KVM: introduce kvm->srcu and convert kvm_set_memory_region to SRCU update
Use two steps for memslot deletion: mark the slot invalid (which stops
instantiation of new shadow pages for that slot, but allows destruction),
then instantiate the new empty slot.
Also simplifies kvm_handle_hva locking.
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 0757c70..b2e4d16 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1382,7 +1382,7 @@
int i, j;
unsigned long base_gfn;
- slots = kvm->memslots;
+ slots = rcu_dereference(kvm->memslots);
for (i = 0; i < slots->nmemslots; i++) {
memslot = &slots->memslots[i];
base_gfn = memslot->base_gfn;
@@ -1837,6 +1837,7 @@
struct kvm_memory_slot *memslot;
int is_dirty = 0;
+ down_write(&kvm->slots_lock);
spin_lock(&kvm->arch.dirty_log_lock);
r = kvm_ia64_sync_dirty_log(kvm, log);
@@ -1856,6 +1857,7 @@
}
r = 0;
out:
+ up_write(&kvm->slots_lock);
spin_unlock(&kvm->arch.dirty_log_lock);
return r;
}