[Qemu-devel] [PATCH 4/8] Add check for cache size smaller than page size

[Juan Quintela <quintela@redhat.com>]

From: Orit Wasserman <owasserm@redhat.com>

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 arch_init.c |  4 ++++
 migration.c | 10 +++++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch_init.c b/arch_init.c
index 66f5e82..8edeabe 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -178,6 +178,10 @@ static struct {

 int64_t xbzrle_cache_resize(int64_t new_size)
 {
+    if (new_size < TARGET_PAGE_SIZE) {
+        return -1;
+    }
+
     if (XBZRLE.cache != NULL) {
         return cache_resize(XBZRLE.cache, new_size / TARGET_PAGE_SIZE) *
             TARGET_PAGE_SIZE;
diff --git a/migration.c b/migration.c
index 7235c23..84587e9 100644
--- a/migration.c
+++ b/migration.c
@@ -469,6 +469,7 @@ void qmp_migrate_cancel(Error **errp)
 void qmp_migrate_set_cache_size(int64_t value, Error **errp)
 {
     MigrationState *s = migrate_get_current();
+    int64_t new_size;

     /* Check for truncation */
     if (value != (size_t)value) {
@@ -477,7 +478,14 @@ void qmp_migrate_set_cache_size(int64_t value, Error **errp)
         return;
     }

-    s->xbzrle_cache_size = xbzrle_cache_resize(value);
+    new_size = xbzrle_cache_resize(value);
+    if (new_size < 0) {
+        error_set(errp, QERR_INVALID_PARAMETER_VALUE, "cache size",
+                  "is smaller than page size");
+        return;
+    }
+
+    s->xbzrle_cache_size = new_size;
 }

 int64_t qmp_query_migrate_cache_size(Error **errp)
-- 
1.8.5.3