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Release of libvirt-12.0.0
by Jiri Denemark 15 Jan '26

15 Jan '26

The 12.0.0 release of both libvirt and libvirt-python is tagged and signed tarballs are available at https://download.libvirt.org/ https://download.libvirt.org/python/ Thanks everybody who helped with this release by sending patches, reviewing, testing, or providing feedback. Your work is greatly appreciated. * New features * bhyve: SLIRP networking support Domain XMLs now can use SLIRP user-mode networking:: <interface type='user'> <model type='virtio'/> </interface> * bhyve: virtio-scsi support Domain XMLs now can use ``virtio-scsi`` devices:: <disk type='ctl'> <source dev='/dev/cam/ctl'/> <target dev='sda' bus='scsi'/> </disk> * bhyve: initial ARM64 support The bhyve driver now supports booting ARM64 domains on ARM64 hosts. This support is still in early stage of development and has some limitations. For example, it requires using ``<clock offset='localtime'/>`` in domain XMLs, and bootrom autofill is not implemented. * Improvements * qemu: Improvements and fixes to firmware selection Firmware selection now works more reliably and predictably in many scenarios. Notably, issues that were preventing the use of firmware designed for confidential VMs on aarch64 have been addressed. * network: Introduce port for DNS forwarder In the ``<dns/>`` section of network configuration users can set up forwarding of DNS requests to custom DNS servers. These are specified using ``addr`` attribute. But configuring port wasn't possible, until now. New ``port`` attribute is introduced, which allows overriding the default DNS port for given address. * Bug fixes * qemu: Fix startup of VMs with more than ~25 external snapshots After switch to json-c VMs with too deeply nested image chains would fail to start due to nesting depth limit in json-c, which is now increased to once again support backing chains up to 200 images deep. * qemu: TPM: Properly handle migration when storage resides on NFS The VM now can be properly migrated in scenarios where TPM data is stored on a shared filesystem on the destination but on the source it's either on a different NFS or unshared completely. * qemu: Treat memory device source nodemask as strict NUMA policy Until now, the NUMA policy for ``<memory/>`` devices was taken either from the guest NUMA node or ``<numatune/>``. But this may lead to discrepancies, where the memory device is configured to bind to a set of host NUMA nodes, but the guest NUMA node is to bind to a disjoint set of host NUMA nodes. To resolve this, specifying ``<nodemask/>`` for a memory device implies ``strict`` policy. * qemu: Relax validation of some hyperv features Since 11.9.0 release, libvirt performs dependency checks for hyperv features, for instance ``stimer`` requires ``synic``. But as it turned out, for some ancient machine types (e.g. 'pc-i440fx-3.0' or 'pc-q35-3.0') some dependencies are not true. Corresponding checks were removed. * esx: URI encode inventory objects twice Formatting domain XML for domains on an ESX server might fail if corresponding datacenter or datastore contained special characters (e.g. '+'). This is now fixed. * Fix race when checking whether a path is on a shared file system Finding an existing parent of a given path and checking whether it's on a shared file system was not atomic and thus the path could have been misinterpreted as non-shared if it was removed between these two operations. This could cause migration with an emulated TPM device stored on a shared file system to fail with the following bogus error:: Operation not supported: the running swtpm does not support migration with shared storage Enjoy. Jirka

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[PATCH] NEWS: Mention shared FS detection race
by Jiri Denemark 14 Jan '26

14 Jan '26

From: Jiri Denemark <jdenemar(a)redhat.com> Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com> --- NEWS.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/NEWS.rst b/NEWS.rst index 9fff3173ec..958ce71375 100644 --- a/NEWS.rst +++ b/NEWS.rst @@ -96,6 +96,16 @@ v12.0.0 (unreleased) corresponding datacenter or datastore contained special characters (e.g. '+'). This is now fixed. + * Fix race when checking whether a path is on a shared file system + + Finding an existing parent of a given path and checking whether it's on a + shared file system was not atomic and thus the path could have been + misinterpreted as non-shared if it was removed between these two + operations. This could cause migration with an emulated TPM device stored + on a shared file system to fail with the following bogus error:: + + Operation not supported: the running swtpm does not support migration with shared storage + v11.10.0 (2025-12-01) ===================== -- 2.52.0

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[PATCH] NEWS: Document features/improvements/bug fixes I've participated in
by Michal Privoznik 14 Jan '26

14 Jan '26

From: Michal Privoznik <mprivozn(a)redhat.com> There are some features/improvements/bug fixes I've either contributed or reviewed/merged. Document them for upcoming release. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- NEWS.rst | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/NEWS.rst b/NEWS.rst index ce55445695..9fff3173ec 100644 --- a/NEWS.rst +++ b/NEWS.rst @@ -52,6 +52,14 @@ v12.0.0 (unreleased) Notably, issues that were preventing the use of firmware designed for confidential VMs on aarch64 have been addressed. + * network: Introduce port for DNS forwarder + + In the ``<dns/>`` section of network configuration users can set up + forwarding of DNS requests to custom DNS servers. These are specified using + ``addr`` attribute. But configuring port wasn't possible, until now. New + ``port`` attribute is introduced, which allows overriding the default DNS + port for given address. + * **Bug fixes** * qemu: Fix startup of VMs with more than ~25 external snapshots @@ -66,6 +74,28 @@ v12.0.0 (unreleased) on a shared filesystem on the destination but on the source it's either on a different NFS or unshared completely. + * qemu: Treat memory device source nodemask as strict NUMA policy + + Until now, the NUMA policy for ``<memory/>`` devices was taken either from + the guest NUMA node or ``<numatune/>``. But this may lead to discrepancies, + where the memory device is configured to bind to a set of host NUMA nodes, + but the guest NUMA node is to bind to a disjoint set of host NUMA nodes. To + resolve this, specifying ``<nodemask/>`` for a memory device implies + ``strict`` policy. + + * qemu: Relax validation of some hyperv features + + Since 11.9.0 release, libvirt performs dependency checks for hyperv + features, for instance ``stimer`` requires ``synic``. But as it turned out, + for some ancient machine types (e.g. 'pc-i440fx-3.0' or 'pc-q35-3.0') some + dependencies are not true. Corresponding checks were removed. + + * esx: URI encode inventory objects twice + + Formatting domain XML for domains on an ESX server might fail if + corresponding datacenter or datastore contained special characters (e.g. + '+'). This is now fixed. + v11.10.0 (2025-12-01) ===================== -- 2.52.0

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Re: [PATCH] apparmor: Upgrade ABI version to 4.0, explicitly enable user namespace creation
by Andrea Bolognani 13 Jan '26

13 Jan '26

[adding libvirt devel list] On Sat, Jan 10, 2026 at 04:14:30PM +0100, Stefano Brivio wrote: > In the 3.0 AppArmor ABI version we currently use, user namespace rules > are not supported, and, as long as we load confined profiles, those > implicitly allow creation of user namespaces. > > However, ABI version 4.0 introduces rules for user namespaces, and if > we don't specify any, we can't create user namespaces, see: > > https://gitlab.com/apparmor/apparmor/-/wikis/unprivileged_userns_restriction > > This wouldn't affect us in general, given that we're using the 3.0 > ABI, but libvirt's policy uses 4.0 instead, and if our abstractions > are used from there, no matter what ABI policy version we declare, > rules for user namespace creation now match ABI policy version 4.0. AFAICT libvirt's policy doesn't explicitly declares any ABI version, so how does that work? Is the most recent one being used in that case? Assuming that's the case, how far back will that result in ABI 4.0 being the effective one? It looks like Debian only got AppArmor 4+ in March of last year. Do we want to make the ABI version explicit in libvirt's policy? If so, should we stick with 3.0 for maximum compatibility? > As a result, when libvirtd runs as root, and its profile includes > passt's abstraction, cf. commit 66769c2de825 ("apparmor: Workaround > for unconfined libvirtd when triggered by unprivileged user"), passt > can't detach user namespaces and will fail to start, as reported by > Niklas: > > ERROR internal error: Child process (passt --one-off --socket /run/libvirt/qemu/passt/1-haos-net0.socket --pid /run/libvirt/qemu/passt/1-haos-net0-passt.pid --tcp-ports 8123) unexpected exit status 1: Multiple interfaces with IPv6 routes, picked first > UNIX domain socket bound at /run/libvirt/qemu/passt/1-haos-net0.socket > Couldn't create user namespace: Permission denied > > This isn't a problem with libvirtd running as regular user, because > in that case, as a workaround, passt currently runs under its own > profile, not as a libvirtd subprofile (see commit referenced above). > > Given that ABI 4.0 has been around for a while, being introduced in > July 2023, finally take the step to upgrade to it and explicitly > enable user namespace creation. > > No further changes are needed in the existing policies to match new > features introduced in AppArmor 4.0. > > Reported-by: Niklas Edmundsson <nikke(a)accum.se> > Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1124801 > Signed-off-by: Stefano Brivio <sbrivio(a)redhat.com> > --- > contrib/apparmor/abstractions/passt | 3 ++- > contrib/apparmor/abstractions/pasta | 2 +- > contrib/apparmor/usr.bin.passt | 2 +- > contrib/apparmor/usr.bin.passt-repair | 2 +- > contrib/apparmor/usr.bin.pasta | 2 +- > 5 files changed, 6 insertions(+), 5 deletions(-) > > diff --git a/contrib/apparmor/abstractions/passt b/contrib/apparmor/abstractions/passt > index 25b2ea8..0ffadaf 100644 > --- a/contrib/apparmor/abstractions/passt > +++ b/contrib/apparmor/abstractions/passt > @@ -11,7 +11,7 @@ > # Copyright (c) 2022 Red Hat GmbH > # Author: Stefano Brivio <sbrivio(a)redhat.com> > > - abi <abi/3.0>, > + abi <abi/4.0>, > > include <abstractions/base> > > @@ -24,6 +24,7 @@ > capability setpcap, > capability net_admin, > capability sys_ptrace, > + userns, > > / r, # isolate_prefork(), isolation.c > mount options=(rw, runbindable) -> /, > diff --git a/contrib/apparmor/abstractions/pasta b/contrib/apparmor/abstractions/pasta > index 9f73bee..251d4a2 100644 > --- a/contrib/apparmor/abstractions/pasta > +++ b/contrib/apparmor/abstractions/pasta > @@ -11,7 +11,7 @@ > # Copyright (c) 2022 Red Hat GmbH > # Author: Stefano Brivio <sbrivio(a)redhat.com> > > - abi <abi/3.0>, > + abi <abi/4.0>, > > include <abstractions/passt> > > diff --git a/contrib/apparmor/usr.bin.passt b/contrib/apparmor/usr.bin.passt > index 62a4514..c123a86 100644 > --- a/contrib/apparmor/usr.bin.passt > +++ b/contrib/apparmor/usr.bin.passt > @@ -11,7 +11,7 @@ > # Copyright (c) 2022 Red Hat GmbH > # Author: Stefano Brivio <sbrivio(a)redhat.com> > > -abi <abi/3.0>, > +abi <abi/4.0>, > > include <tunables/global> > > diff --git a/contrib/apparmor/usr.bin.passt-repair b/contrib/apparmor/usr.bin.passt-repair > index 901189d..23ff1ce 100644 > --- a/contrib/apparmor/usr.bin.passt-repair > +++ b/contrib/apparmor/usr.bin.passt-repair > @@ -11,7 +11,7 @@ > # Copyright (c) 2025 Red Hat GmbH > # Author: Stefano Brivio <sbrivio(a)redhat.com> > > -abi <abi/3.0>, > +abi <abi/4.0>, > > #include <tunables/global> > > diff --git a/contrib/apparmor/usr.bin.pasta b/contrib/apparmor/usr.bin.pasta > index 2483968..56b5024 100644 > --- a/contrib/apparmor/usr.bin.pasta > +++ b/contrib/apparmor/usr.bin.pasta > @@ -11,7 +11,7 @@ > # Copyright (c) 2022 Red Hat GmbH > # Author: Stefano Brivio <sbrivio(a)redhat.com> > > -abi <abi/3.0>, > +abi <abi/4.0>, > > include <tunables/global> > > -- > 2.43.0 >

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[PATCH 0/3] syntax-check: Introduce sc_prohibit_g_autofree_const rule
by Michal Privoznik 13 Jan '26

13 Jan '26

Stems out from discussion here: https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/message/HYT… Michal Prívozník (3): hyperv: Drop const for resourceType in hypervDomainAttachSerial() network: Drop const for forwardIf in pfAddNatFirewallRules() syntax-check: Introduce sc_prohibit_g_autofree_const rule build-aux/syntax-check.mk | 6 ++++++ src/hyperv/hyperv_driver.c | 2 +- src/network/network_pf.c | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) -- 2.52.0

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[PATCH] NEWS: Mention JSON nesting bug and TPM migration quirk with NFS
by Peter Krempa 13 Jan '26

13 Jan '26

From: Peter Krempa <pkrempa(a)redhat.com> Signed-off-by: Peter Krempa <pkrempa(a)redhat.com> --- NEWS.rst | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/NEWS.rst b/NEWS.rst index a0fae3c661..ce55445695 100644 --- a/NEWS.rst +++ b/NEWS.rst @@ -54,6 +54,18 @@ v12.0.0 (unreleased) * **Bug fixes** + * qemu: Fix startup of VMs with more than ~25 external snapshots + + After switch to json-c VMs with too deeply nested image chains would fail + to start due to nesting depth limit in json-c, which is now increased to once + again support backing chains up to 200 images deep. + + * qemu: TPM: Properly handle migration when storage resides on NFS + + The VM now can be properly migrated in scenarios where TPM data is stored + on a shared filesystem on the destination but on the source it's either + on a different NFS or unshared completely. + v11.10.0 (2025-12-01) ===================== -- 2.52.0

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Entering freeze for libvirt-12.0.0
by Jiri Denemark 13 Jan '26

13 Jan '26

I have just tagged v12.0.0-rc1 in the repository and pushed signed tarballs to https://download.libvirt.org/ Please give the release candidate some testing and in case you find a serious issue which should have a fix in the upcoming release, feel free to reply to this thread to make sure the issue is more visible. If you have not done so yet, please update NEWS.rst to document any significant change you made since the last release. Jirka

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[PATCH 0/3] qemu: forbid modifying portForwards with live update-device
by Laine Stump 13 Jan '26

13 Jan '26

See 3/3 for details. Resolves: https://issues.redhat.com/browse/RHEL-7338 Laine Stump (3): util: fix equivalence of AF_UNSPEC virSocketAddrs conf: new function virDomainNetPortForwardIsEqual() qemu: forbid modifying network device portForwards with update-device src/conf/domain_conf.c | 53 ++++++++++++++++++++++++++++++++++++++++ src/conf/domain_conf.h | 3 +++ src/libvirt_private.syms | 1 + src/qemu/qemu_hotplug.c | 9 +++++++ src/util/virsocketaddr.c | 2 ++ 5 files changed, 68 insertions(+) -- 2.52.0

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[PATCH v2 0/1] x86: install modules-load.d file to load msr module
by Hector Cao 12 Jan '26

12 Jan '26

This submission is a follow-up (v2) of the discussion (RFC) that was happening at: https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/ADJ4A... On x86, libvirt makes use of the API exposed by the msr kernel module to read the MSR (Model Specific Registers) values. On some Linux distros, this module is not loaded by default so libvirt might fail to read the MSR values and falls back to /dev/kvm to obtain these values. KVM might be behind in term of exposing all the values of the MSRs so using /dev/kvm is not ideal. This submission tries to make libvirt deploy the modules-load.d configuration so that linux loads the msr module at next boot. One caveat, libvirt installs only the file and does not trigger the load that is only done at next reboot, it is up to each distro to trigger immediately the load of the module without a reboot. v2: - only install the file when qemu driver is enabled Hector Cao (1): x86: install modules-load.d file to load msr module meson_options.txt | 1 + src/util/meson.build | 19 +++++++++++++++++++ src/util/modules-load.d/msr.conf | 1 + tools/virt-host-validate-qemu.c | 7 +++++++ 4 files changed, 28 insertions(+) create mode 100644 src/util/modules-load.d/msr.conf -- 2.45.2

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[PATCH] news: document bhyve new features for 12.0.0
by Roman Bogorodskiy 12 Jan '26

12 Jan '26

Signed-off-by: Roman Bogorodskiy <bogorodskiy(a)gmail.com> --- NEWS.rst | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/NEWS.rst b/NEWS.rst index 6ca49a4c1b..6f9d1d2b34 100644 --- a/NEWS.rst +++ b/NEWS.rst @@ -17,6 +17,31 @@ v12.0.0 (unreleased) * **New features** + * bhyve: SLIRP networking support + + Domain XMLs now can use SLIRP user-mode networking:: + + <interface type='user'> + <model type='virtio'/> + </interface> + + * bhyve: virtio-scsi support + + Domain XMLs now can use ``virtio-scsi`` devices:: + + <disk type='ctl'> + <source dev='/dev/cam/ctl'/> + <target dev='sda' bus='scsi'/> + </disk> + + * bhyve: initial ARM64 support + + The bhyve driver now supports booting ARM64 domains on ARM64 hosts. + This support is still in early stage of development and has some + limitations. For example, it requires using + ``<clock offset='localtime'/>`` in domain XMLs, and + bootrom autofill is not implemented. + * **Improvements** * qemu: Improvements and fixes to firmware selection -- 2.52.0

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