[PATCH RESEND 09/10] Drivers: hv: balloon: Enable dynamic memory protocol negotiation with Windows 10 hosts

K. Y. Srinivasan
2015-06-28T17:40:06Z

From: Alex Ng <alexng@microsoft.com>

Support Win10 protocol for Dynamic Memory. Thia patch allows guests on Win10 hosts
to hot-add memory even when dynamic memory is not enabled on the guest.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/hv/hv_balloon.c | 26 ++++++++++++++++++++------
1 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 8a725cd..b853b4b 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -62,11 +62,13 @@
enum {
DYNMEM_PROTOCOL_VERSION_1 = DYNMEM_MAKE_VERSION(0, 3),
DYNMEM_PROTOCOL_VERSION_2 = DYNMEM_MAKE_VERSION(1, 0),
+ DYNMEM_PROTOCOL_VERSION_3 = DYNMEM_MAKE_VERSION(2, 0),

DYNMEM_PROTOCOL_VERSION_WIN7 = DYNMEM_PROTOCOL_VERSION_1,
DYNMEM_PROTOCOL_VERSION_WIN8 = DYNMEM_PROTOCOL_VERSION_2,
+ DYNMEM_PROTOCOL_VERSION_WIN10 = DYNMEM_PROTOCOL_VERSION_3,

- DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN8
+ DYNMEM_PROTOCOL_VERSION_CURRENT = DYNMEM_PROTOCOL_VERSION_WIN10
};

@@ -1296,13 +1298,25 @@ static void version_resp(struct hv_dynmem_device *dm,
if (dm->next_version == 0)
goto version_error;

- dm->next_version = 0;
memset(&version_req, 0, sizeof(struct dm_version_request));
version_req.hdr.type = DM_VERSION_REQUEST;
version_req.hdr.size = sizeof(struct dm_version_request);
version_req.hdr.trans_id = atomic_inc_return(&trans_id);
- version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN7;
- version_req.is_last_attempt = 1;
+ version_req.version.version = dm->next_version;
+
+ /*
+ * Set the next version to try in case current version fails.
+ * Win7 protocol ought to be the last one to try.
+ */
+ switch (version_req.version.version) {
+ case DYNMEM_PROTOCOL_VERSION_WIN8:
+ dm->next_version = DYNMEM_PROTOCOL_VERSION_WIN7;
+ version_req.is_last_attempt = 0;
+ break;
+ default:
+ dm->next_version = 0;
+ version_req.is_last_attempt = 1;
+ }

ret = vmbus_sendpacket(dm->dev->channel, &version_req,
sizeof(struct dm_version_request),
@@ -1442,7 +1456,7 @@ static int balloon_probe(struct hv_device *dev,

dm_device.dev = dev;
dm_device.state = DM_INITIALIZING;
- dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN7;
+ dm_device.next_version = DYNMEM_PROTOCOL_VERSION_WIN8;
init_completion(&dm_device.host_event);
init_completion(&dm_device.config_event);
INIT_LIST_HEAD(&dm_device.ha_region_list);
@@ -1474,7 +1488,7 @@ static int balloon_probe(struct hv_device *dev,
version_req.hdr.type = DM_VERSION_REQUEST;
version_req.hdr.size = sizeof(struct dm_version_request);
version_req.hdr.trans_id = atomic_inc_return(&trans_id);
- version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN8;
+ version_req.version.version = DYNMEM_PROTOCOL_VERSION_WIN10;
version_req.is_last_attempt = 0;

ret = vmbus_sendpacket(dev->channel, &version_req,
--
1.7.4.1