Calling disk I/O functions in qemu main loop

[Arnabjyoti Kalita]

Hello all,

I am running QEMU version 5.0.1 in TCG mode. And I am looking for a mechanism to actually run disk read and disk write functions in the TCG guest execution loop. I am using the virtio-blk pci device and I am using a qcow2 image file.

static inline tcg_target_ulong cpu_tb_exec(CPUState *cpu, TranslationBlock *itb)

{

    .....

    < disk I/O function here >

    ret = tcg_qemu_tb_exec(env, tb_ptr);

    .....

}

I will run the disk I/O function based on some condition and I want it to execute synchronously. After it finishes I will run the tcg execution loop for that particular translated block.

Is it possible and acceptable to run disk I/O functions within the qemu main loop?

What are the steps I need to follow in order to ensure the disk I/O operation is complete before the execution of the current translated block?

If it matters, the host and target architecture is x86-64.

Thank you very much for all your help so far.

Best regards,

Arnabjyoti Kalita