Merge remote-tracking branch 'remotes/mst/tags/for_upstream' into staging

virtio, pc: fixes, features

New virtio iommu.
Unrealize memory leaks.
In-band kick/call support.
Bugfixes, documentation all over the place.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

# gpg: Signature made Thu 27 Feb 2020 08:46:33 GMT
# gpg:                using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
# gpg:                issuer "mst@redhat.com"
# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
# gpg:                 aka "Michael S. Tsirkin <mst@redhat.com>" [full]
# Primary key fingerprint: 0270 606B 6F3C DF3D 0B17  0970 C350 3912 AFBE 8E67
#      Subkey fingerprint: 5D09 FD08 71C8 F85B 94CA  8A0D 281F 0DB8 D28D 5469

* remotes/mst/tags/for_upstream: (30 commits)
  Fixed assert in vhost_user_set_mem_table_postcopy
  vhost-user: only set slave channel for first vq
  acpi: cpuhp: document CPHP_GET_CPU_ID_CMD command
  libvhost-user: implement in-band notifications
  docs: vhost-user: add in-band kick/call messages
  libvhost-user: handle NOFD flag in call/kick/err better
  libvhost-user-glib: use g_main_context_get_thread_default()
  libvhost-user-glib: fix VugDev main fd cleanup
  libvhost-user: implement VHOST_USER_PROTOCOL_F_REPLY_ACK
  MAINTAINERS: add virtio-iommu related files
  hw/arm/virt: Add the virtio-iommu device tree mappings
  virtio-iommu-pci: Add virtio iommu pci support
  virtio-iommu: Support migration
  virtio-iommu: Implement fault reporting
  virtio-iommu: Implement translate
  virtio-iommu: Implement map/unmap
  virtio-iommu: Implement attach/detach command
  virtio-iommu: Decode the command payload
  virtio-iommu: Add skeleton
  virtio: gracefully handle invalid region caches
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 104 insertions, 18 deletions

diff --git a/docs/interop/vhost-user.rst b/docs/interop/vhost-user.rst
index 5f8b3a456b..401652397c 100644
--- a/docs/interop/vhost-user.rst
+++ b/docs/interop/vhost-user.rst
@@ -2,6 +2,7 @@
 Vhost-user Protocol
 ===================
 :Copyright: 2014 Virtual Open Systems Sarl.
+:Copyright: 2019 Intel Corporation
 :Licence: This work is licensed under the terms of the GNU GPL,
           version 2 or later. See the COPYING file in the top-level
           directory.
@@ -279,6 +280,9 @@ If *master* is unable to send the full message or receives a wrong
 reply it will close the connection. An optional reconnection mechanism
 can be implemented.
 
+If *slave* detects some error such as incompatible features, it may also
+close the connection. This should only happen in exceptional circumstances.
+
 Any protocol extensions are gated by protocol feature bits, which
 allows full backwards compatibility on both master and slave.  As
 older slaves don't support negotiating protocol features, a feature
@@ -315,7 +319,8 @@ it until ring is started, or after it has been stopped.
 
 Client must start ring upon receiving a kick (that is, detecting that
 file descriptor is readable) on the descriptor specified by
-``VHOST_USER_SET_VRING_KICK``, and stop ring upon receiving
+``VHOST_USER_SET_VRING_KICK`` or receiving the in-band message
+``VHOST_USER_VRING_KICK`` if negotiated, and stop ring upon receiving
 ``VHOST_USER_GET_VRING_BASE``.
 
 While processing the rings (whether they are enabled or not), client
@@ -767,25 +772,49 @@ When reconnecting:
 #. Resubmit inflight ``DescStatePacked`` entries in order of their
    counter value
 
+In-band notifications
+---------------------
+
+In some limited situations (e.g. for simulation) it is desirable to
+have the kick, call and error (if used) signals done via in-band
+messages instead of asynchronous eventfd notifications. This can be
+done by negotiating the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS``
+protocol feature.
+
+Note that due to the fact that too many messages on the sockets can
+cause the sending application(s) to block, it is not advised to use
+this feature unless absolutely necessary. It is also considered an
+error to negotiate this feature without also negotiating
+``VHOST_USER_PROTOCOL_F_SLAVE_REQ`` and ``VHOST_USER_PROTOCOL_F_REPLY_ACK``,
+the former is necessary for getting a message channel from the slave
+to the master, while the latter needs to be used with the in-band
+notification messages to block until they are processed, both to avoid
+blocking later and for proper processing (at least in the simulation
+use case.) As it has no other way of signalling this error, the slave
+should close the connection as a response to a
+``VHOST_USER_SET_PROTOCOL_FEATURES`` message that sets the in-band
+notifications feature flag without the other two.
+
 Protocol features
 -----------------
 
 .. code:: c
 
-  #define VHOST_USER_PROTOCOL_F_MQ             0
-  #define VHOST_USER_PROTOCOL_F_LOG_SHMFD      1
-  #define VHOST_USER_PROTOCOL_F_RARP           2
-  #define VHOST_USER_PROTOCOL_F_REPLY_ACK      3
-  #define VHOST_USER_PROTOCOL_F_MTU            4
-  #define VHOST_USER_PROTOCOL_F_SLAVE_REQ      5
-  #define VHOST_USER_PROTOCOL_F_CROSS_ENDIAN   6
-  #define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION 7
-  #define VHOST_USER_PROTOCOL_F_PAGEFAULT      8
-  #define VHOST_USER_PROTOCOL_F_CONFIG         9
-  #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD  10
-  #define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER  11
-  #define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD 12
-  #define VHOST_USER_PROTOCOL_F_RESET_DEVICE   13
+  #define VHOST_USER_PROTOCOL_F_MQ                    0
+  #define VHOST_USER_PROTOCOL_F_LOG_SHMFD             1
+  #define VHOST_USER_PROTOCOL_F_RARP                  2
+  #define VHOST_USER_PROTOCOL_F_REPLY_ACK             3
+  #define VHOST_USER_PROTOCOL_F_MTU                   4
+  #define VHOST_USER_PROTOCOL_F_SLAVE_REQ             5
+  #define VHOST_USER_PROTOCOL_F_CROSS_ENDIAN          6
+  #define VHOST_USER_PROTOCOL_F_CRYPTO_SESSION        7
+  #define VHOST_USER_PROTOCOL_F_PAGEFAULT             8
+  #define VHOST_USER_PROTOCOL_F_CONFIG                9
+  #define VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD        10
+  #define VHOST_USER_PROTOCOL_F_HOST_NOTIFIER        11
+  #define VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD       12
+  #define VHOST_USER_PROTOCOL_F_RESET_DEVICE         13
+  #define VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS 14
 
 Master message types
 --------------------
@@ -947,7 +976,12 @@ Master message types
   Bits (0-7) of the payload contain the vring index. Bit 8 is the
   invalid FD flag. This flag is set when there is no file descriptor
   in the ancillary data. This signals that polling should be used
-  instead of waiting for a kick.
+  instead of waiting for the kick. Note that if the protocol feature
+  ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` has been negotiated
+  this message isn't necessary as the ring is also started on the
+  ``VHOST_USER_VRING_KICK`` message, it may however still be used to
+  set an event file descriptor (which will be preferred over the
+  message) or to enable polling.
 
 ``VHOST_USER_SET_VRING_CALL``
   :id: 13
@@ -960,7 +994,12 @@ Master message types
   Bits (0-7) of the payload contain the vring index. Bit 8 is the
   invalid FD flag. This flag is set when there is no file descriptor
   in the ancillary data. This signals that polling will be used
-  instead of waiting for the call.
+  instead of waiting for the call. Note that if the protocol features
+  ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` and
+  ``VHOST_USER_PROTOCOL_F_SLAVE_REQ`` have been negotiated this message
+  isn't necessary as the ``VHOST_USER_SLAVE_VRING_CALL`` message can be
+  used, it may however still be used to set an event file descriptor
+  or to enable polling.
 
 ``VHOST_USER_SET_VRING_ERR``
   :id: 14
@@ -972,7 +1011,12 @@ Master message types
 
   Bits (0-7) of the payload contain the vring index. Bit 8 is the
   invalid FD flag. This flag is set when there is no file descriptor
-  in the ancillary data.
+  in the ancillary data. Note that if the protocol features
+  ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` and
+  ``VHOST_USER_PROTOCOL_F_SLAVE_REQ`` have been negotiated this message
+  isn't necessary as the ``VHOST_USER_SLAVE_VRING_ERR`` message can be
+  used, it may however still be used to set an event file descriptor
+  (which will be preferred over the message).
 
 ``VHOST_USER_GET_QUEUE_NUM``
   :id: 17
@@ -1205,6 +1249,20 @@ Master message types
   Only valid if the ``VHOST_USER_PROTOCOL_F_RESET_DEVICE`` protocol
   feature is set by the backend.
 
+``VHOST_USER_VRING_KICK``
+  :id: 35
+  :equivalent ioctl: N/A
+  :slave payload: vring state description
+  :master payload: N/A
+
+  When the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` protocol
+  feature has been successfully negotiated, this message may be
+  submitted by the master to indicate that a buffer was added to
+  the vring instead of signalling it using the vring's kick file
+  descriptor or having the slave rely on polling.
+
+  The state.num field is currently reserved and must be set to 0.
+
 Slave message types
 -------------------
 
@@ -1261,6 +1319,34 @@ Slave message types
   ``VHOST_USER_PROTOCOL_F_HOST_NOTIFIER`` protocol feature has been
   successfully negotiated.
 
+``VHOST_USER_SLAVE_VRING_CALL``
+  :id: 4
+  :equivalent ioctl: N/A
+  :slave payload: vring state description
+  :master payload: N/A
+
+  When the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` protocol
+  feature has been successfully negotiated, this message may be
+  submitted by the slave to indicate that a buffer was used from
+  the vring instead of signalling this using the vring's call file
+  descriptor or having the master relying on polling.
+
+  The state.num field is currently reserved and must be set to 0.
+
+``VHOST_USER_SLAVE_VRING_ERR``
+  :id: 5
+  :equivalent ioctl: N/A
+  :slave payload: vring state description
+  :master payload: N/A
+
+  When the ``VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS`` protocol
+  feature has been successfully negotiated, this message may be
+  submitted by the slave to indicate that an error occurred on the
+  specific vring, instead of signalling the error file descriptor
+  set by the master via ``VHOST_USER_SET_VRING_ERR``.
+
+  The state.num field is currently reserved and must be set to 0.
+
 .. _reply_ack:
 
 VHOST_USER_PROTOCOL_F_REPLY_ACK