xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.

[deliverable/linux.git] / arch / x86 / xen / setup.c

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index ead85576d54a6c097f10b9a9d55e2057575e2168..d11ca11d14fc094379e989a6b06fe2e5b2bc72e6 100644 (file)
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -78,9 +78,16 @@ static void __init xen_add_extra_mem(u64 start, u64 size)
        memblock_reserve(start, size);
 
        xen_max_p2m_pfn = PFN_DOWN(start + size);
+       for (pfn = PFN_DOWN(start); pfn < xen_max_p2m_pfn; pfn++) {
+               unsigned long mfn = pfn_to_mfn(pfn);
+
+               if (WARN(mfn == pfn, "Trying to over-write 1-1 mapping (pfn: %lx)\n", pfn))
+                       continue;
+               WARN(mfn != INVALID_P2M_ENTRY, "Trying to remove %lx which has %lx mfn!\n",
+                       pfn, mfn);
 
-       for (pfn = PFN_DOWN(start); pfn <= xen_max_p2m_pfn; pfn++)
                __set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
+       }
 }
 
 static unsigned long __init xen_do_chunk(unsigned long start,