[PATCH] KVM: MMU: Replace atomic allocations by preallocated objects

The mmu sometimes needs memory for reverse mapping and parent pte chains.
however, we can't allocate from within the mmu because of the atomic context.

So, move the allocations to a central place that can be executed before the
main mmu machinery, where we can bail out on failure before any damage is
done.

(error handling is deffered for now, but the basic structure is there)

Signed-off-by: Avi Kivity <avi@qumranet.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/kvm/paging_tmpl.h b/drivers/kvm/paging_tmpl.h
index 6acb16e..4e6670ff 100644
--- a/drivers/kvm/paging_tmpl.h
+++ b/drivers/kvm/paging_tmpl.h
@@ -323,7 +323,7 @@
 	mark_page_dirty(vcpu->kvm, gfn);
 	*shadow_ent |= PT_WRITABLE_MASK;
 	*guest_ent |= PT_DIRTY_MASK;
-	rmap_add(vcpu->kvm, shadow_ent);
+	rmap_add(vcpu, shadow_ent);
 
 	return 1;
 }
@@ -353,6 +353,9 @@
 	int write_pt = 0;
 
 	pgprintk("%s: addr %lx err %x\n", __FUNCTION__, addr, error_code);
+
+	mmu_topup_memory_caches(vcpu);
+
 	/*
 	 * Look up the shadow pte for the faulting address.
 	 */