KVM: MMU: lockless walking shadow page table
Use rcu to protect shadow pages table to be freed, so we can safely walk it,
it should run fastly and is needed by mmio page fault
Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index a198a5b..dd51c83 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -233,6 +233,12 @@
unsigned int unsync_children;
unsigned long parent_ptes; /* Reverse mapping for parent_pte */
DECLARE_BITMAP(unsync_child_bitmap, 512);
+
+#ifdef CONFIG_X86_32
+ int clear_spte_count;
+#endif
+
+ struct rcu_head rcu;
};
struct kvm_pv_mmu_op_buffer {
@@ -486,6 +492,8 @@
u64 hv_guest_os_id;
u64 hv_hypercall;
+ atomic_t reader_counter;
+
#ifdef CONFIG_KVM_MMU_AUDIT
int audit_point;
#endif