September 2026 - Devel - libvirt List Archives

[PATCH v3 0/5] qemu: auto-select win-dmp for Windows guest crash dumps
by Denis V. Lunev 03 Sep '26

03 Sep '26

Auto-triggered dumps (on_crash, watchdog) always use QEMU's elf default, which is not WinDbg-loadable for a Windows guest and cannot be reliably converted after the fact. This was proposed before as a per-domain XML knob (https://www.mail-archive.com/devel@lists.libvirt.org/msg09638.html) Daniel P. Berrange objected: QEMU's query-dump-guest-memory-capability reported win-dmp as available on any x86-64 guest regardless of whether it had actually published a Windows dump header, so trusting it was not safe. QEMU's win_dump_available() has since been fixed to check the guest's vmcoreinfo note (https://lore.kernel.org/qemu-devel/20260619101834.228432-1-den@openvz.org/, commit b4bdad7dce). Validated against real guests: a Windows Server 2022 guest crashed via Sysinternals NotMyFault produces a PAGEDU64 (win-dmp) dump; an AlmaLinux 9 guest crashed via sysrq produces an ELF one. A 1GiB quota across two Linux crashes pruned the older dump and kept the newer, over-quota one. syntax-check and virstringtest pass. Changes since v2: * count a dump as the space it allocates, not its apparent size, so a sparse dump is not over-charged against the quota (Daniel). * rebased onto master. Changes since v1: * detect the 'allowed-by-guest' feature QEMU 11.1 puts on the win-dmp member of DumpGuestMemoryFormat (thanks Daniel for idea) * skip the probe unless that capability is present, so QEMU that offers win-dmp to every x86 guest keeps the elf default (Daniel). * fix the sort position of both new symbols in libvirt_private.syms, which v1 got wrong; picked up Daniel's Reviewed-by. * update virtlogd.aug and test_virtlogd.aug.in for the quoted form (Daniel). * update libvirtd_qemu.aug and test_libvirtd_qemu.aug.in for the new setting, and VIR_INFO -> VIR_DEBUG (both Daniel); count and remove only the dumps libvirt itself wrote, and skip pruning after a failed dump. * renamed test helpers for virStrToBytes * NEWS.rst entries added. Denis V. Lunev (5): qemu: add capability for guest-aware win-dmp availability qemu: auto-select win-dmp for crash- and watchdog-triggered dumps util: add virStrToBytes() and virConfGetValueBytes() for scaled sizes logging: accept a unit suffix in virtlogd's max_size qemu: cap total size of auto-triggered dumps under auto_dump_path NEWS.rst | 19 ++ src/libvirt_private.syms | 2 + src/logging/log_daemon_config.c | 2 +- src/logging/log_daemon_config.h | 2 +- src/logging/test_virtlogd.aug.in | 2 +- src/logging/virtlogd.aug | 5 +- src/logging/virtlogd.conf | 7 +- src/qemu/libvirtd_qemu.aug | 4 + src/qemu/qemu.conf.in | 17 ++ src/qemu/qemu_capabilities.c | 2 + src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_conf.c | 2 + src/qemu/qemu_conf.h | 1 + src/qemu/qemu_driver.c | 165 +++++++++++++++++- src/qemu/test_libvirtd_qemu.aug.in | 1 + src/util/virconf.c | 47 +++++ src/util/virconf.h | 3 + src/util/virutil.c | 23 +++ src/util/virutil.h | 5 + .../caps_11.1.0_aarch64.xml | 1 + .../caps_11.1.0_s390x.xml | 1 + .../caps_11.1.0_x86_64.xml | 1 + tests/qemumonitorjsontest.c | 3 + tests/virstringtest.c | 76 ++++++++ 24 files changed, 385 insertions(+), 7 deletions(-) -- 2.53.0

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[PATCH v2 0/5] qemu: auto-select win-dmp for Windows guest crash dumps
by Denis V. Lunev 01 Sep '26

01 Sep '26

Auto-triggered dumps (on_crash, watchdog) always use QEMU's elf default, which is not WinDbg-loadable for a Windows guest and cannot be reliably converted after the fact. This was proposed before as a per-domain XML knob (https://www.mail-archive.com/devel@lists.libvirt.org/msg09638.html) Daniel P. Berrange objected: QEMU's query-dump-guest-memory-capability reported win-dmp as available on any x86-64 guest regardless of whether it had actually published a Windows dump header, so trusting it was not safe. QEMU's win_dump_available() has since been fixed to check the guest's vmcoreinfo note (https://lore.kernel.org/qemu-devel/20260619101834.228432-1-den@openvz.org/, commit b4bdad7dce). Validated against real guests: a Windows Server 2022 guest crashed via Sysinternals NotMyFault produces a PAGEDU64 (win-dmp) dump; an AlmaLinux 9 guest crashed via sysrq produces an ELF one. A 1GiB quota across two Linux crashes pruned the older dump and kept the newer, over-quota one. syntax-check and virstringtest pass. Changes since v1: * detect the 'allowed-by-guest' feature QEMU 11.1 puts on the win-dmp member of DumpGuestMemoryFormat (thanks Daniel for idea) * skip the probe unless that capability is present, so QEMU that offers win-dmp to every x86 guest keeps the elf default (Daniel). * fix the sort position of both new symbols in libvirt_private.syms, which v1 got wrong; picked up Daniel's Reviewed-by. * update virtlogd.aug and test_virtlogd.aug.in for the quoted form (Daniel). * update libvirtd_qemu.aug and test_libvirtd_qemu.aug.in for the new setting, and VIR_INFO -> VIR_DEBUG (both Daniel); count and remove only the dumps libvirt itself wrote, and skip pruning after a failed dump. * renamed test helpers for virStrToBytes * NEWS.rst entries added. Denis V. Lunev (5): qemu: add capability for guest-aware win-dmp availability qemu: auto-select win-dmp for crash- and watchdog-triggered dumps util: add virStrToBytes() and virConfGetValueBytes() for scaled sizes logging: accept a unit suffix in virtlogd's max_size qemu: cap total size of auto-triggered dumps under auto_dump_path NEWS.rst | 19 ++ src/libvirt_private.syms | 2 + src/logging/log_daemon_config.c | 2 +- src/logging/log_daemon_config.h | 2 +- src/logging/test_virtlogd.aug.in | 2 +- src/logging/virtlogd.aug | 5 +- src/logging/virtlogd.conf | 7 +- src/qemu/libvirtd_qemu.aug | 4 + src/qemu/qemu.conf.in | 17 ++ src/qemu/qemu_capabilities.c | 4 + src/qemu/qemu_capabilities.h | 3 + src/qemu/qemu_conf.c | 2 + src/qemu/qemu_conf.h | 1 + src/qemu/qemu_driver.c | 163 +++++++++++++++++- src/qemu/test_libvirtd_qemu.aug.in | 1 + src/util/virconf.c | 47 +++++ src/util/virconf.h | 3 + src/util/virutil.c | 23 +++ src/util/virutil.h | 5 + .../caps_11.1.0_aarch64.replies | 5 +- .../caps_11.1.0_aarch64.xml | 1 + .../caps_11.1.0_x86_64.replies | 5 +- .../caps_11.1.0_x86_64.xml | 1 + tests/qemumonitorjsontest.c | 3 + tests/virstringtest.c | 76 ++++++++ 25 files changed, 394 insertions(+), 9 deletions(-) -- 2.53.0

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[libvirt PATCH v2] storage: logical: don't write past buffer bounds
by Ján Tomko 01 Sep '26

01 Sep '26

From: Ján Tomko <jtomko(a)redhat.com> If parsed number of extents is 0, the calculated buffer size won't hold the first regex_unit. Closes: https://gitlab.com/libvirt/libvirt/-/work_items/913 Signed-off-by: Ján Tomko <jtomko(a)redhat.com> --- src/storage/storage_backend_logical.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/src/storage/storage_backend_logical.c b/src/storage/storage_backend_logical.c index 51e9337820..6138c6fb81 100644 --- a/src/storage/storage_backend_logical.c +++ b/src/storage/storage_backend_logical.c @@ -127,6 +127,7 @@ virStorageBackendLogicalParseVolExtents(virStorageVolDef *vol, unsigned long long offset; unsigned long long size; unsigned long long length; + g_auto(GStrv) regex_array = NULL; g_autofree char *regex = NULL; /* Assume 1 extent (the regex for 'devices' is "(\\S+)") and only @@ -160,13 +161,10 @@ virStorageBackendLogicalParseVolExtents(virStorageVolDef *vol, } /* Allocate space for 'nextents' regex_unit strings plus a comma for each */ - regex = g_new0(char, nextents * (strlen(regex_unit) + 1) + 1); - strcat(regex, regex_unit); - for (i = 1; i < nextents; i++) { - /* "," is the separator of "devices" field */ - strcat(regex, ","); - strcat(regex, regex_unit); - } + regex_array = g_new0(char *, nextents + 1); + for (i = 0; i < nextents; i++) + regex_array[i] = g_strdup(regex_unit); + regex = g_strjoinv(",", regex_array); re = g_regex_new(regex, 0, 0, &err); if (!re) { -- 2.55.0

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[PATCH 0/6] resctrl: support whole-process allocations and monitoring
by Jedrzej Wasiukiewicz 01 Sep '26

01 Sep '26

Resctrl support in libvirt currently requires allocations and monitors to be associated with a set of vCPUs. This does not accurately model QEMU resource consumption, as IOThreads, worker threads and emulator threads also consume cache, memory bandwidth and energy. This series introduces a whole-process resctrl scope, allowing ``cachetune``, ``memorytune``, ``energytune`` and ``monitor`` elements to omit the ``vcpus`` attribute and apply to the entire QEMU emulator process. By placing the emulator process into the resctrl group before thread creation, all subsequently created threads inherit the same resctrl configuration. Major design choices: * A resctrl allocation or monitor without a ``vcpus`` attribute is treated as a whole-process group. * Whole-process allocations and per-vCPU allocations are mutually exclusive within a domain to avoid ambiguous resource assignment. * Whole-process monitors require a whole-process allocation of the same resource type and are unique per resource. * Monitors without ``vcpus`` inherit the scope of their parent allocation. Under a whole-process allocation they monitor the whole process; under a per-vCPU allocation they monitor the allocation's vCPU set. This reflects the dependency between resctrl monitoring and allocation groups. * Whole-process resctrl groups are created by placing the QEMU process into the target group before thread creation, allowing all subsequently created threads to inherit the same resctrl configuration. The series also updates XML validation, fixes resctrl monitor statistics reporting, and cleans up monitor domstats output. Jedrzej Wasiukiewicz (6): conf: allow omitting vcpus in cachetune/memorytune/energytune conf: implement whole-process resctrl scope qemu: assign whole-process resctrl groups at domain start qemu: fix resctrl monitor stats reporting the wrong group name qemu: clean up resctrl monitor domstats NEWS: Document whole-process resctrl support NEWS.rst | 11 + docs/formatdomain.rst | 57 +++-- src/conf/domain_conf.c | 231 ++++++++++++------ src/conf/domain_conf.h | 2 + src/conf/schemas/domaincommon.rng | 48 ++-- src/libvirt_private.syms | 1 + src/qemu/qemu_driver.c | 29 ++- src/qemu/qemu_process.c | 40 ++- src/util/virresctrl.c | 20 +- src/util/virresctrl.h | 3 + .../cachetune-monitor-empty-vcpus.xml | 30 +++ .../cachetune-monitor-inherit-alloc.xml | 30 +++ .../cachetune-wholeprocess-duplicate.xml | 32 +++ ...chetune-wholeprocess-monitor-duplicate.xml | 31 +++ .../cachetune-wholeprocess-monitors.xml | 31 +++ .../energytune-colliding-monitor.xml | 30 +++ .../energytune-wholeprocess.xml | 29 +++ .../memorytune-wholeprocess.xml | 29 +++ .../resctrl-wholeprocess-alloc-monitor.xml | 32 +++ .../resctrl-wholeprocess-layering.xml | 32 +++ .../resctrl-wholeprocess-monitors.xml | 33 +++ .../cachetune-monitor-inherit-alloc.xml | 30 +++ tests/genericxml2xmltest.c | 11 + 23 files changed, 694 insertions(+), 128 deletions(-) create mode 100644 tests/genericxml2xmlindata/cachetune-monitor-empty-vcpus.xml create mode 100644 tests/genericxml2xmlindata/cachetune-monitor-inherit-alloc.xml create mode 100644 tests/genericxml2xmlindata/cachetune-wholeprocess-duplicate.xml create mode 100644 tests/genericxml2xmlindata/cachetune-wholeprocess-monitor-duplicate.xml create mode 100644 tests/genericxml2xmlindata/cachetune-wholeprocess-monitors.xml create mode 100644 tests/genericxml2xmlindata/energytune-colliding-monitor.xml create mode 100644 tests/genericxml2xmlindata/energytune-wholeprocess.xml create mode 100644 tests/genericxml2xmlindata/memorytune-wholeprocess.xml create mode 100644 tests/genericxml2xmlindata/resctrl-wholeprocess-alloc-monitor.xml create mode 100644 tests/genericxml2xmlindata/resctrl-wholeprocess-layering.xml create mode 100644 tests/genericxml2xmlindata/resctrl-wholeprocess-monitors.xml create mode 100644 tests/genericxml2xmloutdata/cachetune-monitor-inherit-alloc.xml -- 2.43.0 --------------------------------------------------------------------- Intel Technology Poland sp. z o.o. ul. Slowackiego 173 | 80-298 Gdansk | Sad Rejonowy Gdansk Polnoc | VII Wydzial Gospodarczy Krajowego Rejestru Sadowego - KRS 101882 | NIP 957-07-52-316 | Kapital zakladowy 200.000 PLN. Spolka oswiadcza, ze posiada status duzego przedsiebiorcy w rozumieniu ustawy z dnia 8 marca 2013 r. o przeciwdzialaniu nadmiernym opoznieniom w transakcjach handlowych. Ta wiadomosc wraz z zalacznikami jest przeznaczona dla okreslonego adresata i moze zawierac informacje poufne. W razie przypadkowego otrzymania tej wiadomosci, prosimy o powiadomienie nadawcy oraz trwale jej usuniecie; jakiekolwiek przegladanie lub rozpowszechnianie jest zabronione. This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.

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Release of libvirt-12.7.0
by Jiri Denemark 01 Sep '26

01 Sep '26

The 12.7.0 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. * Security * CVE-2026-18917: Integer overflow in RPC handler for ``virNodeGetFreePages`` The RPC handler for ``virNodeGetFreePages`` didn't properly check for overflows in multiplication of integers when calculating the amount of returned data for validation and allocation of the return buffer. Specific values could thus pass validation and cause an undersized buffer to be allocated. The hypervisor driver would then fill the undersized buffer based on the values prior to multiplication and thus cause a write beyond the end of the allocated buffer. This bug can be triggered via a read-only connection. * CVE-2026-77158: Double free of disks array in ``qemuAgentGetDisks`` The qemu hypervisor driver would double-free the array of parsed disks, on error code paths leading to crash of the daemon. The error code path could be reached when the qemu guest agent provided malformed data as response to the ``guest-get-disks`` command. * CVE-2026-77159: ``chown()`` of swtpm log file follows symlinks When starting up a VM with a ``swtpm`` device configured, libvirt ``chown()``-s the log file of swtpm to the (unprivileged) user/group running the swtpm process. The problem is that the directory containing the log files is also owned by the same user/group, thus users with access to that directory could install a symlink to a privileged file that the libvirt daemon would follow and chown the file pointed to. * New features * bhyve: implement ``virDomainGetGuestInfo()`` and ``virDomainAgentSetResponseTimeout()`` APIs The bhyve driver now implements ``virDomainGetGuestInfo()`` which returns information about the guest, and ``virDomainAgentSetResponseTimeout()`` which sets the guest agent response timeout. * bhyve: allow setting disk serial numbers The bhyve driver now allows specifying ``<serial>`` for SATA disks and NVMe controllers:: <disk type='file'> <serial>BHYVE-SER01-0001</serial> <driver name='file' type='raw'/> <source file='/tmp/freebsd1.img'/> <target dev='hda' bus='sata' rotation_rate='7200'/> </disk> <controller type='nvme' index='0'> <serial>BHYVE-NVME0-01234</serial> </controller> It also supports specifying ``<wwn>`` for NVMe disks:: <disk type='file'> <driver name='file' type='raw'/> <source file='/path/to/some.img'/> <target dev='nvme0n1' bus='nvme'/> <wwn>01000000efbeadde</wwn> </disk> * qemu: Add poll-weight support for iothreads The qemu driver now supports the iothread poll-weight property, which controls the weight of the most recent event interval in the adaptive polling duration calculation. * Add guest device info to ``virDomainGetGuestInfo()`` QEMU guest agent has 'guest-get-devices` command, which returns information on guest devices (driver name, version, release date, and so on). This is now exposed via ``virDomainGetGuestInfo()`` API (accessible via ``guestinfo --devices`` virsh command). * Bug fixes * bhyve: fix domain API calls hanging after domain shutdown * remote: Fix stale virStream status In a few cases it might happen that daemon held incorrect state of a virStream leading to an infinite loop. This is now fixed. * esx: Don't crash when parsing unmounted datastore When libvirt constructs domain XML for an ESX domain it traverses through all datastores to find which one stores disks for the domain. But if a datastore wasn't mounted, then a crash would occur. This is now fixed. * virsh: Don't crash when certain error messages are printed A bug in the error printing function could cause ``virsh`` to crash when certain errors (e.g. disk not found in ``virsh detach-disk``) were being reported. Enjoy. Jirka

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