[Xen-devel] [PATCH] xen: restore GNTTABOP_dump_table

[Roger Pau Monne <roger.pau@xxxxxxxxxx>]

This operation was dropped long time ago, but I found it quite helpful
for debugging purposes. This re-implementation uses the code already
present in gnttab_usage_print and adds the maptrack-table dump.

Signed-off-by: Roger Pau Monne <roger.pau@xxxxxxxxxx>
---
 xen/common/grant_table.c      |   83 ++++++++++++++++++++++++++++++++++++++---
 xen/include/xen/grant_table.h |    3 +
 2 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index c8e342b..a5de9c6 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -1393,6 +1393,40 @@ gnttab_setup_table(
     return 0;
 }
 
+static long
+gnttab_dump_table(
+    XEN_GUEST_HANDLE(gnttab_dump_table_t) uop, unsigned int count)
+{
+    struct gnttab_dump_table   op;
+    struct domain        *d;
+
+    if ( !IS_PRIV(current->domain) )
+        return -EPERM;
+
+    if ( unlikely(copy_from_guest(&op, uop, sizeof(op)) != 0) )
+    {
+        gdprintk(XENLOG_INFO, "Fault while reading gnttab_dump_table_t.\n");
+        return -EFAULT;
+    }
+
+    d = gt_lock_target_domain_by_id(op.dom);
+    if ( IS_ERR(d) )
+    {
+        op.status = PTR_ERR(d);
+        goto out;
+    }
+
+    gnttab_usage_print(d, 1);
+
+    rcu_unlock_domain(d);
+
+out:
+    if ( unlikely(copy_to_guest(uop, &op, 1)) )
+        return -EFAULT;
+
+    return 0;
+}
+
 static long 
 gnttab_query_size(
     XEN_GUEST_HANDLE(gnttab_query_size_t) uop, unsigned int count)
@@ -2495,6 +2529,12 @@ do_grant_table_op(
         ASSERT(rc <= 0);
         break;
     }
+    case GNTTABOP_dump_table:
+    {
+        rc = gnttab_dump_table(guest_handle_cast(uop, gnttab_dump_table_t),
+                               count);
+        break;
+    }
     case GNTTABOP_transfer:
     {
         XEN_GUEST_HANDLE(gnttab_transfer_t) transfer =
@@ -2796,7 +2836,7 @@ grant_table_destroy(
     d->grant_table = NULL;
 }
 
-void gnttab_usage_print(struct domain *rd)
+void gnttab_usage_print(struct domain *rd, int print_maptrack)
 {
     int first = 1;
     grant_ref_t ref;
@@ -2808,7 +2848,7 @@ void gnttab_usage_print(struct domain *rd)
     spin_lock(&gt->lock);
 
     if ( gt->gt_version == 0 )
-        goto out;
+        goto out_grant;
 
     for ( ref = 0; ref != nr_grant_entries(gt); ref++ )
     {
@@ -2853,12 +2893,43 @@ void gnttab_usage_print(struct domain *rd)
                sha->domid, frame, status);
     }
 
- out:
-    spin_unlock(&gt->lock);
-
+out_grant:
     if ( first )
         printk("grant-table for remote domain:%5d ... "
                "no active grant table entries\n", rd->domain_id);
+
+    if ( !print_maptrack )
+        goto out;
+
+    first = 1;
+
+    printk("      -------- maptrack --------\n");
+    printk("[ref] domid         gnt    flags\n");
+
+    for ( ref = 0; ref != gt->maptrack_limit; ref++ )
+    {
+        struct grant_mapping *maptrack = &maptrack_entry(gt, ref);
+
+        if ( maptrack->flags ) {
+
+            if ( first )
+            {
+                printk("maptrack-table for remote domain:%5d\n",
+                       rd->domain_id);
+                first = 0;
+            }
+            /*      [ddd] ddddd 0xXXXXXXXX  0xXX */
+            printk("[%3d] %5d  0x%08x     0x%02x\n",
+                    ref, maptrack->domid, maptrack->ref, maptrack->flags);
+        }
+    }
+
+    if ( first )
+        printk("maptrack-table for remote domain:%5d ... "
+               "no active maptrack table entries\n", rd->domain_id);
+
+ out:
+    spin_unlock(&gt->lock);
 }
 
 static void gnttab_usage_print_all(unsigned char key)
@@ -2866,7 +2937,7 @@ static void gnttab_usage_print_all(unsigned char key)
     struct domain *d;
     printk("%s [ key '%c' pressed\n", __FUNCTION__, key);
     for_each_domain ( d )
-        gnttab_usage_print(d);
+        gnttab_usage_print(d, 0);
     printk("%s ] done\n", __FUNCTION__);
 }
 
diff --git a/xen/include/xen/grant_table.h b/xen/include/xen/grant_table.h
index 0820da1..34a8304 100644
--- a/xen/include/xen/grant_table.h
+++ b/xen/include/xen/grant_table.h
@@ -111,6 +111,9 @@ gnttab_release_mappings(
 int
 gnttab_grow_table(struct domain *d, unsigned int req_nr_frames);
 
+/* Print grant table for given domain. */
+void gnttab_usage_print(struct domain *rd, int print_maptrack);
+
 /* Number of grant table frames. Caller must hold d's grant table lock. */
 static inline unsigned int nr_grant_frames(struct grant_table *gt)
 {
-- 
1.7.7.5 (Apple Git-26)


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