[PATCH v5 4/8] xen: make grant resource limits per domain

[Juergen Gross <jgross@suse.com>]

Instead of using the same global resource limits of grant tables (max.
number of grant frames, max. number of maptrack frames) for all domains
make these limits per domain. This will allow setting individual limits
in the future. For now initialize the per domain limits with the global
values.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Paul Durrant <paul.durrant@citrix.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
---
V3:
- correct error message (Paul Durrant)
---
 xen/common/grant_table.c | 82 ++++++++++++++++++++++++++----------------------
 1 file changed, 45 insertions(+), 37 deletions(-)

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 29e7fa539b..ff735a4b47 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -71,6 +71,9 @@ struct grant_table {
      * what version to use yet.
      */
     unsigned              gt_version;
+    /* Resource limits of the domain. */
+    unsigned int          max_grant_frames;
+    unsigned int          max_maptrack_frames;
 };
 
 #ifndef DEFAULT_MAX_NR_GRANT_FRAMES /* to allow arch to override */
@@ -287,8 +290,8 @@ num_act_frames_from_sha_frames(const unsigned int num)
     return DIV_ROUND_UP(num * sha_per_page, ACGNT_PER_PAGE);
 }
 
-#define max_nr_active_grant_frames \
-    num_act_frames_from_sha_frames(max_grant_frames)
+#define max_nr_active_grant_frames(gt) \
+    num_act_frames_from_sha_frames(gt->max_grant_frames)
 
 static inline unsigned int
 nr_active_grant_frames(struct grant_table *gt)
@@ -526,7 +529,7 @@ get_maptrack_handle(
      * out of memory, try stealing an entry from another VCPU (in case the
      * guest isn't mapping across its VCPUs evenly).
      */
-    if ( nr_maptrack_frames(lgt) < max_maptrack_frames )
+    if ( nr_maptrack_frames(lgt) < lgt->max_maptrack_frames )
         new_mt = alloc_xenheap_page();
 
     if ( !new_mt )
@@ -1664,14 +1667,15 @@ grant_table_init(struct domain *d)
     if ( gt->nr_grant_frames )
         return 0;
 
-    gt->nr_grant_frames = INITIAL_NR_GRANT_FRAMES;
+    gt->nr_grant_frames = min_t(unsigned int, INITIAL_NR_GRANT_FRAMES,
+                                              gt->max_grant_frames);
 
     /* Active grant table. */
     if ( (gt->active = xzalloc_array(struct active_grant_entry *,
-                                     max_nr_active_grant_frames)) == NULL )
+                                     max_nr_active_grant_frames(gt))) == NULL )
         goto no_mem_1;
     for ( i = 0;
-          i < num_act_frames_from_sha_frames(INITIAL_NR_GRANT_FRAMES); i++ )
+          i < num_act_frames_from_sha_frames(gt->nr_grant_frames); i++ )
     {
         if ( (gt->active[i] = alloc_xenheap_page()) == NULL )
             goto no_mem_2;
@@ -1681,14 +1685,14 @@ grant_table_init(struct domain *d)
     }
 
     /* Tracking of mapped foreign frames table */
-    gt->maptrack = vzalloc(max_maptrack_frames * sizeof(*gt->maptrack));
+    gt->maptrack = vzalloc(gt->max_maptrack_frames * sizeof(*gt->maptrack));
     if ( gt->maptrack == NULL )
         goto no_mem_2;
 
     /* Shared grant table. */
-    if ( (gt->shared_raw = xzalloc_array(void *, max_grant_frames)) == NULL )
+    if ( (gt->shared_raw = xzalloc_array(void *, gt->max_grant_frames)) == NULL )
         goto no_mem_3;
-    for ( i = 0; i < INITIAL_NR_GRANT_FRAMES; i++ )
+    for ( i = 0; i < gt->nr_grant_frames; i++ )
     {
         if ( (gt->shared_raw[i] = alloc_xenheap_page()) == NULL )
             goto no_mem_4;
@@ -1697,11 +1701,11 @@ grant_table_init(struct domain *d)
 
     /* Status pages for grant table - for version 2 */
     gt->status = xzalloc_array(grant_status_t *,
-                               grant_to_status_frames(max_grant_frames));
+                               grant_to_status_frames(gt->max_grant_frames));
     if ( gt->status == NULL )
         goto no_mem_4;
 
-    for ( i = 0; i < INITIAL_NR_GRANT_FRAMES; i++ )
+    for ( i = 0; i < gt->nr_grant_frames; i++ )
         gnttab_create_shared_page(d, gt, i);
 
     gt->nr_status_frames = 0;
@@ -1709,7 +1713,7 @@ grant_table_init(struct domain *d)
     return 0;
 
  no_mem_4:
-    for ( i = 0; i < INITIAL_NR_GRANT_FRAMES; i++ )
+    for ( i = 0; i < gt->nr_grant_frames; i++ )
         free_xenheap_page(gt->shared_raw[i]);
     xfree(gt->shared_raw);
     gt->shared_raw = NULL;
@@ -1718,7 +1722,7 @@ grant_table_init(struct domain *d)
     gt->maptrack = NULL;
  no_mem_2:
     for ( i = 0;
-          i < num_act_frames_from_sha_frames(INITIAL_NR_GRANT_FRAMES); i++ )
+          i < num_act_frames_from_sha_frames(gt->nr_grant_frames); i++ )
         free_xenheap_page(gt->active[i]);
     xfree(gt->active);
     gt->active = NULL;
@@ -1743,7 +1747,7 @@ gnttab_grow_table(struct domain *d, unsigned int req_nr_frames)
         return 0;
     }
 
-    ASSERT(req_nr_frames <= max_grant_frames);
+    ASSERT(req_nr_frames <= gt->max_grant_frames);
 
     gdprintk(XENLOG_INFO,
             "Expanding dom (%d) grant table from (%d) to (%d) frames.\n",
@@ -1815,15 +1819,6 @@ gnttab_setup_table(
     if ( unlikely(copy_from_guest(&op, uop, 1)) )
         return -EFAULT;
 
-    if ( unlikely(op.nr_frames > max_grant_frames) )
-    {
-        gdprintk(XENLOG_INFO, "Xen only supports up to %d grant-table frames"
-                " per domain.\n",
-                max_grant_frames);
-        op.status = GNTST_general_error;
-        goto out;
-    }
-
     if ( !guest_handle_okay(op.frame_list, op.nr_frames) )
         return -EFAULT;
 
@@ -1843,6 +1838,14 @@ gnttab_setup_table(
     gt = d->grant_table;
     grant_write_lock(gt);
 
+    if ( unlikely(op.nr_frames > gt->max_grant_frames) )
+    {
+        gdprintk(XENLOG_INFO, "Domain is limited to %d grant-table frames.\n",
+                gt->max_grant_frames);
+        op.status = GNTST_general_error;
+        goto unlock;
+    }
+
     if ( gt->gt_version == 0 )
         gt->gt_version = 1;
 
@@ -1853,7 +1856,7 @@ gnttab_setup_table(
     {
         gdprintk(XENLOG_INFO,
                  "Expand grant table to %u failed. Current: %u Max: %u\n",
-                 op.nr_frames, nr_grant_frames(gt), max_grant_frames);
+                 op.nr_frames, nr_grant_frames(gt), gt->max_grant_frames);
         op.status = GNTST_general_error;
         goto unlock;
     }
@@ -1888,6 +1891,7 @@ gnttab_query_size(
 {
     struct gnttab_query_size op;
     struct domain *d;
+    struct grant_table *gt;
 
     if ( count != 1 )
         return -EINVAL;
@@ -1908,13 +1912,15 @@ gnttab_query_size(
         goto out;
     }
 
-    grant_read_lock(d->grant_table);
+    gt = d->grant_table;
+
+    grant_read_lock(gt);
 
-    op.nr_frames     = nr_grant_frames(d->grant_table);
-    op.max_nr_frames = max_grant_frames;
+    op.nr_frames     = nr_grant_frames(gt);
+    op.max_nr_frames = gt->max_grant_frames;
     op.status        = GNTST_okay;
 
-    grant_read_unlock(d->grant_table);
+    grant_read_unlock(gt);
 
  out:
     if ( d )
@@ -3465,6 +3471,8 @@ grant_table_create(
     /* Simple stuff. */
     percpu_rwlock_resource_init(&t->lock, grant_rwlock);
     spin_lock_init(&t->maptrack_lock);
+    t->max_grant_frames = max_grant_frames;
+    t->max_maptrack_frames = max_maptrack_frames;
 
     /* Okay, install the structure. */
     d->grant_table = t;
@@ -3728,7 +3736,7 @@ int gnttab_map_frame(struct domain *d, unsigned long idx, gfn_t gfn,
     }
     else
     {
-        if ( (idx >= nr_grant_frames(gt)) && (idx < max_grant_frames) )
+        if ( (idx >= nr_grant_frames(gt)) && (idx < gt->max_grant_frames) )
             gnttab_grow_table(d, idx + 1);
 
         if ( idx < nr_grant_frames(gt) )
@@ -3755,6 +3763,12 @@ static void gnttab_usage_print(struct domain *rd)
 
     grant_read_lock(gt);
 
+    printk("grant-table for remote domain:%5d (v%d)\n"
+           "  %d frames (%d max), %d maptrack frames (%d max)\n",
+           rd->domain_id, gt->gt_version,
+           nr_grant_frames(gt), gt->max_grant_frames,
+           nr_maptrack_frames(gt), gt->max_maptrack_frames);
+
     for ( ref = 0; ref != nr_grant_entries(gt); ref++ )
     {
         struct active_grant_entry *act;
@@ -3782,12 +3796,7 @@ static void gnttab_usage_print(struct domain *rd)
             status = status_entry(gt, ref);
         }
 
-        if ( first )
-        {
-            printk("grant-table for remote domain:%5d (v%d)\n",
-                   rd->domain_id, gt->gt_version);
-            first = 0;
-        }
+        first = 0;
 
         /*      [0xXXX]  ddddd 0xXXXXXX 0xXXXXXXXX      ddddd 0xXXXXXX 0xXX */
         printk("[0x%03x]  %5d 0x%06lx 0x%08x      %5d 0x%06"PRIx64" 0x%02x\n",
@@ -3799,8 +3808,7 @@ static void gnttab_usage_print(struct domain *rd)
     grant_read_unlock(gt);
 
     if ( first )
-        printk("grant-table for remote domain:%5d ... "
-               "no active grant table entries\n", rd->domain_id);
+        printk("no active grant table entries\n");
 }
 
 static void gnttab_usage_print_all(unsigned char key)
-- 
2.12.3


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