2 files changed, 17 insertions, 5 deletions

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 1093f80c162d..b2c7179fa263 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -173,9 +173,21 @@ static unsigned long __init xen_get_max_pages(void)
         domid_t domid = DOMID_SELF;
         int ret;
 
-        ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
-        if (ret > 0)
-                max_pages = ret;
+        /*
+         * For the initial domain we use the maximum reservation as
+         * the maximum page.
+         *
+         * For guest domains the current maximum reservation reflects
+         * the current maximum rather than the static maximum. In this
+         * case the e820 map provided to us will cover the static
+         * maximum region.
+         */
+        if (xen_initial_domain()) {
+                ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid);
+                if (ret > 0)
+                        max_pages = ret;
+        }
+
         return min(max_pages, MAX_DOMAIN_PAGES);
 }
 
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 8e964b91c447..284798aaf8b1 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -166,7 +166,7 @@ retry:
         /*
          * Get IO TLB memory from any location.
          */
-        xen_io_tlb_start = alloc_bootmem(bytes);
+        xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
         if (!xen_io_tlb_start) {
                 m = "Cannot allocate Xen-SWIOTLB buffer!\n";
                 goto error;
@@ -179,7 +179,7 @@ retry:
                                bytes,
                                xen_io_tlb_nslabs);
         if (rc) {
-                free_bootmem(__pa(xen_io_tlb_start), bytes);
+                free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
                 m = "Failed to get contiguous memory for DMA from Xen!\n"\
                     "You either: don't have the permissions, do not have"\
                     " enough free memory under 4GB, or the hypervisor memory"\