[PATCH 2/2] KVM: Use pci_store/load_saved_state() around VM device usage

Alex Williamson
2011-04-15T19:54:39Z

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>
---

include/linux/kvm_host.h | 1 +
virt/kvm/assigned-dev.c | 8 +++++---
2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index ab42855..d8a1d18 100644
--- 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];
+ void *pci_saved_state;
};

struct kvm_irq_mask_notifier {
diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
index ae72ae6..66c6ccd 100644
--- a/virt/kvm/assigned-dev.c
+++ b/virt/kvm/assigned-dev.c
@@ -197,7 +197,9 @@ static void kvm_free_assigned_device(struct kvm *kvm,
{
kvm_free_assigned_irq(kvm, assigned_dev);

- __pci_reset_function(assigned_dev->dev);
+ pci_reset_function(assigned_dev->dev);
+ pci_load_and_free_saved_state(assigned_dev->dev,
+ &assigned_dev->pci_saved_state);
pci_restore_state(assigned_dev->dev);

pci_release_regions(assigned_dev->dev);
@@ -516,7 +518,7 @@ 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);
match->assigned_dev_id = assigned_dev->assigned_dev_id;
match->host_segnr = assigned_dev->segnr;
match->host_busnr = assigned_dev->busnr;
@@ -546,7 +548,7 @@ out:
mutex_unlock(&kvm->lock);
return r;
out_list_del:
- pci_restore_state(dev);
+ pci_load_and_free_saved_state(dev, &match->pci_saved_state);
list_del(&match->list);
pci_release_regions(dev);