pci: Add flag indicating device has been assigned by KVM
Device drivers that create and destroy SR-IOV virtual functions via
calls to pci_enable_sriov() and pci_disable_sriov can cause catastrophic
failures if they attempt to destroy VFs while they are assigned to
guest virtual machines. By adding a flag for use by the KVM module
to indicate that a device is assigned a device driver can check that
flag and avoid destroying VFs while they are assigned and avoid system
failures.
CC: Ian Campbell <ijc@hellion.org.uk>
CC: Konrad Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Rose <gregory.v.rose@intel.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 4e9eaeb..eaf3a50 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -205,6 +205,8 @@
else
pci_restore_state(assigned_dev->dev);
+ assigned_dev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+
pci_release_regions(assigned_dev->dev);
pci_disable_device(assigned_dev->dev);
pci_dev_put(assigned_dev->dev);
diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 78c80f6..967aba1 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -187,6 +187,8 @@
goto out_unmap;
}
+ pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+
printk(KERN_DEBUG "assign device %x:%x:%x.%x\n",
assigned_dev->host_segnr,
assigned_dev->host_busnr,
@@ -215,6 +217,8 @@
iommu_detach_device(domain, &pdev->dev);
+ pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+
printk(KERN_DEBUG "deassign device %x:%x:%x.%x\n",
assigned_dev->host_segnr,
assigned_dev->host_busnr,