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| author | Tony Nguyen <anthony.l.nguyen@intel.com> | 2017-10-04 08:52:58 -0700 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2017-10-10 19:15:29 -0500 |
| commit | ff26449e415a5601c8bb5b67ac4ae801f7165696 (patch) | |
| tree | 0b453428cf18acd3b065833c15aa81794f1c2ff1 /drivers/pci/iov.c | |
| parent | 27d6162944b9b34c32cd5841acd21786637ee743 (diff) | |
| download | linux-rt-ff26449e415a5601c8bb5b67ac4ae801f7165696.tar.gz | |
PCI: Restore ARI Capable Hierarchy before setting numVFs
In the restore path, we previously read PCI_SRIOV_VF_OFFSET and
PCI_SRIOV_VF_STRIDE before restoring PCI_SRIOV_CTRL_ARI:
pci_restore_state
pci_restore_iov_state
sriov_restore_state
pci_iov_set_numvfs
pci_read_config_word(... PCI_SRIOV_VF_OFFSET, &iov->offset)
pci_read_config_word(... PCI_SRIOV_VF_STRIDE, &iov->stride)
pci_write_config_word(... PCI_SRIOV_CTRL, iov->ctrl)
But per SR-IOV r1.1, sec 3.3.3.5, the device can use PCI_SRIOV_CTRL_ARI to
determine PCI_SRIOV_VF_OFFSET and PCI_SRIOV_VF_STRIDE. Therefore, this
path, which is used for suspend/resume and AER recovery, can corrupt
iov->offset and iov->stride.
Since the iov state is associated with the device, not the driver, if we
reload the driver, it will use the the corrupted data, which may cause
crashes like this:
kernel BUG at drivers/pci/iov.c:157!
RIP: 0010:pci_iov_add_virtfn+0x2eb/0x350
Call Trace:
pci_enable_sriov+0x353/0x440
ixgbe_pci_sriov_configure+0xd5/0x1f0 [ixgbe]
sriov_numvfs_store+0xf7/0x170
dev_attr_store+0x18/0x30
sysfs_kf_write+0x37/0x40
kernfs_fop_write+0x120/0x1b0
vfs_write+0xb5/0x1a0
SyS_write+0x55/0xc0
Restore PCI_SRIOV_CTRL_ARI before calling pci_iov_set_numvfs(), then
restore the rest of PCI_SRIOV_CTRL (which may set PCI_SRIOV_CTRL_VFE)
afterwards.
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
[bhelgaas: changelog, add comment, also clear ARI if necessary]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alexander Duyck <alexander.h.duyck@intel.com>
CC: Emil Tantilov <emil.s.tantilov@intel.com>
Diffstat (limited to 'drivers/pci/iov.c')
| -rw-r--r-- | drivers/pci/iov.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index ce24cf235f01..6bacb8995e96 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -498,6 +498,14 @@ static void sriov_restore_state(struct pci_dev *dev) if (ctrl & PCI_SRIOV_CTRL_VFE) return; + /* + * Restore PCI_SRIOV_CTRL_ARI before pci_iov_set_numvfs() because + * it reads offset & stride, which depend on PCI_SRIOV_CTRL_ARI. + */ + ctrl &= ~PCI_SRIOV_CTRL_ARI; + ctrl |= iov->ctrl & PCI_SRIOV_CTRL_ARI; + pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl); + for (i = PCI_IOV_RESOURCES; i <= PCI_IOV_RESOURCE_END; i++) pci_update_resource(dev, i); |