[Qemu-devel] Regarding TB retranslation code.

[Venkatesh N]

This is regarding  TB retranslation code.

[Qemu-devel] [RFC 00/20] Do away with TB retranslation, Richard Henderson <=

Though i understood the code to avoid the retranslation, i could not
get picture on how "host" or backend registers are ensured to have the
older contents when the guest PC is restored from
"cpu_restore_state_from_tb"

For e.g, lets take these two Guest Instruction.

Instruction 1.  Mov r1, [r2];
Instruction 2.  mov [r1], r3 <-------- faulted instruction

In the above example if r1 is stored in x86 register EAX of the Host
and r3 is stored in EBX of the host.

the return from fault ensures that guest PC [EIP ] is recovered. But,
How does tcg ensures that execution of TB from the restored PC ensures
that HOST registers contents  have instruction 1 context also.

Can somebody please share how this is done are there any assumption
when inserting TCG-Opcode INDEX_op_insn_start is done.