Re: [dpdk-dev] [PATCH 0/3] Enable uio_pci_generic support

[Bruce Richardson <bruce.richardson@intel.com>]

On Thu, Jan 29, 2015 at 05:28:16PM +0800, Danny Zhou wrote:
> Linux kernel provides UIO as well as VFIO mechanism to support writing user
> space device driver. Comparing to UIO which is available since 2.6.32 kernel,
> the VFIO is introduced into kernel since version 3.6.0 with better interrupt
> and memory protection (build on top of Intel VT-d technology) supports.
> Basically, UIO and VFIO do two common things below:
> 1) Map PCIe device's I/O memory space to user space driver
> 2) Support device interrupt notification mechanism that notifies user space
>    driver/application when a device interrupt triggers.
> 
> To run an DPDK application and make use of VFIO, two in_kernel modules
> vfio and vfio-pci module must be loaded. To use UIO, a DPDK kernel
> module igb_uio, which was there since DPDK is invented, must be loaded to
> attach to in_kernel uio module. As an solution to deprecate igb_uio, 
> this patch serials leverage the uio_pci_generic in_kernel module to support
> DPDK user space PMD in a generic fashion (similar to how VFIO works), to
> remove user space DPDK dependency on GPL code igb_uio in kernel. 
> 
> Example to bind Network Ports to uio_pci_generic:
> 	modprobe uio
> 	modprobe uio_pci_generic
> 	/* to bind device 08:00.0, to the uio_pci_generic driver */
> 	./tools/dpdk_nic_bind.py -b uio_pci_generic 08:00.0
> 
> Note: this patch set does not remove igb_uio support due to igb_uio supports
> creating maximum number of SR-IOV VFs (Virtual Functions) by using max_vfs 
> kernel parameter on older kernels (kernel 3.7.x and below).
> Specifically, igb_uio explicitly calls pci_enable_sriov() to create VFs, while
> it is not invoked in either uio or uio_pci_generic kernel modules. On kernel 3.8.x
> and above, user can use the standard sysfs to enable VFs. For examples:
> 
> #echo $num_vf_enabled > /sys/class/net/$dev/device/sriov_numvfs   //enable VFs
> #echo 0 > /sys/class/net/$dev/device/sriov_numvfs                 //disable VFs
> 
> Danny Zhou (3):
>   eal: add interrupt enable/disable routines for uio_pci_generic
>   eal: enable uio_pci_generic support
>   tools: enable binding NIC device to uio_pci_generic
> 
>  lib/librte_eal/common/include/rte_pci.h            |   1 +
>  lib/librte_eal/linuxapp/eal/eal_interrupts.c       |  68 +++++--
>  lib/librte_eal/linuxapp/eal/eal_pci.c              |   2 +-
>  lib/librte_eal/linuxapp/eal/eal_pci_uio.c          | 202 +++++++++++----------
>  .../linuxapp/eal/include/exec-env/rte_interrupts.h |  10 +-
>  tools/dpdk_nic_bind.py                             |   2 +-
>  6 files changed, 172 insertions(+), 113 deletions(-)
> 
> -- 
> 1.8.1.4
> 

Series
Acked-by: Bruce Richardson <bruce.richardson@intel.com>