Previously the spec did not say where in a message the FDs should be
sent. As I understand it, FDs transferred in ancillary data will
always be received along with the first byte of the data they were
sent with, so we should define which byte that is. Going by both
libvhost-user in QEMU and the rust-vmm crate, that byte is the first
byte of the message header. This is important to specify because it
would make back-end implementation significantly more complicated if
receiving file descriptors in the middle of a message had to be
handled.
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20251106192105.3456755-1-hi@alyssa.is>
A few doc comments show command line snippets. The snippets are
indented, which is legible enough. Actually formatting these with
Sphinx would fail with "Unexpected indentation", though. We don't so
far. Add suitable markup anyway.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20251103082354.3273027-9-armbru@redhat.com>
For legibility, wrap text paragraphs so every line is at most 70
characters long. Consistently separate sentences with two spaces.
Consistently separate member descriptions with a blank line.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20251103082354.3273027-7-armbru@redhat.com>
Remove the QAPI doc section heading syntax, use plain rST section
headings instead.
Tests and documentation are updated to match.
Interestingly, Plain rST headings work fine before this patch, except
for over- and underlining with '=', which the doc parser rejected as
invalid QAPI doc section heading in free-form comments.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250618165353.1980365-5-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Add more detail to commit message]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Thanks for your service!
Remove the old qapidoc and the option to enable the transmogrifier,
leaving the "transmogrifier" as the ONLY qapi doc generator. This in
effect also converts the QAPI test to use the new documentation
generator, too.
Update doc-good.txt output to match the new doc generator, which I
should've done exactly when we switched over to the transmogrifier, but,
uhh, oops!
Notes on the new format:
1. per-member IFCOND documentation is missing. Known issue.
2. Freeform documentation without a header is now copied through into
the output. This is a bug fix.
Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250618165353.1980365-4-jsnow@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Fixes: b61a4eb3f3 (docs/qapidoc: support header-less freeform sections)
[Tweak commit message to say it's a bug fix, add Fixes:]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This patch introduces the vfio-user protocol specification (formerly
known as VFIO-over-socket), which is designed to allow devices to be
emulated outside QEMU, in a separate process. vfio-user reuses the
existing VFIO defines, structs and concepts.
It has been earlier discussed as an RFC in:
"RFC: use VFIO over a UNIX domain socket to implement device offloading"
Signed-off-by: Thanos Makatos <thanos.makatos@nutanix.com>
Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250625193012.2316242-20-john.levon@nutanix.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>
The "QEMU QMP Reference Manual" and the "QEMU Storage Daemon QMP
Reference Manual" start with a table of contents that looks like this:
Contents
* Title of the manual
* Title of first first-level section
* Title of its first second-level section
* Title of its second second-level section
...
* Title of second first-level section
...
The first level is useless. Drop it.
While there, delete the option that limits the TOC to depth 3. Its
actual depth was 3 before the patch, and is now 2.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20250404121413.1743790-5-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
The "QEMU Guest Agent Protocol Reference" starts with the following
table of contents:
Contents
* QEMU Guest Agent Protocol Reference
* QEMU guest agent protocol commands and structs
This is useless. Delete the entire TOC.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20250404121413.1743790-4-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
We are not enabling the transmogrifier for QSD or QGA yet because we
don't (yet) have a way to create separate indices, and all of the
definitions will bleed together, which isn't so nice.
For now, QMP is better than nothing at all!
Signed-off-by: John Snow <jsnow@redhat.com>
Message-ID: <20250311034303.75779-62-jsnow@redhat.com>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Some editorial tweaks to the doc:
Add a ref link to Memory region description and Multiple Memory region
description.
Descriptions about memory regions are merged into one line.
Add extra type(64 bits) to Log description structure fields
Fix ’s to 's
Signed-off-by: luzhixing12345 <luzhixing12345@gmail.com>
Message-Id: <20240911060400.3472-1-luzhixing12345@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add in the missing space in the section header.
Fixes: 1084159b31 ("qapi: deprecate drive-backup", v6.2.0)
Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Misc HW patch queue
- Restrict probe_access*() functions to TCG (Phil)
- Extract do_invalidate_device_tlb from vtd_process_device_iotlb_desc (Clément)
- Fixes in Loongson IPI model (Bibo & Phil)
- Make docs/interop/firmware.json compatible with qapi-gen.py script (Thomas)
- Correct MPC I2C MMIO region size (Zoltan)
- Remove useless cast in Loongson3 Virt machine (Yao)
- Various uses of range overlap API (Yao)
- Use ERRP_GUARD macro in nubus_virtio_mmio_realize (Zhao)
- Use DMA memory API in Goldfish UART model (Phil)
- Expose fifo8_pop_buf and introduce fifo8_drop (Phil)
- MAINTAINERS updates (Zhao, Phil)
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# gpg: Signature made Wed 24 Jul 2024 06:36:47 AM AEST
# gpg: using RSA key FAABE75E12917221DCFD6BB2E3E32C2CDEADC0DE
# gpg: Good signature from "Philippe Mathieu-Daudé (F4BUG) <f4bug@amsat.org>" [full]
* tag 'hw-misc-20240723' of https://github.com/philmd/qemu: (28 commits)
MAINTAINERS: Add myself as a reviewer of machine core
MAINTAINERS: Cover guest-agent in QAPI schema
util/fifo8: Introduce fifo8_drop()
util/fifo8: Expose fifo8_pop_buf()
util/fifo8: Rename fifo8_pop_buf() -> fifo8_pop_bufptr()
util/fifo8: Rename fifo8_peek_buf() -> fifo8_peek_bufptr()
util/fifo8: Use fifo8_reset() in fifo8_create()
util/fifo8: Fix style
chardev/char-fe: Document returned value on error
hw/char/goldfish: Use DMA memory API
hw/nubus/virtio-mmio: Fix missing ERRP_GUARD() in realize handler
dump: make range overlap check more readable
crypto/block-luks: make range overlap check more readable
system/memory_mapping: make range overlap check more readable
sparc/ldst_helper: make range overlap check more readable
cxl/mailbox: make range overlap check more readable
util/range: Make ranges_overlap() return bool
hw/mips/loongson3_virt: remove useless type cast
hw/i2c/mpc_i2c: Fix mmio region size
docs/interop/firmware.json: convert "Example" section
...
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Since commit 3c5f6114d9 ("qapi: remove "Example" doc section")
the "Example" section is not valid anymore.
It has been replaced by the "qmp-example" directive.
This was not detected earlier as firmware.json was not validated.
As this validation is about to be added, adapt firmware.json.
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Message-ID: <20240719-qapi-firmware-json-v6-3-c2e3de390b58@linutronix.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Only a small subset of all architectures supported by qemu make use of
firmware files. Introduce and use a new enum to represent this.
This also removes the dependency to machine.json from the global qapi
definitions.
Claim "Since: 3.0" for the new enum, because that's correct for most of
its members, and the members are what matters in the interface.
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240719-qapi-firmware-json-v6-2-c2e3de390b58@linutronix.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Only a small subset of all blockdev drivers make sense for firmware
images. Introduce and use a new enum to represent this.
This also reduces the dependency on firmware.json from the global qapi
definitions.
Claim "Since: 3.0" for the new enum, because that's correct for its
members, and the members are what matters in the interface.
Suggested-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240719-qapi-firmware-json-v6-1-c2e3de390b58@linutronix.de>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
While the `allow-rpcs` option is documented in the CLI options
section, it was missing in the section about the configuration file
syntax.
And while it's mentioned that "the list of keys follows the command line
options", having `block-rpcs` there but not `allow-rpcs` seems like
being a potential source of confusion; and as it's cheap to add let's
just do so.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Message-ID: <20240718140407.444160-1-t.lamprecht@proxmox.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
It is confusing having many different pieces of code enabling and
disabling commands, and it is not clear that they all have the same
semantics, especially wrt prioritization of the block/allow lists.
The code attempted to prevent the user from setting both the block
and allow lists concurrently, however, the logic was flawed as it
checked settings in the configuration file separately from the
command line arguments. Thus it was possible to set a block list
in the config file and an allow list via a command line argument.
The --dump-conf option also creates a configuration file with both
keys present, even if unset, which means it is creating a config
that cannot actually be loaded again.
Centralizing the code in a single method "ga_apply_command_filters"
will provide a strong guarantee of consistency and clarify the
intended behaviour. With this there is no compelling technical
reason to prevent concurrent setting of both the allow and block
lists, so this flawed restriction is removed.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Message-ID: <20240712132459.3974109-23-berrange@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Allowing the user to set the QGA_CONF environment variable to change
the default configuration file path is very unusual practice, made
more obscure since this ability is not documented.
This introduces the more normal '-c PATH' / '--config=PATH' command
line argument approach. This requires that we parse the comamnd line
twice, since we want the command line arguments to take priority over
the configuration file settings in general.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Message-ID: <20240712132459.3974109-22-berrange@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Shared objects lack spoofing protection.
For VHOST_USER_BACKEND_SHARED_OBJECT_REMOVE messages
received by the vhost-user interface, any backend was
allowed to remove entries from the shared table just
by knowing the UUID. Only the owner of the entry
shall be allowed to removed their resources
from the table.
To fix that, add a check for all
*SHARED_OBJECT_REMOVE messages received.
A vhost device can only remove TYPE_VHOST_DEV
entries that are owned by them, otherwise skip
the removal, and inform the device that the entry
has not been removed in the answer.
Signed-off-by: Albert Esteve <aesteve@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20240219143423.272012-2-aesteve@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
docs/interop/bitmaps.rst uses references like
`qemu-qmp-ref <qemu-qmp-ref.html>`_
`query-block <qemu-qmp-ref.html#index-query_002dblock>`_
to refer to and into docs/interop/qemu-qmp-ref.rst.
Clean up the former: use :doc:`qemu-qmp-ref`.
I don't know how to clean up the latter.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240120095327.666239-5-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Deletion of docs/interop/qmp-intro.txt left two dangling references
behind. Replace them by references to docs/interop/qmp-spec.rst.
Fixes: 0ec4468f23 (docs/interop: Delete qmp-intro.txt)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240120095327.666239-3-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
For vhost-user devices, qemu can migrate the virtio state, but not the
back-end's internal state. To do so, we need to be able to transfer
this internal state between front-end (qemu) and back-end.
At this point, this new feature is added for the purpose of virtio-fs
migration. Because virtiofsd's internal state will not be too large, we
believe it is best to transfer it as a single binary blob after the
streaming phase.
These are the additions to the protocol:
- New vhost-user protocol feature VHOST_USER_PROTOCOL_F_DEVICE_STATE
- SET_DEVICE_STATE_FD function: Front-end and back-end negotiate a file
descriptor over which to transfer the state.
- CHECK_DEVICE_STATE: After the state has been transferred through the
file descriptor, the front-end invokes this function to verify
success. There is no in-band way (through the file descriptor) to
indicate failure, so we need to check explicitly.
Once the transfer FD has been established via SET_DEVICE_STATE_FD
(which includes establishing the direction of transfer and migration
phase), the sending side writes its data into it, and the reading side
reads it until it sees an EOF. Then, the front-end will check for
success via CHECK_DEVICE_STATE, which on the destination side includes
checking for integrity (i.e. errors during deserialization).
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20231016134243.68248-5-hreitz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
In vDPA, GET_VRING_BASE does not stop the queried vring, which is why
SUSPEND was introduced so that the returned index would be stable. In
vhost-user, it does stop the vring, so under the same reasoning, it can
get away without SUSPEND.
Still, we do want to clarify that if the device is completely stopped,
i.e. all vrings are stopped, the back-end should cease to modify any
state relating to the guest. Do this by calling it "suspended".
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20231016134243.68248-4-hreitz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Currently, the vhost-user documentation says that rings are to be
initialized in a disabled state when VHOST_USER_F_PROTOCOL_FEATURES is
negotiated. However, by the time of feature negotiation, all rings have
already been initialized, so it is not entirely clear what this means.
At least the vhost-user-backend Rust crate's implementation interpreted
it to mean that whenever this feature is negotiated, all rings are to
put into a disabled state, which means that every SET_FEATURES call
would disable all rings, effectively halting the device. This is
problematic because the VHOST_F_LOG_ALL feature is also set or cleared
this way, which happens during migration. Doing so should not halt the
device.
Other implementations have interpreted this to mean that the device is
to be initialized with all rings disabled, and a subsequent SET_FEATURES
call that does not set VHOST_USER_F_PROTOCOL_FEATURES will enable all of
them. Here, SET_FEATURES will never disable any ring.
This interpretation does not suffer the problem of unintentionally
halting the device whenever features are set or cleared, so it seems
better and more reasonable.
We can clarify this in the documentation by making it explicit that the
enabled/disabled state is tracked even while the vring is stopped.
Every vring is initialized in a disabled state, and SET_FEATURES without
VHOST_USER_F_PROTOCOL_FEATURES simply becomes one way to enable all
vrings.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20231016134243.68248-3-hreitz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
GET_VRING_BASE does not mention that it stops the respective ring. Fix
that.
Furthermore, it is not fully clear what the "base offset" these
commands' documentation refers to is; an offset could be many things.
Be more precise and verbose about it, especially given that these
commands use different payload structures depending on whether the vring
is split or packed.
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20231016134243.68248-2-hreitz@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The VHOST_USER_PROTOCOL_F_XEN_MMAP feature bit was defined in
f21e95ee97, which has been part of qemu's 8.1.0 release. However, it
seems it was never added to qemu's code, but it is well possible that it
is already used by different front-ends outside of qemu (i.e., Xen).
VHOST_USER_PROTOCOL_F_SHARED_OBJECT in contrast was added to qemu's code
in 1609476662, but never defined in the vhost-user specification. As a
consequence, both bits were defined to be 17, which cannot work.
Regardless of whether actual code or the specification should take
precedence, F_XEN_MMAP is already part of a qemu release, while
F_SHARED_OBJECT is not. Therefore, bump the latter to take number 18
instead of 17, and add this to the specification.
Take the opportunity to add at least a little note on the
VhostUserShared structure to the specification. This structure is
referenced by the new commands introduced in 1609476662, but was not
defined.
Fixes: 1609476662
("vhost-user: add shared_object msg")
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>
Message-Id: <20231016083201.23736-1-hreitz@redhat.com>
Reviewed-by: Emmanouil Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Allow a client to request a subset of negotiated meta contexts. For
example, a client may ask to use a single connection to learn about
both block status and dirty bitmaps, but where the dirty bitmap
queries only need to be performed on a subset of the disk; forcing the
server to compute that information on block status queries in the rest
of the disk is wasted effort (both at the server, and on the amount of
traffic sent over the wire to be parsed and ignored by the client).
Qemu as an NBD client never requests to use more than one meta
context, so it has no need to use block status payloads. Testing this
instead requires support from libnbd, which CAN access multiple meta
contexts in parallel from a single NBD connection; an interop test
submitted to the libnbd project at the same time as this patch
demonstrates the feature working, as well as testing some corner cases
(for example, when the payload length is longer than the export
length), although other corner cases (like passing the same id
duplicated) requires a protocol fuzzer because libnbd is not wired up
to break the protocol that badly.
This also includes tweaks to 'qemu-nbd --list' to show when a server
is advertising the capability, and to the testsuite to reflect the
addition to that output.
Of note: qemu will always advertise the new feature bit during
NBD_OPT_INFO if extended headers have alreay been negotiated
(regardless of whether any NBD_OPT_SET_META_CONTEXT negotiation has
occurred); but for NBD_OPT_GO, qemu only advertises the feature if
block status is also enabled (that is, if the client does not
negotiate any contexts, then NBD_CMD_BLOCK_STATUS cannot be used, so
the feature is not advertised).
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-ID: <20230925192229.3186470-26-eblake@redhat.com>
[eblake: fix logic to reject unnegotiated contexts]
Signed-off-by: Eric Blake <eblake@redhat.com>
Time to start supporting clients that request extended headers. Now
we can finally reach the code added across several previous patches.
Even though the NBD spec has been altered to allow us to accept
NBD_CMD_READ larger than the max payload size (provided our response
is a hole or broken up over more than one data chunk), we are not
planning to take advantage of that, and continue to cap NBD_CMD_READ
to 32M regardless of header size.
For NBD_CMD_WRITE_ZEROES and NBD_CMD_TRIM, the block layer already
supports 64-bit operations without any effort on our part. For
NBD_CMD_BLOCK_STATUS, the client's length is a hint, and the previous
patch took care of implementing the required
NBD_REPLY_TYPE_BLOCK_STATUS_EXT.
We do not yet support clients that want to do request payload
filtering of NBD_CMD_BLOCK_STATUS; that will be added in later
patches, but is not essential for qemu as a client since qemu only
requests the single context base:allocation.
Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-ID: <20230925192229.3186470-19-eblake@redhat.com>
Add three new vhost-user protocol
`VHOST_USER_BACKEND_SHARED_OBJECT_* messages`.
These new messages are sent from vhost-user
back-ends to interact with the virtio-dmabuf
table in order to add or remove themselves as
virtio exporters, or lookup for virtio dma-buf
shared objects.
The action taken in the front-end depends
on the type stored in the virtio shared
object hash table.
When the table holds a pointer to a vhost
backend for a given UUID, the front-end sends
a VHOST_USER_GET_SHARED_OBJECT to the
backend holding the shared object.
The messages can only be sent after successfully
negotiating a new VHOST_USER_PROTOCOL_F_SHARED_OBJECT
vhost-user protocol feature bit.
Finally, refactor code to send response message so
that all common parts both for the common REPLY_ACK
case, and other data responses, can call it and
avoid code repetition.
Signed-off-by: Albert Esteve <aesteve@redhat.com>
Message-Id: <20231002065706.94707-4-aesteve@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
