In order to implement NAPI in netvsc, the driver needs access to
control host interrupt mask.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

All current usage of vmbus write uses the acquire_lock flag, therefore
having it be optional is unnecessary. This also fixes a sparse warning
since sparse doesn't like when a function has conditional locking.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since sendpacket no longer uses kickq argument remove it.
Remove it no longer used xmit_more in sendpacket in netvsc as well.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The flag to cause notification of host is unused after
commit a01a291a282f7c2e ("Drivers: hv: vmbus: Base host signaling
strictly on the ring state"). Therefore remove it from the ring
buffer internal API.
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

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: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix a typo.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

With TimeSync version 4 protocol support we started updating system time
continuously through the whole lifetime of Hyper-V guests. Every 5 seconds
there is a time sample from the host which triggers do_settimeofday[64]().
While the time from the host is very accurate such adjustments may cause
issues:
- Time is jumping forward and backward, some applications may misbehave.
- In case an NTP server runs in parallel and uses something else for time
  sync (network, PTP,...) system time will never converge.
- Systemd starts annoying you by printing "Time has been changed" every 5
  seconds to the system log.

Instead of doing in-kernel time adjustments offload the work to an
NTP client by exposing TimeSync messages as a PTP device. Users may now
decide what they want to use as a source.

I tested the solution with chrony, the config was:

 refclock PHC /dev/ptp0 poll 3 dpoll -2 offset 0

The result I'm seeing is accurate enough, the time delta between the guest
and the host is almost always within [-10us, +10us], the in-kernel solution
was giving us comparable results.

I also tried implementing PPS device instead of PTP by using not currently
used Hyper-V synthetic timers (we use only one of four for clockevent) but
with PPS source only chrony wasn't able to give me the required accuracy,
the delta often more that 100us.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Log the negotiated IC versions.
Signed-off-by: NAlex Ng <alexng@messages.microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Previously, we were assuming that each IC protocol version was tied to a
specific host version. For example, some Windows 10 preview hosts only
support v3 TimeSync even though driver assumes v4 is supported by all
Windows 10 hosts.

The guest will stop trying to negotiate even though older supported
versions may still be offered by the host.

Make IC version negotiation more robust by going through all versions
that are supported by the guest.

Fixes: 3da0401b ("Drivers: hv: utils: Fix the mapping between host
version and protocol to use")
Reported-by: NRolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: NAlex Ng <alexng@messages.microsoft.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Coverity scan gives a warning when there is fall through in a switch
without a comment. This fall through is intentional as ol_waitevent needs
to be completed to unblock hv_mem_hot_add() allowing it to process next
requests regardless of the result of if we were able to online this block.
Reported-by: NStephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to cleanup the hypercall page before doing kexec/kdump or the new
kernel may crash if it tries to use it. Reuse the now-empty hv_cleanup
function renaming it to hyperv_cleanup and moving to the arch specific
code.

Fixes: 8730046c ("Drivers: hv vmbus: Move Hypercall page setup out of common code")
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

do_settimeofday() is deprecated, use do_settimeofday64() instead.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: NJohn Stultz <john.stultz@linaro.org>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit a389fcfd ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
added the proper mb(), but removed the test "prev_write_sz < pending_sz"
when making the signal decision.

As a result, the guest can signal the host unnecessarily,
and then the host can throttle the guest because the host
thinks the guest is buggy or malicious; finally the user
running stress test can perceive intermittent freeze of
the guest.

This patch brings back the test, and properly handles the
in-place consumption APIs used by NetVSC (see get_next_pkt_raw(),
put_pkt_raw() and commit_rd_index()).

Fixes: a389fcfd ("Drivers: hv: vmbus: Fix signaling logic in
hv_need_to_signal_on_read()")
Signed-off-by: NDexuan Cui <decui@microsoft.com>
Reported-by: NRolf Neugebauer <rolf.neugebauer@docker.com>
Tested-by: NRolf Neugebauer <rolf.neugebauer@docker.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Get rid of all unused definitions.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of cleaning up architecture specific code, define APIs
to manage interrupt state.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of cleaning up architecture specific code, define an API
to retrieve the virtual procesor index.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of cleaning up architecture specific code, define APIs
to manipulate the interrupt controller state.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of cleaning up architecture specific code, define APIs
to manipulate the event page.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of cleaning up architecture specific code, define APIs
to manipulate the message page.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The version variable while it is initialized is not used;
get rid of it.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to interact with Hyper-V in an instruction set
architecture independent way, use the new API to get the current
tick.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Move the relevant code that programs the hypervisor to an architecture
specific file.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
code for signaling end of message.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
check for detecting if the hypercall page is setup.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
crash notification function.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code,
extract hypervisor version information in an architecture specific
file.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code,
consolidate all Hyper-V specific clocksource code to an architecture
specific code.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
hypercall invocation code to an architecture specific file.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
hypercall page setup to an architecture specific file.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
definition of generate_guest_id() to x86 specific header file.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As part of the effort to separate out architecture specific code, move the
definition of hv_x64_msr_hypercall_contents to x86 specific header file.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

VSS may use a char device to support the communication between
the user level daemon and the driver. When the VSS channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new VSS offer from the host. Implement this logic.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fcopy may use a char device to support the communication between
the user level daemon and the driver. When the Fcopy channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new Fcopy offer from the host. Implement this logic.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

KVP may use a char device to support the communication between
the user level daemon and the driver. When the KVP channel is rescinded
we need to make sure that the char device is fully cleaned up before
we can process a new KVP offer from the host. Implement this logic.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The host can rescind a channel that has been offered to the
guest and once the channel is rescinded, the host does not
respond to any requests on that channel. Deal with the case where
the guest may be blocked waiting for a response from the host.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit e513229b ("Drivers: hv: vmbus: prevent cpu offlining on
newer hypervisors") cpu offlining was disabled. It is still true that we
can't offline CPUs which have VMBus channels bound to them but we may have
'free' CPUs (e.v. we booted with maxcpus= parameter and onlined CPUs after
VMBus was initialized), these CPUs may be disabled without issues.

In future, we may even allow closing CPUs which have only sub-channels
assinged to them by closing these sub-channels. All devices will continue
to work.
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To make it possible to online/offline CPUs switch to cpuhp infrastructure
for doing hv_synic_init()/hv_synic_cleanup().
Signed-off-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>