[Xen-devel] [PATCH v4 07/11] xen: factor out allocation of special pages into separate function

[Juergen Gross <jgross@xxxxxxxx>]

Do the allocation of special pages (start info, console and xenbus
ring buffers) in a separate function. This will allow to do the
allocation at different times of the boot preparations depending on
the features the kernel is supporting.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Daniel Kiper <daniel.kiper@xxxxxxxxxx>
---
 grub-core/loader/i386/xen.c | 48 +++++++++++++++++++++++++++++----------------
 1 file changed, 31 insertions(+), 17 deletions(-)

diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c
index a2fd1f6..a80c0f8 100644
--- a/grub-core/loader/i386/xen.c
+++ b/grub-core/loader/i386/xen.c
@@ -48,6 +48,8 @@ struct xen_loader_state {
   struct start_info next_start;
   struct grub_xen_file_info xen_inf;
   grub_xen_mfn_t *virt_mfn_list;
+  struct start_info *virt_start_info;
+  grub_xen_mfn_t console_pfn;
   grub_uint64_t max_addr;
   struct xen_multiboot_mod_list *module_info_page;
   grub_uint64_t modules_target_start;
@@ -240,22 +242,10 @@ grub_xen_p2m_alloc (void)
 }
 
 static grub_err_t
-grub_xen_boot (void)
+grub_xen_special_alloc (void)
 {
   grub_relocator_chunk_t ch;
   grub_err_t err;
-  struct start_info *nst;
-  grub_uint64_t nr_info_pages;
-  grub_uint64_t nr_pages, nr_pt_pages, nr_need_pages;
-  struct gnttab_set_version gnttab_setver;
-  grub_size_t i;
-
-  if (grub_xen_n_allocated_shared_pages)
-    return grub_error (GRUB_ERR_BUG, "active grants");
-
-  err = grub_xen_p2m_alloc ();
-  if (err)
-    return err;
 
   err = grub_relocator_alloc_chunk_addr (xen_state.relocator, &ch,
                                         xen_state.max_addr,
@@ -263,9 +253,11 @@ grub_xen_boot (void)
   if (err)
     return err;
   xen_state.state.start_info = xen_state.max_addr + 
xen_state.xen_inf.virt_base;
-  nst = get_virtual_current_address (ch);
+  xen_state.virt_start_info = get_virtual_current_address (ch);
   xen_state.max_addr =
     ALIGN_UP (xen_state.max_addr + sizeof (xen_state.next_start), PAGE_SIZE);
+  xen_state.console_pfn = xen_state.max_addr >> PAGE_SHIFT;
+  xen_state.max_addr += 2 * PAGE_SIZE;
 
   xen_state.next_start.nr_pages = grub_xen_start_page_addr->nr_pages;
   grub_memcpy (xen_state.next_start.magic, grub_xen_start_page_addr->magic,
@@ -275,10 +267,28 @@ grub_xen_boot (void)
   xen_state.next_start.console.domU = grub_xen_start_page_addr->console.domU;
   xen_state.next_start.shared_info = grub_xen_start_page_addr->shared_info;
 
-  err = set_mfns (xen_state.max_addr >> PAGE_SHIFT);
+  return GRUB_ERR_NONE;
+}
+
+static grub_err_t
+grub_xen_boot (void)
+{
+  grub_relocator_chunk_t ch;
+  grub_err_t err;
+  grub_uint64_t nr_info_pages;
+  grub_uint64_t nr_pages, nr_pt_pages, nr_need_pages;
+  struct gnttab_set_version gnttab_setver;
+  grub_size_t i;
+
+  if (grub_xen_n_allocated_shared_pages)
+    return grub_error (GRUB_ERR_BUG, "active grants");
+
+  err = grub_xen_p2m_alloc ();
+  if (err)
+    return err;
+  err = grub_xen_special_alloc ();
   if (err)
     return err;
-  xen_state.max_addr += 2 * PAGE_SIZE;
 
   xen_state.next_start.pt_base =
     xen_state.max_addr + xen_state.xen_inf.virt_base;
@@ -309,6 +319,10 @@ grub_xen_boot (void)
   if (err)
     return err;
 
+  err = set_mfns (xen_state.console_pfn);
+  if (err)
+    return err;
+
   generate_page_table (get_virtual_current_address (ch),
                       xen_state.max_addr >> PAGE_SHIFT, nr_pages,
                       xen_state.xen_inf.virt_base, xen_state.virt_mfn_list);
@@ -321,7 +335,7 @@ grub_xen_boot (void)
   xen_state.next_start.nr_pt_frames = nr_pt_pages;
   xen_state.state.paging_size = nr_pt_pages;
 
-  *nst = xen_state.next_start;
+  *xen_state.virt_start_info = xen_state.next_start;
 
   grub_memset (&gnttab_setver, 0, sizeof (gnttab_setver));
 
-- 
2.6.2


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