From 6777829cfe1c4ed78319ad40aaee60254222da76 Mon Sep 17 00:00:00 2001
From: Greg Rose <gregory.v.rose@intel.com>
Date: Fri, 22 Jul 2011 05:46:07 +0000
Subject: [PATCH] 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>
---
include/linux/pci.h | 2 ++
virt/kvm/assigned-dev.c | 2 ++
virt/kvm/iommu.c | 4 ++++
3 files changed, 8 insertions(+)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index f27893b3b7242..d8c8573ecc213 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -174,6 +174,8 @@ enum pci_dev_flags {
PCI_DEV_FLAGS_MSI_INTX_DISABLE_BUG = (__force pci_dev_flags_t) 1,
/* Device configuration is irrevocably lost if disabled into D3 */
PCI_DEV_FLAGS_NO_D3 = (__force pci_dev_flags_t) 2,
+ /* Provide indication device is assigned by a Virtual Machine Manager */
+ PCI_DEV_FLAGS_ASSIGNED = (__force pci_dev_flags_t) 4,
};
enum pci_irq_reroute_variant {
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index 4e9eaeb518c7b..eaf3a50f97694 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -205,6 +205,8 @@ static void kvm_free_assigned_device(struct kvm *kvm,
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 78c80f67f535f..967aba133a624 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -187,6 +187,8 @@ int kvm_assign_device(struct kvm *kvm,
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 @@ int kvm_deassign_device(struct kvm *kvm,
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,
--
2.30.2