diff options
| -rw-r--r-- | drivers/hv/channel.c | 23 | ||||
| -rw-r--r-- | drivers/hv/channel_mgmt.c | 2 | ||||
| -rw-r--r-- | drivers/hv/ring_buffer.c | 7 |
3 files changed, 20 insertions, 12 deletions
diff --git a/drivers/hv/channel.c b/drivers/hv/channel.c index 16f91c8490fe..5e482d7f60cb 100644 --- a/drivers/hv/channel.c +++ b/drivers/hv/channel.c @@ -676,10 +676,18 @@ int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer, * NOTE: in this case, the hvsock channel is an exception, because * it looks the host side's hvsock implementation has a throttling * mechanism which can hurt the performance otherwise. + * + * KYS: Oct. 30, 2016: + * It looks like Windows hosts have logic to deal with DOS attacks that + * can be triggered if it receives interrupts when it is not expecting + * the interrupt. The host expects interrupts only when the ring + * transitions from empty to non-empty (or full to non full on the guest + * to host ring). + * So, base the signaling decision solely on the ring state until the + * host logic is fixed. */ - if (((ret == 0) && kick_q && signal) || - (ret && !is_hvsock_channel(channel))) + if (((ret == 0) && signal)) vmbus_setevent(channel); return ret; @@ -786,9 +794,18 @@ int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *channel, * If we cannot write to the ring-buffer; signal the host * even if we may not have written anything. This is a rare * enough condition that it should not matter. + * + * KYS: Oct. 30, 2016: + * It looks like Windows hosts have logic to deal with DOS attacks that + * can be triggered if it receives interrupts when it is not expecting + * the interrupt. The host expects interrupts only when the ring + * transitions from empty to non-empty (or full to non full on the guest + * to host ring). + * So, base the signaling decision solely on the ring state until the + * host logic is fixed. */ - if (((ret == 0) && kick_q && signal) || (ret)) + if (((ret == 0) && signal)) vmbus_setevent(channel); return ret; diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 96a85cd39580..cbb96f2f0d1a 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -447,8 +447,6 @@ static void vmbus_process_offer(struct vmbus_channel *newchannel) } dev_type = hv_get_dev_type(newchannel); - 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/ring_buffer.c b/drivers/hv/ring_buffer.c index 08043da1a61c..5d11d93eedf4 100644 --- a/drivers/hv/ring_buffer.c +++ b/drivers/hv/ring_buffer.c @@ -75,13 +75,6 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi, 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(); /* |
