On Fri, Nov 11, 2022 at 10:27:18PM +0800, Longpeng(Mike) wrote:It is neither. In our test, we already created physical VFs before, so we skipped the 100ms waiting when writing PCI_SRIOV_CTRL. And our driver only probes PF, it just returns an error if the function is VF.
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(-)
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2.23.0