[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [v5][PATCH 09/10] tools:firmware:hvmloader: check to reserve RMRR mappings in e820



On 2014/9/2 16:47, Jan Beulich wrote:
On 26.08.14 at 13:02, <tiejun.chen@xxxxxxxxx> wrote:
+static unsigned int construct_rmrr_e820_maps(unsigned int nr,

s/construct_rmrr_e820_maps/construct_drm_e820_maps

+                                             uint32_t nr_map,
+                                             struct reserved_device_memory 
*map,
+                                             struct e820entry *e820)
+{
+    unsigned int i = 0, j = 0, m = 0, sum_nr = 0;
+    uint64_t start, end, rmrr_start, rmrr_end;

I rename this pair of variables in this whole function,

s/rmrr_start/drm_start
s/rmrr_end/drm_end

+    unsigned int insert = 0, do_insert = 0;
+
+do_real_construct:

Please indent labels by at least one space (and there are further
coding style issues to address elsewhere).

Is this necessary?

static struct tmem_object_root * obj_find(struct tmem_pool *pool, struct oid *oidp)
{
    struct rb_node *node;
    struct tmem_object_root *obj;

restart_find:
    read_lock(&pool->pool_rwlock);
    ...
                    read_unlock(&pool->pool_rwlock);
                    goto restart_find;


+    sum_nr = nr + nr_map;

Afaict neither nr nor nr_map change before you get here the second
(and last) time. Hence the calculation can be moved up (ideally into
the initializer of the variable).

+    unsigned int i = 0, j = 0, m = 0, sum_nr = nr + nr_map;


+    for ( i = 0; i < nr_map; i++ )
+    {
+        rmrr_start = map[i].start_pfn << PAGE_SHIFT;
+        rmrr_end = rmrr_start + map[i].nr_pages * PAGE_SIZE;
+
+        for ( j = 0; j < nr; j++ )
+        {
+            end = e820[j].addr + e820[j].size;
+            start = e820[j+1].addr;

This is not valid when j == nr - 1 (last iteration).

-        for ( j = 0; j < nr; j++ )
+        for ( j = 0; j < nr - 1; j++ )

+
+            /* Between those existing e820 entries. */
+            if ( (rmrr_start > end) && (rmrr_end < start) )
+            {
+                if (do_insert)

-                if (do_insert)
+                if ( do_insert )

+                {
+                    /* Move to free this entry. */
+                    for ( m = sum_nr - 1; m > j; m-- )
+                    {
+                        e820[m].addr = e820[m-1].addr;
+                        e820[m].size = e820[m-1].size;
+                        e820[m].type = e820[m-1].type;
+                    }
+
+                    /* Then fill RMRR into that entry. */
+                    e820[j+1].addr = rmrr_start;
+                    e820[j+1].size = rmrr_end - rmrr_start;
+                    e820[j+1].type = E820_RESERVED;
+                    nr++;
+                }
+                insert++;
+            }
+            /* Already at the end. */
+            else if ( (rmrr_start > end) && !start )
+            {
+                if ( do_insert )
+                {
+                    e820[nr].addr = rmrr_start;
+                    e820[nr].size = rmrr_end - rmrr_start;
+                    e820[nr].type = E820_RESERVED;
+                    nr++;
+                }
+                insert++;
+            }
+        }
+    }
+
+    /* Just return if done. */
+    if ( do_insert )
+        return nr;
+
+    /* Fine to construct RMRR mappings into e820. */
+    if ( insert == nr_map)

-    if ( insert == nr_map)
+    if ( insert == nr_map )

+    {
+        do_insert = 1;
+        goto do_real_construct;
+    }
+    /* Overlap. */
+    else
+    {
+        printf("RMRR overlap with those existing e820 entries!\n");
+        printf("So we don't construct RMRR mapping in e820!\n");

s/RMRR/DRM

Thanks
Tiejun

+    }
+
+    return nr;
+}
  /* Create an E820 table based on memory parameters provided in hvm_info. */
  int build_e820_table(struct e820entry *e820,
                       unsigned int lowmem_reserved_base,
                       unsigned int bios_image_base)
  {
      unsigned int nr = 0;
+    struct reserved_device_memory *map = NULL;
+    int rc;

      if ( !lowmem_reserved_base )
              lowmem_reserved_base = 0xA0000;
@@ -169,6 +247,29 @@ int build_e820_table(struct e820entry *e820,
          nr++;
      }

+    /* We'd better reserve RMRR mapping for each VM to avoid potential
+     * memory conflict.
+     */
+    if ( hvm_info->nr_reserved_device_memory_map )
+    {
+        if ( !map )
+            map = mem_alloc(hvm_info->nr_reserved_device_memory_map *
sizeof(struct reserved_device_memory), 0);
+        if ( map )
+        {
+            rc = get_reserved_device_memory_map(map,
+
hvm_info->nr_reserved_device_memory_map);
+            if ( !rc )
+            {
+                nr = construct_rmrr_e820_maps(nr,
+
hvm_info->nr_reserved_device_memory_map,
+                                              map,
+                                              e820);
+            }
+        }
+        else
+            printf("No space to get reserved_device_memory_map!\n");
+    }
+
      return nr;
  }

--
1.9.1





_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.