Re: [PATCH v2 13/15] qemuBuildThreadContextProps: Prune .node-affinity wrt <emulatorpin/>

When a thread-context object is specified on the cmd line, then QEMU spawns a thread and sets its affinity to the list of NUMA nodes specified in .node-affinity attribute. And this works just fine, until the main QEMU thread itself is not restricted. Because of v5.3.0-rc1~18 we restrict the main emulator thread even before QEMU is executed and thus then it tries to set affinity of a thread-context thread, it inevitably fails with: Setting CPU affinity failed: Invalid argument Now, we could lift the pinning temporarily, let QEMU spawn all thread-context threads, and enforce pinning again, but that would require some form of communication with QEMU (maybe -preconfig?). But that would still be wrong, because it would circumvent <emulatorpin/>. Technically speaking, thread-context is an internal implementation detail of QEMU, and if it weren't for it, the main emulator thread would be doing the allocation. Therefore, we should honor the pinning and prune the list of node so that inaccessible ones are dropped. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=2154750 Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; Reviewed-by: Andrea Bolognani <abologna(a)redhat.com&gt; --- src/qemu/qemu_command.c | 26 ++++++++++++++++--- src/qemu/qemu_command.h | 1 + ...emory-hotplug-dimm-addr.x86_64-latest.args | 2 +- 3 files changed, 25 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index 6de3b549a0..7137edac8f 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3539,7 +3539,7 @@ qemuBuildMemoryDimmBackendStr(virCommand *cmd, def, mem, true, false, &nodemask) < 0) return -1; - if (qemuBuildThreadContextProps(&tcProps, &props, priv, nodemask) < 0) + if (qemuBuildThreadContextProps(&tcProps, &props, def, priv, nodemask) < 0) return -1; if (tcProps && @@ -3636,10 +3636,13 @@ qemuBuildMemoryDeviceProps(virQEMUDriverConfig *cfg, int qemuBuildThreadContextProps(virJSONValue **tcProps, virJSONValue **memProps, + const virDomainDef *def, qemuDomainObjPrivate *priv, virBitmap *nodemask) { g_autoptr(virJSONValue) props = NULL; + virBitmap *emulatorpin = NULL; + g_autoptr(virBitmap) emulatorNodes = NULL; g_autofree char *tcAlias = NULL; const char *memalias = NULL; bool prealloc = false; @@ -3656,6 +3659,23 @@ qemuBuildThreadContextProps(virJSONValue **tcProps, !prealloc) return 0; + emulatorpin = qemuDomainEvaluateCPUMask(def, + def->cputune.emulatorpin, + priv->autoNodeset); + + if (emulatorpin && + virNumaIsAvailable()) {

+ if (virNumaCPUSetToNodeset(emulatorpin, &emulatorNodes) < 0) + return -1; + + virBitmapIntersect(emulatorNodes, nodemask); + + if (virBitmapIsAllClear(emulatorNodes)) + return 0; + + nodemask = emulatorNodes; + } + memalias = virJSONValueObjectGetString(*memProps, "id"); if (!memalias) { virReportError(VIR_ERR_INTERNAL_ERROR, "%s", @@ -7188,7 +7208,7 @@ qemuBuildMemCommandLineMemoryDefaultBackend(virCommand *cmd, def, &mem, false, true, &nodemask) < 0) return -1; - if (qemuBuildThreadContextProps(&tcProps, &props, priv, nodemask) < 0) + if (qemuBuildThreadContextProps(&tcProps, &props, def, priv, nodemask) < 0) return -1; if (tcProps && @@ -7517,7 +7537,7 @@ qemuBuildNumaCommandLine(virQEMUDriverConfig *cfg, g_autoptr(virJSONValue) tcProps = NULL; if (qemuBuildThreadContextProps(&tcProps, &nodeBackends[i], - priv, nodemask[i]) < 0) + def, priv, nodemask[i]) < 0) goto cleanup; if (tcProps && diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h index 17f326d13b..5fdb138030 100644 --- a/src/qemu/qemu_command.h +++ b/src/qemu/qemu_command.h @@ -153,6 +153,7 @@ qemuBuildMemoryDeviceProps(virQEMUDriverConfig *cfg, int qemuBuildThreadContextProps(virJSONValue **tcProps, virJSONValue **memProps, + const virDomainDef *def, qemuDomainObjPrivate *priv, virBitmap *nodemask); diff --git a/tests/qemuxml2argvdata/memory-hotplug-dimm-addr.x86_64-latest.args b/tests/qemuxml2argvdata/memory-hotplug-dimm-addr.x86_64-latest.args index 84360843fb..6ae1fd1b98 100644 --- a/tests/qemuxml2argvdata/memory-hotplug-dimm-addr.x86_64-latest.args +++ b/tests/qemuxml2argvdata/memory-hotplug-dimm-addr.x86_64-latest.args @@ -28,7 +28,7 @@ XDG_CONFIG_HOME=/var/lib/libvirt/qemu/domain--1-QEMUGuest1/.config \ -no-shutdown \ -boot strict=on \ -device '{"driver":"piix3-usb-uhci","id":"usb","bus":"pci.0","addr":"0x1.0x2"}' \ --object '{"qom-type":"thread-context","id":"tc-memdimm0","node-affinity":[1,2,3]}' \ +-object '{"qom-type":"thread-context","id":"tc-memdimm0","node-affinity":[1,2]}' \ -object '{"qom-type":"memory-backend-file","id":"memdimm0","mem-path":"/dev/hugepages2M/libvirt/qemu/-1-QEMUGuest1","prealloc":true,"size":536870912,"host-nodes":[1,2,3],"policy":"bind","prealloc-context":"tc-memdimm0"}' \ -device '{"driver":"pc-dimm","node":0,"memdev":"memdimm0","id":"dimm0","slot":0,"addr":4294967296}' \ -object '{"qom-type":"memory-backend-ram","id":"memdimm2","size":536870912}' \ -- 2.39.2