KVM: Skip unnecessary "unmap" if gpc is already valid during refresh

When refreshing a gfn=>pfn cache, skip straight to unlocking if the cache
already valid instead of stuffing the "old" variables to turn the
unmapping outro into a nop.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>

diff --git a/virt/kvm/pfncache.c b/virt/kvm/pfncache.c
index a805cc1..2d6aba6 100644 (file)
--- a/virt/kvm/pfncache.c
+++ b/virt/kvm/pfncache.c
@@ -301,9 +301,8 @@ static int __kvm_gpc_refresh(struct gfn_to_pfn_cache *gpc, gpa_t gpa,
                 * may have changed.
                 */
                gpc->khva = old_khva + page_offset;
-               old_pfn = KVM_PFN_ERR_FAULT;
-               old_khva = NULL;
                ret = 0;
+               goto out_unlock;
        }
 
  out: