diff options
| -rw-r--r-- | drivers/xen/xen-pciback/pciback_ops.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/xen/xen-pciback/pciback_ops.c b/drivers/xen/xen-pciback/pciback_ops.c index 4ee5fc080483..73dafdc494aa 100644 --- a/drivers/xen/xen-pciback/pciback_ops.c +++ b/drivers/xen/xen-pciback/pciback_ops.c @@ -212,6 +212,7 @@ int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev, struct xen_pcibk_dev_data *dev_data; int i, result; struct msix_entry *entries; + u16 cmd; if (unlikely(verbose_request)) printk(KERN_DEBUG DRV_NAME ": %s: enable MSI-X\n", @@ -223,7 +224,12 @@ int xen_pcibk_enable_msix(struct xen_pcibk_device *pdev, if (dev->msix_enabled) return -EALREADY; - if (dev->msi_enabled) + /* + * PCI_COMMAND_MEMORY must be enabled, otherwise we may not be able + * to access the BARs where the MSI-X entries reside. + */ + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (dev->msi_enabled || !(cmd & PCI_COMMAND_MEMORY)) return -ENXIO; entries = kmalloc(op->value * sizeof(*entries), GFP_KERNEL); |