VMware balloon: Treat init like reset

Unify the behavior of the first start of the balloon and a reset. Also on
unload, declare that the balloon driver does not have any capabilities
anymore.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Xavier Deguillard <xdeguillard@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 35 deletions

diff --git a/drivers/misc/vmw_balloon.c b/drivers/misc/vmw_balloon.c
index 01519ff443dd..28fe9e5a14ca 100644
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -47,7 +47,7 @@
 
 MODULE_AUTHOR("VMware, Inc.");
 MODULE_DESCRIPTION("VMware Memory Control (Balloon) Driver");
-MODULE_VERSION("1.4.0.0-k");
+MODULE_VERSION("1.4.1.0-k");
 MODULE_ALIAS("dmi:*:svnVMware*:*");
 MODULE_ALIAS("vmware_vmmemctl");
 MODULE_LICENSE("GPL");
@@ -564,12 +564,14 @@ static void vmballoon_pop(struct vmballoon *b)
                 }
         }
 
-        if ((b->capabilities & VMW_BALLOON_BATCHED_CMDS) != 0) {
-                if (b->batch_page)
-                        vunmap(b->batch_page);
+        if (b->batch_page) {
+                vunmap(b->batch_page);
+                b->batch_page = NULL;
+        }
 
-                if (b->page)
-                        __free_page(b->page);
+        if (b->page) {
+                __free_page(b->page);
+                b->page = NULL;
         }
 }
 
@@ -1044,7 +1046,7 @@ static void vmballoon_work(struct work_struct *work)
         if (b->slow_allocation_cycles > 0)
                 b->slow_allocation_cycles--;
 
-        if (vmballoon_send_get_target(b, &target)) {
+        if (!b->reset_required && vmballoon_send_get_target(b, &target)) {
                 /* update target, adjust size */
                 b->target = target;
 
@@ -1076,8 +1078,10 @@ static int vmballoon_debug_show(struct seq_file *f, void *offset)
         /* format capabilities info */
         seq_printf(f,
                    "balloon capabilities:   %#4x\n"
-                   "used capabilities:      %#4lx\n",
-                   VMW_BALLOON_CAPABILITIES, b->capabilities);
+                   "used capabilities:      %#4lx\n"
+                   "is resetting:           %c\n",
+                   VMW_BALLOON_CAPABILITIES, b->capabilities,
+                   b->reset_required ? 'y' : 'n');
 
         /* format size info */
         seq_printf(f,
@@ -1196,35 +1200,14 @@ static int __init vmballoon_init(void)
 
         INIT_DELAYED_WORK(&balloon.dwork, vmballoon_work);
 
-        /*
-         * Start balloon.
-         */
-        if (!vmballoon_send_start(&balloon, VMW_BALLOON_CAPABILITIES)) {
-                pr_err("failed to send start command to the host\n");
-                return -EIO;
-        }
-
-        if ((balloon.capabilities & VMW_BALLOON_BATCHED_CMDS) != 0) {
-                balloon.ops = &vmballoon_batched_ops;
-                balloon.batch_max_pages = VMW_BALLOON_BATCH_MAX_PAGES;
-                if (!vmballoon_init_batching(&balloon)) {
-                        pr_err("failed to init batching\n");
-                        return -EIO;
-                }
-        } else if ((balloon.capabilities & VMW_BALLOON_BASIC_CMDS) != 0) {
-                balloon.ops = &vmballoon_basic_ops;
-                balloon.batch_max_pages = 1;
-        }
-
-        if (!vmballoon_send_guest_id(&balloon)) {
-                pr_err("failed to send guest ID to the host\n");
-                return -EIO;
-        }
-
         error = vmballoon_debugfs_init(&balloon);
         if (error)
                 return error;
 
+        balloon.batch_page = NULL;
+        balloon.page = NULL;
+        balloon.reset_required = true;
+
         queue_delayed_work(system_freezable_wq, &balloon.dwork, 0);
 
         return 0;
@@ -1242,7 +1225,7 @@ static void __exit vmballoon_exit(void)
          * Reset connection before deallocating memory to avoid potential for
          * additional spurious resets from guest touching deallocated pages.
          */
-        vmballoon_send_start(&balloon, VMW_BALLOON_CAPABILITIES);
+        vmballoon_send_start(&balloon, 0);
         vmballoon_pop(&balloon);
 }
 module_exit(vmballoon_exit);