> -----Original Message----- > From: dev [mailto:dev-boun...@dpdk.org] On Behalf Of Tan, Jianfeng > Sent: Thursday, November 02, 2017 8:57 PM > To: Ferruh Yigit <ferruh.yi...@intel.com>; Thomas Monjalon > <tho...@monjalon.net> > Cc: dev@dpdk.org; sta...@dpdk.org; Jingjing Wu <jingjing...@intel.com>; > Shijith Thotton > <shijith.thot...@caviumnetworks.com>; Gregory Etelson <greg...@weka.io>; > Harish Patil > <harish.pa...@cavium.com>; George Prekas <george.pre...@epfl.ch>; Sergio > Gonzalez Monroy > <sergio.gonzalez.mon...@intel.com>; Rasesh Mody <rasesh.m...@cavium.com> > Subject: Re: [dpdk-dev] [PATCH v2] igb_uio: add config option to control reset > > > > On 11/3/2017 8:51 AM, Ferruh Yigit wrote: > > Adding a compile time configuration option to control device reset done > > during DPDK application exit. > > > > Config option is CONFIG_RTE_EAL_IGB_UIO_RESET and enabled by default, > > so by default reset will happen. Having this reset is safer to be sure > > device left in a proper case. > > > > But for special cases [1] it is possible to disable the config option > > to prevent the device reset. > > > > [1] > > http://dpdk.org/ml/archives/dev/2017-November/080927.html > > > > Fixes: b58eedfc7dd5 ("igb_uio: issue FLR during open and release of device > > file") > > Cc: sta...@dpdk.org > > > > Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com> > > Realize that we do have a pci_clear_master() in the release() to disable > the DMA from device until the next open() will enable the DMA again . > Here is my: > > Reviewed-by: Jianfeng Tan <jianfeng....@intel.com> > > Thanks, > Jianfeng > > > --- > > Cc: Jianfeng Tan <jianfeng....@intel.com> > > Cc: Jingjing Wu <jingjing...@intel.com> > > Cc: Shijith Thotton <shijith.thot...@caviumnetworks.com> > > Cc: Gregory Etelson <greg...@weka.io> > > Cc: Harish Patil <harish.pa...@cavium.com> > > Cc: George Prekas <george.pre...@epfl.ch> > > Cc: Sergio Gonzalez Monroy <sergio.gonzalez.mon...@intel.com> > > Cc: Rasesh Mody <rasesh.m...@cavium.com> > > > > v2: > > * fix typo in commit log > > --- > > config/common_base | 1 + > > config/common_linuxapp | 1 + > > lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 2 ++ > > 3 files changed, 4 insertions(+) > > > > diff --git a/config/common_base b/config/common_base > > index 82ee75456..2a9947420 100644 > > --- a/config/common_base > > +++ b/config/common_base > > @@ -102,6 +102,7 @@ CONFIG_RTE_LIBEAL_USE_HPET=n > > CONFIG_RTE_EAL_ALLOW_INV_SOCKET_ID=n > > CONFIG_RTE_EAL_ALWAYS_PANIC_ON_ERROR=n > > CONFIG_RTE_EAL_IGB_UIO=n > > +CONFIG_RTE_EAL_IGB_UIO_RESET=n > > CONFIG_RTE_EAL_VFIO=n > > CONFIG_RTE_MALLOC_DEBUG=n > > CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES=n > > diff --git a/config/common_linuxapp b/config/common_linuxapp > > index 74c7d64ec..b3a602909 100644 > > --- a/config/common_linuxapp > > +++ b/config/common_linuxapp > > @@ -37,6 +37,7 @@ CONFIG_RTE_EXEC_ENV_LINUXAPP=y > > > > CONFIG_RTE_EAL_NUMA_AWARE_HUGEPAGES=y > > CONFIG_RTE_EAL_IGB_UIO=y > > +CONFIG_RTE_EAL_IGB_UIO_RESET=y > > CONFIG_RTE_EAL_VFIO=y > > CONFIG_RTE_KNI_KMOD=y > > CONFIG_RTE_LIBRTE_KNI=y > > diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > index fd320d87d..0325722c0 100644 > > --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > @@ -360,7 +360,9 @@ igbuio_pci_release(struct uio_info *info, struct inode > > *inode) > > /* stop the device from further DMA */ > > pci_clear_master(dev); > > > > +#ifdef RTE_EAL_IGB_UIO_RESET > > pci_reset_function(dev); > > +#endif > > > > return 0; > > }
A compile time configuration option makes life very difficult for application providers. Consider the case where an application such as Open vSwitch with DPDK support is being provided with a Linux distribution. One would want the Open vSwitch binary to support as many vendor NICs as possible---without the need to recompile. With a change such as this, one would need to have different versions of the kernel igb_uio module to support different NICs. The Linux kernel is already aware of, and provides work-arounds for, various PCI quirks. For example, see linux/drivers/pci/quirks.c (http://elixir.free-electrons.com/linux/latest/source/drivers/pci/quirks.c). At this point in igb_uio.c, one is aware of the struct pci_dev "dev" for the device in question. Access to the vendor and device information should be simple: struct pci_dev { struct list_head bus_list; /* node in per-bus list */ struct pci_bus *bus; /* bus this device is on */ struct pci_bus *subordinate; /* bus this device bridges to */ void *sysdata; /* hook for sys-specific extension */ struct proc_dir_entry *procent; /* device entry in /proc/bus/pci */ struct pci_slot *slot; /* Physical slot this device is in */ unsigned int devfn; /* encoded device & function index */ unsigned short vendor; unsigned short device; unsigned short subsystem_vendor; unsigned short subsystem_device; ... One could imagine using logic to implement corresponding PCI quirks that can be evaluated at runtime. For example (in pseudocode), if not (vendor = "Cavium" and device = "bnx2x") then pci_reset_function(dev); There are other possible implementations. If there are enough quirks, one might have action functions defined---and a table of function pointers associated with each PMD to select the proper action. - Lee Roberts
