A supposed exploit of QEMU was recently announced as CVE-2019-12928
claiming that the monitor console was insecure because the "migrate"
command enabled arbitrary command execution for a remote attacker.
To be a security risk the user launching QEMU must have configured
the monitor in a way that allows for other users to access it. The
exploit report quoted use of the "tcp" character device backend for
QMP.
This would indeed allow any network user to connect to QEMU and
execute arbitrary commands, however, this is not a flaw in QEMU.
It is the normal expected behaviour of the monitor console and the
commands it supports. Given a monitor connection, there are many
ways to access host file system content besides the migrate command.
The reality is that the monitor console (whether QMP or HMP) is
considered a privileged interface to QEMU and as such must only
be made available to trusted users. IOW, making it available with
no authentication over TCP is simply a, very serious, user
configuration error not a security flaw in QEMU itself.
The one thing this bogus security report highlights though is that
we have not clearly documented the security implications around the
use of the monitor. Add a few paragraphs of text to the security
docs explaining why the monitor is a privileged interface and making
a recommendation to only use the UNIX socket character device backend.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
The annotated style json we use in QMP documentation is not strict json
and depending on the version of Sphinx (2.0+) or Pygments installed,
might cause the build to fail.
Use the new QMP lexer.
Further, some versions of Sphinx can not apply custom lexers to "code"
directives and require the use of "code-block" directives instead, so
make that change at this time as well.
Tested under:
- Sphinx 1.3.6 and Pygments 2.4
- Sphinx 1.7.6 and Pygments 2.2 (Fedora 29 packages)
- Sphinx 2.0.1 and Pygments 2.4
- Sphinx 3.0.0+/f396b3a783 and Pygments 2.4 (From Sphinx git c4f44bdd)
Reported-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-id: 20190603214653.29369-4-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Sphinx, through Pygments, does not like annotated json examples very
much. In some versions of Sphinx (1.7), it will render the non-json
portions of code blocks in red, but in newer versions (2.0) it will
throw an exception and not highlight the block at all. Though we can
suppress this warning, it doesn't bring back highlighting on non-strict
json blocks.
We can alleviate this by creating a custom lexer for QMP examples that
allows us to properly highlight these examples in a robust way, keeping
our directionality and elision notations.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: John Snow <jsnow@redhat.com>
Reported-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20190603214653.29369-3-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
Pygments and Sphinx get pickier all the time; Sphinx 2.1+ now catches
these errors.
Signed-off-by: John Snow <jsnow@redhat.com>
Reported-by: Aarushi Mehta <mehta.aaru20@gmail.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190603214653.29369-2-jsnow@redhat.com
Signed-off-by: John Snow <jsnow@redhat.com>
The "Multiple queue support" section makes references to vhost-user-net
"queue pairs". This is confusing for two reasons:
1. This actually applies to all device types, not just vhost-user-net.
2. VHOST_USER_GET_QUEUE_NUM returns the number of virtqueues, not the
number of queue pairs.
Reword the section so that the vhost-user-net specific part is relegated
to the very end: we acknowledge that vhost-user-net historically
automatically enabled the first queue pair.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190626074815.19994-5-stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
We already have 'make check-help', use the 'make vm-help' form
to display helps about VM testing. Keep the old target to not
bother old customs.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20190531064341.29730-1-philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Older KVMs on POWER9 don't support destroying/recreating a KVM XICS
device, which is required by 'dual' interrupt controller mode. This
causes QEMU to emit a warning when the guest is rebooted and to fall
back on XICS emulation:
qemu-system-ppc64: warning: kernel_irqchip allowed but unavailable:
Error on KVM_CREATE_DEVICE for XICS: File exists
If kernel irqchip is required, QEMU will thus exit when the guest is
first rebooted. Failing QEMU this late may be a painful experience
for the user.
Detect that and exit at machine init instead.
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <156044430517.125694.6207865998817342638.stgit@bahia.lab.toulouse-stg.fr.ibm.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This includes various small updates and a better description of the
chosen interrupt mode resulting from the combination of the 'ic-mode'
machine option, the 'kernel_irqchip' option, guest support and KVM
support.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190612160425.27670-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Rewrite the implementation of the ssh block driver to use libssh instead
of libssh2. The libssh library has various advantages over libssh2:
- easier API for authentication (for example for using ssh-agent)
- easier API for known_hosts handling
- supports newer types of keys in known_hosts
Use APIs/features available in libssh 0.8 conditionally, to support
older versions (which are not recommended though).
Adjust the iotest 207 according to the different error message, and to
find the default key type for localhost (to properly compare the
fingerprint with).
Contributed-by: Max Reitz <mreitz@redhat.com>
Adjust the various Docker/Travis scripts to use libssh when available
instead of libssh2. The mingw/mxe testing is dropped for now, as there
are no packages for it.
Signed-off-by: Pino Toscano <ptoscano@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Acked-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20190620200840.17655-1-ptoscano@redhat.com
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 5873173.t2JhDm7DL7@lindworm.usersys.redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
Hyper-V on KVM can only use Synthetic timers with Direct Mode (opting for
an interrupt instead of VMBus message). This new capability is only
announced in KVM_GET_SUPPORTED_HV_CPUID.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20190517141924.19024-10-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In many case we just want to give Windows guests all currently supported
Hyper-V enlightenments and that's where this new mode may come handy. We
pass through what was returned by KVM_GET_SUPPORTED_HV_CPUID.
hv_cpuid_check_and_set() is modified to also set cpu->hyperv_* flags as
we may want to check them later (and we actually do for hv_runtime,
hv_synic,...).
'hv-passthrough' is a development only feature, a migration blocker is
added to prevent issues while migrating between hosts with different
feature sets.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20190517141924.19024-6-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Currently, there is no doc describing hv-* CPU flags, people are
encouraged to get the information from Microsoft Hyper-V Top Level
Functional specification (TLFS). There is, however, a bit of QEMU
specifics.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20190517141924.19024-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Now that we have a monitor/ subdirectory, let's move hmp.c and qmp.c
from the root directory there. As they contain implementations of
monitor commands, rename them to {hmp,qmp}-cmds.c, so that {hmp,qmp}.c
are free for the HMP and QMP infrastructure.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190613153405.24769-9-kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Create a new monitor/ subdirectory and move monitor.c there. As the plan
is to move the monitor core into separate files, use the chance to
rename it to misc.c.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190613153405.24769-8-kwolf@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Now we have some rST format docs in the docs/specs/ manual, we should
actually build and install it.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Message-id: 20190610152444.20859-3-peter.maydell@linaro.org
The docs/specs/index.rst has a couple of minor issues which
we didn't notice because we weren't building the manual:
* the ToC entry for the new PPC XIVE docs points to
a nonexistent file
* the initial comment needs to be marked by '..', not '.',
or it will appear in the output
* the title doesn't match the capitialization used by
the existing interop or devel manuals, and uses
'full-system emulation' rather than the 'system emulation'
that the interop manual title uses
Fix these minor issues before we start trying to build the manual.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Message-id: 20190610152444.20859-2-peter.maydell@linaro.org
Our user-facing manual currently has a section "translator internals"
which has some high-level information about the design of the
TCG translator. This should really be in our new devel/ manual.
Convert it to RST format and move it there.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190607152827.18003-2-peter.maydell@linaro.org
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190605131221.29432-1-marcandre.lureau@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Sometimes, the behaviour of QEMU changes without a change in the QMP
syntax (usually by allowing values or operations that previously
resulted in an error). QMP clients may still need to know whether
they can rely on the changed behavior.
Let's add feature flags to the QAPI schema language, so that we can make
such changes visible with schema introspection.
An example for a schema definition using feature flags looks like this:
{ 'struct': 'TestType',
'data': { 'number': 'int' },
'features': [ 'allow-negative-numbers' ] }
Introspection information then looks like this:
{ "name": "TestType", "meta-type": "object",
"members": [
{ "name": "number", "type": "int" } ],
"features": [ "allow-negative-numbers" ] }
This patch implements feature flags only for struct types. We'll
implement them more widely as needed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20190606153803.5278-2-armbru@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Now that we have both ArchCPU and CPUArchState, we can define
this generically instead of via macro in each target's cpu.h.
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The default-configs/ example added in 717171bd20 is no
more accurate since fa212a2b8b (and various further other
commits).
The Kconfig build system is now in place.
Use the aarch64-softmmu config as example.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190529140504.21580-1-philmd@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
All callers of bdrv_set_aio_context() are eliminated now, they have
moved to bdrv_try_set_aio_context() and related safe functions. Remove
bdrv_set_aio_context().
With this, we can now know that the .set_aio_ctx callback must be
present in bdrv_set_aio_context_ignore() because
bdrv_can_set_aio_context() would have returned false previously, so
instead of checking the condition, we can assert it.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Add a new vhost-user message to give a unix socket to a vhost-user
backend for GPU display updates.
Back when I started that work, I added a new GPU channel because the
vhost-user protocol wasn't bidirectional. Since then, there is a
vhost-user-slave channel for the slave to send requests to the master.
We could extend it with GPU messages. However, the GPU protocol is
quite orthogonal to vhost-user, thus I chose to have a new dedicated
channel.
See vhost-user-gpu.rst for the protocol details.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20190524130946.31736-2-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This documents the overall XIVE architecture and the XIVE support for
sPAPR guest machines (pseries).
It also provides documentation on the 'info pic' command.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190521082411.24719-1-clg@kaod.org>
Reviewed-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Update x86 CPU model guidance to recommend that the md-clear feature is
manually enabled with all Intel CPU models, when supported by the host
microcode.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190515141011.5315-3-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20190315180735.13096-1-marcandre.lureau@redhat.com>
Reviewed-by: Jens Freimann <jfreimann@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The Makefile tries to include device Kconfig dependencies via
-include $(SUBDIR_DEVICES_MAK_DEP)
and thus expects files that match *-softmmu/config-devices.mak.d ...
however, the minikconf script currently generates files a la
"*-softmmu-config.devices.mak.d" instead, so the dependency files
simply got ignored so far. For example, after a "touch hw/arm/Kconfig",
the arm-softmmu/config-devices.mak file is currently not re-generated.
Fix it by putting the dependency files in the *-softmmu folders now.
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
This new chapter in the QEMU documentation covers the security
requirements that QEMU is designed to meet and principles for securely
deploying QEMU.
It is just a starting point that can be extended in the future with more
information.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Message-id: 20190509121820.16294-3-stefanha@redhat.com
Message-Id: <20190509121820.16294-3-stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
At KVM Forum 2018 I gave a presentation on security in QEMU:
https://www.youtube.com/watch?v=YAdRf_hwxU8 (video)
https://vmsplice.net/~stefan/stefanha-kvm-forum-2018.pdf (slides)
This patch adds a guide to secure coding practices. This document
covers things that developers should know about security in QEMU. It is
just a starting point that we can expand on later. I hope it will be
useful as a resource for new contributors and will save code reviewers
from explaining the same concepts many times.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Message-id: 20190509121820.16294-2-stefanha@redhat.com
Message-Id: <20190509121820.16294-2-stefanha@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
A test can, optionally, be tagged for one or many architectures. If a
test has been tagged for a single architecture, there's a high chance
that the test won't run on other architectures. This changes the
default order of choosing a default target architecture to use based
on the 'arch' tag value first.
The precedence order is for choosing a QEMU binary to use for a test
is now:
* qemu_bin parameter
* arch parameter
* arch tag value (for example, x86_64 if "🥑 tags=arch:x86_64
is used)
This means that if one runs:
$ avocado run -p qemu_bin=/usr/bin/qemu-system-x86_64 test.py
No arch parameter or tag will influence the selection of the QEMU
target binary. If one runs:
$ avocado run -p arch=ppc64 test.py
The target binary selection mechanism will attempt to find a binary
such as "ppc64-softmmu/qemu-system-ppc64". And finally, if one runs
a test that is tagged (in its docstring) with "arch:aarch64":
$ avocado run aarch64.py
The target binary selection mechanism will attempt to find a binary
such as "aarch64-softmmu/qemu-system-aarch64".
At this time, no provision is made to cancel the execution of tests if
the arch parameter given (manually) does not match the test "arch"
tag, but it may be a useful default behavior to be added in the
future.
Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190312171824.5134-7-crosa@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
It's useful to define the architecture that should be used in
situations such as:
* the intended target of the QEMU binary to be used on tests
* the architecture of code to be run within the QEMU binary, such
as a kernel image or a full blown guest OS image
This commit introduces both a test parameter and a test instance
attribute, that will contain such a value.
Now, when the "arch" test parameter is given, it will influence the
selection of the default QEMU binary, if one is not given explicitly
by means of the "qemu_img" parameter.
Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190312171824.5134-5-crosa@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The "this directory" reference is misleading and confusing, it's a
leftover from when this text was proposed in a README file inside
the "tests/acceptance/avocado_qemu" directory.
When that text was moved to the top level docs directory, the
reference was not updated.
Signed-off-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Caio Carrara <ccarrara@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190312171824.5134-4-crosa@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This just about rewrites the entirety of the bitmaps.rst document to
make it consistent with the 4.0 release. I have added new features seen
in the 4.0 release, as well as tried to clarify some points that keep
coming up when discussing this feature both in-house and upstream.
It does not yet cover pull backups or migration details, but I intend to
keep extending this document to cover those cases.
Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190426221528.30293-3-jsnow@redhat.com
[Adjusted commit message. --js]
Signed-off-by: John Snow <jsnow@redhat.com>
When a file supporting DAX is used as vNVDIMM backend, mmap it with
MAP_SYNC flag in addition which can ensure file system metadata
synced in each guest writes to the backend file, without other QEMU
actions (e.g., periodic fsync() by QEMU).
Current, We have below different possible use cases:
1. pmem=on is set, shared=on is set, MAP_SYNC supported:
a: backend is a dax supporting file.
- MAP_SYNC will active.
b: backend is not a dax supporting file.
- mmap will trigger a warning. then MAP_SYNC flag will be ignored
2. The rest of cases:
- we will never pass the MAP_SYNC to mmap2
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com>
Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com>
[ehabkost: Rebased patch to latest code on master]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Tested-by: Wei Yang <richardw.yang@linux.intel.com>
Message-Id: <20190422004849.26463-2-richardw.yang@linux.intel.com>
[ehabkost: squashed documentation patch]
Message-Id: <20190422004849.26463-3-richardw.yang@linux.intel.com>
[ehabkost: documentation fixup]
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Pankaj Gupta <pagupta@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Allows guest to boot from a vfio configured real dasd device.
Signed-off-by: Jason J. Herne <jjherne@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <1554388475-18329-16-git-send-email-jjherne@linux.ibm.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
While the stibp CPU feature is not commonly used by guest OS for spectre
mitigation due to its performance impact, it is none the less best
practice to expose it to all guest OS. This allows the guest OS to
decide whether to make use or it.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190307121838.6345-3-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
The docs currently say that the spec-ctrl feature is needed for both
Spectre variants, but it is only used to address Spectre v2. Also
remove the note about retpolines. The guest OS is usually treated
as a blackbox from host mgmt pov, so it won't have knowledge about
use of retpolines and thus should unconditionally expose spec-ctrl,
allowing the guest to decide whether to use it or not.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190307121838.6345-2-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This patch introduces two new messages VHOST_USER_GET_INFLIGHT_FD
and VHOST_USER_SET_INFLIGHT_FD to support transferring a shared
buffer between qemu and backend.
Firstly, qemu uses VHOST_USER_GET_INFLIGHT_FD to get the
shared buffer from backend. Then qemu should send it back
through VHOST_USER_SET_INFLIGHT_FD each time we start vhost-user.
This shared buffer is used to track inflight I/O by backend.
Qemu should retrieve a new one when vm reset.
Signed-off-by: Xie Yongji <xieyongji@baidu.com>
Signed-off-by: Chai Wen <chaiwen@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Message-Id: <20190228085355.9614-2-xieyongji@baidu.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>
As discussed during "[PATCH v4 00/29] vhost-user for input & GPU"
review, let's define a common set of backend conventions to help with
management layer implementation, and interoperability.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190308140454.32437-3-marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
One great big block comment isn't the best way to document
the syntax of a language.
Reviewed-by: Bastian Koppelmann <kbastian@mail.uni-paderborn.de>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We already use (we didn't notice it) IN_USE flag for marking bitmap
metadata outdated, such as AUTO flag, which mirrors enabled/disabled
bitmaps. Now we are going to support bitmap resize, so it's good to
write IN_USE meaning with more details.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20190311185147.52309-2-vsementsov@virtuozzo.com
Signed-off-by: John Snow <jsnow@redhat.com>
The previous commit added a way to configure firmware with -blockdev
rather than -drive if=pflash. Document it as the preferred way.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190308131445.17502-13-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Be more specific about the string representation in header extensions.
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
QEMU 2.12 (commit 1221fe6f63) introduced
a new setting called l2-cache-entry-size that allows making entries on
the qcow2 L2 cache smaller than the cluster size.
I have been performing several tests with different cluster and entry
sizes and all of them show that reducing the entry size (aka L2 slice)
consistently improves I/O performance, notably during random I/O (all
tests done with sequential I/O show similar results). This is to be
expected because loading and evicting an L2 slice is more expensive
the larger the slice is.
Here are some numbers on fully populated 40GB qcow2 images. The
rightmost column represents the maximum L2 cache size in both cases.
Cluster size = 64 KB
|-------------+--------------+--------------+--------------|
| | 1MB L2 cache | 3MB L2 cache | 5MB L2 cache |
|-------------+--------------+--------------+--------------|
| 4KB slices | 6545 IOPS | 12045 IOPS | 55680 IOPS |
| 16KB slices | 5177 IOPS | 9798 IOPS | 56278 IOPS |
| 64KB slices | 2718 IOPS | 5326 IOPS | 57355 IOPS |
|-------------+--------------+--------------+--------------|
Cluster size = 256 KB
|--------------+----------------+--------------+-----------------|
| | 512KB L2 cache | 1MB L2 cache | 1280KB L2 cache |
|--------------+----------------+--------------+-----------------|
| 4KB slices | 8539 IOPS | 21071 IOPS | 55417 IOPS |
| 64KB slices | 3598 IOPS | 9772 IOPS | 57687 IOPS |
| 256KB slices | 1415 IOPS | 4120 IOPS | 58001 IOPS |
|--------------+----------------+--------------+-----------------|
As can be seen in the numbers, the only exception to the rule is when
the cache is large enough to hold all L2 tables. This is also to be
expected because in this case no cache entry is ever evicted so
reducing its size doesn't bring any benefit.
This patch sets the default L2 cache entry size to 4KB except when the
cache is large enough for the whole disk.
Signed-off-by: Alberto Garcia <berto@igalia.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Instead of including the same list of devices for each target,
set CONFIG_PCI to true, and make the devices default to present
whenever PCI is available. However, s390x does not want all the
PCI devices, so there is a separate symbol to enable them.
Done mostly with the following script:
while read i; do
i=${i%=y}; i=${i#CONFIG_}
sed -i -e'/^config '$i'$/!b' -en \
-e'a\' -e' default y if PCI_DEVICES\' -e' depends on PCI' \
`grep -lw $i hw/*/Kconfig`
done < default-configs/pci.mak
followed by replacing a few "depends on" clauses with "select"
whenever the symbol is not really related to PCI.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20190123065618.3520-31-yang.zhong@intel.com>
Acked-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Daniel P. Berrangé
John Snow
Stefan Hajnoczi
Philippe Mathieu-Daudé
Liam Merwick
Greg Kurz
Cédric Le Goater
Pino Toscano
Vitaly Kuznetsov
Kevin Wolf
Peter Maydell
Marc-André Lureau
Richard Henderson
Thomas Huth
Cleber Rosa
Zhang Yi
Jason J. Herne
Xie Yongji
Vladimir Sementsov-Ogievskiy
Markus Armbruster
Alberto Garcia
Paolo Bonzini