July 2025 - Devel - libvirt List Archives

Re: Clarification Needed: virsh snapshot-delete Behavior with External Snapshots (--disk-only)
by Peter Krempa 10 Apr '26

10 Apr '26

On Wed, Jul 23, 2025 at 04:57:57 +0000, P, Rajasekar via Users wrote: > Hello libvirt community, > > I am seeking clarification on the behavior of `virsh snapshot-delete` when used with external snapshots (created with the `--disk-only` option). > > **Environment:** > - libvirt version: 10.5.0 Note that this was released almost a year ago. > - Kernel version: 5.14.0-503.22.1.el9_5.x86_64 > - Disk image format: qcow2 > - Host OS: RHEL 9.5 > > **Steps to reproduce:** > 1. Create an external snapshot: > virsh snapshot-create-as --domain <vm> --name snap1 --disk-only --atomic > 2. Delete the snapshot: > virsh snapshot-delete <vm> --snapshotname snap1 > > **Observed behavior:** > - Changes from the overlay (snapshot) file are merged into the base image. > - The snapshot metadata is removed from libvirt. > - The snapshot file remains on disk (appears orphaned). You mean that the original overlay images remained on disk? e.g. /path/to/originalimage.snap1 ? > **Questions:** > - Is the observed automatic merge of the overlay file into the base image during `snapshot-delete` the intended behavior for external snapshots in recent libvirt versions? Or we need separate `blockcommit` step. Yes it is intended, because deleting a snapshot is effectively meaning "I don't want to return to this point any more" so the extra overlay makes no sense. > - Should the snapshot file be deleted automatically, or is manual cleanup required? If you mean the overlay, then yes it should have been deleted. > - Is there any official documentation that clarifies this behavior for external snapshots, as most documentation seems to focus on internal snapshots? The semantics of external and internal snapshots are supposed to be indentical. I don't think we document to a deep extent the actual behaviour WRT to the disk files.

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[PATCH v2] virhostcpu: Fix potential use of unallocated memory
by Felix Huettner 26 Mar '26

26 Mar '26

In case of a host that has a large number of cpus offline the count of host cpus and the last bit set in the virHostCPUGetOnlineBitmap might diverge significantly. This can e.g. be the case when disabling smt via /sys/devices/system/cpu/smt/control. On the host this looks like: ``` $ cat /sys/devices/system/cpu/present 0-255 $ cat /sys/devices/system/cpu/online 0-127 ``` However in this case virBitmapToData previously only allocated 16 bytes for the output bitmap. This is becase the last set bit is on the 15th byte. Users of virHostCPUGetMap however rely on the "cpumap" containing enough space for all existing cpus (so they would expect 32 bytes in this case). E.g. cmdNodeCpuMap relies on this for its output. It will then actually read 32 bytes from the start of the "cpumap" address where in this case the last 16 of these bytes are uninitialized. This manifests itself in flapping outputs of "virsh nodecpumap --pretty" like: ``` $ virsh nodecpumap --pretty CPUs present: 256 CPUs online: 128 CPU map: 0-127,192,194,202 $ virsh nodecpumap --pretty CPUs present: 256 CPUs online: 128 CPU map: 0-127,192,194,197 $ virsh nodecpumap --pretty CPUs present: 256 CPUs online: 128 CPU map: 0-127,192,194,196-197 ``` This in turn potentially causes users of this data to report wrong cpu counts. Note that this only seems to happen with at least 256 physical cpus where at least 128 are offline. We fix this by preallocating the expected bitmap size. Signed-off-by: Felix Huettner <felix.huettner(a)stackit.cloud> --- src/util/virhostcpu.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/src/util/virhostcpu.c b/src/util/virhostcpu.c index 5dbcc8987c..4805484b1d 100644 --- a/src/util/virhostcpu.c +++ b/src/util/virhostcpu.c @@ -1090,28 +1090,26 @@ virHostCPUGetMap(unsigned char **cpumap, unsigned int flags) { g_autoptr(virBitmap) cpus = NULL; - int ret = -1; - int dummy; + int ncpus = virHostCPUGetCount(); virCheckFlags(0, -1); if (!cpumap && !online) - return virHostCPUGetCount(); + return ncpus; if (!(cpus = virHostCPUGetOnlineBitmap())) - goto cleanup; + return -1; + + if (cpumap) { + int len = (ncpus + CHAR_BIT) / CHAR_BIT; + *cpumap = g_new0(unsigned char, len); + virBitmapToDataBuf(cpus, *cpumap, len); + } - if (cpumap) - virBitmapToData(cpus, cpumap, &dummy); if (online) *online = virBitmapCountBits(cpus); - ret = virHostCPUGetCount(); - - cleanup: - if (ret < 0 && cpumap) - VIR_FREE(*cpumap); - return ret; + return ncpus; } base-commit: c5a73f75bc6cae4f466d0a6344d5b3277ac9c2f4 -- 2.43.0

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[PULL 02/18] deprecation: don't enable TCG plugins by default with TCI
by Alex Bennée 28 Feb '26

28 Feb '26

The softmmu memory instrumentation test sees so many more accesses than a normal translated host and its really not worth fixing up. Lets deprecate this odd configuration and save on the CI cycles. Reviewed-by: Pierrick Bouvier <pierrick.bouvier(a)linaro.org> Signed-off-by: Alex Bennée <alex.bennee(a)linaro.org> Message-Id: <20240916085400.1046925-3-alex.bennee(a)linaro.org> diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst index 809b2b9b81..c0aa52def5 100644 --- a/docs/about/deprecated.rst +++ b/docs/about/deprecated.rst @@ -196,6 +196,14 @@ benefits from having plenty of host memory it seems reasonable to encourage users to use 64 bit builds of QEMU for analysis work whatever targets they are instrumenting. +TCG Plugin support not enabled by default with TCI (since 9.2) +'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' + +While the TCG interpreter can interpret the TCG ops used by plugins it +is going to be so much slower it wouldn't make sense for any serious +instrumentation. Due to implementation differences there will also be +anomalies in things like memory instrumentation. + System emulator CPUs -------------------- diff --git a/configure b/configure index cc8e1ed5b8..aa7aae70fa 100755 --- a/configure +++ b/configure @@ -629,6 +629,9 @@ meson_option_parse() { exit 1 fi } +has_meson_option() { + test "${meson_options#*"$1"}" != "$meson_options" +} meson_add_machine_file() { if test "$cross_compile" = "yes"; then @@ -1048,8 +1051,12 @@ if test "$static" = "yes" ; then plugins="no" fi if test "$plugins" != "no" && test $host_bits -eq 64; then - plugins=yes - subdirs="$subdirs contrib/plugins" + if has_meson_option "-Dtcg_interpreter=true"; then + plugins="no" + else + plugins=yes + subdirs="$subdirs contrib/plugins" + fi fi cat > $TMPC << EOF -- 2.39.5

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[PATCH v4 00/23] LIBVIRT: X86: TDX support
by Zhenzhong Duan 07 Jan '26

07 Jan '26

Hi, This series brings libvirt the x86 TDX support. * What's TDX? TDX stands for Trust Domain Extensions which isolates VMs from the virtual-machine manager (VMM)/hypervisor and any other software on the platform. This patchset extends libvirt to support TDX, with which one can start a TDX guest from high level rather than running qemu directly. * Misc As QEMU use a software emulated way to reset guest which isn't supported by TDX guest for security reason. We simulate reboot for TDX guest by kill and create a new one in FakeReboot framework. Complete code can be found at [1]. * Test Tested with upstream qemu v10.0.0-1724-gf9a3def17b shutdown/reboot/reset with virsh shutdown/reboot trigger in guest shutdown with on_poweroff=destroy/restart reboot with on_reboot=destroy/restart GUEST_PANICKED event processing auto firmware matching * Patch organization - patch 1-4: Some preparing work - patch 5-6: Support query of TDX capabilities - patch 7-15: Add TDX type to launchsecurity framework - patch 16-21: Add reboot/reset support to TDX guest - patch 22: Add conf test dump/cases for '+inteltdx' variant - patch 23: Add docs TODO: - add reconnect logic in virsh command [1] https://github.com/intel/libvirt-tdx/commits/tdx_for_upstream_v4 Thanks Zhenzhong Changelog: v4: - add QGS config to qemuxmlconftest (Daniel) - use 0x10000000 policy value in test as debug isn't supported yet (Daniel) - s/mrowner/mrOwner/ s/mrownerconfig/mrOwnerConfig/ (Daniel) - s/quoteGenerationSocket/quoteGenerationService/ (Daniel) - handle "GUEST_PANICKED" event of type tdx (Daniel) - add automatic firmware matching (Daniel) v3: - fix a hiden failure in qemuBuildTDXQGSCommandLine() (Peter Krempa) - avoid the use of the ternary operator (Peter Krempa) - add capability test dump before capability introduced (Peter Krempa) - change tests version number from 11.0.0 to 10.1.0 (Peter Krempa) v2: - add capability and xmlconf test (Peter Krempa) v1: - s/virQEMUCapsKVMSupportsSecureGuestINTEL/virQEMUCapsKVMSupportsSecureGuestTDX (Daniel) - make policy element optional and expose to QEMU directly (Daniel) - s/qemuProcessSecFakeReboot/qemuProcessFakeRebootViaRecreate (Daniel) - simplify QGS element schema by supporting only UNIX socket (Daniel) - add new events VIR_DOMAIN_EVENT_[STOPPED|STARTED] for control plane (Daniel) - s/quoteGenerationService/quoteGenerationSocket as QEMU - add virsh reset support rfcv4: - add a check to tools/virt-host-validate-qemu.c (Daniel) - remove check of q35 (Daniel) - model 'SocktetAddress' QAPI in xml schema (Daniel) - s/Quote-Generation-Service/quoteGenerationService/ (Daniel) - define bits in tdx->policy and add validating logic (Daniel) - presume QEMU choose split kernel irqchip for TDX guest by default (Daniel) - utilize existing FakeReboot framework to do reboot for TDX guest (Daniel) - drop patch11 'conf: Add support to keep same domid for hard reboot' (Daniel) - add test in tests/ to validate parsing and formatting logic (Daniel) - add doc in docs/formatdomain.rst (Daniel) - add R-B rfcv3: - Change to generate qemu cmdline with -bios - drop firmware auto match as -bios is used - add a hard reboot method to reboot TDX guest rfcv3: https://www.mail-archive.com/devel@lists.libvirt.org/msg00385.html rfcv2: - give up using qmp cmd and check TDX directly on host for TDX capabilities. - use launchsecurity framework to support TDX - use <os>.<loader> for general loader - add auto firmware match feature for TDX A example TDVF fimware description file 70-edk2-x86_64-tdx.json: { "description": "UEFI firmware for x86_64, supporting Intel TDX", "interface-types": [ "uefi" ], "mapping": { "device": "generic", "filename": "/usr/share/OVMF/OVMF_CODE-tdx.fd" }, "targets": [ { "architecture": "x86_64", "machines": [ "pc-q35-*" ] } ], "features": [ "intel-tdx", "verbose-dynamic" ], "tags": [ ] } rfcv2: https://www.mail-archive.com/libvir-list@redhat.com/msg219378.html Zhenzhong Duan (23): tools: Secure guest check for Intel in virt-host-validate qemu: Check if INTEL Trust Domain Extention support is enabled qemucapabilitiesdata: Document '+inteltdx' variant qemucapabilitiestest: Add data for the qemu-10.1.0 dev cycle on x86_64 for the '+inteltdx' variant qemu: Add QEMU_CAPS_TDX_GUEST capability conf: Expose TDX feature in domain capabilities conf: Add tdx as launch security type conf: Validate TDX launchSecurity element mrConfigId/mrOwner/mrOwnerConfig qemu: Add command line and validation for TDX type conf: Expose TDX type in domain launch security capability qemu: Force special parameters enabled for TDX guest qemu: log the crash information for TDX qemu_firmware: Pick the right firmware for TDX guests conf: Add Intel TDX Quote Generation Service(QGS) support qemu: Add command line for TDX Quote Generation Service(QGS) qemu: Add FakeReboot support for TDX guest qemu: Support reboot command in guest qemu: Avoid duplicate FakeReboot for secure guest qemu: Send event VIR_DOMAIN_EVENT_[STOPPED|STARTED] during recreation qemu: Bypass sending VIR_DOMAIN_EVENT_RESUMED event when TD VM reboot qemu: Support domain reset command for TDX guest qemuxmlconftest: Add latest version of 'launch-security-tdx*' test data docs: domain: Add documentation for Intel TDX guest docs/formatdomain.rst | 63 + docs/formatdomaincaps.rst | 1 + examples/c/misc/event-test.c | 6 + include/libvirt/libvirt-domain.h | 2 + src/conf/domain_capabilities.c | 1 + src/conf/domain_capabilities.h | 1 + src/conf/domain_conf.c | 82 + src/conf/domain_conf.h | 21 + src/conf/domain_validate.c | 11 + src/conf/schemas/domaincaps.rng | 9 + src/conf/schemas/domaincommon.rng | 41 + src/conf/virconftypes.h | 2 + src/qemu/qemu_capabilities.c | 38 +- src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_cgroup.c | 1 + src/qemu/qemu_command.c | 43 + src/qemu/qemu_domain.h | 1 + src/qemu/qemu_driver.c | 11 +- src/qemu/qemu_firmware.c | 20 + src/qemu/qemu_monitor.c | 50 +- src/qemu/qemu_monitor.h | 13 +- src/qemu/qemu_monitor_json.c | 38 +- src/qemu/qemu_namespace.c | 1 + src/qemu/qemu_process.c | 104 +- src/qemu/qemu_process.h | 2 + src/qemu/qemu_validate.c | 45 + src/security/security_dac.c | 2 + .../qemu_10.1.0-q35.x86_64+inteltdx.xml | 783 + .../domaincapsdata/qemu_10.1.0-q35.x86_64.xml | 7 +- .../qemu_10.1.0-tcg.x86_64+inteltdx.xml | 1830 + .../domaincapsdata/qemu_10.1.0-tcg.x86_64.xml | 6 +- .../qemu_10.1.0.x86_64+inteltdx.xml | 783 + tests/domaincapsdata/qemu_10.1.0.x86_64.xml | 7 +- tests/domaincapsmock.c | 3 +- tests/qemucapabilitiesdata/README.rst | 5 + .../caps_10.1.0_x86_64+inteltdx.replies | 44552 ++++++++++++++++ .../caps_10.1.0_x86_64+inteltdx.xml | 3585 ++ .../caps_10.1.0_x86_64.xml | 1 + .../caps.x86_64+inteltdx.xml | 29 + .../firmware/60-edk2-ovmf-x64-inteltdx.json | 1 + ...h-security-tdx.x86_64-latest+inteltdx.args | 44 + ...ch-security-tdx.x86_64-latest+inteltdx.xml | 75 + tests/qemuxmlconfdata/launch-security-tdx.xml | 28 + tests/qemuxmlconftest.c | 3 + tools/virsh-domain-event.c | 6 +- tools/virt-host-validate-common.c | 31 +- tools/virt-host-validate-common.h | 1 + 47 files changed, 52372 insertions(+), 18 deletions(-) create mode 100644 tests/domaincapsdata/qemu_10.1.0-q35.x86_64+inteltdx.xml create mode 100644 tests/domaincapsdata/qemu_10.1.0-tcg.x86_64+inteltdx.xml create mode 100644 tests/domaincapsdata/qemu_10.1.0.x86_64+inteltdx.xml create mode 100644 tests/qemucapabilitiesdata/caps_10.1.0_x86_64+inteltdx.replies create mode 100644 tests/qemucapabilitiesdata/caps_10.1.0_x86_64+inteltdx.xml create mode 100644 tests/qemucaps2xmloutdata/caps.x86_64+inteltdx.xml create mode 100644 tests/qemuxmlconfdata/launch-security-tdx.x86_64-latest+inteltdx.args create mode 100644 tests/qemuxmlconfdata/launch-security-tdx.x86_64-latest+inteltdx.xml create mode 100644 tests/qemuxmlconfdata/launch-security-tdx.xml -- 2.47.1

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[Libvir] Hang with virt-install graphic=no on FC 6 6.93/F7 RC2
by libvirtuser 23 Dec '25

23 Dec '25

I had this problem and another user confirmed the same behavior on his machine: http://pastie.caboo.se/65417 Haven't tried it with *2925.10* yet. Also, is there a way to get more verbose info about what calls are causing the "configuration file syntax error" errors? Thanks. virt-install How large would you like the disk () to be (in gigabytes)? 4 ERROR: Must provide a file, not a directory for the disk What would you like to use as the disk (path)? /xen/images/x6.img Would you like to enable graphics support? (yes or no) no What is the install location? http://mirror.anl.gov/pub/fedora-linux-core/test/6.93/Fedora/i386/os/ Starting install... libvir: Xen Daemon error : GET operation failed: libvir: error : configuration file syntax error: expecting a name libvir: error : configuration file syntax error: expecting a name libvir: error : configuration file syntax error: expecting a name Retrieving Fedora... 276 kB 00:01 Retrieving vmlinuz... 100% |=========================| 2.1 MB 00:16 Retrieving initrd.img... 100% |=========================| 5.4 MB 00:28 libvir: Xen Daemon error : GET operation failed: libvir: error : configuration file syntax error: expecting a name libvir: error : configuration file syntax error: expecting a name libvir: error : configuration file syntax error: expecting a name Creating domain... 0 B 00:06 Linux version 2.6.20-2925.5.fc7xen (brewbuilder(a)ls20-bc1-14.build.redhat.com) (gcc version 4.1.2 20070317 (Red Hat 4.1.2-5)) #1 SMP Thu Mar 22 13:51:38 EDT 2007 BIOS-provided physical RAM map: sanitize start sanitize bail 0 copy_e820_map() start: 0000000000000000 size: 0000000020800000 end: 0000000020800000 type: 1 Xen: 0000000000000000 - 0000000020800000 (usable) 0MB HIGHMEM available. 520MB LOWMEM available. Using x86 segment limits to approximate NX protection Zone PFN ranges: DMA 0 -> 133120 Normal 133120 -> 133120 HighMem 133120 -> 133120 early_node_map[1] active PFN ranges 0: 0 -> 133120 ACPI in unprivileged domain disabled Built 1 zonelists. Total pages: 132080 Kernel command line: method=http://mirror.anl.gov/pub/fedora-linux-core/test/6.93/Fedora/i386/os/ Enabling fast FPU save and restore... done. Enabling unmasked SIMD FPU exception support... done. Initializing CPU#0 CPU 0 irqstacks, hard=c135f000 soft=c133f000 PID hash table entries: 4096 (order: 12, 16384 bytes) Xen reported: 1694.994 MHz processor. Console: colour dummy device 80x25 Lock dependency validator: Copyright (c) 2006 Red Hat, Inc., Ingo Molnar ... MAX_LOCKDEP_SUBCLASSES: 8 ... MAX_LOCK_DEPTH: 30 ... MAX_LOCKDEP_KEYS: 2048 ... CLASSHASH_SIZE: 1024 ... MAX_LOCKDEP_ENTRIES: 8192 ... MAX_LOCKDEP_CHAINS: 16384 ... CHAINHASH_SIZE: 8192 memory used by lock dependency info: 1064 kB per task-struct memory footprint: 1200 bytes Dentry cache hash table entries: 131072 (order: 7, 524288 bytes) Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) Software IO TLB disabled vmalloc area: e1000000-f4ffe000, maxmem 2d7fe000 Memory: 503936k/532480k available (2030k kernel code, 19948k reserved, 1079k data, 180k init, 0k highmem) virtual kernel memory layout: fixmap : 0xf5315000 - 0xf57fe000 (5028 kB) pkmap : 0xf5000000 - 0xf5200000 (2048 kB) vmalloc : 0xe1000000 - 0xf4ffe000 ( 319 MB) lowmem : 0xc0000000 - 0xe0800000 ( 520 MB) .init : 0xc130e000 - 0xc133b000 ( 180 kB) .data : 0xc11fb9d9 - 0xc1309714 (1079 kB) .text : 0xc1000000 - 0xc11fb9d9 (2030 kB) Checking if this processor honours the WP bit even in supervisor mode... Ok. Calibrating delay using timer specific routine.. 4262.67 BogoMIPS (lpj=8525343) Security Framework v1.0.0 initialized SELinux: Initializing. SELinux: Starting in permissive mode selinux_register_security: Registering secondary module capability Capability LSM initialized as secondary Mount-cache hash table entries: 512 CPU: Trace cache: 12K uops, L1 D cache: 8K CPU: L2 cache: 256K Checking 'hlt' instruction... OK. SMP alternatives: switching to UP code Freeing SMP alternatives: 11k freed Brought up 1 CPUs Grant table initialized NET: Registered protocol family 16 Brought up 1 CPUs PCI: Fatal: No config space access function found PCI: setting up Xen PCI frontend stub Setting up standard PCI resources ACPI: Interpreter disabled. Linux Plug and Play Support v0.97 (c) Adam Belay pnp: PnP ACPI: disabled xen_mem: Initialising balloon driver. usbcore: registered new interface driver usbfs usbcore: registered new interface driver hub usbcore: registered new device driver usb PCI: System does not support PCI PCI: System does not support PCI NetLabel: Initializing NetLabel: domain hash size = 128 NetLabel: protocols = UNLABELED CIPSOv4 NetLabel: unlabeled traffic allowed by default NET: Registered protocol family 2 IP route cache hash table entries: 32768 (order: 5, 131072 bytes) TCP established hash table entries: 131072 (order: 10, 4194304 bytes) TCP bind hash table entries: 65536 (order: 9, 2097152 bytes) TCP: Hash tables configured (established 131072 bind 65536) TCP reno registered checking if image is initramfs... it is Freeing initrd memory: 7256k freed IA-32 Microcode Update Driver: v1.14-xen <tigran(a)veritas.com> audit: initializing netlink socket (disabled) audit(1180379657.981:1): initialized VFS: Disk quotas dquot_6.5.1 Dquot-cache hash table entries: 1024 (order 0, 4096 bytes) SELinux: Registering netfilter hooks io scheduler noop registered io scheduler anticipatory registered io scheduler deadline registered io scheduler cfq registered (default) pci_hotplug: PCI Hot Plug PCI Core version: 0.5 BUG: at kernel/fork.c:994 copy_process() [<c1005d9a>] show_trace_log_lvl+0x1a/0x2f [<c1006343>] show_trace+0x12/0x14 [<c10063be>] dump_stack+0x16/0x18 [<c101d044>] copy_process+0x195/0x1245 [<c101e144>] do_fork+0x50/0x117 [<c1003351>] kernel_thread+0x8e/0x96 [<c102c701>] __call_usermodehelper+0x2d/0x46 [<c102cd4f>] run_workqueue+0x89/0x145 [<c102d711>] worker_thread+0xd5/0x102 [<c102ff27>] kthread+0xb3/0xdc [<c10058db>] kernel_thread_helper+0x7/0x10 ======================= rtc: IRQ 8 is not free. Non-volatile memory driver v1.2 Linux agpgart interface v0.101 (c) Dave Jones RAMDISK driver initialized: 16 RAM disks of 16384K size 4096 blocksize input: Macintosh mouse button emulation as /class/input/input0 Xen virtual console successfully installed as xvc0 Event-channel device installed. usbcore: registered new interface driver libusual usbcore: registered new interface driver hiddev usbcore: registered new interface driver usbhid drivers/usb/input/hid-core.c: v2.6:USB HID core driver PNP: No PS/2 controller found. Probing ports directly. i8042.c: No controller found. mice: PS/2 mouse device common for all mice TCP bic registered Initializing XFRM netlink socket NET: Registered protocol family 1 NET: Registered protocol family 17 Using IPI No-Shortcut mode XENBUS: Device with no driver: device/vbd/51712 XENBUS: Device with no driver: device/vif/0 Freeing unused kernel memory: 180k freed Write protecting the kernel read-only data: 762k ^[Domain installation still in progress. You can reconnect

2 1

[ PATCH vf-token 0/8] Introduce vf-token when using userspace PF
by Vivek Kashyap 23 Dec '25

23 Dec '25

The VFIO PCI ABI has been extended to require userspace PF driver to set a VF token to a known value. The VF drivers are then required to provide this token to access the VF device. The vf-token is set by the PF driver before VF drivers can access the device. The kernel provides no means to retrieve the token in use; but there is no specification describing the distribution or level of confidentiality of the token. Qemu has been extended to require the vf-token when vf device is used. An important point to note is that the vf-token is required only when both the PF and VF are used in userspace. This patch series adds support to provide the vf-token (uuid format) in the domain XML and to generate the qemu commandline including the vf-token. To support vf-token the new element will be used as follows: <hostdev mode='subsystem' type='pci' managed='yes'> <driver name='vfio'/> <source> <address domain='0x0000' bus='0x0' slot='0x00' function='0x1'> <vf-token uuid='00112233-4455-6677-8899-aabbccddeeff'/> </address> </source> <address type='pci' domain='0x0000' bus='0x00' slot='0x01' function='0x0'/> </hostdev> The generated commandline will include the following: -device {"driver":"vfio-pci","host":"0000:00:0.1", "vf-token":"00112233-4455-6677-8899-aabbccddeeff", "id":"hostdev0","bus":"pci.0","addr":"0x1"} Changes since initial RFC based on review comments received: 1. Added documentation 2. Added test cases and ran successful test suite after each patch commit 3. fixed spaces, coding sytle, and uuid string format 4. Used S:vftoken in virJSONValueObjectAdd instead of a conditional Vivek Kashyap (8): Define the vf-token extension for PCI device Introduce the vf-token qemu capability This patch introduces the PCI address extension flag for vf-token This patch introduces new XML parser/formatter functions for parsing the vf-token Introduce a validation function for vf-token support in qemu and generate vf-token device attribute in qemu command line Provide information about the vf-token flag Add tests for the vf-token flag to the qemuxml2argv and qemuxml2xml test suites Update news about vf-token NEWS.rst | 8 +++ docs/formatdomain.rst | 3 ++ src/conf/device_conf.c | 49 ++++++++++++++++--- src/conf/domain_addr.h | 1 + src/conf/domain_conf.c | 8 +++ src/conf/schemas/basictypes.rng | 7 +++ src/libvirt_private.syms | 1 + src/qemu/qemu_capabilities.c | 3 ++ src/qemu/qemu_capabilities.h | 1 + src/qemu/qemu_command.c | 8 +++ src/qemu/qemu_domain_address.c | 3 ++ src/qemu/qemu_validate.c | 20 ++++++++ src/util/virpci.c | 7 +++ src/util/virpci.h | 10 ++++ .../qemucapabilitiesdata/caps_8.1.0_s390x.xml | 1 + .../caps_8.1.0_x86_64.xml | 1 + .../caps_8.2.0_x86_64.xml | 1 + .../hostdev-vfio-vf-token.x86_64-latest.args | 34 +++++++++++++ .../hostdev-vfio-vf-token.xml | 22 +++++++++ tests/qemuxml2argvtest.c | 1 + .../hostdev-vfio-vf-token.x86_64-latest.xml | 40 +++++++++++++++ tests/qemuxml2xmltest.c | 1 + 22 files changed, 223 insertions(+), 7 deletions(-) create mode 100644 tests/qemuxml2argvdata/hostdev-vfio-vf-token.x86_64-latest.args create mode 100644 tests/qemuxml2argvdata/hostdev-vfio-vf-token.xml create mode 100644 tests/qemuxml2xmloutdata/hostdev-vfio-vf-token.x86_64-latest.xml -- 2.33.8

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[PATCH 0/1] cpu_map: fix vmx-* features wrong bitmaps
by Hector Cao 12 Nov '25

12 Nov '25

Hello, I'm unable to make virsh capabilities to detect the right CPU model on an Intel Granite Rapids platform. I would expect the get the CPU model defined in one of the src/cpu_map/x86_GraniteRapids*.xml files. The cause of the wrong detection is the fact that some vmx-* are not correctly detected and considered missing on this platform. When I take a look at the src/cpu_map/x86_features.xml file, I think that some of the vmx-* are wrongly defined. Taking as an example the vmx-apicv-xapic feature, it is defined as the first bit in the EAX register when we read the MSR 0x0000048b . But in Intel specification, this feature is represented as the first bit in the EDX register (32 higher bits). You can find in this submission the patch that fixes this issue, and this for all the affected MSRs. I tested this fix on my Granite Rapids platform and the CPU model is now correctly detected. Hector Cao (1): cpu_map: fix vmx-* features wrong bitmaps src/cpu_map/x86_features.xml | 136 +++++++++++++++++------------------ 1 file changed, 68 insertions(+), 68 deletions(-) -- 2.45.2

4 10

[RFC PATCH v4 0/5] Added virtio-net RSS with eBPF support.
by Andrew Melnychenko 14 Oct '25

14 Oct '25

This series of rfc patches adds support for loading the RSS eBPF program and passing it to the QEMU. Comments and suggestions would be useful. QEMU with vhost may work with RSS through eBPF. To load eBPF, the capabilities required that Libvirt may provide. eBPF program and maps may be unique for particular QEMU and Libvirt retrieves eBPF through qapi. For now, there is only "RSS" eBPF object in QEMU, in the future, there may be another one(g.e. network filters). That's why in Libvirt added logic to load and store any eBPF object that QEMU provides using qapi schema. One of the reasons why this series of patches is in RFC are tests. To this series of patches, the tests were added. For now, the tests are synthetic, the proper "reply" file should be generated with a new "caps" file. Currently, there are changes in caps-9.0.0* and caps-9.1.0 files. There was added support for ebpf_rss_fds feature, and request-ebpf command. So, overall, the tests are required for review, comment, and discussion how we want them to be implemented in the future. For virtio-net RSS, the document has not changed. ``` <interface type="network"> <model type="virtio"/> <driver queues="4" rss="on" rss_hash_report="off"/> <interface type="network"> ``` Simplified routine for RSS: * Libvirt retrieves eBPF "RSS" and load it. * Libvirt passes file descriptors to virtio-net with property "ebpf_rss_fds" ("rss" property should be "on" too). * if fds was provided - QEMU using eBPF RSS implementation. * if fds was not provided - QEMU tries to load eBPF RSS in own context and use it. * if eBPF RSS was not loaded - QEMU uses "in-qemu" RSS(vhost not supported). Changes since RFC v3: * changed tests a bit * refactored and rebased * removed "allowEBPF" from qemu config(now env is used for tests) Changes since RFC v2: * refactored and rebased. * applied changes according to the Qemu. * added basic test. Changes since RFC v1: * changed eBPF format saved in the XML cache. * refactored and checked with syntax test. * refactored patch hunks. Andrew Melnychenko (5): qemu_monitor: Added QEMU's "request-ebpf" support. qemu_capabilities: Added logic for retrieving eBPF objects from QEMU. qemu_interface: Added routine for loading the eBPF objects. qemu_command: Added "ebpf_rss_fds" support for virtio-net. tests: Added tests for eBPF blob loading. libvirt.spec.in | 3 + meson.build | 7 + meson_options.txt | 1 + src/qemu/meson.build | 1 + src/qemu/qemu_capabilities.c | 132 ++++++++++++ src/qemu/qemu_capabilities.h | 5 + src/qemu/qemu_command.c | 60 ++++++ src/qemu/qemu_domain.c | 4 + src/qemu/qemu_domain.h | 3 + src/qemu/qemu_interface.c | 87 ++++++++ src/qemu/qemu_interface.h | 7 + src/qemu/qemu_monitor.c | 9 + src/qemu/qemu_monitor.h | 4 + src/qemu/qemu_monitor_json.c | 27 +++ src/qemu/qemu_monitor_json.h | 4 + .../caps_9.0.0_sparc.replies | 95 +++++---- .../qemucapabilitiesdata/caps_9.0.0_sparc.xml | 3 + .../caps_9.0.0_x86_64.replies | 199 ++++++++++-------- .../caps_9.0.0_x86_64.xml | 4 + .../caps_9.1.0_x86_64.replies | 199 ++++++++++-------- .../caps_9.1.0_x86_64.xml | 4 + tests/qemuxml2argvmock.c | 24 +++ .../net-virtio-rss-bpf.x86_64-latest.args | 37 ++++ .../net-virtio-rss-bpf.x86_64-latest.xml | 46 ++++ tests/qemuxmlconfdata/net-virtio-rss-bpf.xml | 46 ++++ tests/qemuxmlconftest.c | 5 + 26 files changed, 792 insertions(+), 224 deletions(-) create mode 100644 tests/qemuxmlconfdata/net-virtio-rss-bpf.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/net-virtio-rss-bpf.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/net-virtio-rss-bpf.xml -- 2.45.2

3 7

[PATCHv2] passt: Define backend hostname and fqdn
by Enrique Llorente 03 Sep '25

03 Sep '25

This commit introduces a feature enhancement for configuring hostnames in virtual machines (VMs) using DHCP. It adds new options to the "passt" tool to set the hostname and fully qualified domain name (FQDN) for VMs. These map to DHCP option 12 for the hostname and options 81 (IPv4) and 39 (IPv6) for the FQDN. The update enables passt to dynamically assign hostnames to DHCP-aware VMs. To achieve this, the commit adds two fields to the passt domain XML backend. These fields allow passt to configure the hostname and FQDN for the virtual machine, ensuring smooth integration with the DHCP protocol. This improvement is particularly valuable in environments where VMs need dynamic hostname configuration, enhancing flexibility and automation in virtualized network setups. libvirt: Integrate passt --hostname --fqdn options Resolves: https://issues.redhat.com/browse/RHEL-79806 Signed-off-by: Enrique Llorente <ellorent(a)redhat.com> --- Compared to v1 this fix the mapping between backend fqdn and hostname docs/formatdomain.rst | 8 +++++--- src/conf/domain_conf.c | 10 +++++++++- src/conf/domain_conf.h | 2 ++ src/conf/schemas/domaincommon.rng | 6 ++++++ src/qemu/qemu_passt.c | 6 ++++++ tests/qemuxmlconfdata/net-user-passt.x86_64-7.2.0.xml | 2 +- tests/qemuxmlconfdata/net-user-passt.x86_64-latest.xml | 2 +- tests/qemuxmlconfdata/net-user-passt.xml | 2 +- .../net-vhostuser-passt.x86_64-latest.xml | 2 +- tests/qemuxmlconfdata/net-vhostuser-passt.xml | 2 +- 10 files changed, 33 insertions(+), 9 deletions(-) diff --git a/docs/formatdomain.rst b/docs/formatdomain.rst index 8753ee9c23..9c80aa9270 100644 --- a/docs/formatdomain.rst +++ b/docs/formatdomain.rst @@ -5372,10 +5372,12 @@ came from the host's IP. There are a few other options that are configurable only for the passt backend. For example, the ``<backend>`` attribute ``logFile`` can be used to tell the passt process for this interface where to write its -message log, and the ``<source>`` attribute ``dev`` can tell it a +message log, the ``<source>`` attribute ``dev`` can tell it a particular host interface to use when deriving the routes given to the -guest for forwarding traffic upstream. Due to the design decisions of -passt, when using SELinux on the host, it is recommended that the log +guest for forwarding traffic upstream and the ``hostname`` and ``fqdn`` +will conigure the DHCP option 12 hostname and DHCP option 81 and DHCPv6 +option 39 fqdn attribute. Due to the design decisions of passt, when using +SELinux on the host, it is recommended that the log file reside in the runtime directory of the user under which the passt process will run, most probably ``/run/user/$UID`` (where ``$UID`` is the UID of that user), e.g. ``/run/user/1000``. Be aware that libvirt diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c index b3b0bd7329..15143f8fa2 100644 --- a/src/conf/domain_conf.c +++ b/src/conf/domain_conf.c @@ -2909,6 +2909,8 @@ virDomainNetDefFree(virDomainNetDef *def) g_free(def->backend.tap); g_free(def->backend.vhost); g_free(def->backend.logFile); + g_free(def->backend.hostname); + g_free(def->backend.fqdn); virDomainNetTeamingInfoFree(def->teaming); g_free(def->virtPortProfile); g_free(def->script); @@ -9757,6 +9759,8 @@ virDomainNetBackendParseXML(xmlNodePtr node, } def->backend.logFile = virXMLPropString(node, "logFile"); + def->backend.hostname = virXMLPropString(node, "hostname"); + def->backend.fqdn = virXMLPropString(node, "fqdn"); if (tap) def->backend.tap = virFileSanitizePath(tap); @@ -20757,7 +20761,9 @@ virDomainNetBackendIsEqual(virDomainNetBackend *src, if (src->type != dst->type || STRNEQ_NULLABLE(src->tap, dst->tap) || STRNEQ_NULLABLE(src->vhost, dst->vhost) || - STRNEQ_NULLABLE(src->logFile, dst->logFile)) { + STRNEQ_NULLABLE(src->logFile, dst->logFile) || + STRNEQ_NULLABLE(src->hostname, dst->hostname) || + STRNEQ_NULLABLE(src->fqdn, dst->fqdn)) { return false; } return true; @@ -24838,6 +24844,8 @@ virDomainNetBackendFormat(virBuffer *buf, virBufferEscapeString(&attrBuf, " tap='%s'", backend->tap); virBufferEscapeString(&attrBuf, " vhost='%s'", backend->vhost); virBufferEscapeString(&attrBuf, " logFile='%s'", backend->logFile); + virBufferEscapeString(&attrBuf, " hostname='%s'", backend->hostname); + virBufferEscapeString(&attrBuf, " fqdn='%s'", backend->fqdn); virXMLFormatElement(buf, "backend", &attrBuf, NULL); } diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h index 58b97a2b54..79fd2f1f63 100644 --- a/src/conf/domain_conf.h +++ b/src/conf/domain_conf.h @@ -1067,6 +1067,8 @@ struct _virDomainNetBackend { char *vhost; /* The following are currently only valid/used when backend type='passt' */ char *logFile; /* path to logfile used by passt process */ + char *hostname; /* hostname of the passt process */ + char *fqdn; /* fully qualified domain name of the passt process */ }; struct _virDomainNetPortForwardRange { diff --git a/src/conf/schemas/domaincommon.rng b/src/conf/schemas/domaincommon.rng index 5597d5a66b..f64199ca18 100644 --- a/src/conf/schemas/domaincommon.rng +++ b/src/conf/schemas/domaincommon.rng @@ -3913,6 +3913,12 @@ <ref name="absFilePath"/> </attribute> </optional> + <optional> + <attribute name="hostname"/> + </optional> + <optional> + <attribute name="fqdn"/> + </optional> </element> </optional> <optional> diff --git a/src/qemu/qemu_passt.c b/src/qemu/qemu_passt.c index fcc34de384..81e5c51f6c 100644 --- a/src/qemu/qemu_passt.c +++ b/src/qemu/qemu_passt.c @@ -229,6 +229,12 @@ qemuPasstStart(virDomainObj *vm, if (net->backend.logFile) virCommandAddArgList(cmd, "--log-file", net->backend.logFile, NULL); + if (net->backend.hostname) + virCommandAddArgList(cmd, "--hostname", net->backend.hostname, NULL); + + if (net->backend.fqdn) + virCommandAddArgList(cmd, "--fqdn", net->backend.fqdn, NULL); + /* Add IP address info */ for (i = 0; i < net->guestIP.nips; i++) { const virNetDevIPAddr *ip = net->guestIP.ips[i]; diff --git a/tests/qemuxmlconfdata/net-user-passt.x86_64-7.2.0.xml b/tests/qemuxmlconfdata/net-user-passt.x86_64-7.2.0.xml index cfe07cc627..77da297936 100644 --- a/tests/qemuxmlconfdata/net-user-passt.x86_64-7.2.0.xml +++ b/tests/qemuxmlconfdata/net-user-passt.x86_64-7.2.0.xml @@ -50,7 +50,7 @@ <range start='443' to='344'/> </portForward> <model type='rtl8139'/> - <backend type='passt' logFile='/var/log/loglaw.blog'/> + <backend type='passt' logFile='/var/log/loglaw.blog' hostname='hostname1' fqdn='hostname1.test.local'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </interface> <input type='mouse' bus='ps2'/> diff --git a/tests/qemuxmlconfdata/net-user-passt.x86_64-latest.xml b/tests/qemuxmlconfdata/net-user-passt.x86_64-latest.xml index d7e0ef5f90..917a9edaa0 100644 --- a/tests/qemuxmlconfdata/net-user-passt.x86_64-latest.xml +++ b/tests/qemuxmlconfdata/net-user-passt.x86_64-latest.xml @@ -50,7 +50,7 @@ <range start='443' to='344'/> </portForward> <model type='rtl8139'/> - <backend type='passt' logFile='/var/log/loglaw.blog'/> + <backend type='passt' logFile='/var/log/loglaw.blog' hostname='hostname1' fqdn='hostname1.test.local'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </interface> <input type='mouse' bus='ps2'/> diff --git a/tests/qemuxmlconfdata/net-user-passt.xml b/tests/qemuxmlconfdata/net-user-passt.xml index 20c9f50542..80d15de2ed 100644 --- a/tests/qemuxmlconfdata/net-user-passt.xml +++ b/tests/qemuxmlconfdata/net-user-passt.xml @@ -47,7 +47,7 @@ <range start='443' to='344'/> </portForward> <model type='rtl8139'/> - <backend type='passt' logFile='/var/log/loglaw.blog'/> + <backend type='passt' logFile='/var/log/loglaw.blog' hostname='hostname1' fqdn='hostname1.test.local'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </interface> <input type='mouse' bus='ps2'/> diff --git a/tests/qemuxmlconfdata/net-vhostuser-passt.x86_64-latest.xml b/tests/qemuxmlconfdata/net-vhostuser-passt.x86_64-latest.xml index 529aff11f8..5802754c4b 100644 --- a/tests/qemuxmlconfdata/net-vhostuser-passt.x86_64-latest.xml +++ b/tests/qemuxmlconfdata/net-vhostuser-passt.x86_64-latest.xml @@ -53,7 +53,7 @@ <range start='443' to='344'/> </portForward> <model type='virtio'/> - <backend type='passt' logFile='/var/log/loglaw.blog'/> + <backend type='passt' logFile='/var/log/loglaw.blog' hostname='hostname1' fqdn='hostname1.test.local'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </interface> <interface type='vhostuser'> diff --git a/tests/qemuxmlconfdata/net-vhostuser-passt.xml b/tests/qemuxmlconfdata/net-vhostuser-passt.xml index 71b845329b..0a37511a0f 100644 --- a/tests/qemuxmlconfdata/net-vhostuser-passt.xml +++ b/tests/qemuxmlconfdata/net-vhostuser-passt.xml @@ -50,7 +50,7 @@ <range start='443' to='344'/> </portForward> <model type='virtio'/> - <backend type='passt' logFile='/var/log/loglaw.blog'/> + <backend type='passt' logFile='/var/log/loglaw.blog' hostname='hostname1' fqdn='hostname1.test.local'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </interface> <interface type='vhostuser'> -- 2.49.0

6 12

[PATCH 0/3] hw/sd/sdcard: Deprecate support for spec v1.10
by Philippe Mathieu-Daudé 02 Sep '25

02 Sep '25

Deprecate SD spec v1.10, use v3.01 as new default. Philippe Mathieu-Daudé (3): hw/sd/sdcard: Deprecate support for spec v1.10 hw/sd/sdcard: Use spec v3.01 by default hw/sd/sdcard: Remove support for spec v1.10 docs/about/removed-features.rst | 5 +++++ include/hw/sd/sd.h | 1 - hw/sd/sd.c | 14 +++----------- 3 files changed, 8 insertions(+), 12 deletions(-) -- 2.41.0

2 10