4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nadav Amit <namit@xxxxxxxxxx>
commit ce664331b2487a5d244a51cbdd8cb54f866fbe5d upstream.
When vmballoon_vmci_init() sets a doorbell using VMCI_DOORBELL_SET, for
some reason it does not consider the status and looks at the result.
However, the hypervisor does not update the result - it updates the
status. This might cause VMCI doorbell not to be enabled, resulting in
degraded performance.
Fixes: 48e3d668b790 ("VMware balloon: Enable notification via VMCI")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Xavier Deguillard <xdeguillard@xxxxxxxxxx>
Signed-off-by: Nadav Amit <namit@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/misc/vmw_balloon.c | 37 +++++++++++++++++++------------------
1 file changed, 19 insertions(+), 18 deletions(-)
--- a/drivers/misc/vmw_balloon.c
+++ b/drivers/misc/vmw_balloon.c
@@ -1036,29 +1036,30 @@ static void vmballoon_vmci_cleanup(struc
*/
static int vmballoon_vmci_init(struct vmballoon *b)
{
- int error = 0;
+ unsigned long error, dummy;
- if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) != 0) {
- error = vmci_doorbell_create(&b->vmci_doorbell,
- VMCI_FLAG_DELAYED_CB,
- VMCI_PRIVILEGE_FLAG_RESTRICTED,
- vmballoon_doorbell, b);
-
- if (error == VMCI_SUCCESS) {
- VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET,
- b->vmci_doorbell.context,
- b->vmci_doorbell.resource, error);
- STATS_INC(b->stats.doorbell_set);
- }
- }
+ if ((b->capabilities & VMW_BALLOON_SIGNALLED_WAKEUP_CMD) == 0)
+ return 0;
- if (error != 0) {
- vmballoon_vmci_cleanup(b);
+ error = vmci_doorbell_create(&b->vmci_doorbell, VMCI_FLAG_DELAYED_CB,
+ VMCI_PRIVILEGE_FLAG_RESTRICTED,
+ vmballoon_doorbell, b);
- return -EIO;
- }
+ if (error != VMCI_SUCCESS)
+ goto fail;
+
+ error = VMWARE_BALLOON_CMD(VMCI_DOORBELL_SET, b->vmci_doorbell.context,
+ b->vmci_doorbell.resource, dummy);
+
+ STATS_INC(b->stats.doorbell_set);
+
+ if (error != VMW_BALLOON_SUCCESS)
+ goto fail;
return 0;
+fail:
+ vmballoon_vmci_cleanup(b);
+ return -EIO;
}
/*
