Ideally, every assigned device should in a clear condition before and after
assignment, so that the former state of device won't affect later work.
Some devices provide a mechanism named Function Level Reset, which is
defined in PCI/PCI-e document. We should execute it before and after device
assignment.
(But sadly, the feature is new, and most device on the market now don't
support it. We are considering using D0/D3hot transmit to emulate it later,
but not that elegant and reliable as FLR itself.)
Signed-off-by: Sheng Yang <[EMAIL PROTECTED]>
---
arch/x86/kvm/x86.c | 2 +-
virt/kvm/kvm_main.c | 5 +++++
2 files changed, 6 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 38f79b6..9a4a39c 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4148,8 +4148,8 @@ static void kvm_free_vcpus(struct kvm *kvm)
void kvm_arch_destroy_vm(struct kvm *kvm)
{
- kvm_iommu_unmap_guest(kvm);
kvm_free_all_assigned_devices(kvm);
+ kvm_iommu_unmap_guest(kvm);
kvm_free_pit(kvm);
kfree(kvm->arch.vpic);
kfree(kvm->arch.vioapic);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4f43abe..64c5129 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -152,6 +152,8 @@ static void kvm_free_assigned_device(struct kvm *kvm,
*/
kvm_put_kvm(kvm);
+ pci_reset_function(assigned_dev->dev);
+
pci_release_regions(assigned_dev->dev);
pci_disable_device(assigned_dev->dev);
pci_dev_put(assigned_dev->dev);
@@ -272,6 +274,9 @@ static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
r = -EINVAL;
goto out_free;
}
+
+ pci_reset_function(dev);
+
if (pci_enable_device(dev)) {
printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
r = -EBUSY;
--
1.5.4.5
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