Hi all, i am trying to figure out the code path which translate the emulated disk IO issued by VM to actual physical disk IO on host side. Can anyone give me a clear view about this? i read the kvm side code about the VMexit handling, the handle_io() will be called for IO exits. for IO job that cannot be handled inside the hyperviser, it will switch to qemu-kvm process and the handle_io() at qemu side will be called. finally it seems invoke the ioport_read()/ioport_write() which invoke the actual registered read/write operator. Then i get lost here, i do not know for emulated disk io which function will be responsible for the remaining job. i.e. catch the cmd for accessing the virtual disk and translate to the read/write to offset of the disk img file (assume we use file for virtual disk), and then issue the system call to the host to issue the real io cmd to physical disk. i really hope someone can help me with it. if my understanding is not correct, please figure out. i will be appreciated. Thanks, Sheng -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html