[Xen-changelog] [xen stable-4.4] kexec: add more pages to v1 environment

[patchbot@xxxxxxx]

commit b51d47e368ba1ede2681f59af23be9e6afe61ec7
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Mon Jul 13 14:02:46 2015 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Mon Jul 13 14:02:46 2015 +0200

    kexec: add more pages to v1 environment
    
    Destination pages need mappings to be added to the page tables in the
    v1 case (where nothing else calls machine_kexec_add_page() for them).
    
    Further, without the tools mapping the low 1Mb (expected by at least
    some Linux version), we need to do so in the hypervisor in the v1 case.
    
    Suggested-by: David Vrabel <david.vrabel@xxxxxxxxxx>
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Tested-by: Alan Robinson <alan.robinson@xxxxxxxxxxxxxx>
    Reviewed-by: David Vrabel <david.vrabel@xxxxxxxxxx>
    Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    master commit: 5cb57f4bddee1f11079e69bf43c193a8b104c476
    master date: 2015-06-09 16:00:24 +0200
---
 xen/common/kexec.c  |   18 ++++++++++++++++++
 xen/common/kimage.c |    5 +++++
 2 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/xen/common/kexec.c b/xen/common/kexec.c
index 23d964e..8b75280 100644
--- a/xen/common/kexec.c
+++ b/xen/common/kexec.c
@@ -1003,6 +1003,24 @@ static int kexec_do_load_v1(xen_kexec_load_v1_t *load, 
int compat)
     if ( ret < 0 )
         goto error;
 
+    if ( arch == EM_386 || arch == EM_X86_64 )
+    {
+        /*
+         * Ensure 0 - 1 MiB is mapped and accessible by the image.
+         *
+         * This allows access to VGA memory and the region purgatory copies
+         * in the crash case.
+         */
+        unsigned long addr;
+
+        for ( addr = 0; addr < MB(1); addr += PAGE_SIZE )
+        {
+            ret = machine_kexec_add_page(kimage, addr, addr);
+            if ( ret < 0 )
+                goto error;
+        }
+    }
+
     ret = kexec_load_slot(kimage);
     if ( ret < 0 )
         goto error;
diff --git a/xen/common/kimage.c b/xen/common/kimage.c
index 9b79a5e..8c4854d 100644
--- a/xen/common/kimage.c
+++ b/xen/common/kimage.c
@@ -923,6 +923,11 @@ int kimage_build_ind(struct kexec_image *image, unsigned 
long ind_mfn,
             ret = kimage_add_page(image, page_to_maddr(xen_page));
             if ( ret < 0 )
                 goto done;
+
+            ret = machine_kexec_add_page(image, dest, dest);
+            if ( ret < 0 )
+                goto done;
+
             dest += PAGE_SIZE;
             break;
         }
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.4

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