Enable save/restore for PAE domains.

This includes quite a few cleanups / refactoring of the old code, some
of which is intended to prepare for 64-bit save/restore. 

Signed-off-by: Steven Hand <steven@xensource.com> 

1 files changed, 123 insertions, 0 deletions

diff --git a/tools/libxc/xg_save_restore.h b/tools/libxc/xg_save_restore.h
new file mode 100644
index 0000000000..2bef27437b
--- /dev/null
+++ b/tools/libxc/xg_save_restore.h
@@ -0,0 +1,123 @@
+/*
+** xg_save_restore.h
+** 
+** Defintions and utilities for save / restore. 
+*/
+
+#define DEBUG    1
+#define PROGRESS 0
+
+#define ERR(_f, _a...) do {                     \
+    fprintf(stderr, _f "\n" , ## _a);           \
+    fflush(stderr); }                           \
+while (0)
+
+#if DEBUG
+#define DPRINTF(_f, _a...) fprintf(stderr, _f , ## _a)
+#else
+#define DPRINTF(_f, _a...) ((void)0)
+#endif
+
+
+#if PROGRESS
+#define PPRINTF(_f, _a...) fprintf(stderr, _f , ## _a)
+#else
+#define PPRINTF(_f, _a...)
+#endif
+
+
+/*
+** We process save/restore/migrate in batches of pages; the below 
+** determines how many pages we (at maximum) deal with in each batch. 
+*/
+#define MAX_BATCH_SIZE 1024   /* up to 1024 pages (4MB) at a time */
+
+/* When pinning page tables at the end of restore, we also use batching. */
+#define MAX_PIN_BATCH  1024
+
+
+
+/*
+** Determine various platform information required for save/restore, in 
+** particular: 
+**
+**    - the maximum MFN on this machine, used to compute the size of 
+**      the M2P table; 
+** 
+**    - the starting virtual address of the the hypervisor; we use this 
+**      to determine which parts of guest address space(s) do and don't 
+**      require canonicalization during save/restore; and 
+** 
+**    - the number of page-table levels for save/ restore. This should 
+**      be a property of the domain, but for the moment we just read it 
+**      from the hypervisor.
+**
+** Returns 1 on success, 0 on failure. 
+*/
+static int get_platform_info(int xc_handle, uint32_t dom, 
+                             /* OUT */ uint32_t *max_mfn,  
+                             /* OUT */ uint32_t *hvirt_start, 
+                             /* OUT */ uint32_t *pt_levels)
+    
+{ 
+    xen_capabilities_info_t xen_caps = "";
+    xen_parameters_info_t xen_parms;
+    xc_physinfo_t physinfo;
+    
+    if (xc_physinfo(xc_handle, &physinfo) != 0) 
+        return 0;
+    
+    if (xc_version(xc_handle, XENVER_parameters, &xen_parms) != 0)
+        return 0;
+    
+    if (xc_version(xc_handle, XENVER_capabilities, &xen_caps) != 0)
+        return 0;
+
+    *max_mfn =     physinfo.total_pages;
+    *hvirt_start = xen_parms.virt_start;
+
+    if (strstr(xen_caps, "xen-3.0-x86_64"))
+        *pt_levels = 4;
+    else if (strstr(xen_caps, "xen-3.0-x86_32p"))
+        *pt_levels = 3; 
+    else if (strstr(xen_caps, "xen-3.0-x86_32"))
+        *pt_levels = 2; 
+    else 
+        return 0; 
+    
+    return 1;
+} 
+
+
+/* 
+** Save/restore deal with the mfn_to_pfn (M2P) and pfn_to_mfn (P2M) tables. 
+** The M2P simply holds the corresponding PFN, while the top bit of a P2M
+** entry tell us whether or not the the PFN is currently mapped.
+*/
+
+#define PFN_TO_KB(_pfn) ((_pfn) * PAGE_SIZE / 1024)
+#define ROUNDUP(_x,_w) (((unsigned long)(_x)+(1UL<<(_w))-1) & ~((1UL<<(_w))-1))
+
+/* Size in bytes of the M2P and P2M (both rounded up to nearest PAGE_SIZE) */
+#define M2P_SIZE ROUNDUP((max_mfn * sizeof(unsigned long)), PAGE_SHIFT) 
+#define P2M_SIZE ROUNDUP((max_pfn * sizeof(unsigned long)), PAGE_SHIFT) 
+
+
+/* Number of unsigned longs in a page */
+#define ulpp            (PAGE_SIZE/sizeof(unsigned long))
+
+/* Number of entries in the pfn_to_mfn_frame_list */
+#define P2M_FL_ENTRIES  (((max_pfn)+ulpp-1)/ulpp)
+
+/* Size in bytes of the pfn_to_mfn_frame_list     */
+#define P2M_FL_SIZE     ((P2M_FL_ENTRIES)*sizeof(unsigned long))
+
+/* Number of entries in the pfn_to_mfn_frame_list_list */
+#define P2M_FLL_ENTRIES (((max_pfn)+(ulpp*ulpp)-1)/(ulpp*ulpp))
+
+/* Returns TRUE if the PFN is currently mapped */
+#define is_mapped(pfn_type) (!((pfn_type) & 0x80000000UL))
+
+
+
+