KVM: Add PV MSR to enable asynchronous page faults delivery.

Guest enables async PF vcpu functionality using this MSR.

Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index e97eae965a4c..1f59498561b2 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -190,3 +190,23 @@ retry_sync:
         kmem_cache_free(async_pf_cache, work);
         return 0;
 }
+
+int kvm_async_pf_wakeup_all(struct kvm_vcpu *vcpu)
+{
+        struct kvm_async_pf *work;
+
+        if (!list_empty(&vcpu->async_pf.done))
+                return 0;
+
+        work = kmem_cache_zalloc(async_pf_cache, GFP_ATOMIC);
+        if (!work)
+                return -ENOMEM;
+
+        work->page = bad_page;
+        get_page(bad_page);
+        INIT_LIST_HEAD(&work->queue); /* for list_del to work */
+
+        list_add_tail(&work->link, &vcpu->async_pf.done);
+        vcpu->async_pf.queued++;
+        return 0;
+}