Staging: hv: vmbus: Retry vmbus_post_msg() before giving up

The function hv_post_msg() can fail because of transient resource
conditions. It may be useful to retry the operation.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/arch/x86/include/asm/hyperv.h b/arch/x86/include/asm/hyperv.h
index 5df477a..b80420b 100644
--- a/arch/x86/include/asm/hyperv.h
+++ b/arch/x86/include/asm/hyperv.h
@@ -189,5 +189,6 @@
 #define HV_STATUS_INVALID_HYPERCALL_CODE	2
 #define HV_STATUS_INVALID_HYPERCALL_INPUT	3
 #define HV_STATUS_INVALID_ALIGNMENT		4
+#define HV_STATUS_INSUFFICIENT_BUFFERS		19
 
 #endif