platforms and SystemC

59. Checkpointing for SystemC

60. Conclusions Virtual Platforms and SystemC

62. Synchronization strategy

63. Generic bridge

66. Virtual Platforms and SystemC Execution time Synch VP SystemC Virtual execution

68. Generic fabric bus (TLM) -> any architecture

70. QEMU-SC Linux Driver VP SystemC module SC_Bridge SC_Link TLM Socket Application

75. Finish all protocol phases before return to VP

76. Communication - LT

77. Communication - AT

82. QEMU is a TLM-2 Initiator module

83. Easy integration

84. Focus on many SystemC

85. models

86. QBox

87. QBox internal architecture

88. QBox complex example QEMU Wrapper NIC TILE TILE TILE QEMU NoC

91. QEMU-SC Test System TLM Socket QEMU SystemC iDCT acc. SC_Bridge SC_Link DMI Pointer Reg. File IRQ IRQ Linux Driver MPEG accelerator irq_event MPEG-2 decoder

93. No acc. w/ drivers

94. QEMU style 1 acc.

95. SystemC 1 acc.

96. QEMU style 2 acc.

97. SystemC 2 acc.

98. SystemC skel. (1 acc.)

99. SystemC skel. (2 acc.)

101. No acc. w/ drivers

102. QEMU style 1 acc.

103. SystemC 1 acc.

104. QEMU style 2 acc.

105. SystemC 2 acc.

106. SystemC skel. (1 acc.)

107. SystemC skel. (2 acc.) Penalty 8% ~ 14%

108. Complex QBox system DMI Pointer TLM 2 Socket SignalSocket (IRQ) QEMU Wrapper GreenRouter TLM 2 Socket (Ethernet) Linux QEMU NE2000 NE2000 Testbench

109. QBox Test System TLM Socket SystemC iDCT acc. Reg. File IRQ SignalSocket (IRQ) QEMU Wrapper GreenRouter Linux Driver irq_event QEMU MPEG-2 decoder

111. No acc. w/ drivers

112. QEMU style 1 acc.

113. SystemC 1 acc.

114. QEMU style 2 acc.

115. SystemC 2 acc.

116. SystemC skel. (1 acc.)

117. SystemC skel. (2 acc.)

119. No acc. w/ drivers

120. QEMU style 1 acc.

121. SystemC 1 acc.

122. QEMU style 2 acc.

123. SystemC 2 acc.

124. SystemC skel. (1 acc.)

125. SystemC skel. (2 acc.) Penalty ~ 100%!!!

126. QBox Test System TLM Socket SystemC iDCT acc. Reg. File IRQ SignalSocket (IRQ) QEMU Wrapper GreenRouter Linux Driver irq_event QEMU MPEG-2 decoder Penalty ~ 100%!!!

128. Objectives

129. Virtual Platforms and SystemC

130. Checkpointing for SystemC

133. Objectives

134. Virtual Platforms and SystemC

135. Checkpointing for SystemC

139. State-variables save and restore

140. Process save checkpointing Save Restore O.S. HW O.S. HW VP VP

141. Process save checkpointing Save Restore O.S. HW O.S. HW HW VP VP

142. Process save checkpointing Save Restore O.S. HW O.S. HW HW VP VP

143. Process save checkpointing Save Restore O.S. HW O.S. HW HW O.S. VP VP

144. Process save checkpointing Save Restore O.S. HW O.S. HW HW O.S. VP VP

145. State save checkpointing Save Restore O.S. HW O.S. HW VP VP chkp_mng chkp_mng

146. State save checkpointing Save Restore O.S. HW O.S. HW VP VP chkp_mng chkp_mng

147. State save checkpointing Save Restore O.S. HW O.S. HW HW VP VP chkp_mng chkp_mng

148. State save checkpointing Save Restore O.S. HW O.S. HW HW O.S. VP VP chkp_mng chkp_mng

151. stored values

154. do_restore()

157. restore()

159. Channels state and data

162. Editable

164. channels state and data

171. Callbacks functions

173. Callbacks functions

179. Other cases about a 50%

181. pending events

183. Fast saving to disk time

184. Reverse execution

185. Checkpoint data # OSCI data 55000 60000;Initiator.initiator_func; # FIFO “my_fifo” Target.my_fifo=14;Target.my_fifo=0; Target.my_fifo=0.5;Target.my_fifo=1; ... Target.my_fifo=6.5; # gs_params Initiator.initiator_func_fsm_param 0 Initiator.int_param 6 Target.data_gs_param {"0" "0.5" "1" "1.5" "2" "2.5" "0" "0" "0" "0"} Target.data_gs_paramB.0 0 Target.data_gs_paramB.1 0.5 Target.data_gs_paramB.2 1 Target.data_gs_paramB.3 1.5 Target.data_gs_paramB.4 2 ... Target.data_gs_paramB.9 0 OSCI kernel data Channels data User modules data

187. Objectives

188. Virtual Platforms and SystemC

189. Checkpointing for SystemC

190. Conclusions Conclusions

192. Objectives

193. Virtual Platforms and SystemC

194. Checkpointing for SystemC

195. Conclusions Conclusions

199. Published as open-sourced projects www.greensocs.com Conclusions – SystemC

200. Conclusions – SystemC Simulation Manager Penalty System for QEMU-SC Yes 10% SW QBox No 25~30% HW

202. Close source -> new device manages SystemC

203. Same strategy than QEMU-SC

205. SystemC QT = 1 ms.

206. SystemC QT = 1 μ s.

207. Simics DML Microbenchmark

209. SystemC QT = 1 ms.

210. SystemC QT = 1 μ s.

211. Simics DML Microbenchmark Penalty ~ 5%

215. Saving only necessary data, not the entire process

216. Focused on VP modeling

217. With limitations but enough for VP devices

219. Inspect OSCI kernel when checkpointing

224. performance issues

225. Thank you! Questions?

226. BACKUP SLIDES

227. Conclusions – Simics Virtutech

228. QEMU ecosystem