From 5c23d2dac35b93f160f6285f874a163544992115 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 23 Jun 2011 13:35:22 -0300 Subject: [PATCH] Revert "KVM: Save/restore state of assigned PCI device" 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 Acked-by: Jan Kiszka Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- virt/kvm/assigned-dev.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c index ae72ae604c8..e3f1235a9ae 100644 --- a/virt/kvm/assigned-dev.c +++ b/virt/kvm/assigned-dev.c @@ -197,8 +197,7 @@ 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); pci_release_regions(assigned_dev->dev); pci_disable_device(assigned_dev->dev); @@ -515,7 +514,6 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm, } 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: -- 2.11.4.GIT