[Xen-devel] [PATCH] update comments regarding pv-domain memory layout

[Juergen Gross <jgross@xxxxxxxx>]

The comments describing the initial pv-domain memory layout are not
complete. They do not mention the pages with console info and xenstore
data.

Add this information to the comments.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/include/public/xen.h | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h
index 17ecb94..619bb2a 100644
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -718,24 +718,27 @@ typedef struct shared_info shared_info_t;
  *  3. This the order of bootstrap elements in the initial virtual region:
  *      a. relocated kernel image
  *      b. initial ram disk              [mod_start, mod_len]
+ *         (may be omitted)
  *      c. list of allocated page frames [mfn_list, nr_pages]
  *         (unless relocated due to XEN_ELFNOTE_INIT_P2M)
  *      d. start_info_t structure        [register ESI (x86)]
- *      e. bootstrap page tables         [pt_base and CR3 (x86)]
- *      f. bootstrap stack               [register ESP (x86)]
+ *         in case of dom0 this page contains the console info, too
+ *      e. unless dom0: xenstore ring page
+ *      f. unless dom0: console ring page
+ *      g. bootstrap page tables         [pt_base and CR3 (x86)]
+ *      h. bootstrap stack               [register ESP (x86)]
  *  4. Bootstrap elements are packed together, but each is 4kB-aligned.
- *  5. The initial ram disk may be omitted.
- *  6. The list of page frames forms a contiguous 'pseudo-physical' memory
+ *  5. The list of page frames forms a contiguous 'pseudo-physical' memory
  *     layout for the domain. In particular, the bootstrap virtual-memory
  *     region is a 1:1 mapping to the first section of the pseudo-physical map.
- *  7. All bootstrap elements are mapped read-writable for the guest OS. The
+ *  6. All bootstrap elements are mapped read-writable for the guest OS. The
  *     only exception is the bootstrap page table, which is mapped read-only.
- *  8. There is guaranteed to be at least 512kB padding after the final
+ *  7. There is guaranteed to be at least 512kB padding after the final
  *     bootstrap element. If necessary, the bootstrap virtual region is
  *     extended by an extra 4MB to ensure this.
  *
  * Note: Prior to 25833:bb85bbccb1c9. ("x86/32-on-64 adjust Dom0 initial page
- * table layout") a bug caused the pt_base (3.e above) and cr3 to not point
+ * table layout") a bug caused the pt_base (3.g above) and cr3 to not point
  * to the start of the guest page tables (it was offset by two pages).
  * This only manifested itself on 32-on-64 dom0 kernels and not 32-on-64 domU
  * or 64-bit kernels of any colour. The page tables for a 32-on-64 dom0 got
-- 
2.1.4


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