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Subject[105/107] Revert "KVM: Save/restore state of assigned PCI device"
2.6.39-stable review patch.  If anyone has any objections, please let us know.

------------------
From: Alex Williamson <alex.williamson@redhat.com>

This reverts ed78661f2614d3c9f69c23e280db3bafdabdf5bb as it assumes
the saved PCI state will remain valid for the entire length of time
that it is attached to a guest. This fails when userspace makes use
of the pci-sysfs reset interface, which invalidates the saved device
state, leaving nothing to be restored after the device is reset on
de-assignment. This leaves the device in an unusable state.

3.0.0 will add an interface for KVM to save the PCI state in a
buffer unaffected by other callers of pci_reset_function(), but the
most appropriate stable fix seems to be reverting this change since
the original assumption about the device saved state persisting is
incorrect.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
virt/kvm/assigned-dev.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -197,8 +197,7 @@ static void kvm_free_assigned_device(str
{
kvm_free_assigned_irq(kvm, assigned_dev);

- __pci_reset_function(assigned_dev->dev);
- pci_restore_state(assigned_dev->dev);
+ pci_reset_function(assigned_dev->dev);

pci_release_regions(assigned_dev->dev);
pci_disable_device(assigned_dev->dev);
@@ -515,7 +514,6 @@ static int kvm_vm_ioctl_assign_device(st
}

pci_reset_function(dev);
- pci_save_state(dev);

match->assigned_dev_id = assigned_dev->assigned_dev_id;
match->host_segnr = assigned_dev->segnr;
@@ -546,7 +544,6 @@ out:
mutex_unlock(&kvm->lock);
return r;
out_list_del:
- pci_restore_state(dev);
list_del(&match->list);
pci_release_regions(dev);
out_disable:



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