From: Keir Fraser <keir@xensource.com>
Date: Wed, 4 Apr 2007 21:47:20 +0000 (+0100)
Subject: xen: No need for shadow_drop_references() in remove_page().
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~15264^2~25
X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=7ae14cd96984794b5dcbada72d7baa73ddbf010d;p=xen.git

xen: No need for shadow_drop_references() in remove_page().

Because:
    guest_physmap_remove_page()
 -> p2m_remove_page()
 -> set_p2m_entry()
 -> paging_write_p2m_entry()
 -> shadow_write_p2m_entry()

And shadow_write_p2m_entry() calls sh_remove_all_*() fns.

Signed-off-by: Keir Fraser <keir@xensource.com>
---

diff --git a/xen/common/memory.c b/xen/common/memory.c
index 139a0e89b3..8fe4523582 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -173,12 +173,6 @@ int guest_remove_page(struct domain *d, unsigned long gmfn)
     if ( test_and_clear_bit(_PGC_allocated, &page->count_info) )
         put_page(page);
 
-    if ( unlikely((page->count_info & PGC_count_mask) != 1) )
-    {
-        shadow_drop_references(d, page);
-        /* NB: still may have foreign references to the page at this stage */
-    }
-
     guest_physmap_remove_page(d, gmfn, mfn);
 
     put_page(page);