diff options
| -rw-r--r-- | drivers/hv/connection.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/hv/connection.c b/drivers/hv/connection.c index cadfb34b38d8..0475be4356dd 100644 --- a/drivers/hv/connection.c +++ b/drivers/hv/connection.c @@ -14,6 +14,7 @@ #include <linux/wait.h> #include <linux/delay.h> #include <linux/mm.h> +#include <linux/module.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/hyperv.h> @@ -55,6 +56,16 @@ static __u32 vmbus_versions[] = { VERSION_WS2008 }; +/* + * Maximal VMBus protocol version guests can negotiate. Useful to cap the + * VMBus version for testing and debugging purpose. + */ +static uint max_version = VERSION_WIN10_V5_2; + +module_param(max_version, uint, S_IRUGO); +MODULE_PARM_DESC(max_version, + "Maximal VMBus protocol version which can be negotiated"); + int vmbus_negotiate_version(struct vmbus_channel_msginfo *msginfo, u32 version) { int ret = 0; @@ -240,6 +251,8 @@ int vmbus_connect(void) goto cleanup; version = vmbus_versions[i]; + if (version > max_version) + continue; ret = vmbus_negotiate_version(msginfo, version); if (ret == -ETIMEDOUT) |