Messages in this thread | | | Subject | Re: [PATCH 1/1] net/mlx5: Call pci_disable_sriov() on remove | From | Niklas Schnelle <> | Date | Thu, 30 Apr 2020 21:47:48 +0200 |
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On 4/30/20 5:58 PM, Saeed Mahameed wrote: > On Thu, 2020-04-30 at 14:03 +0200, Niklas Schnelle wrote: >> as described in Documentation/PCI/pci-iov-howto.rst a driver with SR- >> IOV >> support should call pci_disable_sriov() in the remove handler. > > Hi Niklas, > > looking at the documentation, it doesn't say "should" it just gives the > code as example. > >> Otherwise removing a PF (e.g. via pci_stop_and_remove_bus_device()) >> with >> attached VFs does not properly shut the VFs down before shutting down >> the PF. This leads to the VF drivers handling defunct devices and >> accompanying error messages. >> > > Which should be the admin responsibility .. if the admin want to do > this, then let it be.. why block him ? > > our mlx5 driver in the vf handles this gracefully and once pf > driver/device is back online the vf driver quickly recovers. See my answer to your other answer ;-) > >> In the current code pci_disable_sriov() is already called in >> mlx5_sriov_disable() but not in mlx5_sriov_detach() which is called >> from >> the remove handler. Fix this by moving the pci_disable_sriov() call >> into >> mlx5_device_disable_sriov() which is called by both. >> >> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> >> --- >> drivers/net/ethernet/mellanox/mlx5/core/sriov.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c >> b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c >> index 3094d20297a9..2401961c9f5b 100644 >> --- a/drivers/net/ethernet/mellanox/mlx5/core/sriov.c >> +++ b/drivers/net/ethernet/mellanox/mlx5/core/sriov.c >> @@ -114,6 +114,8 @@ mlx5_device_disable_sriov(struct mlx5_core_dev >> *dev, int num_vfs, bool clear_vf) >> int err; >> int vf; >> >> + pci_disable_sriov(dev->pdev); >> + >> for (vf = num_vfs - 1; vf >= 0; vf--) { >> if (!sriov->vfs_ctx[vf].enabled) >> continue; >> @@ -156,7 +158,6 @@ static void mlx5_sriov_disable(struct pci_dev >> *pdev) >> struct mlx5_core_dev *dev = pci_get_drvdata(pdev); >> int num_vfs = pci_num_vf(dev->pdev); >> >> - pci_disable_sriov(pdev); > > this patch is no good as it breaks code symmetry.. and could lead to > many new issues. Ah you're right I totally missed that there is a matching pci_enable_sriov() in mlx5_enable_sriov() haven't used these myself before and since it wasn't in the documentation example I somehow expected it to happen in non-driver code, so for symmetry that would also have to move to mlx5_device_enable_sriov(), sorry for the oversight. > > >> mlx5_device_disable_sriov(dev, num_vfs, true); >> } >> >
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