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s390/docs: fix warnings for vfio_ap driver lock usage doc 

Fix multiple warnings produced by make htmldocs

Fixes: e32d3827f3 ("s390/Docs: new doc describing lock usage by the vfio_ap device driver")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
This commit is contained in:
Alexander Gordeev 2022-07-21 15:29:05 +02:00
parent 5fcd0d8ae2
commit d384690c6a
2 changed files with 40 additions and 29 deletions
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1
Documentation/s390/index.rst
View File

@ -12,6 +12,7 @@ s390 Architecture
qeth
s390dbf
vfio-ap
vfio-ap-locking
vfio-ccw
zfcpdump
common_io

68
Documentation/s390/vfio-ap-locking.rst
View File

@ -7,19 +7,23 @@ This document describes the locks that are pertinent to the secure operation
of the vfio_ap device driver. Throughout this document, the following variables
will be used to denote instances of the structures herein described:
struct ap_matrix_dev *matrix_dev;
struct ap_matrix_mdev *matrix_mdev;
struct kvm *kvm;
.. code-block:: c
struct ap_matrix_dev *matrix_dev;
struct ap_matrix_mdev *matrix_mdev;
struct kvm *kvm;
The Matrix Devices Lock (drivers/s390/crypto/vfio_ap_private.h)
--------------------------------------------------------------
---------------------------------------------------------------
struct ap_matrix_dev {
...
struct list_head mdev_list;
struct mutex mdevs_lock;
...
}
.. code-block:: c
struct ap_matrix_dev {
...
struct list_head mdev_list;
struct mutex mdevs_lock;
...
}
The Matrix Devices Lock (matrix_dev->mdevs_lock) is implemented as a global
mutex contained within the single object of struct ap_matrix_dev. This lock
@ -31,11 +35,13 @@ representing one of the vfio_ap device driver's mediated devices.
The KVM Lock (include/linux/kvm_host.h)
---------------------------------------
struct kvm {
...
struct mutex lock;
...
}
.. code-block:: c
struct kvm {
...
struct mutex lock;
...
}
The KVM Lock (kvm->lock) controls access to the state data for a KVM guest. This
lock must be held by the vfio_ap device driver while one or more AP adapters,
@ -48,12 +54,14 @@ been attached to the KVM guest.
The Guests Lock (drivers/s390/crypto/vfio_ap_private.h)
-----------------------------------------------------------
struct ap_matrix_dev {
...
struct list_head mdev_list;
struct mutex guests_lock;
...
}
.. code-block:: c
struct ap_matrix_dev {
...
struct list_head mdev_list;
struct mutex guests_lock;
...
}
The Guests Lock (matrix_dev->guests_lock) controls access to the
matrix_mdev instances (matrix_dev->mdev_list) that represent mediated devices
@ -89,17 +97,19 @@ resources, so only the matrix_dev->mdevs_lock needs to be held.
The PQAP Hook Lock (arch/s390/include/asm/kvm_host.h)
-----------------------------------------------------
typedef int (*crypto_hook)(struct kvm_vcpu *vcpu);
.. code-block:: c
struct kvm_s390_crypto {
...
struct rw_semaphore pqap_hook_rwsem;
crypto_hook *pqap_hook;
...
};
typedef int (*crypto_hook)(struct kvm_vcpu *vcpu);
struct kvm_s390_crypto {
...
struct rw_semaphore pqap_hook_rwsem;
crypto_hook *pqap_hook;
...
};
The PQAP Hook Lock is a r/w semaphore that controls access to the function
pointer of the handler (*kvm->arch.crypto.pqap_hook) to invoke when the
pointer of the handler ``(*kvm->arch.crypto.pqap_hook)`` to invoke when the
PQAP(AQIC) instruction sub-function is intercepted by the host. The lock must be
held in write mode when pqap_hook value is set, and in read mode when the
pqap_hook function is called.