On Mon, Jul 10, 2017 at 09:00:38AM +0000, Tan, Jianfeng wrote: > > > > -----Original Message----- > > From: Shijith Thotton [mailto:shijith.thot...@caviumnetworks.com] > > Sent: Monday, July 10, 2017 3:11 PM > > To: Tan, Jianfeng > > Cc: dev@dpdk.org; Yigit, Ferruh; Gregory Etelson; Thomas Monjalon; > > Stephen Hemminger; Lu, Wenzhuo > > Subject: Re: [PATCH v2] igb_uio: issue FLR during open and release of device > > file > > > > On Mon, Jul 10, 2017 at 03:38:34AM +0000, Tan, Jianfeng wrote: > > > Hi Thotton, > > > > > > > -----Original Message----- > > > > From: Shijith Thotton [mailto:shijith.thot...@caviumnetworks.com] > > > > Sent: Friday, July 7, 2017 7:14 PM > > > > To: dev@dpdk.org > > > > Cc: Yigit, Ferruh; Gregory Etelson; Thomas Monjalon; Stephen > > Hemminger; > > > > Tan, Jianfeng; Lu, Wenzhuo > > > > Subject: [PATCH v2] igb_uio: issue FLR during open and release of device > > file > > > > > > > > Set UIO info device file operations open and release. Call pci reset > > > > function inside open and release to clear device state at start and end. > > > > Copied this behaviour from vfio_pci kernel module code. With this patch, > > > > it is not mandatory to issue FLR by PMD's during init and close. > > > > > > I'm afraid this will not work for restarted DPDK process. In current > > > probe(), > > we set up the I/O mem and I/O port; and those sys files are used by EAL > > IGB_UIO initialization code to map I/O mem and port. After reset in > > release(), > > we will lose those sys files in next open(). > > > > > > Thanks, > > > Jianfeng > > > > > > > > > > > Bus master enable and disable are added in open and release > > respectively > > > > to take care of device DMA. > > > > > > > > Signed-off-by: Shijith Thotton <shijith.thot...@caviumnetworks.com> > > > > --- > > > > v2 changes: > > > > - Replaced pci_try_reset_function with pci_reset_function as it is not > > > > available in older kernel versions. > > > > > > > > v1 changes: > > > > - Added pci set master inside open and clear master inside release. > > > > - Remove obvious comments. > > > > > > > > RFC: http://dpdk.org/ml/archives/dev/2017-May/066917.html > > > > > > > > lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 33 > > > > +++++++++++++++++++++++++++++++ > > > > 1 file changed, 33 insertions(+) > > > > > > > > diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > > > b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > > > index b9d427c..07a19a3 100644 > > > > --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > > > +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c > > > > @@ -170,6 +170,37 @@ struct rte_uio_pci_dev { > > > > return IRQ_HANDLED; > > > > } > > > > > > > > +/** > > > > + * This gets called while opening uio device file. > > > > + */ > > > > +static int > > > > +igbuio_pci_open(struct uio_info *info, struct inode *inode) > > > > +{ > > > > + struct rte_uio_pci_dev *udev = info->priv; > > > > + struct pci_dev *dev = udev->pdev; > > > > + > > > > + pci_reset_function(dev); > > > > + > > > > + /* set bus master, which was cleared by the reset function */ > > > > + pci_set_master(dev); > > > > + > > > > + return 0; > > > > +} > > > > + > > > > +static int > > > > +igbuio_pci_release(struct uio_info *info, struct inode *inode) > > > > +{ > > > > + struct rte_uio_pci_dev *udev = info->priv; > > > > + struct pci_dev *dev = udev->pdev; > > > > + > > > > + /* stop the device from further DMA */ > > > > + pci_clear_master(dev); > > > > + > > > > + pci_reset_function(dev); > > > > + > > > > + return 0; > > > > +} > > > > + > > > > #ifdef CONFIG_XEN_DOM0 > > > > static int > > > > igbuio_dom0_mmap_phys(struct uio_info *info, struct vm_area_struct > > > > *vma) > > > > @@ -372,6 +403,8 @@ struct rte_uio_pci_dev { > > > > udev->info.version = "0.1"; > > > > udev->info.handler = igbuio_pci_irqhandler; > > > > udev->info.irqcontrol = igbuio_pci_irqcontrol; > > > > + udev->info.open = igbuio_pci_open; > > > > + udev->info.release = igbuio_pci_release; > > > > #ifdef CONFIG_XEN_DOM0 > > > > /* check if the driver run on Xen Dom0 */ > > > > if (xen_initial_domain()) > > > > -- > > > > 1.8.3.1 > > > > > > > Hi Jianfeng, > > > > I have tested the patch with LiquidIO VFs in VM using testpmd and could not > > see > > any issue over multiple runs. > > I got that, you are using pci_reset_function() instead of pci_disable_device > (the function I was trying). So only one question left, from the comment of > pci_reset_function(), it "saves and restores device state over the reset", > then is __pci_reset_function() is more proper here?
Per comments of __pci_reset_function: * Resetting the device will make the contents of PCI configuration space * random, so any caller of this must be prepared to reinitialise the * device including MSI, bus mastering, BARs, decoding IO and memory spaces, * etc. So thought, pci_reset_function would be proper as it saves and restores state. Please correct if I assumed it wrong. Shijith
