On 1/29/2015 5:28 PM, 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.
I would like to say that, VFIO is not only for X86. Thanks, Michael > 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(-) >