KVM: Use pci_store/load_saved_state() around VM device usage

Store the device saved state so that we can reload the device back
to the original state when it's unassigned.  This has the benefit
that the state survives across pci_reset_function() calls via
the PCI sysfs reset interface while the VM is using the device.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Acked-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ab428552af8e80744cf5ab3d2eb1924208d26d75..9272db03a3e540c405c9c3691d9275e6bc318953 100644 (file)
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -513,6 +513,7 @@ struct kvm_assigned_dev_kernel {
        struct kvm *kvm;
        spinlock_t intx_lock;
        char irq_name[32];
+       struct pci_saved_state *pci_saved_state;
 };
 
 struct kvm_irq_mask_notifier {

diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index ae72ae604c897f44f5c5211cb1d13648a55a18ea..6cc4b97ec4581eef917221a264602c49582dc701 100644 (file)
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -197,8 +197,13 @@ static void kvm_free_assigned_device(struct kvm *kvm,
 {
        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);
+       if (pci_load_and_free_saved_state(assigned_dev->dev,
+                                         &assigned_dev->pci_saved_state))
+               printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
+                      __func__, dev_name(&assigned_dev->dev->dev));
+       else
+               pci_restore_state(assigned_dev->dev);
 
        pci_release_regions(assigned_dev->dev);
        pci_disable_device(assigned_dev->dev);
@@ -516,7 +521,10 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
 
        pci_reset_function(dev);
        pci_save_state(dev);
-
+       match->pci_saved_state = pci_store_saved_state(dev);
+       if (!match->pci_saved_state)
+               printk(KERN_DEBUG "%s: Couldn't store %s saved state\n",
+                      __func__, dev_name(&dev->dev));
        match->assigned_dev_id = assigned_dev->assigned_dev_id;
        match->host_segnr = assigned_dev->segnr;
        match->host_busnr = assigned_dev->busnr;
@@ -546,7 +554,9 @@ out:
        mutex_unlock(&kvm->lock);
        return r;
 out_list_del:
-       pci_restore_state(dev);
+       if (pci_load_and_free_saved_state(dev, &match->pci_saved_state))
+               printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
+                      __func__, dev_name(&dev->dev));
        list_del(&match->list);
        pci_release_regions(dev);
 out_disable: