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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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