For some SR-IOV devices, the number of available virtual functions
increases after enabling ARI. Currently, SRIOV_NUM_VF is read and saved
off before the ARI control bit is enabled. This causes an issue when VFs
are enabled.
At device init, SRIOV_INITIAL_VF and SRIOV_NUM_VF are specified to contain
the number of available VFs for the device. sriov_enable() does a sanity
check that PCI_SRIOV_INITIAL_VF is not greater than iov->total_VFs, the
saved-off value of SRIOV_NUM_VF. Since the value of both SRIOV_INITIAL_VF
and SRIOV_NUM_VF has increased after enabling the ARI bit, the check fails,
and the VFs cannot be enabled.
To fix the issue, after ARI is enabled for a device, reread SRIOV_NUM_VF.
Signed-off-by: Ben Shelton <benjamin.h.shelton@xxxxxxxxx>
---
drivers/pci/iov.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index ee0ebff..88b1959 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -388,6 +388,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
struct pci_sriov *iov;
struct resource *res;
struct pci_dev *pdev;
+ bool total_needs_reread = false;
if (pci_pcie_type(dev) != PCI_EXP_TYPE_RC_END &&
pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT)
@@ -409,12 +410,18 @@ static int sriov_init(struct pci_dev *dev, int pos)
goto found;
pdev = NULL;
- if (pci_ari_enabled(dev->bus))
+ if (pci_ari_enabled(dev->bus)) {
ctrl |= PCI_SRIOV_CTRL_ARI;
+ total_needs_reread = true;
+ }
found:
pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);
pci_write_config_word(dev, pos + PCI_SRIOV_NUM_VF, 0);
+
+ if (total_needs_reread)
+ pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
+
pci_read_config_word(dev, pos + PCI_SRIOV_VF_OFFSET, &offset);
pci_read_config_word(dev, pos + PCI_SRIOV_VF_STRIDE, &stride);
if (!offset || (total > 1 && !stride))
--
1.9.5
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