The vmbus/hyperv interrupt handling is another complete trainwreck and
probably the worst of all currently in tree.

If CONFIG_HYPERV=y then the interrupt delivery to the vmbus happens
via the direct HYPERVISOR_CALLBACK_VECTOR. So far so good, but:

  The driver requests first a normal device interrupt. The only reason
  to do so is to increment the interrupt stats of that device
  interrupt. For no reason it also installs a private flow handler.

  We have proper accounting mechanisms for direct vectors, but of
  course it's too much effort to add that 5 lines of code.

  Aside of that the alloc_intr_gate() is not protected against
  reallocation which makes module reload impossible.

Solution to the problem is simple to rip out the whole mess and
implement it correctly.

First of all move all that code to arch/x86/kernel/cpu/mshyperv.c and
merily install the HYPERVISOR_CALLBACK_VECTOR with proper reallocation
protection and use the proper direct vector accounting mechanism.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linuxdrivers <devel@linuxdriverproject.org>
Cc: x86 <x86@kernel.org>
Link: http://lkml.kernel.org/r/20140223212739.028307673@linutronix.deSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

When the guest attempts to connect with the host when there may already be a
connection with the host (as would be the case during the kdump/kexec path),
it is difficult to guarantee timely response from the host. Starting with
WS2012 R2, the host supports this ability to re-connect with the host
(explicitly to support kexec). Prior to responding to the guest, the host
needs to ensure that device states based on the previous connection to
the host have been properly torn down. This may introduce unbounded delays.
To deal with this issue, don't do a timed wait during the initial connect
with 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>

During the initial VMBUS connect phase, starting with WS2012 R2, we should
specify the VPCU in the guest that should receive the notification. Fix this
issue. This fix is required to properly connect to the host in the kexeced
kernel.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>        [3.9+]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This will allow us to use bigger receive buffer, and prevent allocation failure
due to fragmented memory.
Signed-off-by: NHaiyang Zhang <haiyangz@microsoft.com>
Reviewed-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch marks the function hv_synic_free_cpu() as static in hv.c
because it is not used outside this file.

Thus, it also eliminates the following warning in hv.c:
drivers/hv/hv.c:304:6: warning: no previous prototype for ‘hv_synic_free_cpu’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace direct inclusions of <acpi/acpi.h>, <acpi/acpi_bus.h> and
<acpi/acpi_drivers.h>, which are incorrect, with <linux/acpi.h>
inclusions and remove some inclusions of those files that aren't
necessary.

First of all, <acpi/acpi.h>, <acpi/acpi_bus.h> and <acpi/acpi_drivers.h>
should not be included directly from any files that are built for
CONFIG_ACPI unset, because that generally leads to build warnings about
undefined symbols in !CONFIG_ACPI builds.  For CONFIG_ACPI set,
<linux/acpi.h> includes those files and for CONFIG_ACPI unset it
provides stub ACPI symbols to be used in that case.

Second, there are ordering dependencies between those files that always
have to be met.  Namely, it is required that <acpi/acpi_bus.h> be included
prior to <acpi/acpi_drivers.h> so that the acpi_pci_root declarations the
latter depends on are always there.  And <acpi/acpi.h> which provides
basic ACPICA type declarations should always be included prior to any other
ACPI headers in CONFIG_ACPI builds.  That also is taken care of including
<linux/acpi.h> as appropriate.
Signed-off-by: NLv Zheng <lv.zheng@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com> (drivers/pci stuff)
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> (Xen stuff)
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Rescind of subchannels were not being correctly handled. Fix the bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>        [3.11+]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 90d33f3e as it's not
the correct fix for this issue, and it causes a build warning to be
added to the kernel tree.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The check for calling free_page() on hv_context.synic_event_page[cpu] is the
same for hv_context.synic_message_page[cpu], like a copy-paste error.
Signed-off-by: NFelipe Pena <felipensp@gmail.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Rescind of subchannels were not being correctly handled. Fix the bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: <stable@vger.kernel.org>        [3.11+]
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Don't return success if the buffer has not been initialized.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 666b9adc terminated vmbus
version negotiation incorrectly. We need to terminate the version
negotiation only if the current negotiation were to timeout.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: Olaf Hering <ohering@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current code does not correctly negotiate the version numbers for the util
driver when hosted on earlier hosts. The version numbers presented by this
driver were not compatible with the version numbers supported by Windows Server
2008. Fix this problem.

I would like to thank Olaf Hering (ohering@suse.com) for identifying the problem.
Reported-by: NOlaf Hering <ohering@suse.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the ringbuffer bus attributes to the dev_groups structure,
deletes the now unneeded struct hv_device_info, and removes some now
unused functions, and variables as everything is now moved to the
dev_groups structure, dev_attrs is no longer needed.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's no longer needed, and the struct hv_ring_buffer_debug_info
structure shouldn't be "global" so move it to the local .h file instead.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's only used once, only contains 2 function calls, so just make those
calls directly, deleting the function, and the now unneeded structure
entirely.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "client_monitor_conn_id" and "server_monitor_conn_id" bus
attributes to the dev_groups structure, removing the need for it to be
in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "client_monitor_latency" and "server_monitor_latency" bus
attributes to the dev_groups structure, removing the need for it to be
in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "client_monitor_pending" and "server_monitor_pending" bus
attributes to the dev_groups structure, removing the need for it to be
in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

monitor_pages was a void pointer, containing an unknown number of arrays that
we just "knew" were a child and parent array of a specific size.  Instead of
that implicit knowledge, let's make them a real pointer, allowing us to have
type safety, and a semblance of sane addressing schemes.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "device_id" bus attribute to the dev_groups structure,
removing the need for it to be in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "class_id" bus attribute to the dev_groups structure,
removing the need for it to be in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "state" bus attribute to the dev_groups structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "state" bus attribute to the dev_groups structure,
removing the need for it to be in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This moves the "state" bus attribute to the dev_groups structure,
removing the need for it to be in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch is the first in a series that moves the hv bus code to use the
dev_groups field instead of dev_attrs, as dev_attrs is going away in future
kernel releases.

It moves the id sysfs file to the dev_groups structure, and creates the needed
show/store functions, instead of relying on one "universal" function for this.
By doing this, it removes the need for this to be in a temporary structure.
Tested-by: N"K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The variable execute_shutdown is only assigned the values true and
false. Change its type to bool.

The simplified semantic patch that find this problem is as
follows (http://coccinelle.lip6.fr/):

@exists@
type T;
identifier b;
@@
- T
+ bool
  b = ...;
  ... when any
  b = \(true\|false\)
Signed-off-by: NPeter Senna Tschudin <peter.senna@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current code would attempt to negotiate a different protocol version if
the current negotiation timed out. This triggers an assert in the host (on debug
builds). Avoid this by negotiating a newer version only if the host properly
rejects the current version being negotiated.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The channel state should be correctly set before registering the device. In the current
code the driver probe would fail for channels that have been rescinded and subsequently
re-offered. Fix the bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: stable <stable@vger.kernel.org> # 3.11
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove HV_DRV_VERSION, it has no meaning for upstream drivers.

Initially it was supposed to show the "Linux Integration Services"
version, now it is not in sync anymore with the out-of-tree drivers
available from the MSFT website.

The only place where a version string is still required is the KVP
command "IntegrationServicesVersion" which is handled by
tools/hv/hv_kvp_daemon.c. To satisfy such KVP request from the host pass
the current string to the daemon during KVP userland registration.
Signed-off-by: NOlaf Hering <olaf@aepfle.de>
Acked-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Each message sent from the guest carries with it a transaction ID.
Assign the transaction ID just before putting the message on the VMBUS.
This would help in debugging on the host side.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current code picked the highest version advertised by the host. WS2012 R2
has implemented a protocol version for KVP that is not compatible with prior
protocol versions of KVP. Fix the bug in the current code by explicitly specifying
the protocol version that the guest can support.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When we are posting pressure status, we may get interrupted and handle
the un-balloon operation. In this case just don't post the status as we
know the pressure status is stale.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: Stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As we hot-add 128 MB chunks of memory, we wait to ensure that the memory
is onlined before attempting to hot-add the next chunk. If the udev rule for
memory hot-add is not executed within the allowed time, we would rollback the
state and abort further hot-add. Since the hot-add has succeeded and the only
failure is that the memory is not onlined within the allowed time, we should not
be rolling back the state. Fix this bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: Stable <stable@vger.kernel.org>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Whenever a device is unregistered in vmbus_device_unregister (drivers/hv/vmbus_drv.c), the device name in the log message may contain garbage as the memory has already been freed by the time pr_info is called. Log example:
 [ 3149.170475] hv_vmbus: child device àõsèè0_5 unregistered

By logging the message just before calling device_unregister, the correct device name is printed:
[ 3145.034652] hv_vmbus: child device vmbus_0_5 unregistered

Also changing register & unregister messages to debug to avoid unnecessarily cluttering the kernel log.
Signed-off-by: NFernando M Soto <fsoto@bluecatnetworks.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We currently allocate synic structures in hv_sync_init(), but there's no way for
the driver to know about the allocation failure and it may continue to use the
uninitialized pointers. Solve this by introducing helpers for allocating and
freeing and doing the allocation before the on_each_cpu() call in
vmbus_bus_init().

Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patches add a read barriers to force the driver to check the interrupt mask
before read_index. Otherwise we may lost a kick to host.

Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Even if guest were compiled without SMP support, it could not assume that host
wasn't. So switch to use mb() instead of smp_mb() to force memory barriers for
UP guest.
Signed-off-by: NJason Wang <jasowang@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Starting with Win8, the host supports multiple sub-channels for a given
device. As in the past, the initial channel offer specifies the device and
is associated with both the type and the instance GUIDs. For performance
critical devices, the host may support multiple sub-channels. The sub-channels
share the same type and instance GUID as the primary channel. The number of
sub-channels offerrred to the guest depends on the number of virtual CPUs
assigned to the guest. The guest can request the creation of these sub-channels
and once created and opened, the guest can distribute the traffic across all
the channels (the primary and the sub-channels). A request sent on a sub-channel
will have the response delivered on the same sub-channel.

At channel (sub-channel) creation we bind the channel interrupt to a CPU and
with this sub-channel support we will be able to spread the interrupt load
of a given device across all available CPUs.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Reviewed-by: NHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Linux' notion of cpuid is different from the Host's notion of CPUID. In the
call to bind the channel interrupts, we should use the host's notion of
CPU Ids. Fix this bug.
Signed-off-by: NK. Y. Srinivasan <kys@microsoft.com>
Cc: Stable <stable@vger.kernel.org> (V3.9)
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>