October 2026 - Devel - libvirt List Archives

[PATCH] bhyve: respect network MTU
by Roman Bogorodskiy 30 Oct '26

30 Oct '26

Update the bhyve driver to propagate the network interface's MTU: - Configure the SLIRP backend MTU for user networking. - Configure the TAP interface MTU for bridge networking. - Advertise the MTU to the guest for virtio-net devices. The e1000 device does not support advertising an MTU to the guest. Its backend MTU is still configured, but the guest interface must be configured separately. Signed-off-by: Roman Bogorodskiy <bogorodskiy(a)gmail.com> --- src/bhyve/bhyve_command.c | 19 ++++++++---- .../x86_64/bhyvexml2argv-net-mtu-bridge.args | 11 +++++++ .../bhyvexml2argv-net-mtu-bridge.ldargs | 4 +++ .../x86_64/bhyvexml2argv-net-mtu-bridge.xml | 31 +++++++++++++++++++ .../x86_64/bhyvexml2argv-net-mtu-slirp.args | 11 +++++++ .../x86_64/bhyvexml2argv-net-mtu-slirp.ldargs | 4 +++ .../x86_64/bhyvexml2argv-net-mtu-slirp.xml | 29 +++++++++++++++++ tests/bhyvexml2argvmock.c | 8 +++-- tests/bhyvexml2argvtest.c | 2 ++ 9 files changed, 111 insertions(+), 8 deletions(-) create mode 100644 tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.args create mode 100644 tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.ldargs create mode 100644 tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.xml create mode 100644 tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.args create mode 100644 tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.ldargs create mode 100644 tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.xml diff --git a/src/bhyve/bhyve_command.c b/src/bhyve/bhyve_command.c index 09ef61e798..7e3d3d4553 100644 --- a/src/bhyve/bhyve_command.c +++ b/src/bhyve/bhyve_command.c @@ -49,6 +49,7 @@ bhyveBuildNetArgStr(const virDomainDef *def, virCommand *cmd, bool dryRun) { + g_auto(virBuffer) netarg = VIR_BUFFER_INITIALIZER; char macaddr[VIR_MAC_STRING_BUFLEN]; char *realifname = NULL; const char *brname = NULL; @@ -97,8 +98,11 @@ bhyveBuildNetArgStr(const virDomainDef *def, break; case VIR_DOMAIN_NET_TYPE_USER: virCommandAddArg(cmd, "-s"); - virCommandAddArgFormat(cmd, "%d:0,%s,slirp,mac=%s,open", - net->info.addr.pci.slot, nic_model, macaddr); + virBufferAsprintf(&netarg, "%d:0,%s,slirp,mac=%s,open", + net->info.addr.pci.slot, nic_model, macaddr); + if (net->mtu) + virBufferAsprintf(&netarg, ",mtu=%u", net->mtu); + virCommandAddArgBuffer(cmd, &netarg); return 0; case VIR_DOMAIN_NET_TYPE_ETHERNET: case VIR_DOMAIN_NET_TYPE_DIRECT: @@ -125,7 +129,7 @@ bhyveBuildNetArgStr(const virDomainDef *def, virDomainNetGetActualVirtPortProfile(net), virDomainNetGetActualVlan(net), virDomainNetGetActualPortOptionsIsolated(net), - NULL, 0, NULL, + NULL, net->mtu, NULL, VIR_NETDEV_TAP_CREATE_IFUP | VIR_NETDEV_TAP_CREATE_PERSIST) < 0) { goto cleanup; } @@ -148,9 +152,12 @@ bhyveBuildNetArgStr(const virDomainDef *def, virCommandAddArg(cmd, "-s"); - virCommandAddArgFormat(cmd, "%d:0,%s,%s,mac=%s", - net->info.addr.pci.slot, nic_model, - realifname, macaddr); + virBufferAsprintf(&netarg, "%d:0,%s,%s,mac=%s", + net->info.addr.pci.slot, nic_model, + realifname, macaddr); + if (net->mtu && net->model == VIR_DOMAIN_NET_MODEL_VIRTIO) + virBufferAsprintf(&netarg, ",mtu=%u", net->mtu); + virCommandAddArgBuffer(cmd, &netarg); ret = 0; cleanup: diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.args b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.args new file mode 100644 index 0000000000..6eb2da65ed --- /dev/null +++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.args @@ -0,0 +1,11 @@ +bhyve \ +-c 1 \ +-m 214 \ +-u \ +-H \ +-P \ +-s 0:0,hostbridge \ +-s 2:0,ahci,hd:/tmp/freebsd.img \ +-s 3:0,virtio-net,faketapdev,mac=52:54:00:00:00:01,mtu=9000 \ +-s 4:0,e1000,faketapdev,mac=52:54:00:00:00:02 \ +bhyve diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.ldargs b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.ldargs new file mode 100644 index 0000000000..5905f4b3e6 --- /dev/null +++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.ldargs @@ -0,0 +1,4 @@ +bhyveload \ +-m 214 \ +-d /tmp/freebsd.img \ +bhyve diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.xml b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.xml new file mode 100644 index 0000000000..6ed278b0d7 --- /dev/null +++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-bridge.xml @@ -0,0 +1,31 @@ +<domain type='bhyve'> + <name>bhyve</name> + <uuid>df3be7e7-a104-11e3-aeb0-50e5492bd3dc</uuid> + <memory>219136</memory> + <vcpu>1</vcpu> + <os> + <type>hvm</type> + </os> + <devices> + <disk type='file'> + <driver name='file' type='raw'/> + <source file='/tmp/freebsd.img'/> + <target dev='hda' bus='sata'/> + <address type='drive' controller='0' bus='0' target='2' unit='0'/> + </disk> + <interface type='bridge'> + <mac address='52:54:00:00:00:01'/> + <source bridge='mtu-br0'/> + <model type='virtio'/> + <mtu size='9000'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> + </interface> + <interface type='bridge'> + <mac address='52:54:00:00:00:02'/> + <source bridge='mtu-br0'/> + <model type='e1000'/> + <mtu size='9000'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> + </interface> + </devices> +</domain> diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.args b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.args new file mode 100644 index 0000000000..0f67b4aa43 --- /dev/null +++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.args @@ -0,0 +1,11 @@ +bhyve \ +-c 1 \ +-m 214 \ +-u \ +-H \ +-P \ +-s 0:0,hostbridge \ +-s 2:0,ahci,hd:/tmp/freebsd.img \ +-s 3:0,virtio-net,slirp,mac=52:54:00:00:00:01,open,mtu=9000 \ +-s 4:0,e1000,slirp,mac=52:54:00:00:00:02,open,mtu=9000 \ +bhyve diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.ldargs b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.ldargs new file mode 100644 index 0000000000..5905f4b3e6 --- /dev/null +++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.ldargs @@ -0,0 +1,4 @@ +bhyveload \ +-m 214 \ +-d /tmp/freebsd.img \ +bhyve diff --git a/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.xml b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.xml new file mode 100644 index 0000000000..ff2467fda4 --- /dev/null +++ b/tests/bhyvexml2argvdata/x86_64/bhyvexml2argv-net-mtu-slirp.xml @@ -0,0 +1,29 @@ +<domain type='bhyve'> + <name>bhyve</name> + <uuid>df3be7e7-a104-11e3-aeb0-50e5492bd3dc</uuid> + <memory>219136</memory> + <vcpu>1</vcpu> + <os> + <type>hvm</type> + </os> + <devices> + <disk type='file'> + <driver name='file' type='raw'/> + <source file='/tmp/freebsd.img'/> + <target dev='hda' bus='sata'/> + <address type='drive' controller='0' bus='0' target='2' unit='0'/> + </disk> + <interface type='user'> + <mac address='52:54:00:00:00:01'/> + <model type='virtio'/> + <mtu size='9000'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> + </interface> + <interface type='user'> + <mac address='52:54:00:00:00:02'/> + <model type='e1000'/> + <mtu size='9000'/> + <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> + </interface> + </devices> +</domain> diff --git a/tests/bhyvexml2argvmock.c b/tests/bhyvexml2argvmock.c index 2248b721d0..93289ba572 100644 --- a/tests/bhyvexml2argvmock.c +++ b/tests/bhyvexml2argvmock.c @@ -61,7 +61,7 @@ void virMacAddrGenerate(const unsigned char prefix[VIR_MAC_PREFIX_BUFLEN], addr->addr[5] = 0; } -int virNetDevTapCreateInBridgePort(const char *brname G_GNUC_UNUSED, +int virNetDevTapCreateInBridgePort(const char *brname, char **ifname, const virMacAddr *macaddr G_GNUC_UNUSED, const unsigned char *vmuuid G_GNUC_UNUSED, @@ -72,10 +72,14 @@ int virNetDevTapCreateInBridgePort(const char *brname G_GNUC_UNUSED, const virNetDevVlan *virtVlan G_GNUC_UNUSED, virTristateBool isolatedPort G_GNUC_UNUSED, virNetDevCoalesce *coalesce G_GNUC_UNUSED, - unsigned int mtu G_GNUC_UNUSED, + unsigned int mtu, unsigned int *actualMTU G_GNUC_UNUSED, unsigned int fakeflags G_GNUC_UNUSED) { + /* Validate MTU passed by the net-mtu-bridge test */ + if (STREQ(brname, "mtu-br0") && mtu != 9000) + return -1; + VIR_FREE(*ifname); *ifname = g_strdup("vnet0"); return 0; diff --git a/tests/bhyvexml2argvtest.c b/tests/bhyvexml2argvtest.c index 650563821b..0b700cc5b0 100644 --- a/tests/bhyvexml2argvtest.c +++ b/tests/bhyvexml2argvtest.c @@ -260,6 +260,8 @@ mymain(void) DO_TEST("serial-grub"); DO_TEST("localtime"); DO_TEST("net-e1000"); + DO_TEST("net-mtu-bridge"); + DO_TEST("net-mtu-slirp"); DO_TEST("passthru"); DO_TEST("passthru-multiple-devs"); DO_TEST("uefi"); -- 2.55.0

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[PATCH] Ignore .wraplock file generated by meson
by Jiri Denemark 30 Oct '26

30 Oct '26

From: Jiri Denemark <jdenemar(a)redhat.com> Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com> --- .gitignore | 3 +++ 1 file changed, 3 insertions(+) diff --git a/.gitignore b/.gitignore index 4695391342..c0ba8d79dd 100644 --- a/.gitignore +++ b/.gitignore @@ -24,3 +24,6 @@ tags # clangd related ignores .clangd compile_commands.json + +# meson related ignores +/subprojects/.wraplock -- 2.56.0

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[PATCH] NEWS: Document features/improvements/bug fixes I've participated in
by Michal Privoznik 29 Oct '26

29 Oct '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 | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/NEWS.rst b/NEWS.rst index bba5c66dac..f1353ac698 100644 --- a/NEWS.rst +++ b/NEWS.rst @@ -57,6 +57,14 @@ v12.9.0 (unreleased) event on the source host. The event includes the newly added VIR_DOMAIN_EVENT_UNDEFINED_MIGRATED detail. + * qemu: report guest reboot as shutdown detail for on_reboot=destroy + + Libvirt now reports the reason of shutdown event properly. + + * qemu: Consider vhost net for MSHV accelerator + + This release enables vhost networking for both KVM and MSHV accelerators. + * **Bug fixes** * bhyve: fix shutdown handling on arm64 @@ -64,6 +72,34 @@ v12.9.0 (unreleased) Signal-based shutdown now correctly handles bhyve terminating directly on arm64, preventing stopped domains from remaining reported as running. + * virpci: fix handling newline in PCI device class + + This releases fixes a regression introduced in ``v12.2.0`` release which + kept libvirt unable to parse PCI related files from a sysfs mount, if they + contained a newline character. + + * security: Check if R/O or shared disk is not directory + + Starting a domain with a read only disk (e.g. cdrom), or attaching one to + an already running domain might have resulted in mangled permissions, if a + directory was given as the disk source. + + * esx: Avoid integer overflow in esxDomainGetInfo() + + The ESX driver implementation for ``virDomainGetInfo()`` API fetches domain + memory size and domain max memory size in MiB and then multiplies both + values by factor of 1024, since the API reports those sizes in KiB. But + these multiplications can overflow and thus report invalid values. An error + is reported instead. + + * conf: Deny negative vcpu count + + If a negative value was specified for the number of vCPUs in domain XML, + libvirt would try to allocate absurdly large amounts of memory which would + trigger OOM killer and kill the daemon. Non-positive values are forbidden + now. + + v12.8.0 (2026-10-01) ==================== -- 2.56.0

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[PATCH 0/5] virtio-blk: Deprecate silent truncation of serial
by Kevin Wolf 29 Oct '26

29 Oct '26

QEMU has allowed the user to specify serials of arbitrary length for virtio-blk devices, even though the virtio-blk protocol can only communicate 20 characters of the serial to the guest. This means that a longer serial number on the command line is silently truncated to 20 characters from the guest perspective. As a first step to fix this, deprecate the silent truncation and turn it into a warning; we can later make this a hard error. While touching GET_ID, let's make it more spec compliant and clean up the internal state. Another part is planned that will actually enable users to use longer serials and additional device identifiers. This will need spec changes and would take more time than we have until the QEMU 11.2 freeze anyway, so I'll address this later. For now, the important thing is to get the deprecation period started. Kevin Wolf (5): virtio-blk: Implement full NUL padding for GET_ID virtio-blk-test: Add a basic GET_ID test case virtio-blk: Deprecate silent truncation of serial virtio-blk: Represent truncated serial in qdev property virtio-blk-test: Test truncated serial docs/about/deprecated.rst | 13 +++++ hw/block/virtio-blk.c | 24 +++++++-- tests/qtest/virtio-blk-test.c | 92 +++++++++++++++++++++++++++++++++++ 3 files changed, 125 insertions(+), 4 deletions(-) -- 2.56.0

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Plans for 12.9.0 release (freeze on 2026-10-26)
by Jiri Denemark 29 Oct '26

29 Oct '26

We are getting close to 12.9.0 release of libvirt. To aim for the release on Monday 02 Nov I suggest entering the freeze on Monday 26 Oct and tagging RC2 on Thursday 29 Oct. I hope this works for everyone. Jirka

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[PATCH 0/2] A couple of memleak fixes
by Michal Privoznik 29 Oct '26

29 Oct '26

for upcoming release. Michal Prívozník (2): virnwfilterobj: Don't leak @objs in virNWFilterObjListExport() nwfilter: Release driver config in nwfilterStateCleanupLocked() src/conf/virnwfilterobj.c | 1 + src/nwfilter/nwfilter_driver.c | 1 + 2 files changed, 2 insertions(+) -- 2.56.0

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Plans for 12.7.0 release (freeze on 2026-08-24)
by Jiri Denemark 29 Oct '26

29 Oct '26

We are getting close to 12.7.0 release of libvirt. To aim for the release on Tuesday 01 Sep I suggest entering the freeze on Monday 24 Aug and tagging RC2 on Thursday 27 Aug. I hope this works for everyone. Jirka

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Re: [PULL 51/59] system: Remove deprecated 'debug-threads' option for -name
by Philippe Mathieu-Daudé 28 Oct '26

28 Oct '26

(Cc'ing migration compat and libvirt teams) On 28/10/26 02:01, Richard Henderson wrote: > On 10/27/26 14:23, Philippe Mathieu-Daudé wrote: >> 'debug-threads' option for -name was deprecated in v11.0 >> (commit 1b65aeed2a0 "system: unconditionally enable thread >> naming") thus can now be removed. >> >> Signed-off-by: Philippe Mathieu-Daudé<philmd(a)oss.qualcomm.com> >> Reviewed-by: Pierrick Bouvier<pierrick.bouvier(a)oss.qualcomm.com> >> Reviewed-by: Ján Tomko<jtomko(a)redhat.com> >> Reviewed-by: Dr. David Alan Gilbert<dave(a)treblig.org> >> Message-Id:<20261018232917.7716-1-philmd(a)oss.qualcomm.com> >> --- >> docs/about/deprecated.rst | 7 ------- >> docs/about/removed-features.rst | 9 +++++++-- >> system/vl.c | 11 ----------- >> tests/qtest/migration/framework.c | 4 ++-- >> tests/qtest/migration/precopy-tests.c | 2 +- >> qemu-options.hx | 7 +++---- >> 6 files changed, 13 insertions(+), 27 deletions(-) > > You need to remove this from the testsuite as well: > > https://gitlab.com/qemu-project/qemu/-/jobs/17523155796#L58 Hmm I was surprised because the pipeline in my fork passed, but then looking clearer this job is marked as "allow_failure: true" for me, why is it blocking on the mainstream repo? Back to the test, this is the migration-compat-x86_64 job running previous release binary vs latest one, so I'd think this is the expected behavior, v11.0 and v11.1 have that deprecated option, and we can not test vs v11.2 which removed it. If we want to change that workflow, then when deprecating on v11.0 we also need to remove the tests coverage, so when we remove the feature at $deprecation_release+2 the migration-compat test does not break. Here the question is, do we want to keep testing deprecated features? Maybe yes in the case of unmaintained area when the deprecation process triggers new maintainers stepping in and the deprecation to be cancelled. We could also mark the feature removed but keep it ignored and undocumented until the next release but we'll likely forget and miss that in workflow so I don't recommend that way. Maybe there are another ways to resolve that but I'm not seeing them. Ideas?

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[PATCH v2 1/1] qemu: add support for zero-page-detection migration parameter
by Tejus GK 28 Oct '26

28 Oct '26

QEMU supports a migration parameter to determine whether zero-page checking should be performed and if yes, where it should be performed (i.e., in the main migration thread or multifd threads). Add support for this in libvirt in the form of a boolean VIR_MIGRATE_PARAM_ZERO_PAGE_DETECTION migration parameter. Setting this to true with multifd will offload the check to multifd threads. Without multifd enabled, the check will happen in the main migration thread. Setting this to false disables zero-page checking. When the parameter is not set, QEMU's default is kept. Signed-off-by: Tejus GK <tejus.gk(a)nutanix.com> --- docs/manpages/virsh.rst | 6 ++++++ include/libvirt/libvirt-domain.h | 16 ++++++++++++++++ src/qemu/qemu_migration.c | 1 + src/qemu/qemu_migration_params.c | 30 ++++++++++++++++++++++++++++++ src/qemu/qemu_migration_params.h | 1 + tools/virsh-domain.c | 11 +++++++++++ 6 files changed, 65 insertions(+) diff --git a/docs/manpages/virsh.rst b/docs/manpages/virsh.rst index f533a10776..b5a796a00a 100644 --- a/docs/manpages/virsh.rst +++ b/docs/manpages/virsh.rst @@ -3802,6 +3802,7 @@ migrate [--bandwidth bandwidth] [--tls-destination hostname] [--disks-uri URI] [--copy-storage-synchronous-writes] [--available-switchover-bandwidth bandwidth] + [--zero-page-detection] Migrate domain to another host. Add *--live* for live migration; <--p2p> for peer-2-peer migration; *--direct* for direct migration; or *--tunnelled* @@ -3953,6 +3954,11 @@ parallel connections. The number of such connections can be set using network link between the source and the target and thus speeding up the migration. +*--zero-page-detection* requests pages containing only zeros to be detected by +the parallel migration threads rather than the main migration thread. Without +*--parallel*, zero pages are detected by the main migration thread. When the +option is not set, the hypervisor default is used. + Running migration can be canceled by interrupting virsh (usually using ``Ctrl-C``) or by ``domjobabort`` command sent from another virsh instance. diff --git a/include/libvirt/libvirt-domain.h b/include/libvirt/libvirt-domain.h index 9ee153c6eb..0e68a572c3 100644 --- a/include/libvirt/libvirt-domain.h +++ b/include/libvirt/libvirt-domain.h @@ -1468,6 +1468,22 @@ typedef enum { */ # define VIR_MIGRATE_PARAM_TLS_DESTINATION "tls.destination" +/** + * VIR_MIGRATE_PARAM_ZERO_PAGE_DETECTION: + * + * virDomainMigrate* params field: whether zero page detection should be + * performed during migration. As VIR_TYPED_PARAM_BOOLEAN. + * + * When enabled with parallel migration, zero pages are detected by the multifd + * threads rather than the main migration thread. When enabled without parallel + * migration, zero pages are detected by the main migration thread. + * When disabled, zero pages are transferred as normal pages. + * When not set, the hypervisor default is used. + * + * Since: 12.9.0 + */ +# define VIR_MIGRATE_PARAM_ZERO_PAGE_DETECTION "zero_page_detection" + /* Domain migration. */ virDomainPtr virDomainMigrate (virDomainPtr domain, virConnectPtr dconn, unsigned long flags, const char *dname, diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 76661de09a..13113ceaff 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -110,6 +110,7 @@ const virTypedParamValidationTemplate qemuMigrationParametersValidation[] = { { VIR_MIGRATE_PARAM_TLS_DESTINATION, VIR_TYPED_PARAM_STRING }, { VIR_MIGRATE_PARAM_DISKS_URI, VIR_TYPED_PARAM_STRING }, { VIR_MIGRATE_PARAM_BANDWIDTH_AVAIL_SWITCHOVER, VIR_TYPED_PARAM_ULLONG }, + { VIR_MIGRATE_PARAM_ZERO_PAGE_DETECTION, VIR_TYPED_PARAM_BOOLEAN }, { "", 0 } }; diff --git a/src/qemu/qemu_migration_params.c b/src/qemu/qemu_migration_params.c index dd47516742..e1ead04068 100644 --- a/src/qemu/qemu_migration_params.c +++ b/src/qemu/qemu_migration_params.c @@ -131,6 +131,7 @@ VIR_ENUM_IMPL(qemuMigrationParam, "multifd-zstd-level", "avail-switchover-bandwidth", "direct-io", + "zero-page-detection", ); typedef struct _qemuMigrationParamsAlwaysOnItem qemuMigrationParamsAlwaysOnItem; @@ -332,6 +333,9 @@ static const qemuMigrationParamInfoItem qemuMigrationParamInfo[] = { [QEMU_MIGRATION_PARAM_DIRECT_IO] = { .type = QEMU_MIGRATION_PARAM_TYPE_BOOL, }, + [QEMU_MIGRATION_PARAM_ZERO_PAGE_DETECTION] = { + .type = QEMU_MIGRATION_PARAM_TYPE_STRING, + }, }; G_STATIC_ASSERT(G_N_ELEMENTS(qemuMigrationParamInfo) == QEMU_MIGRATION_PARAM_LAST); @@ -692,6 +696,29 @@ qemuMigrationParamsSetCompression(virTypedParameterPtr params, } +static int +qemuMigrationParamsSetZeroPageDetection(virTypedParameterPtr params, + int nparams, + qemuMigrationParams *migParams) +{ + int zeroPageDetection; + int rc; + + if ((rc = virTypedParamsGetBoolean(params, nparams, + VIR_MIGRATE_PARAM_ZERO_PAGE_DETECTION, + &zeroPageDetection)) < 0) + return -1; + + if (rc == 1) { + migParams->params[QEMU_MIGRATION_PARAM_ZERO_PAGE_DETECTION].value.s = + g_strdup(zeroPageDetection ? "multifd" : "none"); + migParams->params[QEMU_MIGRATION_PARAM_ZERO_PAGE_DETECTION].set = true; + } + + return 0; +} + + void qemuMigrationParamsSetBlockDirtyBitmapMapping(qemuMigrationParams *migParams, virJSONValue **params) @@ -792,6 +819,9 @@ qemuMigrationParamsFromFlags(virTypedParameterPtr params, if (qemuMigrationParamsSetCompression(params, nparams, flags, migParams) < 0) return NULL; + if (qemuMigrationParamsSetZeroPageDetection(params, nparams, migParams) < 0) + return NULL; + return g_steal_pointer(&migParams); } diff --git a/src/qemu/qemu_migration_params.h b/src/qemu/qemu_migration_params.h index b7a829b85a..131fe82fc0 100644 --- a/src/qemu/qemu_migration_params.h +++ b/src/qemu/qemu_migration_params.h @@ -67,6 +67,7 @@ typedef enum { QEMU_MIGRATION_PARAM_MULTIFD_ZSTD_LEVEL, QEMU_MIGRATION_PARAM_AVAIL_SWITCHOVER_BANDWIDTH, QEMU_MIGRATION_PARAM_DIRECT_IO, + QEMU_MIGRATION_PARAM_ZERO_PAGE_DETECTION, QEMU_MIGRATION_PARAM_LAST } qemuMigrationParam; diff --git a/tools/virsh-domain.c b/tools/virsh-domain.c index 2c64f19a19..18854ad0c3 100644 --- a/tools/virsh-domain.c +++ b/tools/virsh-domain.c @@ -11432,6 +11432,10 @@ static const vshCmdOptDef opts_migrate[] = { .type = VSH_OT_INT, .help = N_("bandwidth (in MiB/s) available for the final phase of migration") }, + {.name = "zero-page-detection", + .type = VSH_OT_BOOL, + .help = N_("enable zero page detection in parallel migration threads") + }, {.name = NULL} }; @@ -11733,6 +11737,13 @@ doMigrate(void *opaque) goto save_error; } + if (vshCommandOptBool(cmd, "zero-page-detection")) { + if (virTypedParamsAddBoolean(&params, &nparams, &maxparams, + VIR_MIGRATE_PARAM_ZERO_PAGE_DETECTION, + true) < 0) + goto save_error; + } + if ((rv = vshCommandOptInt(ctl, cmd, "comp-zlib-level", &intOpt)) < 0) { goto out; } else if (rv > 0) { -- 2.43.7

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[PATCH libvirt v2 0/4] s390x CPU model compatibility check for incoming migration
by Rorie Reyes 28 Oct '26

28 Oct '26

Changelog: V2 - - patch 1 (new patch, split from v1 patch 1): - fix result string to enum mapping; move into monitor layer - update unit test for all four result strings - report unknown result strings as errors - patch 2: - squash v1 patch 2 (propagate responsibleProps through monitor layer) into this patch - drop GenericError interception block - fix virReportError overwriting error from virJSONValueArrayToStringList - update qemu_driver.c caller to pass NULL - patch 3 (split from v1 patch 1): - add block scopes per subtest - use STRNEQ_NULLABLE - drop "superset + type" test case - fix bullet list to only include cases added by this patch - patch 4: - replace qemuCPUModelCompatResult enum with virCPUCompareResult - move "type" property filtering into qemuProcessCheckS390CPU() - wire check into qemuProcessUpdateGuestCPU() instead of qemu_migration.c - simplify qemuConnectCPUModelComparison() to delegate to new helper - report unknown results as errors ------------------- This series extends the qemu-cpu-model-comparison QMP interface in libvirt to surface the "responsible-properties" array returned by QEMU, and uses that information to perform a pre-flight CPU compatibility check on s390x before an incoming migration is accepted. Background ---------- On x86, QEMU rejects an incompatible CPU model at domain start time and produces a meaningful error. On s390x the guest starts successfully but may fail later in an opaque way if the destination host lacks required CPU features. This series brings s390x in line with x86 by catching the incompatibility early, aborting the migration cleanly, and reporting exactly which CPU properties are responsible. Functional Test Instructions ----------------------------- Prerequisites: - Two s390x hosts (source and destination) with different CPU feature levels from the same generation lineage (e.g. z16 and z17). - libvirt and QEMU built from this series on both hosts. - QEMU must support the query-cpu-model-comparison QMP command (QEMU >= 5.1). Test case 1 — Incompatible CPU model is rejected cleanly: 1. Define a guest on the source host using a custom s390x CPU model that includes features not present on the destination host. 2. Initiate a live migration to the destination host: virsh migrate --live <domain> qemu+ssh://dest-host/system 3. Expected result: migration fails immediately with a clear libvirt error before QEMU starts on the destination, e.g.: error: operation failed: guest CPU model is a newer generation than the destination host CPU model or, for a feature-level mismatch within the same generation: error: operation failed: destination host CPU model is missing features required by the guest CPU model: <prop1>, <prop2> 4. Verify the guest is still running cleanly on the source host: virsh domstate <domain> # should report: running Test case 2 — Compatible CPU model migrates successfully: 1. Define a guest using a CPU model fully supported by the destination (e.g. gen16a-base guest migrating to a gen17 host). 2. Initiate the same live migration. 3. Expected result: migration completes successfully with no errors. Rorie Reyes (4): qemu: refactor GetCPUModelComparison to return virCPUCompareResult qemu: extend GetCPUModelComparison to return responsible-properties tests: extend qemuMonitorJSONGetCPUModelComparison test coverage qemu: introduce qemuProcessCheckS390CPU helper src/qemu/qemu_driver.c | 27 +----- src/qemu/qemu_monitor.c | 11 +-- src/qemu/qemu_monitor.h | 4 +- src/qemu/qemu_monitor_json.c | 45 +++++++--- src/qemu/qemu_monitor_json.h | 4 +- src/qemu/qemu_process.c | 75 ++++++++++++++++ src/qemu/qemu_process.h | 9 ++ tests/qemumonitorjsontest.c | 167 ++++++++++++++++++++++++++++++++--- 8 files changed, 284 insertions(+), 58 deletions(-) -- 2.48.1

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