From: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
For synthetic NIC channels, enable explicit signaling policy as netvsc wants to
explicitly control when the host is to be signaled.
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/hv/channel.c | 18 ++++--------------
drivers/hv/channel_mgmt.c | 2 ++
drivers/hv/hyperv_vmbus.h | 3 ++-
drivers/hv/ring_buffer.c | 15 ++++++++++++---
4 files changed, 20 insertions(+), 18 deletions(-)
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c
index a68830c..da022d3 100644
--- a/drivers/hv/channel.c
+++ b/drivers/hv/channel.c
@@ -657,7 +657,7 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, num_vecs,
- &signal, lock);
+ &signal, lock, channel->signal_policy);
/*
* Signalling the host is conditional on many factors:
@@ -678,11 +678,6 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer,
* mechanism which can hurt the performance otherwise.
*/
- if (channel->signal_policy)
- signal = true;
- else
- kick_q = true;
-
if (((ret == 0) && kick_q && signal) ||
(ret && !is_hvsock_channel(channel)))
vmbus_setevent(channel);
@@ -775,7 +770,7 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
- &signal, lock);
+ &signal, lock, channel->signal_policy);
/*
* Signalling the host is conditional on many factors:
@@ -793,11 +788,6 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel,
* enough condition that it should not matter.
*/
- if (channel->signal_policy)
- signal = true;
- else
- kick_q = true;
-
if (((ret == 0) && kick_q && signal) || (ret))
vmbus_setevent(channel);
@@ -859,7 +849,7 @@ int vmbus_sendpacket_mpb_desc(struct vmbus_channel *channel,
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
- &signal, lock);
+ &signal, lock, channel->signal_policy);
if (ret == 0 && signal)
vmbus_setevent(channel);
@@ -924,7 +914,7 @@ int vmbus_sendpacket_multipagebuffer(struct vmbus_channel *channel,
bufferlist[2].iov_len = (packetlen_aligned - packetlen);
ret = hv_ringbuffer_write(&channel->outbound, bufferlist, 3,
- &signal, lock);
+ &signal, lock, channel->signal_policy);
if (ret == 0 && signal)
vmbus_setevent(channel);
diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c
index b6c1211..8345869 100644
--- a/drivers/hv/channel_mgmt.c
+++ b/drivers/hv/channel_mgmt.c
@@ -406,6 +406,8 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel)
}
dev_type = hv_get_dev_type(&newchannel->offermsg.offer.if_type);
+ if (dev_type == HV_NIC)
+ set_channel_signal_state(newchannel, HV_SIGNAL_POLICY_EXPLICIT);
init_vp_index(newchannel, dev_type);
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index dfa9fac..ddcc348 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -529,7 +529,8 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);
int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
struct kvec *kv_list,
- u32 kv_count, bool *signal, bool lock);
+ u32 kv_count, bool *signal, bool lock,
+ enum hv_signal_policy policy);
int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
void *buffer, u32 buflen, u32 *buffer_actual_len,
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index fe586bf..e3edcae 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -66,12 +66,20 @@ u32 hv_end_read(struct hv_ring_buffer_info *rbi)
* arrived.
*/
-static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
+static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi,
+ enum hv_signal_policy policy)
{
virt_mb();
if (READ_ONCE(rbi->ring_buffer->interrupt_mask))
return false;
+ /*
+ * When the client wants to control signaling,
+ * we only honour the host interrupt mask.
+ */
+ if (policy == HV_SIGNAL_POLICY_EXPLICIT)
+ return true;
+
/* check interrupt_mask before read_index */
virt_rmb();
/*
@@ -264,7 +272,8 @@ void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info)
/* Write to the ring buffer. */
int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
- struct kvec *kv_list, u32 kv_count, bool *signal, bool lock)
+ struct kvec *kv_list, u32 kv_count, bool *signal, bool lock,
+ enum hv_signal_policy policy)
{
int i = 0;
u32 bytes_avail_towrite;
@@ -326,7 +335,7 @@ int hv_ringbuffer_write(struct hv_ring_buffer_info *outring_info,
if (lock)
spin_unlock_irqrestore(&outring_info->ring_lock, flags);
- *signal = hv_need_to_signal(old_write, outring_info);
+ *signal = hv_need_to_signal(old_write, outring_info, policy);
return 0;
}
--
1.7.4.1
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