Commit Graph

380 Commits

Author SHA1 Message Date
Stephan Mueller
4b44f2d18a random: add interrupt callback to VMBus IRQ handler
The Hyper-V Linux Integration Services use the VMBus implementation for
communication with the Hypervisor. VMBus registers its own interrupt
handler that completely bypasses the common Linux interrupt handling.
This implies that the interrupt entropy collector is not triggered.

This patch adds the interrupt entropy collection callback into the VMBus
interrupt handler function.

Cc: stable@kernel.org
Signed-off-by: Stephan Mueller <stephan.mueller@atsec.com>
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-06-13 11:54:33 -04:00
Vitaly Kuznetsov
d19a55d6ed Drivers: hv: balloon: reset host_specified_ha_region
We set host_specified_ha_region = true on certain request but this is a
global state which stays 'true' forever. We need to reset it when we
receive a request where ha_region is not specified. I did not see any
real issues, the bug was found by code inspection.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Vitaly Kuznetsov
77c0c9735b Drivers: hv: balloon: don't crash when memory is added in non-sorted order
When we iterate through all HA regions in handle_pg_range() we have an
assumption that all these regions are sorted in the list and the
'start_pfn >= has->end_pfn' check is enough to find the proper region.
Unfortunately it's not the case with WS2016 where host can hot-add regions
in a different order. We end up modifying the wrong HA region and crashing
later on pages online. Modify the check to make sure we found the region
we were searching for while iterating. Fix the same check in pfn_covered()
as well.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Vitaly Kuznetsov
cd95aad557 Drivers: hv: vmbus: handle various crash scenarios
Kdump keeps biting. Turns out CHANNELMSG_UNLOAD_RESPONSE is always
delivered to the CPU which was used for initial contact or to CPU0
depending on host version. vmbus_wait_for_unload() doesn't account for
the fact that in case we're crashing on some other CPU we won't get the
CHANNELMSG_UNLOAD_RESPONSE message and our wait on the current CPU will
never end.

Do the following:
1) Check for completion_done() in the loop. In case interrupt handler is
   still alive we'll get the confirmation we need.

2) Read message pages for all CPUs message page as we're unsure where
   CHANNELMSG_UNLOAD_RESPONSE is going to be delivered to. We can race with
   still-alive interrupt handler doing the same, add cmpxchg() to
   vmbus_signal_eom() to not lose CHANNELMSG_UNLOAD_RESPONSE message.

3) Cleanup message pages on all CPUs. This is required (at least for the
   current CPU as we're clearing CPU0 messages now but we may want to bring
   up additional CPUs on crash) as new messages won't be delivered till we
   consume what's pending. On boot we'll place message pages somewhere else
   and we won't be able to read stale messages.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Vitaly Kuznetsov
4dbfc2e680 Drivers: hv: kvp: fix IP Failover
Hyper-V VMs can be replicated to another hosts and there is a feature to
set different IP for replicas, it is called 'Failover TCP/IP'. When
such guest starts Hyper-V host sends it KVP_OP_SET_IP_INFO message as soon
as we finish negotiation procedure. The problem is that it can happen (and
it actually happens) before userspace daemon connects and we reply with
HV_E_FAIL to the message. As there are no repetitions we fail to set the
requested IP.

Solve the issue by postponing our reply to the negotiation message till
userspace daemon is connected. We can't wait too long as there is a
host-side timeout (cca. 75 seconds) and if we fail to reply in this time
frame the whole KVP service will become inactive. The solution is not
ideal - if it takes userspace daemon more than 60 seconds to connect
IP Failover will still fail but I don't see a solution with our current
separation between kernel and userspace parts.

Other two modules (VSS and FCOPY) don't require such delay, leave them
untouched.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 09:23:14 -07:00
Jake Oshins
ea37a6b8a0 drivers:hv: Separate out frame buffer logic when picking MMIO range
Simplify the logic that picks MMIO ranges by pulling out the
logic related to trying to lay frame buffer claim on top of where
the firmware placed the frame buffer.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins
6d146aefba drivers:hv: Record MMIO range in use by frame buffer
Later in the boot sequence, we need to figure out which memory
ranges can be given out to various paravirtual drivers.  The
hyperv_fb driver should, ideally, be placed right on top of
the frame buffer, without some other device getting plopped on
top of this range in the meantime.  Recording this now allows
that to be guaranteed.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins
be000f93e5 drivers:hv: Track allocations of children of hv_vmbus in private resource tree
This patch changes vmbus_allocate_mmio() and vmbus_free_mmio() so
that when child paravirtual devices allocate memory-mapped I/O
space, they allocate it privately from a resource tree pointed
at by hyperv_mmio and also by the public resource tree
iomem_resource.  This allows the region to be marked as "busy"
in the private tree, but a "bridge window" in the public tree,
guaranteeing that no two bridge windows will overlap each other
but while also allowing the PCI device children of the bridge
windows to overlap that window.

One might conclude that this belongs in the pnp layer, rather
than in this driver.  Rafael Wysocki, the maintainter of the
pnp layer, has previously asked that we not modify the pnp layer
as it is considered deprecated.  This patch is thus essentially
a workaround.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins
23a0683186 drivers:hv: Reverse order of resources in hyperv_mmio
A patch later in this series allocates child nodes
in this resource tree.  For that to work, this tree
needs to be sorted in ascending order.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins
97fb77dc87 drivers:hv: Make a function to free mmio regions through vmbus
This patch introduces a function that reverses everything
done by vmbus_allocate_mmio().  Existing code just called
release_mem_region().  Future patches in this series
require a more complex sequence of actions, so this function
is introduced to wrap those actions.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
Jake Oshins
e16dad6bfe drivers:hv: Lock access to hyperv_mmio resource tree
In existing code, this tree of resources is created
in single-threaded code and never modified after it is
created, and thus needs no locking.  This patch introduces
a semaphore for tree access, as other patches in this
series introduce run-time modifications of this resource
tree which can happen on multiple threads.

Signed-off-by: Jake Oshins <jakeo@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:01:37 -07:00
K. Y. Srinivasan
ab028db41c Drivers: hv: vmbus: Implement APIs to support "in place" consumption of vmbus packets
Implement APIs for in-place consumption of vmbus packets. Currently, each
packet is copied and processed one at a time and as part of processing
each packet we potentially may signal the host (if it is waiting for
room to produce a packet).

These APIs help batched in-place processing of vmbus packets.
We also optimize host signaling by having a separate API to signal
the end of in-place consumption. With netvsc using these APIs,
on an iperf run on average I see about 20X reduction in checks to
signal the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan
687f32e6d9 Drivers: hv: vmbus: Move some ring buffer functions to hyperv.h
In preparation for implementing APIs for in-place consumption of VMBUS
packets, movve some ring buffer functionality into hyperv.h

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan
5cc472477f Drivers: hv: vmbus: Export the vmbus_set_event() API
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 <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan
dcd0eeca44 Drivers: hv: vmbus: Use the new virt_xx barrier code
Use the virt_xx barriers that have been defined for use in virtual machines.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan
d45faaeedb Drivers: hv: vmbus: Use READ_ONCE() to read variables that are volatile
Use the READ_ONCE macro to access variabes that can change asynchronously.
This is the recommended mechanism for dealing with "unsafe" compiler
optimizations.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan
a6341f0000 Drivers: hv: vmbus: Introduce functions for estimating room in the ring buffer
Introduce separate functions for estimating how much can be read from
and written to the ring buffer.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:19 -07:00
K. Y. Srinivasan
a389fcfd2c Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read()
On the consumer side, we have interrupt driven flow management of the
producer. It is sufficient to base the signaling decision on the
amount of space that is available to write after the read is complete.
The current code samples the previous available space and uses this
in making the signaling decision. This state can be stale and is
unnecessary. Since the state can be stale, we end up not signaling
the host (when we should) and this can result in a hang. Fix this
problem by removing the unnecessary check. I would like to thank
Arseney Romanenko <arseneyr@microsoft.com> for pointing out this issue.

Also, issue a full memory barrier before making the signaling descision
to correctly deal with potential reordering of the write (read index)
followed by the read of pending_sz.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Dexuan Cui <decui@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-30 14:00:16 -07:00
Linus Torvalds
8eee93e257 Char/Misc patches for 4.6-rc1
Here is the big char/misc driver update for 4.6-rc1.
 
 The majority of the patches here is hwtracing and some new mic drivers,
 but there's a lot of other driver updates as well.  Full details in the
 shortlog.
 
 All have been in linux-next for a while with no reported issues.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here is the big char/misc driver update for 4.6-rc1.

  The majority of the patches here is hwtracing and some new mic
  drivers, but there's a lot of other driver updates as well.  Full
  details in the shortlog.

  All have been in linux-next for a while with no reported issues"

* tag 'char-misc-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (238 commits)
  goldfish: Fix build error of missing ioremap on UM
  nvmem: mediatek: Fix later provider initialization
  nvmem: imx-ocotp: Fix return value of imx_ocotp_read
  nvmem: Fix dependencies for !HAS_IOMEM archs
  char: genrtc: replace blacklist with whitelist
  drivers/hwtracing: make coresight-etm-perf.c explicitly non-modular
  drivers: char: mem: fix IS_ERROR_VALUE usage
  char: xillybus: Fix internal data structure initialization
  pch_phub: return -ENODATA if ROM can't be mapped
  Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
  Drivers: hv: vmbus: Support handling messages on multiple CPUs
  Drivers: hv: utils: Remove util transport handler from list if registration fails
  Drivers: hv: util: Pass the channel information during the init call
  Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
  Drivers: hv: vmbus: remove code duplication in message handling
  Drivers: hv: vmbus: avoid wait_for_completion() on crash
  Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
  misc: at24: replace memory_accessor with nvmem_device_read
  eeprom: 93xx46: extend driver to plug into the NVMEM framework
  eeprom: at25: extend driver to plug into the NVMEM framework
  ...
2016-03-17 13:47:50 -07:00
Alex Ng
7268644734 Drivers: hv: vmbus: Support kexec on ws2012 r2 and above
WS2012 R2 and above hosts can support kexec in that thay can support
reconnecting to the host (as would be needed in the kexec path)
on any CPU. Enable this. Pre ws2012 r2 hosts don't have this ability
and consequently cannot support kexec.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
K. Y. Srinivasan
d81274aae6 Drivers: hv: vmbus: Support handling messages on multiple CPUs
Starting with Windows 2012 R2, message inteerupts can be delivered
on any VCPU in the guest. Support this functionality.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Alex Ng
e66853b090 Drivers: hv: utils: Remove util transport handler from list if registration fails
If util transport fails to initialize for any reason, the list of transport
handlers may become corrupted due to freeing the transport handler without
removing it from the list. Fix this by cleaning it up from the list.

Signed-off-by: Alex Ng <alexng@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
K. Y. Srinivasan
b9830d120c Drivers: hv: util: Pass the channel information during the init call
Pass the channel information to the util drivers that need to defer
reading the channel while they are processing a request. This would address
the following issue reported by Vitaly:

Commit 3cace4a616 ("Drivers: hv: utils: run polling callback always in
interrupt context") removed direct *_transaction.state = HVUTIL_READY
assignments from *_handle_handshake() functions introducing the following
race: if a userspace daemon connects before we get first non-negotiation
request from the server hv_poll_channel() won't set transaction state to
HVUTIL_READY as (!channel) condition will fail, we set it to non-NULL on
the first real request from the server.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reported-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov
d452ab7b4c Drivers: hv: vmbus: avoid unneeded compiler optimizations in vmbus_wait_for_unload()
Message header is modified by the hypervisor and we read it in a loop,
we need to prevent compilers from optimizing accesses. There are no such
optimizations at this moment, this is just a future proof.

Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov
0f70b66975 Drivers: hv: vmbus: remove code duplication in message handling
We have 3 functions dealing with messages and they all implement
the same logic to finalize reads, move it to vmbus_signal_eom().

Suggested-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov
75ff3a8a91 Drivers: hv: vmbus: avoid wait_for_completion() on crash
wait_for_completion() may sleep, it enables interrupts and this
is something we really want to avoid on crashes because interrupt
handlers can cause other crashes. Switch to the recently introduced
vmbus_wait_for_unload() doing busy wait instead.

Reported-by: Radim Krcmar <rkrcmar@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Vitaly Kuznetsov
7be3e16944 Drivers: hv: vmbus: don't loose HVMSG_TIMER_EXPIRED messages
We must handle HVMSG_TIMER_EXPIRED messages in the interrupt context
and we offload all the rest to vmbus_on_msg_dpc() tasklet. This functions
loops to see if there are new messages pending. In case we'll ever see
HVMSG_TIMER_EXPIRED message there we're going to lose it as we can't
handle it from there. Avoid looping in vmbus_on_msg_dpc(), we're OK
with handling one message per interrupt.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Radim Kr.má<rkrcmar@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-01 16:57:20 -08:00
Andrey Smetanin
18f098618a drivers/hv: Move VMBus hypercall codes into Hyper-V UAPI header
VMBus hypercall codes inside Hyper-V UAPI header will
be used by QEMU to implement VMBus host devices support.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: Joerg Roedel <joro@8bytes.org>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
[Do not rename the constant at the same time as moving it, as that
 would cause semantic conflicts with the Hyper-V tree. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2016-02-16 18:48:40 +01:00
K. Y. Srinivasan
fe760e4d64 Drivers: hv: vmbus: Give control over how the ring access is serialized
On the channel send side, many of the VMBUS
device drivers explicity serialize access to the
outgoing ring buffer. Give more control to the
VMBUS device drivers in terms how to serialize
accesss to the outgoing ring buffer.
The default behavior will be to aquire the
ring lock to preserve the current behavior.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
K. Y. Srinivasan
3eba9a77d5 Drivers: hv: vmbus: Eliminate the spin lock on the read path
The function hv_ringbuffer_read() is called always on a pre-assigned
CPU. Each chnnel is bound to a specific CPU and this function is
always called on the CPU the channel is bound. There is no need to
acquire the spin lock; get rid of this overhead.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui
85d9aa7051 Drivers: hv: vmbus: add an API vmbus_hvsock_device_unregister()
The hvsock driver needs this API to release all the resources related
to the channel.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui
499e8401a5 Drivers: hv: vmbus: add a per-channel rescind callback
This will be used by the coming hv_sock driver.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui
8981da320a Drivers: hv: vmbus: add a hvsock flag in struct hv_driver
Only the coming hv_sock driver has a "true" value for this flag.

We treat the hvsock offers/channels as special VMBus devices.
Since the hv_sock driver handles all the hvsock offers/channels, we need to
tweak vmbus_match() for hv_sock driver, so we introduce this flag.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui
5c23a1a5c6 Drivers: hv: vmbus: define a new VMBus message type for hvsock
A function to send the type of message is also added.

The coming net/hvsock driver will use this function to proactively request
the host to offer a VMBus channel for a new hvsock connection.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Dexuan Cui
5f363bc38f Drivers: hv: vmbus: vmbus_sendpacket_ctl: hvsock: avoid unnecessary signaling
When the hvsock channel's outbound ringbuffer is full (i.e.,
hv_ringbuffer_write() returns -EAGAIN), we should avoid the unnecessary
signaling the host.

Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Vitaly Kuznetsov
3ccb4fd8f4 Drivers: hv: vmbus: don't manipulate with clocksources on crash
clocksource_change_rating() involves mutex usage and can't be called
in interrupt context. It also makes sense to avoid doing redundant work
on crash.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Vitaly Kuznetsov
415719160d Drivers: hv: vmbus: avoid scheduling in interrupt context in vmbus_initiate_unload()
We have to call vmbus_initiate_unload() on crash to make kdump work but
the crash can also be happening in interrupt (e.g. Sysrq + c results in
such) where we can't schedule or the following will happen:

[  314.905786] bad: scheduling from the idle thread!

Just skipping the wait (and even adding some random wait here) won't help:
to make host-side magic working we're supposed to receive CHANNELMSG_UNLOAD
(and actually confirm the fact that we received it) but we can't use
interrupt-base path (vmbus_isr()-> vmbus_on_msg_dpc()). Implement a simple
busy wait ignoring all the other messages and use it if we're in an
interrupt context.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
Vitaly Kuznetsov
79fd8e7066 Drivers: hv: vmbus: avoid infinite loop in init_vp_index()
When we pick a CPU to use for a new subchannel we try find a non-used one
on the appropriate NUMA node, we keep track of them with the
primary->alloced_cpus_in_node mask. Under normal circumstances we don't run
out of available CPUs but it is possible when we we don't initialize some
cpus in Linux, e.g. when we boot with 'nr_cpus=' limitation.

Avoid the infinite loop in init_vp_index() by checking that we still have
non-used CPUs in the alloced_cpus_in_node mask and resetting it in case
we don't.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:34:12 -08:00
K. Y. Srinivasan
7047f17d70 Drivers: hv: vmbus: Add vendor and device atttributes
Add vendor and device attributes to VMBUS devices. These will be used
by Hyper-V tools as well user-level RDMA libraries that will use the
vendor/device tuple to discover the RDMA device.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:32:57 -08:00
K. Y. Srinivasan
1b807e1011 Drivers: hv: vmbus: Cleanup vmbus_set_event()
Cleanup vmbus_set_event() by inlining the hypercall to post
the event and since the return value of vmbus_set_event() is not checked,
make it void. As part of this cleanup, get rid of the function
hv_signal_event() as it is only callled from vmbus_set_event().

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-07 21:32:57 -08:00
Linus Torvalds
4c257ec37b char/misc patches for 4.5-rc1
Here's the big set of char/misc patches for 4.5-rc1.
 
 Nothing major, lots of different driver subsystem updates, full details
 in the shortlog.  All of these have been in linux-next for a while.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull char/misc updates from Greg KH:
 "Here's the big set of char/misc patches for 4.5-rc1.

  Nothing major, lots of different driver subsystem updates, full
  details in the shortlog.  All of these have been in linux-next for a
  while"

* tag 'char-misc-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (71 commits)
  mei: fix fasync return value on error
  parport: avoid assignment in if
  parport: remove unneeded space
  parport: change style of NULL comparison
  parport: remove unnecessary out of memory message
  parport: remove braces
  parport: quoted strings should not be split
  parport: code indent should use tabs
  parport: fix coding style
  parport: EXPORT_SYMBOL should follow function
  parport: remove trailing white space
  parport: fix a trivial typo
  coresight: Fix a typo in Kconfig
  coresight: checking for NULL string in coresight_name_match()
  Drivers: hv: vmbus: Treat Fibre Channel devices as performance critical
  Drivers: hv: utils: fix hvt_op_poll() return value on transport destroy
  Drivers: hv: vmbus: fix the building warning with hyperv-keyboard
  extcon: add Maxim MAX3355 driver
  Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek()
  Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw()
  ...
2016-01-13 10:23:36 -08:00
K. Y. Srinivasan
879a650a27 Drivers: hv: vmbus: Treat Fibre Channel devices as performance critical
For performance critical devices, we distribute the incoming
channel interrupt load across available CPUs in the guest.
Include Fibre channel devices in the set of devices for which
we would distribute the interrupt load.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-21 13:14:56 -08:00
Vitaly Kuznetsov
77b744a598 Drivers: hv: utils: fix hvt_op_poll() return value on transport destroy
The return type of hvt_op_poll() is unsigned int and -EBADF is
inappropriate, poll functions return POLL* statuses.

Reported-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-21 13:14:56 -08:00
Andrey Smetanin
c71acc4c74 drivers/hv: Move struct hv_timer_message_payload into UAPI Hyper-V x86 header
This struct is required for Hyper-V SynIC timers implementation inside KVM
and for upcoming Hyper-V VMBus support by userspace(QEMU). So place it into
Hyper-V UAPI header.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:41 +01:00
Andrey Smetanin
5b423efe11 drivers/hv: Move struct hv_message into UAPI Hyper-V x86 header
This struct is required for Hyper-V SynIC timers implementation inside KVM
and for upcoming Hyper-V VMBus support by userspace(QEMU). So place it into
Hyper-V UAPI header.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:40 +01:00
Andrey Smetanin
4f39bcfd1c drivers/hv: Move HV_SYNIC_STIMER_COUNT into Hyper-V UAPI x86 header
This constant is required for Hyper-V SynIC timers MSR's
support by userspace(QEMU).

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:40 +01:00
Andrey Smetanin
7797dcf63f drivers/hv: replace enum hv_message_type by u32
enum hv_message_type inside struct hv_message, hv_post_message
is not size portable. Replace enum by u32.

Signed-off-by: Andrey Smetanin <asmetanin@virtuozzo.com>
CC: Gleb Natapov <gleb@kernel.org>
CC: Paolo Bonzini <pbonzini@redhat.com>
CC: "K. Y. Srinivasan" <kys@microsoft.com>
CC: Haiyang Zhang <haiyangz@microsoft.com>
CC: Vitaly Kuznetsov <vkuznets@redhat.com>
CC: Roman Kagan <rkagan@virtuozzo.com>
CC: Denis V. Lunev <den@openvz.org>
CC: qemu-devel@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2015-12-16 18:49:39 +01:00
Vitaly Kuznetsov
940b68e2c3 Drivers: hv: ring_buffer: eliminate hv_ringbuffer_peek()
Currently, there is only one user for hv_ringbuffer_read()/
hv_ringbuffer_peak() functions and the usage of these functions is:
- insecure as we drop ring_lock between them, someone else (in theory
  only) can acquire it in between;
- non-optimal as we do a number of things (acquire/release the above
  mentioned lock, calculate available space on the ring, ...) twice and
  this path is performance-critical.

Remove hv_ringbuffer_peek() moving the logic from __vmbus_recvpacket() to
hv_ringbuffer_read().

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov
667d374064 Drivers: hv: remove code duplication between vmbus_recvpacket()/vmbus_recvpacket_raw()
vmbus_recvpacket() and vmbus_recvpacket_raw() are almost identical but
there are two discrepancies:
1) vmbus_recvpacket() doesn't propagate errors from hv_ringbuffer_read()
   which looks like it is not desired.
2) There is an error message printed in packetlen > bufferlen case in
   vmbus_recvpacket(). I'm removing it as it is usless for users to see
   such messages and /vmbus_recvpacket_raw() doesn't have it.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00
Vitaly Kuznetsov
b5f53dde8d Drivers: hv: ring_buffer: remove code duplication from hv_ringbuffer_peek/read()
hv_ringbuffer_peek() does the same as hv_ringbuffer_read() without
advancing the read index. The only functional change this patch brings
is moving hv_need_to_signal_on_read() call under the ring_lock but this
function is just a couple of comparisons.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-12-14 19:27:30 -08:00