The whole RDMA subsystem was deprecated in commit e9a54265f5
("hw/rdma: Deprecate the pvrdma device and the rdma subsystem")
released in v8.2.
Remove:
- PVRDMA device
- generated vmw_pvrdma/ directory from linux-headers
- rdmacm-mux tool from contrib/
Cc: Yuval Shaia <yuval.shaia.ml@gmail.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Message-Id: <20240328130255.52257-2-philmd@linaro.org>
AF_XDP is a network socket family that allows communication directly
with the network device driver in the kernel, bypassing most or all
of the kernel networking stack. In the essence, the technology is
pretty similar to netmap. But, unlike netmap, AF_XDP is Linux-native
and works with any network interfaces without driver modifications.
Unlike vhost-based backends (kernel, user, vdpa), AF_XDP doesn't
require access to character devices or unix sockets. Only access to
the network interface itself is necessary.
This patch implements a network backend that communicates with the
kernel by creating an AF_XDP socket. A chunk of userspace memory
is shared between QEMU and the host kernel. 4 ring buffers (Tx, Rx,
Fill and Completion) are placed in that memory along with a pool of
memory buffers for the packet data. Data transmission is done by
allocating one of the buffers, copying packet data into it and
placing the pointer into Tx ring. After transmission, device will
return the buffer via Completion ring. On Rx, device will take
a buffer form a pre-populated Fill ring, write the packet data into
it and place the buffer into Rx ring.
AF_XDP network backend takes on the communication with the host
kernel and the network interface and forwards packets to/from the
peer device in QEMU.
Usage example:
-device virtio-net-pci,netdev=guest1,mac=00:16:35:AF:AA:5C
-netdev af-xdp,ifname=ens6f1np1,id=guest1,mode=native,queues=1
XDP program bridges the socket with a network interface. It can be
attached to the interface in 2 different modes:
1. skb - this mode should work for any interface and doesn't require
driver support. With a caveat of lower performance.
2. native - this does require support from the driver and allows to
bypass skb allocation in the kernel and potentially use
zero-copy while getting packets in/out userspace.
By default, QEMU will try to use native mode and fall back to skb.
Mode can be forced via 'mode' option. To force 'copy' even in native
mode, use 'force-copy=on' option. This might be useful if there is
some issue with the driver.
Option 'queues=N' allows to specify how many device queues should
be open. Note that all the queues that are not open are still
functional and can receive traffic, but it will not be delivered to
QEMU. So, the number of device queues should generally match the
QEMU configuration, unless the device is shared with something
else and the traffic re-direction to appropriate queues is correctly
configured on a device level (e.g. with ethtool -N).
'start-queue=M' option can be used to specify from which queue id
QEMU should start configuring 'N' queues. It might also be necessary
to use this option with certain NICs, e.g. MLX5 NICs. See the docs
for examples.
In a general case QEMU will need CAP_NET_ADMIN and CAP_SYS_ADMIN
or CAP_BPF capabilities in order to load default XSK/XDP programs to
the network interface and configure BPF maps. It is possible, however,
to run with no capabilities. For that to work, an external process
with enough capabilities will need to pre-load default XSK program,
create AF_XDP sockets and pass their file descriptors to QEMU process
on startup via 'sock-fds' option. Network backend will need to be
configured with 'inhibit=on' to avoid loading of the program.
QEMU will need 32 MB of locked memory (RLIMIT_MEMLOCK) per queue
or CAP_IPC_LOCK.
There are few performance challenges with the current network backends.
First is that they do not support IO threads. This means that data
path is handled by the main thread in QEMU and may slow down other
work or may be slowed down by some other work. This also means that
taking advantage of multi-queue is generally not possible today.
Another thing is that data path is going through the device emulation
code, which is not really optimized for performance. The fastest
"frontend" device is virtio-net. But it's not optimized for heavy
traffic either, because it expects such use-cases to be handled via
some implementation of vhost (user, kernel, vdpa). In practice, we
have virtio notifications and rcu lock/unlock on a per-packet basis
and not very efficient accesses to the guest memory. Communication
channels between backend and frontend devices do not allow passing
more than one packet at a time as well.
Some of these challenges can be avoided in the future by adding better
batching into device emulation or by implementing vhost-af-xdp variant.
There are also a few kernel limitations. AF_XDP sockets do not
support any kinds of checksum or segmentation offloading. Buffers
are limited to a page size (4K), i.e. MTU is limited. Multi-buffer
support implementation for AF_XDP is in progress, but not ready yet.
Also, transmission in all non-zero-copy modes is synchronous, i.e.
done in a syscall. That doesn't allow high packet rates on virtual
interfaces.
However, keeping in mind all of these challenges, current implementation
of the AF_XDP backend shows a decent performance while running on top
of a physical NIC with zero-copy support.
Test setup:
2 VMs running on 2 physical hosts connected via ConnectX6-Dx card.
Network backend is configured to open the NIC directly in native mode.
The driver supports zero-copy. NIC is configured to use 1 queue.
Inside a VM - iperf3 for basic TCP performance testing and dpdk-testpmd
for PPS testing.
iperf3 result:
TCP stream : 19.1 Gbps
dpdk-testpmd (single queue, single CPU core, 64 B packets) results:
Tx only : 3.4 Mpps
Rx only : 2.0 Mpps
L2 FWD Loopback : 1.5 Mpps
In skb mode the same setup shows much lower performance, similar to
the setup where pair of physical NICs is replaced with veth pair:
iperf3 result:
TCP stream : 9 Gbps
dpdk-testpmd (single queue, single CPU core, 64 B packets) results:
Tx only : 1.2 Mpps
Rx only : 1.0 Mpps
L2 FWD Loopback : 0.7 Mpps
Results in skb mode or over the veth are close to results of a tap
backend with vhost=on and disabled segmentation offloading bridged
with a NIC.
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> (docker/lcitool)
Signed-off-by: Jason Wang <jasowang@redhat.com>
HAX is deprecated since commits 73741fda6c ("MAINTAINERS: Abort
HAXM maintenance") and 90c167a1da ("docs/about/deprecated: Mark
HAXM in QEMU as deprecated"), released in v8.0.0.
Per the latest HAXM release (v7.8 [*]), the latest QEMU supported
is v7.2:
Note: Up to this release, HAXM supports QEMU from 2.9.0 to 7.2.0.
The next commit (https://github.com/intel/haxm/commit/da1b8ec072)
added:
HAXM v7.8.0 is our last release and we will not accept
pull requests or respond to issues after this.
It became very hard to build and test HAXM. Its previous
maintainers made it clear they won't help. It doesn't seem to be
a very good use of QEMU maintainers to spend their time in a dead
project. Save our time by removing this orphan zombie code.
[*] https://github.com/intel/haxm/releases/tag/v7.8.0
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Acked-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230831082016.60885-1-philmd@linaro.org>
Reuse --enable/--disable-download to control git submodules as well.
Adjust the error messages of git-submodule.sh to refer to the new
option.
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The scenario for which --with-git= was introduced was to use a SOCKS proxy
such as tsocks. However, this was back in 2017 when QEMU's submodules
used the git:// protocol, and it is not as important when using the
"smart HTTP" backend; for example, neither "meson subprojects download"
nor scripts/checkpatch.pl obey the GIT environment variable.
So remove the knob, but test for the presence of git in the configure and
git-submodule.sh scripts, and suggest using --with-git-submodules=validate
+ a manual invocation of git-submodule.sh when git does not work. Hopefully
in the future the GIT environment variable will be supported by Meson.
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Remove all the virtiofsd build and docs infrastructure.
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@redhat.com>
vhost-scsi and vhost-user-scsi are two devices of their own; it should
be possible to enable/disable them with --without-default-devices, not
--without-default-features. Compute their default value in Kconfig to
obtain the more intuitive behavior.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
vhost-vsock and vhost-user-vsock are two devices of their own; it should
be possible to enable/disable them with --without-default-devices, not
--without-default-features. Compute their default value in Kconfig to
obtain the more intuitive behavior.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Libpng is only detected if VNC is enabled currently. This patch adds a
generalised png option in the meson build which is aimed to replace use of
CONFIG_VNC_PNG with CONFIG_PNG.
Signed-off-by: Kshitij Suri <kshitij.suri@nutanix.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220408071336.99839-2-kshitij.suri@nutanix.com>
[ kraxel: add meson-buildoptions.sh updates ]
[ kraxel: fix centos8 testcase ]
[ kraxel: update --enable-vnc-png too ]
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
--enable-vnc-png fixup
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
For a long time, we assumed that libxml2 is necessary for parallels
block format support (block/parallels*). However, this format actually
does not use libxml [*]. Since this is the only user of libxml2 in
whole QEMU tree, we can drop all libxml2 checks and dependencies too.
It is even more: --enable-parallels configure option was the only
option which was silently ignored when it's (fake) dependency
(libxml2) isn't installed.
Drop all mentions of libxml2.
[*] Actually the basis for libxml use were introduced in commit
ed279a06c5 ("configure: add dependency") but the implementation
was never merged:
https://lore.kernel.org/qemu-devel/70227bbd-a517-70e9-714f-e6e0ec431be9@openvz.org/
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-Id: <20220119090423.149315-1-mjt@msgid.tls.msk.ru>
Tested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
[PMD: Updated description and adapted to use lcitool]
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20220121154134.315047-5-f4bug@amsat.org>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20220204204335.1689602-9-alex.bennee@linaro.org>
The handling for the XFS_IOC_DIOINFO ioctl is currently quite excessive:
This is not a "real" feature like the other features that we provide with
the "--enable-xxx" and "--disable-xxx" switches for the configure script,
since this does not influence lots of code (it's only about one call to
xfsctl() in file-posix.c), so people don't gain much with the ability to
disable this with "--disable-xfsctl".
It's also unfortunate that the ioctl will be disabled on Linux in case
the user did not install the right xfsprogs-devel package before running
configure. Thus let's simplify this by providing the ioctl definition
on our own, so we can completely get rid of the header dependency and
thus the related code in the configure script.
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20211215125824.250091-1-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This introduces three different parts of a job designed to run
on a custom runner managed by Red Hat. The goals include:
a) propose a model for other organizations that want to onboard
their own runners, with their specific platforms, build
configuration and tests.
b) bring awareness to the differences between upstream QEMU and the
version available under CentOS Stream, which is "A preview of
upcoming Red Hat Enterprise Linux minor and major releases".
c) because of b), it should be easier to identify and reduce the gap
between Red Hat's downstream and upstream QEMU.
The components of this custom job are:
I) OS build environment setup code:
- additions to the existing "build-environment.yml" playbook
that can be used to set up CentOS/EL 8 systems.
- a CentOS Stream 8 specific "build-environment.yml" playbook
that adds to the generic one.
II) QEMU build configuration: a script that will produce binaries with
features as similar as possible to the ones built and packaged on
CentOS stream 8.
III) Scripts that define the minimum amount of testing that the
binaries built with the given configuration (point II) under the
given OS build environment (point I) should be subjected to.
IV) Job definition: GitLab CI jobs that will dispatch the build/test
jobs (see points #II and #III) to the machine specifically
configured according to #I.
Signed-off-by: Cleber Rosa <crosa@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Willian Rampazzo <willianr@redhat.com>
Tested-by: Willian Rampazzo <willianr@redhat.com>
Message-Id: <20211111160501.862396-2-crosa@redhat.com>
Message-Id: <20211115142915.3797652-6-alex.bennee@linaro.org>
Philippe Mathieu-Daudé