From: Peter Xu peterx@redhat.com
This patch has been added to the stable tree. If you have any objections, please let us know.
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[ Upstream commit df630b8c1e851b5e265dc2ca9c87222e342c093b ]
When releasing the bus, let's clear the bus pointers to mark it out. If any further device unregister happens on this bus, we know that we're done if we found the bus being released already.
Signed-off-by: Peter Xu peterx@redhat.com Signed-off-by: Radim Krčmář rkrcmar@redhat.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- virt/kvm/kvm_main.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index f9746f29f870..f0b703cf1aaf 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -600,8 +600,10 @@ static void kvm_destroy_vm(struct kvm *kvm) list_del(&kvm->vm_list); spin_unlock(&kvm_lock); kvm_free_irq_routing(kvm); - for (i = 0; i < KVM_NR_BUSES; i++) + for (i = 0; i < KVM_NR_BUSES; i++) { kvm_io_bus_destroy(kvm->buses[i]); + kvm->buses[i] = NULL; + } kvm_coalesced_mmio_free(kvm); #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER) mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm); @@ -3143,6 +3145,14 @@ int kvm_io_bus_unregister_dev(struct kvm *kvm, enum kvm_bus bus_idx, struct kvm_io_bus *new_bus, *bus;
bus = kvm->buses[bus_idx]; + + /* + * It's possible the bus being released before hand. If so, + * we're done here. + */ + if (!bus) + return 0; + r = -ENOENT; for (i = 0; i < bus->dev_count; i++) if (bus->range[i].dev == dev) {