Executing a kernel device driver as a user space process
A method, including receiving, by a user space driver framework (UDF) library executing from a user space of a memory over a monolithic operating system kernel, a kernel application programming interface (API) call from a device driver executing from the user space. The UDF library then performs an operation corresponding to the kernel API call.
1. A method, comprising:
receiving, by a user space driver framework (UDF) library executing from a user space of a memory over an operating system kernel operated by a device driver executing from the user space, a kernel application programming interface (API) call from a device driver executing from the user space;
determining that the operation comprises a privileged operation, wherein if the operation is privileged:
conveying, via a file descriptor, the API call to a UDF kernel module executing from a kernel space of the memory over the operating system kernel, and
performing, by a kernel space emulation module, the privileged operation from the kernel space while conveying completion information back to the UDF library.
2. The method according to claim 1 , further including a non-privileged operation.
3. The method according to claim 2 , wherein the non-privileged operation is selected from a group of operations comprising maintaining a list, maintaining a timer, and maintaining a process scheduler.
4. The method according to claim 1 , wherein the privileged operation is selected from a group of operations comprising catching an interrupt, allocating direct memory access (DMA) memory, and mapping input/output (I/O) memory addresses.
5. The method according to claim 1 , wherein the device driver comprises a Peripheral Component Interconnect (PCI) device driver.
6. A computer program product, the computer program product comprising:
a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising:
computer readable program code configured to receive, by a user space driver framework (UDF) library executing from a user space of a memory over an operating system kernel operated by a device driver executing from the user space, a kernel application programming interface (API) call from a device driver executing from the user space; and
computer readable program code configured to determine that the operation comprises a privileged operation, wherein if the operation is privileged, the API call is conveyed, via a file descriptor, to a UDF kernel module executing from a kernel space of the memory over the operating system kernel, and the privileged operation is performed, by a kernel space emulation module, the privileged operation from the kernel space while conveying completion information back to the UDF library.
7. The computer program product according to claim 6 , further including a non-privileged operation.
8. The computer program product according to claim 7 , wherein the computer readable program code is configured to select the non-privileged operation from a group of operations comprising maintaining a list, maintaining a timer, and maintaining a process scheduler.
9. The computer program product according to claim 6 , wherein the computer readable program code is configured to select the privileged operation from a group of operations comprising catching an interrupt, allocating direct memory access (DMA) memory, and mapping input/output (I/O) memory addresses.
10. The computer program product according to claim 6 , wherein the device driver comprises a Peripheral Component Interconnect (PCI) device driver.