The specification for VHOST_USER_ADD/REM_MEM_REG messages is unclear
in several points, which has led to clients having incompatible
implementations. This changes the specification to be more explicit
about them:
* VHOST_USER_ADD_MEM_REG is not specified as receiving a file
descriptor, though it obviously does need to do so. All
implementations agree on this one, fix the specification.
* VHOST_USER_REM_MEM_REG is not specified as receiving a file
descriptor either, and it also has no reason to do so. rust-vmm does
not send file descriptors for removing a memory region (in agreement
with the specification), libvhost-user and QEMU do (which is a bug),
though libvhost-user doesn't actually make any use of it.
Change the specification so that for compatibility QEMU's behaviour
becomes legal, even if discouraged, but rust-vmm's behaviour becomes
the explicitly recommended mode of operation.
* VHOST_USER_ADD_MEM_REG doesn't have a documented return value, which
is the desired behaviour in the non-postcopy case. It also implemented
like this in QEMU and rust-vmm, though libvhost-user is buggy and
sometimes sends an unexpected reply. This will be fixed in a separate
patch.
However, in postcopy mode it does reply like VHOST_USER_SET_MEM_TABLE.
This behaviour is shared between libvhost-user and QEMU; rust-vmm
doesn't implement postcopy mode yet. Mention it explicitly in the
spec.
* The specification doesn't mention how VHOST_USER_REM_MEM_REG
identifies the memory region to be removed. Change it to describe the
existing behaviour of libvhost-user (guest address, user address and
size must match).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220407133657.155281-2-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Make the language about feature negotiation explicitly clear about the
handling of the VHOST_USER_F_PROTOCOL_FEATURES feature bit. Try and
avoid the sort of bug introduced in vhost.rs REPLY_ACK processing:
https://github.com/rust-vmm/vhost/pull/24
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Cc: Jiang Liu <gerry@linux.alibaba.com>
Message-Id: <20210226111619.21178-1-alex.bennee@linaro.org>
Message-Id: <20220321153037.3622127-8-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This matches the nomenclature that is generally used. Also commonly used
is client/server, but it is not as clear because sometimes the front-end
exposes a passive (server) socket that the back-end connects to.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210226143413.188046-4-pbonzini@redhat.com>
Message-Id: <20220321153037.3622127-7-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This section is using the word "back-end" to refer to the
"slave's back-end", and talking about the "client" for
what the rest of the document calls the "slave".
Rework it to free the use of the term "back-end", which in
the next patch will replace "slave".
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210226143413.188046-3-pbonzini@redhat.com>
Message-Id: <20220321153037.3622127-6-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
It is not necessary to mention which side is sending/receiving
each payload; it is more interesting to say which is the request
and which is the reply. This also matches what vhost-user-gpu.rst
already does.
While at it, ensure that all messages list both the request and
the reply payload.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210226143413.188046-2-pbonzini@redhat.com>
Message-Id: <20220321153037.3622127-5-alex.bennee@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
According to the NBD spec, a server that advertises
NBD_FLAG_CAN_MULTI_CONN promises that multiple client connections will
not see any cache inconsistencies: when properly separated by a single
flush, actions performed by one client will be visible to another
client, regardless of which client did the flush.
We always satisfy these conditions in qemu - even when we support
multiple clients, ALL clients go through a single point of reference
into the block layer, with no local caching. The effect of one client
is instantly visible to the next client. Even if our backend were a
network device, we argue that any multi-path caching effects that
would cause inconsistencies in back-to-back actions not seeing the
effect of previous actions would be a bug in that backend, and not the
fault of caching in qemu. As such, it is safe to unconditionally
advertise CAN_MULTI_CONN for any qemu NBD server situation that
supports parallel clients.
Note, however, that we don't want to advertise CAN_MULTI_CONN when we
know that a second client cannot connect (for historical reasons,
qemu-nbd defaults to a single connection while nbd-server-add and QMP
commands default to unlimited connections; but we already have
existing means to let either style of NBD server creation alter those
defaults). This is visible by no longer advertising MULTI_CONN for
'qemu-nbd -r' without -e, as in the iotest nbd-qemu-allocation.
The harder part of this patch is setting up an iotest to demonstrate
behavior of multiple NBD clients to a single server. It might be
possible with parallel qemu-io processes, but I found it easier to do
in python with the help of libnbd, and help from Nir and Vladimir in
writing the test.
Signed-off-by: Eric Blake <eblake@redhat.com>
Suggested-by: Nir Soffer <nsoffer@redhat.com>
Suggested-by: Vladimir Sementsov-Ogievskiy <v.sementsov-og@mail.ru>
Message-Id: <20220512004924.417153-3-eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
The specification for VHOST_USER_ADD/REM_MEM_REG messages is unclear
in several points, which has led to clients having incompatible
implementations. This changes the specification to be more explicit
about them:
* VHOST_USER_ADD_MEM_REG is not specified as receiving a file
descriptor, though it obviously does need to do so. All
implementations agree on this one, fix the specification.
* VHOST_USER_REM_MEM_REG is not specified as receiving a file
descriptor either, and it also has no reason to do so. rust-vmm does
not send file descriptors for removing a memory region (in agreement
with the specification), libvhost-user and QEMU do (which is a bug),
though libvhost-user doesn't actually make any use of it.
Change the specification so that for compatibility QEMU's behaviour
becomes legal, even if discouraged, but rust-vmm's behaviour becomes
the explicitly recommended mode of operation.
* VHOST_USER_ADD_MEM_REG doesn't have a documented return value, which
is the desired behaviour in the non-postcopy case. It also implemented
like this in QEMU and rust-vmm, though libvhost-user is buggy and
sometimes sends an unexpected reply. This will be fixed in a separate
patch.
However, in postcopy mode it does reply like VHOST_USER_SET_MEM_TABLE.
This behaviour is shared between libvhost-user and QEMU; rust-vmm
doesn't implement postcopy mode yet. Mention it explicitly in the
spec.
* The specification doesn't mention how VHOST_USER_REM_MEM_REG
identifies the memory region to be removed. Change it to describe the
existing behaviour of libvhost-user (guest address, user address and
size must match).
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20220407133657.155281-2-kwolf@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add a section explaining how vhost-user is supported on platforms
other than Linux.
Signed-off-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220304100854.14829-5-slp@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The current firmware descriptor schema for flash requires that both the
executable to NVRAM template paths be provided. This is fine for the
most common usage of EDK2 builds in virtualization where the separate
_CODE and _VARS files are provided.
With confidential computing technology like AMD SEV, persistent storage
of variables may be completely disabled because the firmware requires a
known clean state on every cold boot. There is no way to express this
in the firmware descriptor today.
Even with regular EDK2 builds it is possible to create a firmware that
has both executable code and variable persistence in a single file. This
hasn't been commonly used, since it would mean every guest bootup would
need to clone the full firmware file, leading to redundant duplicate
storage of the code portion. In some scenarios this may not matter and
might even be beneficial. For example if a public cloud allows users to
bring their own firmware, such that the user can pre-enroll their own
secure boot keys, you're going to have this copied on disk for each
tenant already. At this point the it can be simpler to just deal with
a single file rather than split builds. The firmware descriptor ought
to be able to express this combined firmware model too.
This all points towards expanding the schema for flash with a 'mode'
concept:
- "split" - the current implicit behaviour with separate files
for code and variables.
- "combined" - the alternate behaviour where a single file contains
both code and variables.
- "stateless" - the confidential computing use case where storage
of variables is completely disable, leaving only the code.
Reviewed-by: Kashyap Chamarthy <kchamart@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The virtio-balloon-stats documentation might be useful for people that
are implementing software that talks to QEMU via QMP, so this should
reside in the docs/interop/ directory. While we're at it, also convert
the file to restructured text and mention it in the MAINTAINERS file.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20220105115245.420945-1-thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Wire up the dbus-display documentation. The interface and feature is
implemented next.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Use the source XML document as single reference, importing its
documentation via the dbus-doc directive.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Modern way is using blockdev-add + blockdev-backup, which provides a
lot more control on how target is opened.
As example of drive-backup problems consider the following:
User of drive-backup expects that target will be opened in the same
cache and aio mode as source. Corresponding logic is in
drive_backup_prepare(), where we take bs->open_flags of source.
It works rather bad if source was added by blockdev-add. Assume source
is qcow2 image. On blockdev-add we should specify aio and cache options
for file child of qcow2 node. What happens next:
drive_backup_prepare() looks at bs->open_flags of qcow2 source node.
But there no BDRV_O_NOCAHE neither BDRV_O_NATIVE_AIO: BDRV_O_NOCAHE is
places in bs->file->bs->open_flags, and BDRV_O_NATIVE_AIO is nowhere,
as file-posix parse options and simply set s->use_linux_aio.
The documentation is updated in a minimal way, so that drive-backup is
noted only as a deprecated command, and blockdev-backup used in most of
places.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
We are going to deprecate drive-backup, so use modern interface here.
In examples where target image creation is shown, show blockdev-add as
well. If target creation omitted, omit blockdev-add as well.
Reviewed-by: Kashyap Chamarthy <kchamart@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
The single backtick markup in ReST is the "default role". Currently,
Sphinx's default role is called "content". Sphinx suggests you can use
the "Any" role instead to turn any single-backtick enclosed item into a
cross-reference.
This is useful for things like autodoc for Python docstrings, where it's
often nicer to reference other types with `foo` instead of the more
laborious :py:meth:`foo`. It's also useful in multi-domain cases to
easily reference definitions from other Sphinx domains, such as
referencing C code definitions from outside of kerneldoc comments.
Before we do that, though, we'll need to turn all existing usages of the
"content" role to inline verbatim markup wherever it does not correctly
resolve into a cross-refernece by using double backticks instead.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Alexander Bulekov <alxndr@bu.edu>
Message-Id: <20211004215238.1523082-2-jsnow@redhat.com>
Use a standard heading format for the index.rst file in a directory.
Using overlines makes it clear that individual documents can use e.g.
=== for chapter titles and --- for section titles, as suggested in the
Linux kernel guidelines[1]. They could do it anyway, because documents
included in a toctree are parsed separately and therefore are not tied
to the same conventions for headings. However, keeping some consistency is
useful since sometimes files are included from multiple places.
[1] https://www.kernel.org/doc/html/latest/doc-guide/sphinx.html
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Most of docs/barrier.txt is describing the protocol implemented
by the input-barrier device. Move this into the interop
section of the manual, and rstify it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-id: 20210727204112.12579-2-peter.maydell@linaro.org
In rST markup, single backticks `like this` represent "interpreted
text", which can be handled as a bunch of different things if tagged
with a specific "role":
https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#interpreted-text
(the most common one for us is "reference to a URL, which gets
hyperlinked").
The default "role" if none is specified is "title_reference",
intended for references to book or article titles, and it renders
into the HTML as <cite>...</cite> (usually comes out as italics).
This commit fixes various places in the manual which were
using single backticks when double backticks (for literal text)
were intended, and covers those files where only one or two
instances of these errors were made.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Our built HTML documentation now has a standard footer which
gives the license for QEMU (and its documentation as a whole).
In almost all pages, we either don't bother to state the
copyright/license for the individual rST sources, or we put
it in an rST comment. There are just three pages which render
copyright or license information into the user-visible HTML.
Quoting a specific (different) license for an individual HTML
page within the manual is confusing. Downgrade the license
and copyright info to a comment within the rST source, bringing
these pages in line with the rest of our documents.
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Message-id: 20210722192016.24915-3-peter.maydell@linaro.org
Since commits 13f934e79f and 3a50c8f306, our HTML docs include a
footer to all pages stating the license and version. We can
therefore delete the TODO comments suggesting we should do that from
our .rst files.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20210722192016.24915-2-peter.maydell@linaro.org
While we do mention some of this stuff in the various daemons and
manuals the subtleties of the socket and memory sharing are sometimes
missed. This document attempts to give some background on vhost-user
daemons in general terms.
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20210720232703.10650-4-alex.bennee@linaro.org>
Since the top-level subsections aren't self-contained manuals
any more, the "Contents:" lines at the top of each of their
index pages look a bit odd; remove them.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20210705095547.15790-4-peter.maydell@linaro.org
We merged our previous multiple-manual setup into a single Sphinx
manual, but we left some text in the various index.rst lines that
still calls the top level subsections separate 'manuals'. Update
them to talk about "this section of the manual" instead, and remove
now-obsolete comments about how the index.rst files are the "top
level page for the 'foo' manual".
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20210705095547.15790-3-peter.maydell@linaro.org
In downstream, we want to use a different name for the QEMU binary,
and some people might also use the docs for non-x86 binaries, that's
why we already created the |qemu_system| placeholder in the past.
Use it now in the live-block-operations doc, too.
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210607172311.915385-1-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Create an enum definition, '@amd-sev-es', for SEV-ES and add documention
for the new enum. Add an example that shows some of the requirements for
SEV-ES, including not having SMM support and the requirement for an
X64-only build.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Connor Kuehl <ckuehl@redhat.com>
Message-Id: <b941a7ee105dfeb67607cf2d24dafcb82658b212.1619208498.git.thomas.lendacky@amd.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The QAPI reference docs for the guest agent, storage daemon and QMP are
all rather long and hard to navigate unless you already know the name of
the command and can do full text search for it.
A table of contents in each doc will help people locate stuff much more
easily.
Reviewed-by: Connor Kuehl <ckuehl@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The default "alabaster" sphinx theme has a couple shortcomings:
- the navbar moves along the page
- the search bar is not always at the same place
- it lacks some contrast and colours
The "rtd" theme from readthedocs.org is a popular third party theme used
notably by the kernel, with a custom style sheet. I like it better,
perhaps others do too. It also simplifies the "Edit on Gitlab" links.
Tweak a bit the custom theme to match qemu.org style, use the
QEMU logo, and favicon etc.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Message-Id: <20210323115328.4146052-1-marcandre.lureau@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Now that we merged into one doc, it makes the nav looks nicer.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20210323074704.4078381-1-marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Actually L1 table entry offset is in 512 bytes sectors. Fix the spec.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20210224104707.88430-3-vsementsov@virtuozzo.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This has the following visible changes:
- GBM is required only for OpenGL dma-buf.
- X11 is explicitly required by gtk-egl.
- EGL is now mandatory for the OpenGL displays.
The last one needs some detailed description. Before this change,
EGL was tested only for OpenGL dma-buf with the check of
EGL_MESA_image_dma_buf_export. However, all of the OpenGL
displays depend on EGL and EGL_MESA_image_dma_buf_export is always
defined by epoxy's EGL interface.
Therefore, it makes more sense to always check the presence of EGL
and say the OpenGL displays are available along with OpenGL dma-buf
if it is present.
Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Message-Id: <20210223060307.87736-1-akihiko.odaki@gmail.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
The preferred syntax is to use "foo=on|off", rather than a bare
"+foo" or "-foo"
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210216191027.595031-10-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The preferred syntax is to use "foo=on|off", rather than a bare
"foo" or "nofoo".
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20210216191027.595031-8-berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Original specification says that l1 table size if 64 * l1_size, which
is obviously wrong. The size of the l1 entry is 64 _bits_, not bytes.
Thus 64 is to be replaces with 8 as specification says about bytes.
There is also minor tweak, field name is renamed from l1 to l1_table,
which matches with the later text.
Signed-off-by: Denis V. Lunev <den@openvz.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20210128171313.2210947-1-den@openvz.org
CC: Stefan Hajnoczi <stefanha@redhat.com>
CC: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
[Replace the original commit message "docs: fix mistake in dirty bitmap
feature description" as suggested by Eric Blake.
--Stefan]
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210127144734.2367693-1-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
When we first converted our documentation to Sphinx, we split it into
multiple manuals (system, interop, tools, etc), which are all built
separately. The primary driver for this was wanting to be able to
avoid shipping the 'devel' manual to end-users. However, this is
working against the grain of the way Sphinx wants to be used and
causes some annoyances:
* Cross-references between documents become much harder or
possibly impossible
* There is no single index to the whole documentation
* Within one manual there's no links or table-of-contents info
that lets you easily navigate to the others
* The devel manual doesn't get published on the QEMU website
(it would be nice to able to refer to it there)
Merely hiding our developer documentation from end users seems like
it's not enough benefit for these costs. Combine all the
documentation into a single manual (the same way that the readthedocs
site builds it) and install the whole thing. The previous manual
divisions remain as the new top level sections in the manual.
* The per-manual conf.py files are no longer needed
* The man_pages[] specifications previously in each per-manual
conf.py move to the top level conf.py
* docs/meson.build logic is simplified as we now only need to run
Sphinx once for the HTML and then once for the manpages5B
* The old index.html.in that produced the top-level page with
links to each manual is no longer needed
Unfortunately this means that we now have to build the HTML
documentation into docs/manual in the build tree rather than directly
into docs/; otherwise it is too awkward to ensure we install only the
built manual and not also the dependency info, stamp file, etc. The
manual still ends up in the same place in the final installed
directory, but anybody who was consulting documentation from within
the build tree will have to adjust where they're looking.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-id: 20210115154449.4801-1-peter.maydell@linaro.org
Although individual qemu-storage-daemon QMP commands are identical to
QEMU QMP commands, qemu-storage-daemon only supports a subset of QEMU's
QMP commands. Generate a manual page of just the commands supported by
qemu-storage-daemon so that users know exactly what is available in
qemu-storage-daemon.
Add an h1 heading in storage-daemon/qapi/qapi-schema.json so that
block-core.json is at the h2 heading level.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201209103802.350848-2-stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Fix also a similar typo in a code comment.
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Message-Id: <20201117193448.393472-1-sw@weilnetz.de>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
QEMU currently truncates the mmap_offset field when sending
VHOST_USER_ADD_MEM_REG and VHOST_USER_REM_MEM_REG messages. The struct
layout looks like this:
typedef struct VhostUserMemoryRegion {
uint64_t guest_phys_addr;
uint64_t memory_size;
uint64_t userspace_addr;
uint64_t mmap_offset;
} VhostUserMemoryRegion;
typedef struct VhostUserMemRegMsg {
uint32_t padding;
/* WARNING: there is a 32-bit hole here! */
VhostUserMemoryRegion region;
} VhostUserMemRegMsg;
The payload size is calculated as follows when sending the message in
hw/virtio/vhost-user.c:
msg->hdr.size = sizeof(msg->payload.mem_reg.padding) +
sizeof(VhostUserMemoryRegion);
This calculation produces an incorrect result of only 36 bytes.
sizeof(VhostUserMemRegMsg) is actually 40 bytes.
The consequence of this is that the final field, mmap_offset, is
truncated. This breaks x86_64 TCG guests on s390 hosts. Other guest/host
combinations may get lucky if either of the following holds:
1. The guest memory layout does not need mmap_offset != 0.
2. The host is little-endian and mmap_offset <= 0xffffffff so the
truncation has no effect.
Fix this by extending the existing 32-bit padding field to 64-bit. Now
the padding reflects the actual compiler padding. This can be verified
using pahole(1).
Also document the layout properly in the vhost-user specification. The
vhost-user spec did not document the exact layout. It would be
impossible to implement the spec without looking at the QEMU source
code.
Existing vhost-user frontends and device backends continue to work after
this fix has been applied. The only change in the wire protocol is that
QEMU now sets hdr.size to 40 instead of 36. If a vhost-user
implementation has a hardcoded size check for 36 bytes, then it will
fail with new QEMUs. Both QEMU and DPDK/SPDK don't check the exact
payload size, so they continue to work.
Fixes: f1aeb14b08 ("Transmit vhost-user memory regions individually")
Cc: Raphael Norwitz <raphael.norwitz@nutanix.com>
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20201109174355.1069147-1-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Fixes: f1aeb14b08 ("Transmit vhost-user memory regions individually")
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Add a link to the top of the sidebar in every docs page that takes the
user back to the source code in gitlab.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20201102130926.161183-5-berrange@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
'qemu-img map' provides a way to determine which extents of an image
come from the top layer vs. inherited from a backing chain. This is
useful information worth exposing over NBD. There is a proposal to
add a QMP command block-dirty-bitmap-populate which can create a dirty
bitmap that reflects allocation information, at which point the
qemu:dirty-bitmap:NAME metadata context can expose that information
via the creation of a temporary bitmap, but we can shorten the effort
by adding a new qemu:allocation-depth metadata context that does the
same thing without an intermediate bitmap (this patch does not
eliminate the need for that proposal, as it will have other uses as
well).
While documenting things, remember that although the NBD protocol has
NBD_OPT_SET_META_CONTEXT, the rest of its documentation refers to
'metadata context', which is a more apt description of what is
actually being used by NBD_CMD_BLOCK_STATUS: the user is requesting
metadata by passing one or more context names. So I also touched up
some existing wording to prefer the term 'metadata context' where it
makes sense.
Note that this patch does not actually enable any way to request a
server to enable this context; that will come in the next patch.
Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20201027050556.269064-10-eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
This patch introduces the icount field for saving within the snapshot.
It is required for navigation between the snapshots in record/replay mode.
Signed-off-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Acked-by: Kevin Wolf <kwolf@redhat.com>
--
v7 changes:
- also fix the test which checks qcow2 snapshot extra data
Message-Id: <160174518284.12451.2301137308458777398.stgit@pasha-ThinkPad-X280>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Convert qemu-qmp-ref to rST format. This includes dropping
the plain-text, pdf and info format outputs for this document;
as with all our other Sphinx-based documentation, we provide
HTML and manpage only.
The qemu-qmp-ref.rst is somewhat more stripped down than
the .texi was, because we do not (currently) attempt to
generate indexes for the commands, events and data types
being documented.
Again, we drop the direct link from index.html.in now that
the QMP ref is part of the interop manual.
This commit removes the code from the root meson.build file that
handled the various Texinfo-based outputs, because we no longer
generate any documentation except for the Sphinx HTML manuals and the
manpages, and the code can't handle having an empty list of files
to process.. We'll do further cleanup of the remainders of
Texinfo support in subsequent commits.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200925162316.21205-10-peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unicode legacy literal dumbed down to plain string literal, TODO
comment on displaying QEMU version added, "make html" fixed,
storage-daemon/qapi/meson.build updated]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Convert qemu-ga-ref to rST format. This includes dropping
the plain-text, pdf and info format outputs for this document;
as with all our other Sphinx-based documentation, we provide
HTML and manpage only.
The qemu-ga-ref.rst is somewhat more stripped down than
the .texi was, because we do not (currently) attempt to
generate indexes for the commands, events and data types
being documented.
As the GA ref is now part of the Sphinx 'interop' manual,
we can delete the direct link from index.html.in.
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200925162316.21205-9-peter.maydell@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Unicode legacy literal dumbed down to plain string literal, TODO
comment on displaying QEMU version added]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
I found that there are many spelling errors in the comments of qemu,
so I used the spellcheck tool to check the spelling errors
and finally found some spelling errors in the docs folder.
Signed-off-by: zhaolichang <zhaolichang@huawei.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-Id: <20200917075029.313-4-zhaolichang@huawei.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Commit 4d8bb958fa0..231aaf3a821 integrated the contents of
docs/qmp-events.txt into QAPI schema doc comments. It left dangling
references to qmp-events.txt behind. Fix to point to the QEMU QMP
reference manual generated from the QAPI schema.
Add a similar reference for commands.
Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200806081147.3123652-2-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Subcluster allocation in qcow2 is implemented by extending the
existing L2 table entries and adding additional information to
indicate the allocation status of each subcluster.
This patch documents the changes to the qcow2 format and how they
affect the calculation of the L2 cache size.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <5199f2e1c717bcaa58b48142c9062b803145ff7f.1594396418.git.berto@igalia.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Kevin Wolf
Michael S. Tsirkin
Alex Bennée
Paolo Bonzini
Eric Blake
Sergio Lopez
Daniel P. Berrangé
Thomas Huth
Marc-André Lureau
Philippe Mathieu-Daudé
Vladimir Sementsov-Ogievskiy
John Snow
Peter Maydell
Tom Lendacky
Akihiko Odaki
Denis V. Lunev
Markus Armbruster
Stefan Hajnoczi
Stefan Weil
Pavel Dovgalyuk
zhaolichang
Alberto Garcia