From: Roger Pau Monne <roger.pau@citrix.com>
Date: Mon, 7 Nov 2016 15:32:00 +0000 (+0100)
Subject: libxc: properly account for the page offset when copying ACPI data
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~110
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=fac7f77b69797d0659489e49dfb3f35f8acf2b97;p=xen.git

libxc: properly account for the page offset when copying ACPI data

Or else ACPI data is always copied at the start of the page pointed by
guest_addr_out, ignoring the page offset.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-and-Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Release-acked-by: Wei Liu <wei.liu2@citrix.com>
---

diff --git a/tools/libxc/xc_dom_core.c b/tools/libxc/xc_dom_core.c
index e177667e93..ad819dd187 100644
--- a/tools/libxc/xc_dom_core.c
+++ b/tools/libxc/xc_dom_core.c
@@ -1090,8 +1090,9 @@ static int xc_dom_load_acpi(struct xc_dom_image *dom)
                   dom->acpi_modules[i].length,
                   dom->acpi_modules[i].guest_addr_out);
 
-        num_pages = (dom->acpi_modules[i].length + (XC_PAGE_SIZE - 1)) >>
-                       XC_PAGE_SHIFT;
+        num_pages = (dom->acpi_modules[i].length +
+                     (dom->acpi_modules[i].guest_addr_out & ~XC_PAGE_MASK) +
+                     (XC_PAGE_SIZE - 1)) >> XC_PAGE_SHIFT;
         extents = malloc(num_pages * sizeof(*extents));
         if ( !extents )
         {
@@ -1118,6 +1119,9 @@ static int xc_dom_load_acpi(struct xc_dom_image *dom)
             goto err;
         }
 
+        ptr = (uint8_t *)ptr +
+              (dom->acpi_modules[i].guest_addr_out & ~XC_PAGE_MASK);
+
         memcpy(ptr, dom->acpi_modules[i].data, dom->acpi_modules[i].length);
         munmap(ptr, XC_PAGE_SIZE * num_pages);