bitkeeper revision 1.495 (3f841454kYDagBZ_MGwN-X40dU79WA)

GUEST_CHANGES:
  new file

diff --git a/.rootkeys b/.rootkeys
index b23dd2ba659efda4e169fed1557bd221fc52ca0d..e212512e4bf8d3ffc181cbc4db2554e9dd061344 100644 (file)
--- a/.rootkeys
+++ b/.rootkeys
@@ -184,6 +184,7 @@
 3f13d81e6Z6806ihYYUw8GVKNkYnuw tools/misc/xen_nat_enable.README
 3f1668d4F29Jsw0aC0bJEIkOBiagiQ tools/misc/xen_read_console.c
 3f72f1bdJPsV3JCnBqs9ddL9tr6D2g xen/COPYING
+3f841450eJvqAD1Dldc0_aOweGiglQ xen/GUEST_CHANGES
 3ddb79bcbOVHh38VJzc97-JEGD4dJQ xen/Makefile
 3ddb79bcWnTwYsQRWl_PaneJfa6p0w xen/Rules.mk
 3e74d2be6ELqhaY1sW0yyHRKhpOvDQ xen/TODO

diff --git a/xen/GUEST_CHANGES b/xen/GUEST_CHANGES
new file mode 100644 (file)
index 0000000..b9f25d4
--- /dev/null
+++ b/xen/GUEST_CHANGES
@@ -0,0 +1,26 @@
+
+The interface between Xen and overlying guest OSes has changed in the
+following ways since version 1.0:
+
+Modified hypercall 'pt_update'
+------------------------------
+Page-table updates passed to the 'pt_update' hypercall must now
+specify a virtual address that maps the PTE to be modified. Previously
+a physical address was used, requiring Xen to temporarily map the PTE
+into its own private region so that it could be read and written.
+This affects only commands of type PGREQ_NORMAL_UPDATE and
+PGREQ_UNCHECKED_UPDATE.
+
+New hypercall 'update_va_mapping'
+---------------------------------
+A new high-speed page-table update method has been introduced, which
+may be of particular benefit when fixing up application page faults.
+Invoked as 'update_va_mapping(page_number, new_pte_value, flags)':
+ <page_number>: The virtual page number in the current address space 
+                whose PTE is to be modified.
+ <new_pte_value>: The new value to write into the PTE.
+ <flags>: An ORed combination of
+          UVMF_INVLPG: Flush stale TLB entry of the updated page mapping
+          UVMF_FLUSH_TLB: Flush all TLB entries
+You can see this new call in use in Xenolinux (common/memory.c).
+