[uml-devel] How to convert UML user-space virtual address into HOST user-space virtual address?

[Pablo P. <ppe...@ho...>]

Hi:
    I am writing a UML device driver wrapper (uml/drivers),  and I need to convert an address of a UML user-space process into an address of UML kernel space.

i.e.

Process_running_within_UML(){
         char uml_usr_buffer[MAXBUF];
         .....
          ret = ioctl(dvk_fd,DVK_IOCSDCINIT, (int) uml_usr_buffer);
}

UML ioctl() syscall is translated by UML to os_ioctl_generic<https://elixir.bootlin.com/linux/v4.9.88/ident/os_ioctl_generic>()  which then calls host ioctl().

The uml_usr_buffer address is a UML virtual address, not host virtual address.
I need to convert this UML user-space virtual address into user-space HOST virtual address.

Can I use, virt_to_phys() ??

Thanks in advance.
PAP