KVM: Add kvm_arch_sync_events to sync with asynchronize events

kvm_arch_sync_events is introduced to quiet down all other events may happen
contemporary with VM destroy process, like IRQ handler and work struct for
assigned device.

For kvm_arch_sync_events is called at the very beginning of kvm_destroy_vm(), so
the state of KVM here is legal and can provide a environment to quiet down other
events.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

4 files changed, 16 insertions, 0 deletions

diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 4e586f6110aa..28f982045f29 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1337,6 +1337,10 @@ static void kvm_release_vm_pages(struct kvm *kvm)
 	}
 }
 
+void kvm_arch_sync_events(struct kvm *kvm)
+{
+}
+
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_iommu_unmap_guest(kvm);
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 2822c8ccfaaf..5f81256287f5 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -125,6 +125,10 @@ static void kvmppc_free_vcpus(struct kvm *kvm)
 	}
 }
 
+void kvm_arch_sync_events(struct kvm *kvm)
+{
+}
+
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvmppc_free_vcpus(kvm);
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index be8497186b96..0d33893e1e89 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -212,6 +212,10 @@ static void kvm_free_vcpus(struct kvm *kvm)
 	}
 }
 
+void kvm_arch_sync_events(struct kvm *kvm)
+{
+}
+
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_free_vcpus(kvm);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cc17546a2406..b0fc079f1bee 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4127,6 +4127,10 @@ static void kvm_free_vcpus(struct kvm *kvm)
 
 }
 
+void kvm_arch_sync_events(struct kvm *kvm)
+{
+}
+
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_free_all_assigned_devices(kvm);