On Fri, Mar 2, 2018 at 3:59 PM, Alex Williamson <alex.williamson@xxxxxxxxxx> wrote: > On Fri, 02 Mar 2018 15:44:25 -0800 > Alexander Duyck <alexander.duyck@xxxxxxxxx> wrote: > >> From: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> >> >> This patch is meant to add some basic functionality to support for SR-IOV >> on devices when the VFs are not managed by the kernel. The functions >> provided here can be used by drivers such as vfio-pci and virtio to enable >> SR-IOV on devices that are either managed by userspace, or by some sort of >> firmware entity respectively. >> >> A new sysfs value called sriov_unmanaged_autoprobe has been added. This >> value is used as the drivers_autoprobe setting of the VFs when they are >> being managed by an external entity such as userspace or device firmware >> instead of being managed by the kernel. >> >> One side effect of this change is that the sriov_drivers_autoprobe and >> sriov_unmanaged_autoprobe will only apply their updates when SR-IOV is >> disabled. Attempts to update them when SR-IOV is in use will only update >> the local value and will not update sriov->autoprobe. >> >> Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> >> --- >> Documentation/ABI/testing/sysfs-bus-pci | 17 ++++++++++++++ >> drivers/pci/iov.c | 37 +++++++++++++++++++++++++++++++ >> drivers/pci/pci-driver.c | 2 +- >> drivers/pci/pci-sysfs.c | 29 ++++++++++++++++++++++++ >> drivers/pci/pci.h | 4 +++ >> include/linux/pci.h | 1 + >> 6 files changed, 88 insertions(+), 2 deletions(-) >> >> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci >> index 44d4b2be92fd..ff0b6c19cb1a 100644 >> --- a/Documentation/ABI/testing/sysfs-bus-pci >> +++ b/Documentation/ABI/testing/sysfs-bus-pci >> @@ -323,3 +323,20 @@ Description: >> >> This is similar to /sys/bus/pci/drivers_autoprobe, but >> affects only the VFs associated with a specific PF. >> + >> +What: /sys/bus/pci/devices/.../sriov_unmanaged_autoprobe >> +Date: March 2018 >> +Contact: Alexander Duyck <alexander.h.duyck@xxxxxxxxx> >> +Description: >> + This file is associated with the PF of a device that >> + supports SR-IOV. It determines whether newly-enabled VFs >> + are immediately bound to a driver when the PF driver does >> + not manage the VFs itself. It initially contains 0, which >> + means the kernel will not automatically bind VFs to a driver. >> + If an application writes 1 to the file before enabling VFs, >> + the kernel will bind VFs to a compatible driver immediately >> + after they are enabled. >> + >> + This overrides /sys/bus/pci/devices/.../sriov_drivers_autoprobe >> + when a PF driver is not present to manage a device, or the PF >> + driver does not provide functionality to support SR-IOV. > > > Given a pf, how does a user determine whether it is managed or unmanaged > and therefore which autoprobe attributes are in effect? Thanks, > > Alex Basically it comes down to what driver is loaded on it. For now vfio-pci and virtio would be the only two using the "unmanaged" version of things. Really you don't know which autoprobe is in effect until SR-IOV is enabled by whatever driver. As such you should really be setting both the drivers_autoprobe and the unmanaged_autoprobe based on the expected use case. - Alex
