nitro_enclaves: Remove redundant 'flush_workqueue()' calls

'destroy_workqueue()' already drains the queue before destroying it, so
there is no need to flush it explicitly.

Remove the redundant 'flush_workqueue()' calls.

This was generated with coccinelle:

@@
expression E;
@@
- flush_workqueue(E);
destroy_workqueue(E);

Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/d57f5c7e362837a8dfcde0d726a76b56f114e619.1636736947.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nitro_enclaves: Update copyright statement to include 2021

Update the copyright statement to include 2021, as a change has been
made over this year.

Check commit d874742f6a73 ("nitro_enclaves: Set Bus Master for the NE
PCI device") for the codebase update from this file (ne_pci_dev.c).

Reviewed-by: George-Aurelian Popescu <popegeo@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20210827154930.40608-5-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nitro_enclaves: Set Bus Master for the NE PCI device

Enable Bus Master for the NE PCI device, according to the PCI spec
for submitting memory or I/O requests:

Master Enable – Controls the ability of a PCI Express
Endpoint to issue Memory and I/O Read/Write Requests, and
the ability of a Root or Switch Port to forward Memory and
I/O Read/Write Requests in the Upstream direction

Cc: Andra Paraschiv <andraprs@amazon.com>
Cc: Alexandru Vasile <lexnv@amazon.com>
Cc: Alexandru Ciobotaru <alcioa@amazon.com>
Reviewed-by: Andra Paraschiv <andraprs@amazon.com>
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Link: https://lore.kernel.org/r/20210621004046.1419-1-longpeng2@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nitro_enclaves: Init misc device providing the ioctl interface

The Nitro Enclaves driver provides an ioctl interface to the user space
for enclave lifetime management e.g. enclave creation / termination and
setting enclave resources such as memory and CPU.

This ioctl interface is mapped to a Nitro Enclaves misc device.

Changelog

v9 -> v10

* Update commit message to include the changelog before the SoB tag(s).

v8 -> v9

* Use the ne_devs data structure to get the refs for the NE misc device
in the NE PCI device driver logic.

v7 -> v8

* Add define for the CID of the primary / parent VM.
* Update the NE PCI driver shutdown logic to include misc device
deregister.

v6 -> v7

* Set the NE PCI device the parent of the NE misc device to be able to
use it in the ioctl logic.
* Update the naming and add more comments to make more clear the logic
of handling full CPU cores and dedicating them to the enclave.

v5 -> v6

* Remove the ioctl to query API version.
* Update documentation to kernel-doc format.

v4 -> v5

* Update the size of the NE CPU pool string from 4096 to 512 chars.

v3 -> v4

* Use dev_err instead of custom NE log pattern.
* Remove the NE CPU pool init during kernel module loading, as the CPU
pool is now setup at runtime, via a sysfs file for the kernel
parameter.
* Add minimum enclave memory size definition.

v2 -> v3

* Remove the GPL additional wording as SPDX-License-Identifier is
already in place.
* Remove the WARN_ON calls.
* Remove linux/bug and linux/kvm_host includes that are not needed.
* Remove "ratelimited" from the logs that are not in the ioctl call
paths.
* Remove file ops that do nothing for now - open and release.

v1 -> v2

* Add log pattern for NE.
* Update goto labels to match their purpose.
* Update ne_cpu_pool data structure to include the global mutex.
* Update NE misc device mode to 0660.
* Check if the CPU siblings are included in the NE CPU pool, as full CPU
cores are given for the enclave(s).

Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-8-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nitro_enclaves: Handle out-of-band PCI device events

In addition to the replies sent by the Nitro Enclaves PCI device in
response to command requests, out-of-band enclave events can happen e.g.
an enclave crashes. In this case, the Nitro Enclaves driver needs to be
aware of the event and notify the corresponding user space process that
abstracts the enclave.

Register an MSI-X interrupt vector to be used for this kind of
out-of-band events. The interrupt notifies that the state of an enclave
changed and the driver logic scans the state of each running enclave to
identify for which this notification is intended.

Create an workqueue to handle the out-of-band events. Notify user space
enclave process that is using a polling mechanism on the enclave fd.

Changelog

v9 -> v10

* Update commit message to include the changelog before the SoB tag(s).

v8 -> v9

* Use the reference to the pdev directly from the ne_pci_dev instead of
the one from the enclave data structure.

v7 -> v8

* No changes.

v6 -> v7

* No changes.

v5 -> v6

* Update documentation to kernel-doc format.

v4 -> v5

* Remove sanity checks for situations that shouldn't happen, only if
buggy system or broken logic at all.

v3 -> v4

* Use dev_err instead of custom NE log pattern.
* Return IRQ_NONE when interrupts are not handled.

v2 -> v3

* Remove the WARN_ON calls.
* Update static calls sanity checks.
* Remove "ratelimited" from the logs that are not in the ioctl call
paths.

v1 -> v2

* Add log pattern for NE.
* Update goto labels to match their purpose.

Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Alexandru-Catalin Vasile <lexnv@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-7-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nitro_enclaves: Handle PCI device command requests

The Nitro Enclaves PCI device exposes a MMIO space that this driver
uses to submit command requests and to receive command replies e.g. for
enclave creation / termination or setting enclave resources.

Add logic for handling PCI device command requests based on the given
command type.

Register an MSI-X interrupt vector for command reply notifications to
handle this type of communication events.

Changelog

v9 -> v10

* Update commit message to include the changelog before the SoB tag(s).

v8 -> v9

* No changes.

v7 -> v8

* Update function signature for submit request and retrive reply
functions as they only returned 0, no error code.
* Include command type value in the error logs of ne_do_request().

v6 -> v7

* No changes.

v5 -> v6

* Update documentation to kernel-doc format.

v4 -> v5

* Remove sanity checks for situations that shouldn't happen, only if
buggy system or broken logic at all.

v3 -> v4

* Use dev_err instead of custom NE log pattern.
* Return IRQ_NONE when interrupts are not handled.

v2 -> v3

* Remove the WARN_ON calls.
* Update static calls sanity checks.
* Remove "ratelimited" from the logs that are not in the ioctl call
paths.

v1 -> v2

* Add log pattern for NE.
* Remove the BUG_ON calls.
* Update goto labels to match their purpose.
* Add fix for kbuild report:
https://lore.kernel.org/lkml/202004231644.xTmN4Z1z%25lkp@intel.com/

Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Alexandru-Catalin Vasile <lexnv@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-6-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

nitro_enclaves: Init PCI device driver

The Nitro Enclaves PCI device is used by the kernel driver as a means of
communication with the hypervisor on the host where the primary VM and
the enclaves run. It handles requests with regard to enclave lifetime.

Setup the PCI device driver and add support for MSI-X interrupts.

Changelog

v9 -> v10

* Update commit message to include the changelog before the SoB tag(s).

v8 -> v9

* Init the reference to the ne_pci_dev in the ne_devs data structure.

v7 -> v8

* Add NE PCI driver shutdown logic.

v6 -> v7

* No changes.

v5 -> v6

* Update documentation to kernel-doc format.

v4 -> v5

* Remove sanity checks for situations that shouldn't happen, only if
buggy system or broken logic at all.

v3 -> v4

* Use dev_err instead of custom NE log pattern.
* Update NE PCI driver name to "nitro_enclaves".

v2 -> v3

* Remove the GPL additional wording as SPDX-License-Identifier is
already in place.
* Remove the WARN_ON calls.
* Remove linux/bug include that is not needed.
* Update static calls sanity checks.
* Remove "ratelimited" from the logs that are not in the ioctl call
paths.
* Update kzfree() calls to kfree().

v1 -> v2

* Add log pattern for NE.
* Update PCI device setup functions to receive PCI device data structure and
then get private data from it inside the functions logic.
* Remove the BUG_ON calls.
* Add teardown function for MSI-X setup.
* Update goto labels to match their purpose.
* Implement TODO for NE PCI device disable state check.
* Update function name for NE PCI device probe / remove.

Reviewed-by: Alexander Graf <graf@amazon.com>
Signed-off-by: Alexandru-Catalin Vasile <lexnv@amazon.com>
Signed-off-by: Alexandru Ciobotaru <alcioa@amazon.com>
Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
Link: https://lore.kernel.org/r/20200921121732.44291-5-andraprs@amazon.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>