July 2024 - Devel - libvirt List Archives

[PATCH 00/12] Introduce SEV-SNP support
by Michal Privoznik 22 Jan '25

22 Jan '25

SEV-SNP support just landed in QEMU. Here is the first round of patches to incorporate support into libvirt. TODOs (aka problems of future me): - Teach tools/virt-qemu-sev-validate how to deal with SEV-SNP - Try to find a SEV-SNP machine a test these patches in real worl - Write a kbase article on attestation with SEV-SNP Michal Prívozník (12): qemu_monitor_json: Report error in error paths in SEV related code conf: Move some members of virDomainSEVDef into virDomainSEVCommonDef conf: Separate SEV formatting into a function Drop needless typecast to virDomainLaunchSecurity src: Convert some _virDomainSecDef::sectype checks to switch() qemu_monitor: Allow querying SEV-SNP state in 'query-sev' qemu: Report snp-policy in virDomainGetLaunchSecurityInfo() qemu_capabilities: Introduce QEMU_CAPS_SEV_SNP_GUEST conf: Introduce SEV-SNP support qemu: Build cmd line for SEV-SNP qemu: Allow setting launch security for SEV-SNP qemu_firmware: Pick the right firmware for SEV-SNP guests docs/formatdomain.rst | 108 ++++++++++++ include/libvirt/libvirt-domain.h | 10 ++ src/conf/domain_conf.c | 156 ++++++++++++++---- src/conf/domain_conf.h | 28 +++- src/conf/domain_validate.c | 44 +++++ src/conf/schemas/domaincommon.rng | 73 ++++++-- src/conf/virconftypes.h | 4 + src/qemu/qemu_capabilities.c | 4 + src/qemu/qemu_capabilities.h | 3 + src/qemu/qemu_cgroup.c | 19 ++- src/qemu/qemu_command.c | 56 ++++++- src/qemu/qemu_driver.c | 60 +++++-- src/qemu/qemu_firmware.c | 20 ++- src/qemu/qemu_monitor.c | 7 +- src/qemu/qemu_monitor.h | 41 ++++- src/qemu/qemu_monitor_json.c | 67 ++++++-- src/qemu/qemu_monitor_json.h | 8 +- src/qemu/qemu_namespace.c | 3 +- src/qemu/qemu_process.c | 34 ++-- src/qemu/qemu_validate.c | 13 +- src/security/security_dac.c | 34 +++- .../caps_9.1.0_x86_64.xml | 1 + .../firmware/60-edk2-ovmf-x64-amdsev.json | 1 + tests/qemumonitorjsontest.c | 65 +++++++- ...launch-security-sev-snp.x86_64-latest.args | 35 ++++ .../launch-security-sev-snp.x86_64-latest.xml | 1 + .../launch-security-sev-snp.xml | 47 ++++++ tests/qemuxmlconftest.c | 2 + 28 files changed, 817 insertions(+), 127 deletions(-) create mode 100644 tests/qemuxmlconfdata/launch-security-sev-snp.x86_64-latest.args create mode 120000 tests/qemuxmlconfdata/launch-security-sev-snp.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/launch-security-sev-snp.xml -- 2.44.2

5 31

[PATCH] qemuDomainDiskChangeSupported: Add missing iothreads check
by Adam Julis 18 Nov '24

18 Nov '24

GSList of iothreads is not allowed to be changed while the virtual machine is running. Resolves: https://issues.redhat.com/browse/RHEL-23607 Signed-off-by: Adam Julis <ajulis(a)redhat.com> --- While the qemuDomainDiskChangeSupported() design primarily uses its macros (CHECK_EQ and CHECK_STREQ_NULLABLE), the logic for comparing 2 GSList of iothreads could perhaps be extracted into a separate function (e.g. IothreadsGslistCompare(GSList *first, GSList *second)). I am absolutely not sure about this idea so feel free to comment. src/qemu/qemu_domain.c | 53 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 53 insertions(+) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 298f4bfb9e..2b5222c685 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -8505,6 +8505,59 @@ qemuDomainDiskChangeSupported(virDomainDiskDef *disk, CHECK_EQ(discard, "discard", true); CHECK_EQ(iothread, "iothread", true); + /* compare list of iothreads, no change allowed */ + if (orig_disk->iothreads != disk->iothreads) { + GSList *old; + GSList *new = disk->iothreads; + bool print_err = true; + + for (old = orig_disk->iothreads; old; old = old->next) { + virDomainDiskIothreadDef *orig = old->data; + virDomainDiskIothreadDef *update; + print_err = false; + + if (new == NULL) { + print_err = true; + break; + } + + update = new->data; + + if (orig->id != update->id) { + print_err = true; + break; + } + + if (orig->nqueues != update->nqueues) { + print_err = true; + break; + } + + if (orig->nqueues != 0) { + ssize_t i = 0; + + while (i < orig->nqueues) { + if (orig->queues[i] != update->queues[i]) { + print_err = true; + break; + } + } + } + + new = new->next; + if (new) + print_err = true; + } + + if (print_err) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, + _("cannot modify field '%1$s' (or it's parts) of the disk"), + "iothreads"); + return false; + } + } + + CHECK_STREQ_NULLABLE(domain_name, "backenddomain"); -- 2.45.2

3 2

[PATCH v2 0/4] multiple memory backend support for CPR Live Updates
by mgalaxy＠akamai.com 23 Oct '24

23 Oct '24

From: Michael Galaxy <mgalaxy(a)akamai.com> CPR-based support for whole-hypervisor kexec-based live updates is now finally merged into QEMU. In support of this, we need NUMA to be supported in these kinds of environments. To do this we use a technology called PMEM (persistent memory) in Linux, which underpins the ability for CPR Live Updates to work so that QEMU memory can remain in RAM and be recovered after a kexec operationg has completed. Our systems are highly NUMA-aware, and so this patch series enables NUMA awareness for live updates. Further, we make a small change that allows live migrations to work between *non* PMEM-based systems and PMEM-based systems (and vice-versa). This allows for seemless upgrades from non-live-compatible systems to live-update-compatible sytems without any downtime. Michael Galaxy (4): qemu.conf changes to support multiple memory backend Support live migration between file-backed memory and anonymous memory. Update unit test to support multiple memory backends Update documentation to reflect memory_backing_dir change in qemu.conf NEWS.rst | 7 ++ docs/kbase/virtiofs.rst | 2 + src/qemu/qemu.conf.in | 2 + src/qemu/qemu_command.c | 8 ++- src/qemu/qemu_conf.c | 141 +++++++++++++++++++++++++++++++++++----- src/qemu/qemu_conf.h | 14 ++-- src/qemu/qemu_domain.c | 24 +++++-- src/qemu/qemu_driver.c | 29 +++++---- src/qemu/qemu_hotplug.c | 6 +- src/qemu/qemu_process.c | 44 +++++++------ src/qemu/qemu_process.h | 7 +- tests/testutilsqemu.c | 5 +- 12 files changed, 221 insertions(+), 68 deletions(-) -- 2.34.1

3 26

[PATCH V2 0/4] Rework qemu internal active snapshots to use QMP
by Nikolai Barybin 03 Oct '24

03 Oct '24

Den, Peter, Daniel thank you for your comments! I'm sending v2 of this patchset. Changes since last revision: - dropped [PATCH 4/4] qemu monitor: reap qemu_monitor_text - added new patch: qemu capabilities: add QEMU_CAPS_SNAPSHOT_SAVE/_DELETE - preserved old-style snapshotting (HMP savevm) in case we have QEMU < 6.0 - enhanced requirements for allowing snapshotting. All writable disks should be qcow2, non-shared. If such disks exist and we have qcow2 NVRAM, add NVRAM device to the list of wrdevs. But never save vmstate to NVRAM - make char** wrdevs list allocation inside qemuSnapshotActiveInternalGetWrdevListHelper() Nikolai Barybin (4): qemu monitor: add snaphot-save/delete QMP commands qemu blockjob: add snapshot-save/delete job types qemu capabilities: add QEMU_CAPS_SNAPSHOT_SAVE/_DELETE qemu snapshot: use QMP snapshot-save/delete for internal snapshots src/qemu/qemu_block.c | 2 + src/qemu/qemu_blockjob.c | 6 +- src/qemu/qemu_blockjob.h | 2 + src/qemu/qemu_capabilities.c | 4 + src/qemu/qemu_capabilities.h | 2 + src/qemu/qemu_domain.c | 4 + src/qemu/qemu_monitor.c | 30 +++ src/qemu/qemu_monitor.h | 13 ++ src/qemu/qemu_monitor_json.c | 66 ++++++ src/qemu/qemu_monitor_json.h | 13 ++ src/qemu/qemu_snapshot.c | 207 ++++++++++++++++-- .../caps_6.0.0_aarch64.xml | 2 + .../qemucapabilitiesdata/caps_6.0.0_s390x.xml | 2 + .../caps_6.0.0_x86_64.xml | 2 + .../caps_6.1.0_x86_64.xml | 2 + .../caps_6.2.0_aarch64.xml | 2 + .../qemucapabilitiesdata/caps_6.2.0_ppc64.xml | 2 + .../caps_6.2.0_x86_64.xml | 2 + .../caps_7.0.0_aarch64+hvf.xml | 2 + .../caps_7.0.0_aarch64.xml | 2 + .../qemucapabilitiesdata/caps_7.0.0_ppc64.xml | 2 + .../caps_7.0.0_x86_64.xml | 2 + .../qemucapabilitiesdata/caps_7.1.0_ppc64.xml | 2 + .../caps_7.1.0_x86_64.xml | 2 + tests/qemucapabilitiesdata/caps_7.2.0_ppc.xml | 2 + .../caps_7.2.0_x86_64+hvf.xml | 2 + .../caps_7.2.0_x86_64.xml | 2 + .../caps_8.0.0_riscv64.xml | 2 + .../caps_8.0.0_x86_64.xml | 2 + .../qemucapabilitiesdata/caps_8.1.0_s390x.xml | 2 + .../caps_8.1.0_x86_64.xml | 2 + .../caps_8.2.0_aarch64.xml | 2 + .../caps_8.2.0_armv7l.xml | 2 + .../caps_8.2.0_loongarch64.xml | 2 + .../qemucapabilitiesdata/caps_8.2.0_s390x.xml | 2 + .../caps_8.2.0_x86_64.xml | 2 + .../qemucapabilitiesdata/caps_9.0.0_sparc.xml | 2 + .../caps_9.0.0_x86_64.xml | 2 + .../caps_9.1.0_x86_64.xml | 2 + 39 files changed, 391 insertions(+), 14 deletions(-) -- 2.43.5

2 14

[libvirt PATCH 0/6] scripts: group-qemu-caps: improve readability
by Ján Tomko 02 Oct '24

02 Oct '24

Even though it still stays a Perl script at heart. Ján Tomko (6): scripts: group-qemu-caps: use read scripts: group-qemu-caps: remove cryptic bool scripts: group-qemu-caps: remove unecessary regex scripts: group-qemu-caps: separate file loading scripts: group-qemu-caps: regroup_caps: operate on split lines scripts: group-qemu-caps: separate file operations from the check scripts/group-qemu-caps.py | 120 +++++++++++++++++++++---------------- 1 file changed, 68 insertions(+), 52 deletions(-) -- 2.45.2

2 7

[RFC PATCH] conf: check for migration job during domain start
by Sergey Dyasli 27 Aug '24

27 Aug '24

It's possible to hit the following situation during qemu p2p live migration: 1. qemu has live migrated and exited (making virDomainObjIsActive() return false) 2. the live migration job is still in progress, waiting for a confirmation from the remote libvirt daemon. This may last for a while with a presence of networking issues (up to keepalive timeout). Any attempt to start the domain again would fail with "domain is already being started" message which is misleading in this situation as it doesn't reflect what's really happening. Add a check for the migration job and report a different error message if the migration job is still running. Signed-off-by: Sergey Dyasli <sergey.dyasli(a)nutanix.com> --- src/conf/virdomainobjlist.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/src/conf/virdomainobjlist.c b/src/conf/virdomainobjlist.c index bb5807d00b42..166bbc5cfd57 100644 --- a/src/conf/virdomainobjlist.c +++ b/src/conf/virdomainobjlist.c @@ -301,9 +301,15 @@ virDomainObjListAddLocked(virDomainObjList *doms, goto error; } if (!vm->persistent) { - virReportError(VIR_ERR_OPERATION_INVALID, - _("domain '%1$s' is already being started"), - vm->def->name); + if (vm->job->asyncJob == VIR_ASYNC_JOB_MIGRATION_OUT) { + virReportError(VIR_ERR_OPERATION_INVALID, + _("domain '%1$s' is being migrated out"), + vm->def->name); + } else { + virReportError(VIR_ERR_OPERATION_INVALID, + _("domain '%1$s' is already being started"), + vm->def->name); + } goto error; } } -- 2.22.3

2 1

[PATCH RFC v3 00/16] Support throttle block filters
by wucf＠linux.ibm.com 23 Aug '24

23 Aug '24

From: Chun Feng Wu <wucf(a)linux.ibm.com> Hi, I am thinking to leverage "throttle block filter" in QEMU to support more flexible I/O limits(e.g. tiered I/O groups), one sample provided by QEMU doc is: https://github.com/qemu/qemu/blob/master/docs/throttle.txt "For example, let's say that we have three different drives and we want to set I/O limits for each one of them and an additional set of limits for the combined I/O of all three drives." The implementation idea is to - Define throttle groups(limit) in domain - Define throttle filter to reference throttle group within disk - Within domain disk, throttle filters references multiple throttle groups to form filter chain to apply multiple limits in QEMU like above sample - Add new virsh cmds for throttle group management: throttlegroupset Add or update a throttling group. throttlegroupdel Delete a throttling group. throttlegroupinfo Get a throttling group. throttlegrouplist list all domain throttlegroups - Update "attach-disk" to add one more option "--throttle-groups" to apply throttle filters e.g. "virsh attach-disk $VM_ID ${DISK_PATH}/vm1_disk_2.qcow2 vdd --driver qemu --subdriver qcow2 --targetbus virtio --throttle-groups limit2,limit012" - I chose above semantics as I felt they're appropriate, if there are better ones please kindly suggest. Note, this implementation requires flag "QEMU_CAPS_OBJECT_JSON". From QMP perspective, the sample flow works this way: - Throttle group creation: virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit0","limits":{"iops-total":200,"iops-read":0,"iops-total-max":200,"iops-total-max-length":1}}}' virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit1","limits":{"iops-total":250,"iops-read":0,"iops-total-max":250,"iops-total-max-length":1}}}' virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit2","limits":{"iops-total":300,"iops-read":0,"iops-total-max":300,"iops-total-max-length":1}}}' virsh qemu-monitor-command 1 '{"execute":"object-add", "arguments":{"qom-type":"throttle-group","id":"limit012","limits":{"iops-total":400,"iops-read":0,"iops-total-max":400,"iops-total-max-length":1}}}' - Chain up filters during attaching disk to apply two filters(limit0 and limit012): virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments": {"driver":"file","filename":"/virt/disks/vm1_disk_1.qcow2","node-name":"test-3-storage","auto-read-only":true,"discard":"unmap"}}' virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments":{"node-name":"test-4-format","read-only":false,"driver":"qcow2","file":"test-3-storage","backing":null}}' virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments":{"driver":"throttle","node-name":"libvirt-5-filter","throttle-group": "limit0","file":"test-4-format"}}' virsh qemu-monitor-command 1 '{"execute":"blockdev-add", "arguments": {"driver":"throttle","node-name":"libvirt-6-filter","throttle-group":"limit012","file":"libvirt-5-filter"}}' virsh qemu-monitor-command 1 '{"execute": "device_add", "arguments": {"driver":"virtio-blk-pci","scsi":false,"bus":"pci.0","addr":"0x5","drive":"libvirt-6-filter","id":"virtio-disk1"}}' This patchset includes: - Throttle group XML schema definition in patch 1 - Throttle filter XML schema definition in patch 2 - Throttle group struct definition, parsing and formating in patch 3 - Throttle filter struct definition, parsing and formating in patch 4 - New QMP processing to update and get throttle group in patch 5&6 - New API definition and implementation in patch 7 - QEMU driver implementation in patch 8 - Hotplug processing for throttle filters in patch 9 - Extract common iotune validation in patch 10 - qemuProcessLaunch flow implemenation for throttle group in patch 11 - qemuProcessLaunch flow implemenation for throttle filter in patch 12 - Domain XML test for processing throttle groups and filters in patch 13 - Test new implemented driver in patch 14 - New virsh cmd implementation for group in patch 15 - Update Virsh cmd "attach_disk" to include throttle filters in patch 16 v3 changes: - re-org commits by splitting changes containing throttle group and filters - update commits msgs - move schema commits to be the first ones - refactor "diskIoTune" to extract common schema "iotune" - add new tests for throttle groups and filters in qemuxmlconftest - check flag "QEMU_CAPS_OBJECT_JSON" when preparing "-object"(qemu: command: Support throttle groups during qemuProcessLaunch ) or creating throttle group (qemu: Implement qemu driver for throttle API) - when creating throttle group through "object-add" (qemu: Implement qemu driver for throttle API), reuse "qemuMonitorAddObject" to check if "objectAddNoWrap"("props") is requried - remove "virObject parent;" in "_virDomainThrottleFilterDef" in domain_conf.h - remove "virDomainThrottleGroupIndexByName" in both domain_conf.h and domain_conf.c - remove "virDomainThrottleFilterDefNew" in domain_conf.c - update "virDomainThrottleFilterDefFree" to use "g_free" rather than "VIR_FREE" in domain_conf.c - update "virDomainDiskThrottleFilterDefParse" to remove "xmlXPathContextPtr ctx" parameter and check NULL against "filter->group_name" in domain_conf.c - use "virBufferEscapeString" instead of "virBufferAsprintf" in "virDomainDiskDefFormatThrottleFilterChain" - use "group->val > 0" instead of "if (group->val)" in FORMAT_THROTTLE_GROUP - remove NULL check for "group->group_name" since virBufferEscapeString checked NULL already in "virDomainThrottleGroupFormat" - I haven't added new conf module (src/conf/virdomainthrottle.c/h) because "virDomainThrottleGroupDef" is alias of "_virDomainBlockIoTuneInfo", try to avoid circular dependency - remove "NULLSTR" in qemuMonitorUpdateThrottleGroup and qemuMonitorGetThrottleGroup in qemu_monitor.c - refactor "qemuMonitorMakeThrottleGroupLimits" to use virJSONValueObjectAdd in qemu_monitor_json.c - use "g_strdup_printf" to avoid static buffers in "qemuMonitorJSONGetThrottleGroup" - remove virReportError after qemuMonitorJSONGetReply in "qemuMonitorJSONGetThrottleGroup" to avoid overriding error - remove "VIR_DOMAIN_THROTTLE_GROUP" in libvirt/include/libvirt/libvirt-domain.h - update "virDomainGetThrottleGroup" to not first query the number of parameters, - update "remote_domain_get_throttle_group_args" and "remote_domain_get_throttle_group_ret" to remove "nparams" in src/remote_protocol-structs, also updated "remote_domain_get_throttle_group_args" and "remote_domain_get_throttle_group_ret" in src/remote/remote_protocol.x - update parameter "virTypedParameterPtr params" to be "virTypedParameterPtr *params" in "virDrvDomainGetThrottleGroup" in driver-hypervisor.h - update "qemuDomainSetThrottleGroup" to not query number of parameters first - remove wrapper "qemuDomainThrottleGroupByName" and "qemuDomainSetThrottleGroupDefaults" - refactor "qemuDomainSetThrottleGroup" and "qemuDomainSetBlockIoTune" to use common logic - update "qemuDomainDelThrottleGroup" to use VIR_JOB_MODIFY by referencing "qemuDomainHotplugDelIOThread" - check if group is still being used by some filter(qemuDomainCheckThrottleGroupRef) during deletion - replace "ThrottleFilterChain" with "ThrottleFilters" - update "qemuDomainDiskGetTopNodename" to take top throttle node name if disk has throttles, and reuse "qemuDomainDiskGetBackendAlias" in "qemuBuildDiskDeviceProps" to get top node name as "drive" - after enabling throttlerfilter and if disk has throttlefilters, during blockcommit, the top node name is not "libvirt-x-format" anymore, instead, top node name referencies top filter like "libvirt-x-filter" - add check "cdrom device with throttle filters isn't supported" - delete "filternodenameindex" and reuse "nodenameindex" to generate index for throttle nodes - refactor detaching filters by adding "qemuBuildThrottleFiltersDetachPrepareBlockdev" to just build parameters for "blockdev-del" - refactor "testDomainSetBlockIoTune" and "testDomainSetThrottleGroup" to use common logic Any comments/suggestions will be appriciated! Chun Feng Wu (16): schema: Add new domain elements to support multiple throttle groups schema: Add new domain elements to support multiple throttle filters config: Introduce ThrottleGroup and corresponding XML parsing config: Introduce ThrottleFilter and corresponding XML parsing qemu: monitor: Add support for ThrottleGroup operations tests: Test qemuMonitorJSONGetThrottleGroup and qemuMonitorJSONUpdateThrottleGroup remote: New APIs for ThrottleGroup lifecycle management qemu: Implement qemu driver for throttle API qemu: hotplug: Support hot attach and detach block disk along with throttle filters config: validate: Refactor disk iotune validation for reuse qemu: command: Support throttle groups during qemuProcessLaunch qemu: command: Support throttle filters during qemuProcessLaunch qemuxmlconftest: Add 'throttlefilter' tests test_driver: Test throttle group lifecycle APIs virsh: Add support for throttle group operations virsh: Add option "throttle-groups" to "attach_disk" docs/formatdomain.rst | 48 ++ include/libvirt/libvirt-domain.h | 21 + src/conf/domain_conf.c | 376 +++++++++++ src/conf/domain_conf.h | 51 ++ src/conf/domain_validate.c | 118 +++- src/conf/schemas/domaincommon.rng | 293 +++++---- src/conf/virconftypes.h | 4 + src/driver-hypervisor.h | 22 + src/libvirt-domain.c | 196 ++++++ src/libvirt_private.syms | 9 + src/libvirt_public.syms | 7 + src/qemu/qemu_block.c | 131 ++++ src/qemu/qemu_block.h | 53 ++ src/qemu/qemu_command.c | 182 ++++++ src/qemu/qemu_command.h | 12 + src/qemu/qemu_domain.c | 39 +- src/qemu/qemu_domain.h | 8 + src/qemu/qemu_driver.c | 617 +++++++++++++++--- src/qemu/qemu_hotplug.c | 33 + src/qemu/qemu_monitor.c | 34 + src/qemu/qemu_monitor.h | 14 + src/qemu/qemu_monitor_json.c | 150 +++++ src/qemu/qemu_monitor_json.h | 14 + src/remote/remote_daemon_dispatch.c | 44 ++ src/remote/remote_driver.c | 40 ++ src/remote/remote_protocol.x | 48 +- src/remote_protocol-structs | 28 + src/test/test_driver.c | 452 +++++++++---- tests/qemumonitorjsontest.c | 86 +++ .../throttlefilter.x86_64-latest.args | 43 ++ .../throttlefilter.x86_64-latest.xml | 65 ++ tests/qemuxmlconfdata/throttlefilter.xml | 55 ++ tests/qemuxmlconftest.c | 1 + tools/virsh-completer-domain.c | 64 ++ tools/virsh-completer-domain.h | 5 + tools/virsh-domain.c | 453 ++++++++++++- 36 files changed, 3447 insertions(+), 369 deletions(-) create mode 100644 tests/qemuxmlconfdata/throttlefilter.x86_64-latest.args create mode 100644 tests/qemuxmlconfdata/throttlefilter.x86_64-latest.xml create mode 100644 tests/qemuxmlconfdata/throttlefilter.xml -- 2.34.1

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Re: [PATCH v2 4/4] virtio-net: Add support for USO features
by Thomas Huth 19 Aug '24

19 Aug '24

On 26/07/2024 08.08, Michael S. Tsirkin wrote: > On Thu, Jul 25, 2024 at 06:18:20PM -0400, Peter Xu wrote: >> On Tue, Aug 01, 2023 at 01:31:48AM +0300, Yuri Benditovich wrote: >>> USO features of virtio-net device depend on kernel ability >>> to support them, for backward compatibility by default the >>> features are disabled on 8.0 and earlier. >>> >>> Signed-off-by: Yuri Benditovich <yuri.benditovich(a)daynix.com> >>> Signed-off-by: Andrew Melnychecnko <andrew(a)daynix.com> >> >> Looks like this patch broke migration when the VM starts on a host that has >> USO supported, to another host that doesn't.. > > This was always the case with all offloads. The answer at the moment is, > don't do this. May I ask for my understanding: "don't do this" = don't automatically enable/disable virtio features in QEMU depending on host kernel features, or "don't do this" = don't try to migrate between machines that have different host kernel features? > Long term, we need to start exposing management APIs > to discover this, and management has to disable unsupported features. Ack, this likely needs some treatments from the libvirt side, too. Thomas

8 93

[PATCH RFC 0/9] qemu: Support mapped-ram migration capability
by Jim Fehlig 16 Aug '24

16 Aug '24

This series is a RFC for support of QEMU's mapped-ram migration capability [1] for saving and restoring VMs. It implements the first part of the design approach we discussed for supporting parallel save/restore [2]. In summary, the approach is 1. Add mapped-ram migration capability 2. Steal an element from save header 'unused' for a 'features' variable and bump save version to 3. 3. Add /etc/libvirt/qemu.conf knob for the save format version, defaulting to latest v3 4. Use v3 (aka mapped-ram) by default 5. Use mapped-ram with BYPASS_CACHE for v3, old approach for v2 6. include: Define constants for parallel save/restore 7. qemu: Add support for parallel save. Implies mapped-ram, reject if v2 8. qemu: Add support for parallel restore. Implies mapped-ram. Reject if v2 9. tools: add parallel parameter to virsh save command 10. tools: add parallel parameter to virsh restore command This series implements 1-5, with the BYPASS_CACHE support in patches 8 and 9 being quite hacky. They are included to discuss approaches to make them less hacky. See the patches for details. The QEMU mapped-ram capability currently does not support directio. Fabino is working on that now [3]. This complicates merging support in libvirt. I don't think it's reasonable to enable mapped-ram by default when BYPASS_CACHE cannot be supported. Should we wait until the mapped-ram directio support is merged in QEMU before supporting mapped-ram in libvirt? For the moment, compression is ignored in the new save version. Currently, libvirt connects the output of QEMU's save stream to the specified compression program via a pipe. This approach is incompatible with mapped-ram since the fd provided to QEMU must be seekable. One option is to reopen and compress the saved image after the actual save operation has completed. This has the downside of requiring the iohelper to handle BYPASS_CACHE, which would preclude us from removing it sometime in the future. Other suggestions much welcomed. Note the logical file size of mapped-ram saved images is slightly larger than guest RAM size, so the files are often much larger than the files produced by the existing, sequential format. However, actual blocks written to disk is often lower with mapped-ram saved images. E.g. a saved image from a 30G, freshly booted, idle guest results in the following 'Size' and 'Blocks' values reported by stat(1) Size Blocks sequential 998595770 1950392 mapped-ram 34368584225 1800456 With the same guest running a workload that dirties memory Size Blocks sequential 33173330615 64791672 mapped-ram 34368578210 64706944 Thanks for any comments on this RFC! [1] https://gitlab.com/qemu-project/qemu/-/blob/master/docs/devel/migration/map… [2] https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/message/K4B… [3] https://mail.gnu.org/archive/html/qemu-devel/2024-05/msg04432.html Jim Fehlig (9): qemu: Enable mapped-ram migration capability qemu_fd: Add function to retrieve fdset ID qemu: Add function to get migration params for save qemu: Add a 'features' element to save image header and bump version qemu: conf: Add setting for save image version qemu: Add support for mapped-ram on save qemu: Enable mapped-ram on restore qemu: Support O_DIRECT with mapped-ram on save qemu: Support O_DIRECT with mapped-ram on restore src/qemu/libvirtd_qemu.aug | 1 + src/qemu/qemu.conf.in | 6 + src/qemu/qemu_conf.c | 8 ++ src/qemu/qemu_conf.h | 1 + src/qemu/qemu_driver.c | 25 ++-- src/qemu/qemu_fd.c | 18 +++ src/qemu/qemu_fd.h | 3 + src/qemu/qemu_migration.c | 99 ++++++++++++++- src/qemu/qemu_migration.h | 11 +- src/qemu/qemu_migration_params.c | 20 +++ src/qemu/qemu_migration_params.h | 4 + src/qemu/qemu_monitor.c | 40 ++++++ src/qemu/qemu_monitor.h | 5 + src/qemu/qemu_process.c | 63 +++++++--- src/qemu/qemu_process.h | 16 ++- src/qemu/qemu_saveimage.c | 187 +++++++++++++++++++++++------ src/qemu/qemu_saveimage.h | 20 ++- src/qemu/qemu_snapshot.c | 12 +- src/qemu/test_libvirtd_qemu.aug.in | 1 + 19 files changed, 455 insertions(+), 85 deletions(-) -- 2.44.0

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[PATCH] conf: Check for bandwidth limits during parsing
by Michal Privoznik 13 Aug '24

13 Aug '24

The 'tc' program stores speeds in 64bit integers (unit is bytes per second) and sizes in uints (unit is bytes). We use different units: kilobytes per second and kibibytes and therefore we can parse values larger than 'tc' can handle. Reject those values right away. And while at it, fix the schema which assumed speed values fit into uint. Resolves: https://issues.redhat.com/browse/RHEL-45200 Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com> --- src/conf/netdev_bandwidth_conf.c | 17 +++++++++++++++++ src/conf/schemas/networkcommon.rng | 2 +- 2 files changed, 18 insertions(+), 1 deletion(-) diff --git a/src/conf/netdev_bandwidth_conf.c b/src/conf/netdev_bandwidth_conf.c index 9faa46a27f..f3f0b2209a 100644 --- a/src/conf/netdev_bandwidth_conf.c +++ b/src/conf/netdev_bandwidth_conf.c @@ -24,6 +24,16 @@ #define VIR_FROM_THIS VIR_FROM_NONE +#define CHECK_LIMIT(val, limit, name) \ + do { \ + if ((val) > (limit)) { \ + virReportError(VIR_ERR_OVERFLOW, \ + _("value '%1$llu' is too big for '%2$s' parameter, maximum is '%3$llu'"), \ + val, name, (unsigned long long) limit); \ + return -1; \ + } \ + } while (0) + static int virNetDevBandwidthParseRate(xmlNodePtr node, virNetDevBandwidthRate *rate, @@ -50,6 +60,11 @@ virNetDevBandwidthParseRate(xmlNodePtr node, &rate->floor)) < 0) return -1; + CHECK_LIMIT(rate->average, 1ULL << 54, "average"); + CHECK_LIMIT(rate->peak, 1ULL << 54, "peak"); + CHECK_LIMIT(rate->burst, UINT_MAX >> 10, "burst"); + CHECK_LIMIT(rate->floor, 1ULL << 54, "floor"); + if (!rc_average && !rc_floor) { virReportError(VIR_ERR_XML_DETAIL, "%s", _("Missing mandatory average or floor attributes")); @@ -71,6 +86,8 @@ virNetDevBandwidthParseRate(xmlNodePtr node, return 0; } +#undef CHECK_LIMIT + /** * virNetDevBandwidthParse: * @bandwidth: parsed bandwidth diff --git a/src/conf/schemas/networkcommon.rng b/src/conf/schemas/networkcommon.rng index 6df6d43f54..2b3f902ffe 100644 --- a/src/conf/schemas/networkcommon.rng +++ b/src/conf/schemas/networkcommon.rng @@ -180,7 +180,7 @@ </define> <define name="speed"> - <data type="unsignedInt"> + <data type="unsignedLong"> <param name="pattern">[0-9]+</param> <param name="minInclusive">1</param> </data> -- 2.44.2

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