[PATCH 17/28] Drivers: hv: Add state to manage incoming channel interrupt load

K. Y. Srinivasan
2012-12-01T14:25:54Z

Add state to bind a channel to a specific VCPU. This will help us better
distribute incoming interrupt load.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
---
drivers/hv/channel.c | 2 +-
drivers/hv/channel_mgmt.c | 2 ++
include/linux/hyperv.h | 21 +++++++++++++++++++--
3 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index 70a34da..9303252 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -181,7 +181,7 @@ int vmbus_open(struct vmbus_channel *newchannel, u32 send_ringbuffer_size,
open_msg->ringbuffer_gpadlhandle = newchannel->ringbuffer_gpadlhandle;
open_msg->downstream_ringbuffer_pageoffset = send_ringbuffer_size >>
PAGE_SHIFT;
- open_msg->server_contextarea_gpadlhandle = 0;
+ open_msg->target_vp = newchannel->target_vp;

if (userdatalen > MAX_USER_DEFINED_BYTES) {
err = -EINVAL;
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index f4d9902..56ed45c 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -302,6 +302,8 @@ static void vmbus_onoffer(struct vmbus_channel_message_header *hdr)
offer->connection_id;
}

+ newchannel->target_vp = 0;
+
memcpy(&newchannel->offermsg, offer,
sizeof(struct vmbus_channel_offer_channel));
newchannel->monitor_grp = (u8)offer->monitorid / 32;
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index c6e2c44..8c3cb1f 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -732,8 +732,15 @@ struct vmbus_channel_open_channel {
/* GPADL for the channel's ring buffer. */
u32 ringbuffer_gpadlhandle;

- /* GPADL for the channel's server context save area. */
- u32 server_contextarea_gpadlhandle;
+ /*
+ * Starting with win8, this field will be used to specify
+ * the target virtual processor on which to deliver the interrupt for
+ * the host to guest communication.
+ * Prior to win8, incoming channel interrupts would only
+ * be delivered on cpu 0. Setting this value to 0 would
+ * preserve the earlier behavior.
+ */
+ u32 target_vp;

/*
* The upstream ring buffer begins at offset zero in the memory
@@ -971,6 +978,16 @@ struct vmbus_channel {
bool is_dedicated_interrupt;
struct hv_input_signal_event_buffer sig_buf;
struct hv_input_signal_event *sig_event;
+
+ /*
+ * Starting with win8, this field will be used to specify
+ * the target virtual processor on which to deliver the interrupt for
+ * the host to guest communication.
+ * Prior to win8, incoming channel interrupts would only
+ * be delivered on cpu 0. Setting this value to 0 would
+ * preserve the earlier behavior.
+ */
+ u32 target_vp;
};

static inline void set_channel_read_state(struct vmbus_channel *c, bool state)
--
1.7.4.1