[RFC Patch v2 09/16] colo: implement restore_callbacks update_p2m()

[Wen Congyang <wency@cn.fujitsu.com>]

This patch implements restore callbacks for colo:
1. update_p2m(): Just update the dirty pages which store p2m.

Signed-off-by: Ye Wei <wei.ye1987@gmail.com>
Signed-off-by: Jiang Yunhong <yunhong.jiang@intel.com>
Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
---
 tools/libxc/xc_domain_restore_colo.c |   78 ++++++++++++++++++++++++++++++++++
 tools/libxc/xc_save_restore_colo.h   |    1 +
 2 files changed, 79 insertions(+), 0 deletions(-)

diff --git a/tools/libxc/xc_domain_restore_colo.c b/tools/libxc/xc_domain_restore_colo.c
index 50009fa..70cdd16 100644
--- a/tools/libxc/xc_domain_restore_colo.c
+++ b/tools/libxc/xc_domain_restore_colo.c
@@ -524,3 +524,81 @@ int colo_flush_memory(struct restore_data *comm_data, void *data)
 
     return 0;
 }
+
+int colo_update_p2m_table(struct restore_data *comm_data, void *data)
+{
+    struct restore_colo_data *colo_data = data;
+    unsigned long i, j, n, pfn;
+    unsigned long *p2m_frame_list = comm_data->p2m_frame_list;
+    struct domain_info_context *dinfo = comm_data->dinfo;
+    unsigned long *pfn_type = comm_data->pfn_type;
+    xc_interface *xch = comm_data->xch;
+    uint32_t dom = comm_data->dom;
+    unsigned long *dirty_pages = colo_data->dirty_pages;
+    unsigned long *p2m_frame_list_temp = colo_data->p2m_frame_list_temp;
+
+    /* A temporay mapping of the guest's p2m table(all dirty pages) */
+    xen_pfn_t *live_p2m;
+    /* A temporay mapping of the guest's p2m table(1 page) */
+    xen_pfn_t *live_p2m_one;
+    unsigned long *p2m;
+
+    j = 0;
+    for (i = 0; i < P2M_FL_ENTRIES; i++)
+    {
+        pfn = p2m_frame_list[i];
+        if ((pfn >= dinfo->p2m_size) || (pfn_type[pfn] != XEN_DOMCTL_PFINFO_NOTAB))
+        {
+            ERROR("PFN-to-MFN frame number %li (%#lx) is bad", i, pfn);
+            return -1;
+        }
+
+        if (!test_bit(pfn, dirty_pages))
+            continue;
+
+        p2m_frame_list_temp[j++] = comm_data->p2m[pfn];
+    }
+
+    if (j)
+    {
+        /* Copy the P2M we've constructed to the 'live' P2M */
+        if (!(live_p2m = xc_map_foreign_pages(xch, dom, PROT_WRITE,
+                                              p2m_frame_list_temp, j)))
+        {
+            PERROR("Couldn't map p2m table");
+            return -1;
+        }
+
+        j = 0;
+        for (i = 0; i < P2M_FL_ENTRIES; i++)
+        {
+            pfn = p2m_frame_list[i];
+            if (!test_bit(pfn, dirty_pages))
+                continue;
+
+            live_p2m_one = (xen_pfn_t *)((char *)live_p2m + PAGE_SIZE * j++);
+            /* If the domain we're restoring has a different word size to ours,
+             * we need to adjust the live_p2m assignment appropriately */
+            if (dinfo->guest_width > sizeof (xen_pfn_t))
+            {
+                n = (i + 1) * FPP - 1;
+                for (i = FPP - 1; i >= 0; i--)
+                    ((uint64_t *)live_p2m_one)[i] = (long)comm_data->p2m[n--];
+            }
+            else if (dinfo->guest_width < sizeof (xen_pfn_t))
+            {
+                n = i * FPP;
+                for (i = 0; i < FPP; i++)
+                    ((uint32_t *)live_p2m_one)[i] = comm_data->p2m[n++];
+            }
+            else
+            {
+                p2m = (xen_pfn_t *)((char *)comm_data->p2m + PAGE_SIZE * i);
+                memcpy(live_p2m_one, p2m, PAGE_SIZE);
+            }
+        }
+        munmap(live_p2m, j * PAGE_SIZE);
+    }
+
+    return 0;
+}
diff --git a/tools/libxc/xc_save_restore_colo.h b/tools/libxc/xc_save_restore_colo.h
index 8af75b4..98e5128 100644
--- a/tools/libxc/xc_save_restore_colo.h
+++ b/tools/libxc/xc_save_restore_colo.h
@@ -8,5 +8,6 @@ extern int colo_init(struct restore_data *, void **);
 extern void colo_free(struct restore_data *, void *);
 extern char *colo_get_page(struct restore_data *, void *, unsigned long);
 extern int colo_flush_memory(struct restore_data *, void *);
+extern int colo_update_p2m_table(struct restore_data *, void *);
 
 #endif
-- 
1.7.4