Coverity reported a file descriptor leak (CID 1490785) that happens if
`vhost_vdpa_get_max_queue_pairs()` returns 0, since in that case
net_host_vdpa_init(), which should take ownership of the fd, is never
called.
vhost_vdpa_get_max_queue_pairs() returns 1 if VIRTIO_NET_F_MQ is not
negotiated, or a negative error if the ioctl() fails, or the maximum
number of queue pairs exposed by the device in the config space in the
`max_virtqueue_pairs` field. In the VIRTIO spec we have:
The device MUST set max_virtqueue_pairs to between 1 and 0x8000
inclusive, if it offers VIRTIO_NET_F_MQ.
So, if `vhost_vdpa_get_max_queue_pairs()` returns 0, it's really an
error since the device is violating the VIRTIO spec.
Treat also `queue_pairs == 0` as an error, and jump to the `err` label,
to return a negative value to the caller in any case.
Coverity: CID 1490785
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20250714101156.30024-1-sgarzare@redhat.com>
Suggested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Acked-by: Jason Wang <jasowang@redhat.com>
The "err" variable was declared but never used within the
chr_closed_bh() function. This resulted in a dead code
warning (CID 1612365) from Coverity.
Remove the unused variable and the associated error block
to resolve the issue.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This was flagged by Coverity as a memory illegal access.
Initialize the pointer to NULL at declaration.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
In passt_vhost_user_start(), if vhost_net_init() fails, the "net"
variable is NULL and execution jumps to the "err:" label.
The cleanup code within this label is conditioned on "if (net)",
which can never be true in this error case. This makes the cleanup
block dead code, as reported by Coverity (CID 1612371).
Refactor the error handling to occur inline, removing the goto and
the unreachable cleanup block.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The "err" variable was declared but never used within the
net_vhost_user_event() function. This resulted in a dead code
warning (CID 1612372) from Coverity.
Remove the unused variable and the associated error block
to resolve the issue.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The "err" variable was declared but never used within the
passt_vhost_user_event() function. This resulted in a dead code
warning (CID 1612375) from Coverity.
Remove the unused variable and the associated error block
to resolve the issue.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
net_init_tap intends to return 0 for success and -1 on error. However,
when net_init_tap() succeeds for a multi-queue device, it returns 1,
because of this code where ret becomes 1 when g_unix_set_fd_nonblocking
succeeds:
ret = g_unix_set_fd_nonblocking(fd, true, NULL);
if (!ret) {
... error ...
free_fail:
...
return ret;
Luckily, the only current call site checks for negative, rather than non-zero:
net_client_init1()
if (net_client_init_fun[](...) < 0)
Also, in the unlikely case that g_unix_set_fd_nonblocking fails and returns
false, ret=0 is returned, and net_client_init1 will use a broken interface.
Fix it to be future proof.
Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Theoretically tap_read_packet() may return size less than
s->host_vnet_hdr_len, and next, we'll work with negative size
(in case of !s->using_vnet_hdr). Let's avoid it.
Don't proceed with size == s->host_vnet_hdr_len as well in case
of !s->using_vnet_hdr, it doesn't make sense.
Tested-by: Lei Yang <leiyang@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Signed-off-by: Jason Wang <jasowang@redhat.com>
virtio,pci,pc: features, fixes, tests
SPCR acpi table can now be disabled
vhost-vdpa can now report hashing capability to guest
PPTT acpi table now tells guest vCPUs are identical
vost-user-blk now shuts down faster
loongarch64 now supports bios-tables-test
intel_iommu now supports ATS
cxl now supports DCD Fabric Management Command Set
arm now supports acpi pci hotplug
fixes, cleanups
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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# gpg: Signature made Tue 15 Jul 2025 02:56:48 EDT
# gpg: using RSA key 5D09FD0871C8F85B94CA8A0D281F0DB8D28D5469
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# gpg: Good signature from "Michael S. Tsirkin <mst@kernel.org>" [full]
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* tag 'for_upstream' of https://git.kernel.org/pub/scm/virt/kvm/mst/qemu: (97 commits)
hw/cxl: mailbox-utils: 0x5605 - FMAPI Initiate DC Release
hw/cxl: mailbox-utils: 0x5604 - FMAPI Initiate DC Add
hw/cxl: Create helper function to create DC Event Records from extents
hw/cxl: mailbox-utils: 0x5603 - FMAPI Get DC Region Extent Lists
hw/cxl: mailbox-utils: 0x5602 - FMAPI Set DC Region Config
hw/mem: cxl_type3: Add DC Region bitmap lock
hw/cxl: Move definition for dynamic_capacity_uuid and enum for DC event types to header
hw/cxl: mailbox-utils: 0x5601 - FMAPI Get Host Region Config
hw/mem: cxl_type3: Add dsmas_flags to CXLDCRegion struct
hw/cxl: mailbox-utils: 0x5600 - FMAPI Get DCD Info
hw/cxl: fix DC extent capacity tracking
tests: virt: Update expected ACPI tables for virt test
hw/acpi/aml-build: Build a root node in the PPTT table
hw/acpi/aml-build: Set identical implementation flag for PPTT processor nodes
tests: virt: Allow changes to PPTT test table
qtest/bios-tables-test: Generate reference blob for DSDT.acpipcihp
qtest/bios-tables-test: Generate reference blob for DSDT.hpoffacpiindex
tests/qtest/bios-tables-test: Add aarch64 ACPI PCI hotplug test
tests/qtest/bios-tables-test: Prepare for addition of acpi pci hp tests
hw/arm/virt: Let virt support pci hotplug/unplug GED event
...
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Conflicts:
net/vhost-vdpa.c
vhost_vdpa_set_steering_ebpf() was removed, resolve the context
conflict.
Extend 'inhibit=on' setting with the option to specify a pinned XSK map
path along with a starting index (default 0) to push the created XSK
sockets into. Example usage:
# ./build/qemu-system-x86_64 [...] \
-netdev af-xdp,ifname=enp2s0f0np0,id=net0,mode=native,queues=2,start-queue=14,inhibit=on,map-path=/sys/fs/bpf/xsks_map,map-start-index=14 \
-device virtio-net-pci,netdev=net0 [...]
This is useful for the case where an existing XDP program with XSK map
is present on the AF_XDP supported phys device and the XSK map is not
yet populated. For example, the former could have been pre-loaded onto
the netdevice by a control plane, which later launches QEMU to populate
it with XSK sockets.
Normally, the main idea behind 'inhibit=on' is that the QEMU instance
doesn't need to have a lot of privileges to use the pre-loaded program
and the pre-created sockets, but this mentioned use-case here is different
where QEMU still needs privileges to create the sockets.
The 'map-start-index' parameter is optional and defaults to 0. It allows
flexible placement of the XSK sockets, and is up to the user to specify
when the XDP program with XSK map was already preloaded. In the simplest
case the queue-to-map-slot mapping is just 1:1 based on ctx->rx_queue_index
but the user might as well have a different scheme (or smaller map size,
e.g. ctx->rx_queue_index % max_size) to push the inbound traffic to one
of the XSK sockets.
Note that the bpf_xdp_query_id() is now only tested for 'inhibit=off'
since only in the latter case the libxdp takes care of installing the
XDP program which was installed based on the s->xdp_flags pointing to
either driver or skb mode. For 'inhibit=on' we don't make any assumptions
and neither go down the path of probing all possible options in which
way the user installed the XDP program.
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ilya Maximets <i.maximets@ovn.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
While testing, it turned out that upon error in the queue creation loop,
we never trigger the af_xdp_cleanup() handler. This is because we pass
errp instead of a local err pointer into the various AF_XDP setup functions
instead of a scheme like:
bool fn(..., Error **errp)
{
Error *err = NULL;
foo(arg, &err);
if (err) {
handle the error...
error_propagate(errp, err);
return false;
}
...
}
The same is true for the attachment probing with bpf_xdp_query_id(). With a
conversion into the above format, the af_xdp_cleanup() handler is called as
expected. Note the error_propagate() handles a NULL err internally.
Fixes: cb039ef3d9 ("net: add initial support for AF_XDP network backend")
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ilya Maximets <i.maximets@ovn.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
There are two issues with the XDP program removal in af_xdp_cleanup():
1) Starting from libxdp 1.3.0 [0] the XDP program gets automatically
detached when we call xsk_socket__delete() for the last successfully
configured queue. libxdp internally keeps track of that. For QEMU
we require libxdp >= 1.4.0. Given QEMU is not loading the program,
lets also not attempt to remove it and delegate this instead.
2) The removal logic is incorrect anyway because we are setting n_queues
into the last queue that never has xdp_flags on failure, so the logic
is always skipped since the non-zero test for s->xdp_flags in
af_xdp_cleanup() fails.
Fixes: cb039ef3d9 ("net: add initial support for AF_XDP network backend")
Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Cc: Ilya Maximets <i.maximets@ovn.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Anton Protopopov <aspsk@isovalent.com>
Link: https://github.com/xdp-project/xdp-tools/commit/38c2914988fd5c1ef65f2381fc8af9f3e8404e2b [0]
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit adds support for the vhost-user interface to the passt
network backend, enabling high-performance, accelerated networking for
guests using passt.
The passt backend can now operate in a vhost-user mode, where it
communicates with the guest's virtio-net device over a socket pair
using the vhost-user protocol. This offloads the datapath from the
main QEMU loop, significantly improving network performance.
When the vhost-user=on option is used with -netdev passt, the new
vhost initialization path is taken instead of the standard
stream-based connection.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit introduces support for passt as a new network backend.
passt is an unprivileged, user-mode networking solution that provides
connectivity for virtual machines by launching an external helper process.
The implementation reuses the generic stream data handling logic. It
launches the passt binary using GSubprocess, passing it a file
descriptor from a socketpair() for communication. QEMU connects to
the other end of the socket pair to establish the network data stream.
The PID of the passt daemon is tracked via a temporary file to
ensure it is terminated when QEMU exits.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Introduce a boolean is_vhost_user field to the vhost_net
structure. This flag is initialized during vhost_net_init based
on whether the backend is vhost-user.
This refactoring simplifies checks for vhost-user specific behavior,
replacing direct comparisons of 'net->nc->info->type' with the new
flag. It improves readability and encapsulates the backend type
information directly within the vhost_net instance.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit refactors how the maximum transmit queue size for
virtio-net devices is determined, making the mechanism more generic
and extensible.
Previously, virtio_net_max_tx_queue_size() contained hardcoded
checks for specific network backend types (vhost-user and
vhost-vdpa) to determine their supported maximum queue size. This
created direct dependencies and would require modifications for
every new backend that supports variable queue sizes.
To improve flexibility, a new max_tx_queue_size field is added
to the vhost_net structure. This allows each network backend
to advertise its supported maximum transmit queue size directly.
The virtio_net_max_tx_queue_size() function now retrieves the max
TX queue size from the vhost_net struct, if available and set.
Otherwise, it defaults to VIRTIO_NET_TX_QUEUE_DEFAULT_SIZE.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit introduces a save_acked_features function pointer to
vhost_net and converts the vhost_net function into a generic dispatcher.
The vhost-user backend provides the callback, making its function static.
With this change, no other module has a direct dependency on the
vhost-user implementation.
This cleanup allows for the complete removal of the net/vhost-user.h
header file.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This patch continues the effort to decouple the generic vhost layer
from specific network backend implementations.
Previously, the vhost_net initialization code contained a hardcoded
check for the vhost-user client type to retrieve its acked features
by calling vhost_user_get_acked_features(). This exposed an
internal vhost-user function in a public header and coupled the two
modules.
The vhost-user backend is updated to provide a callback, and its
getter function is now static. The call site in vhost_net.c is
simplified to use the new generic helper, removing the type check and
the direct dependency.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Previously, the vhost_net_get_feature_bits() function in
hw/net/vhost_net.c used a large switch statement to determine
the appropriate feature bits based on the NetClientDriver type.
This created unnecessary coupling between the generic vhost layer
and specific network backends (like TAP, vhost-user, and
vhost-vdpa).
This patch moves the definition of vhost feature bits directly into the
vhost_net structure for each relevant network client.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
The get_vhost_net() function previously contained a large switch
statement to find the VHostNetState pointer based on the net
client's type. This created a tight coupling, requiring the generic
vhost layer to be aware of every specific backend that supported
vhost, such as tap, vhost-user, and vhost-vdpa.
This approach is not scalable and requires modifying a central function
for any new backend. It also forced each backend to expose its internal
getter function in a public header file.
This patch refactors the logic by introducing a new get_vhost_net
function pointer to the NetClientInfo struct. The central
get_vhost_net() function is now a simple, generic dispatcher that
invokes the callback provided by the net client.
Each backend now implements its own private getter and registers it in
its NetClientInfo.
Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
