| Message ID | 1426263012-22935-7-git-send-email-andre.przywara@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Mar 13, 2015 at 04:10:06PM +0000, Andre Przywara wrote: > In kvm_destroy_vm() we call kvm_io_bus_destroy() pretty early, > especially before calling kvm_arch_destroy_vm(). To avoid > unregistering devices from the already destroyed bus, let's mark > the bus with NULL to let other users know it has been destroyed > already. > This avoids a crash on a VM shutdown with the VGIC using the > kvm_io_bus later (the unregistering is in there to be able to roll > back a faulting init). > > Signed-off-by: Andre Przywara <andre.przywara@arm.com> > --- > virt/kvm/kvm_main.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 8c7ab0b..6f164eb 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -604,8 +604,10 @@ 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); this smells a bit like papering over an ordering issue with the teardown, is there no other way to fix it? -Christoffer -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 8c7ab0b..6f164eb 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -604,8 +604,10 @@ 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);
In kvm_destroy_vm() we call kvm_io_bus_destroy() pretty early, especially before calling kvm_arch_destroy_vm(). To avoid unregistering devices from the already destroyed bus, let's mark the bus with NULL to let other users know it has been destroyed already. This avoids a crash on a VM shutdown with the VGIC using the kvm_io_bus later (the unregistering is in there to be able to roll back a faulting init). Signed-off-by: Andre Przywara <andre.przywara@arm.com> --- virt/kvm/kvm_main.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)