kernel.git/drivers/hv/connection.c, branch linux-4.12.y

vmbus: only reschedule tasklet if time limit exceeded

2017-03-17T06:10:48Z

The change to reschedule tasklet if more data arrives in ring buffer can cause performance regression if host timing is such that the next response happens in small window. Go back to a modified version of the original looping behavior. If the race occurs in a small time, then loop. But if the tasklet has been running for a long interval due to flood, then reschedule the tasklet to allow migration to ksoftirqd. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: add direct isr callback mode

2017-02-14T18:20:35Z

Change the simple boolean batched_reading into a tri-value. For future NAPI support in netvsc driver, the callback needs to occur directly in interrupt handler. Batched mode is also changed to disable host interrupts immediately in interrupt routine (to avoid unnecessary host signals), and the tasklet is rescheduled if more data is detected. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: change to per channel tasklet

2017-02-14T18:20:35Z

Make the event handling tasklet per channel rather than per-cpu. This allows for better fairness when getting lots of data on the same cpu. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: put related per-cpu variable together

2017-02-14T18:20:35Z

The hv_context structure had several arrays which were per-cpu and was allocating small structures (tasklet_struct). Instead use a single per-cpu array. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

vmbus: use kernel bitops for traversing interrupt mask

2017-02-10T14:43:30Z

Use standard kernel operations for find first set bit to traverse the channel bit array. This has added benefit of speeding up lookup on 64 bit and because it uses find first set instruction. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Move the extracting of Hypervisor version information

2017-01-20T13:48:03Z

As part of the effort to separate out architecture specific code, extract hypervisor version information in an architecture specific file. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Raise retry/wait limits in vmbus_post_msg()

2017-01-10T20:46:40Z

DoS protection conditions were altered in WS2016 and now it's easy to get -EAGAIN returned from vmbus_post_msg() (e.g. when we try changing MTU on a netvsc device in a loop). All vmbus_post_msg() callers don't retry the operation and we usually end up with a non-functional device or crash. While host's DoS protection conditions are unknown to me my tests show that it can take up to 10 seconds before the message is sent so doing udelay() is not an option, we really need to sleep. Almost all vmbus_post_msg() callers are ready to sleep but there is one special case: vmbus_initiate_unload() which can be called from interrupt/NMI context and we can't sleep there. I'm also not sure about the lonely vmbus_send_tl_connect_request() which has no in-tree users but its external users are most likely waiting for the host to reply so sleeping there is also appropriate. Signed-off-by: Vitaly Kuznetsov Signed-off-by: K. Y. Srinivasan Cc: Signed-off-by: Greg Kroah-Hartman

uio-hv-generic: new userspace i/o driver for VMBus

2016-12-06T10:52:49Z

This is a new driver to enable userspace networking on VMBus. It is based largely on the similar driver that already exists for PCI, and earlier work done by Brocade to support DPDK. Signed-off-by: Stephen Hemminger Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Reduce the delay between retries in vmbus_post_msg()

2016-08-31T11:05:41Z

The current delay between retries is unnecessarily high and is negatively affecting the time it takes to boot the system. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman

Drivers: hv: vmbus: Export the vmbus_set_event() API

2016-04-30T21:00:19Z

In preparation for moving some ring buffer functionality out of the vmbus driver, export the API for signaling the host. Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman