On Fri, Nov 11, 2022 at 10:27:18PM +0800, Longpeng(Mike) wrote: > From: Longpeng <longpeng2@xxxxxxxxxx> > > We can enable SRIOV and add VFs by /sys/bus/pci/devices/..../sriov_numvfs, but > this operation needs to spend lots of time if there has a large amount of VFs. > > For example, if the machine has 10 PFs and 250 VFs per-PF, enable all the VFs > concurrently would cost about 200-250ms. However most of them are not need to be > used at the moment, so we can enable SRIOV first but add VFs on demand. It is unclear what took 200-250ms, is it physical VF creation or bind of the driver to these VFs? If the latter, you can try with sriov_drivers_autoprobe set to true. This is how ennoblement of large SR-IOV systems is done. Also PCI spec declares "VF enable" bit, which is applicable to all VFs associated to that PF, see section "9.3.3.3.1 VF Enable". Thanks > > This series introduces two interfaces: > 1. sriov_numvfs_no_scan: enable SRIOV without add the VFs. > 2. sriov_scan_vf_id: add a specific VF. > > Longpeng (4): > pci/sriov: extract sriov_numvfs common helper > pci/sriov: add vf_bitmap to mark the vf id allocation > pci/sriov: add sriov_numfs_no_scan interface > pci/sriov: add sriov_scan_vf_id interface > > drivers/pci/iov.c | 162 +++++++++++++++++++++++++++++++++++++++++----- > drivers/pci/pci.h | 1 + > 2 files changed, 148 insertions(+), 15 deletions(-) > > -- > 2.23.0 >
