On 11/10/2014 06:53 AM, Sathya Perla wrote:
A user must not be allowed to disable VFs while they are already assigned to
a guest. This check is being made in each individual driver that implements
the sriov_configure PCI method.
This patch-set fixes this code duplication by moving this check from
drivers to the sriov_nuvfs_store() routine just before invoking
sriov_configure() when num_vfs is equal to 0.
Vasundhara Volam (4):
pci: move pci_assivned_vfs() check while disabling VFs to pci
sub-system
bnx2x: remove pci_assigned_vfs() check while disabling VFs
i40e: remove pci_assigned_vfs() check while disabling VFs
qlcnic: remove pci_assigned_vfs() check while disabling VFs
drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c | 2 +-
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c | 7 +------
.../net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c | 10 ----------
drivers/pci/pci-sysfs.c | 5 +++++
4 files changed, 7 insertions(+), 17 deletions(-)
I have had a side conversation with Alex Williamson, VFIO author.
VFIO is the upstream method that device-assignment is managed/handled on kvm now.
It does not set the PCI_DEV_FLAGS_ASSIGNED pci dev-flags, and thus,
this check will not work when VFIO is used.
This patch set will only work for the former, kvm-managed, device-assignment method,
which is currently being deprecated in qemu as well.
So, yes, it works for kvm managed device-assignment, but not the
newer, VFIO-based device-assignment.
Note, also, that the pci_assigned_vfs() check in the drivers will
always return 0 when VFIO is used for device assignment, so keeping
these checks in the drivers doesn't do what they imply either.
So, taking in the patch solves old, kvm-managed, device assignment,
but a new method is needed when VFIO is involved.
- Don
ps -- Note: just adding the flag setting in vfio-pci does not necessarily
solve this problem. VFIO does not know if a device is assigned to a guest;
it only knows a caller of the ioctl requesting the device to be assigned
to vfio, and to be dma-mapped for a region of memory, has been requested.
So, a new PF<->VF mechanism needs to be put in place to
determine the equivalent information.
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