https://bugzilla.redhat.com/show_bug.cgi?id=1624223 There are two ways to request memory preallocation on cmd line: -mem-prealloc and .prealloc attribute to memory-backend-file. However, as it turns out it's not safe to use both at the same time. Prefer -mem-prealloc as it is more backward compatible compared to switching to "-numa node,memdev= + -object memory-backend-file". Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_command.c | 37 +++++++++++++------ src/qemu/qemu_command.h | 1 + src/qemu/qemu_domain.c | 2 + src/qemu/qemu_domain.h | 3 ++ src/qemu/qemu_hotplug.c | 3 +- .../hugepages-numa-default-dimm.args | 2 +- 6 files changed, 35 insertions(+), 13 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index e338d3172e..0294030f0e 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3123,6 +3123,7 @@ qemuBuildControllerDevCommandLine(virCommandPtr cmd, * @def: domain definition object * @mem: memory definition object * @autoNodeset: fallback nodeset in case of automatic NUMA placement + * @forbidPrealloc: don't set prealloc attribute * @force: forcibly use one of the backends * * Creates a configuration object that represents memory backend of given guest @@ -3136,6 +3137,9 @@ qemuBuildControllerDevCommandLine(virCommandPtr cmd, * Then, if one of the two memory-backend-* should be used, the @qemuCaps is * consulted to check if qemu does support it. * + * If @forbidPrealloc is true then 'prealloc' attribute of the backend is not + * set. This may come handy when global -mem-prealloc is already specified. + * * Returns: 0 on success, * 1 on success and if there's no need to use memory-backend-* * -1 on error. @@ -3148,6 +3152,7 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps, virDomainDefPtr def, virDomainMemoryDefPtr mem, virBitmapPtr autoNodeset, + bool forbidPrealloc, bool force) { const char *backendType = "memory-backend-file"; @@ -3265,11 +3270,13 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps, if (mem->nvdimmPath) { if (VIR_STRDUP(memPath, mem->nvdimmPath) < 0) goto cleanup; - prealloc = true; + if (!forbidPrealloc) + prealloc = true; } else if (useHugepage) { if (qemuGetDomainHupageMemPath(def, cfg, pagesize, &memPath) < 0) goto cleanup; - prealloc = true; + if (!forbidPrealloc) + prealloc = true; } else { /* We can have both pagesize and mem source. If that's the case, * prefer hugepages as those are more specific. */ @@ -3398,7 +3405,8 @@ qemuBuildMemoryCellBackendStr(virDomainDefPtr def, mem.info.alias = alias; if ((rc = qemuBuildMemoryBackendProps(&props, alias, cfg, priv->qemuCaps, - def, &mem, priv->autoNodeset, false)) < 0) + def, &mem, priv->autoNodeset, + priv->memPrealloc, false)) < 0) goto cleanup; if (virQEMUBuildObjectCommandlineFromJSON(buf, props) < 0) @@ -3435,7 +3443,8 @@ qemuBuildMemoryDimmBackendStr(virBufferPtr buf, goto cleanup; if (qemuBuildMemoryBackendProps(&props, alias, cfg, priv->qemuCaps, - def, mem, priv->autoNodeset, true) < 0) + def, mem, priv->autoNodeset, + priv->memPrealloc, true) < 0) goto cleanup; if (virQEMUBuildObjectCommandlineFromJSON(buf, props) < 0) @@ -7443,7 +7452,8 @@ qemuBuildSmpCommandLine(virCommandPtr cmd, static int qemuBuildMemPathStr(virQEMUDriverConfigPtr cfg, const virDomainDef *def, - virCommandPtr cmd) + virCommandPtr cmd, + qemuDomainObjPrivatePtr priv) { const long system_page_size = virGetSystemPageSizeKB(); char *mem_path = NULL; @@ -7465,8 +7475,10 @@ qemuBuildMemPathStr(virQEMUDriverConfigPtr cfg, return 0; } - if (def->mem.allocation != VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE) + if (def->mem.allocation != VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE) { virCommandAddArgList(cmd, "-mem-prealloc", NULL); + priv->memPrealloc = true; + } virCommandAddArgList(cmd, "-mem-path", mem_path, NULL); VIR_FREE(mem_path); @@ -7479,7 +7491,8 @@ static int qemuBuildMemCommandLine(virCommandPtr cmd, virQEMUDriverConfigPtr cfg, const virDomainDef *def, - virQEMUCapsPtr qemuCaps) + virQEMUCapsPtr qemuCaps, + qemuDomainObjPrivatePtr priv) { if (qemuDomainDefValidateMemoryHotplug(def, qemuCaps, NULL) < 0) return -1; @@ -7498,15 +7511,17 @@ qemuBuildMemCommandLine(virCommandPtr cmd, virDomainDefGetMemoryInitial(def) / 1024); } - if (def->mem.allocation == VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE) + if (def->mem.allocation == VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE) { virCommandAddArgList(cmd, "-mem-prealloc", NULL); + priv->memPrealloc = true; + } /* * Add '-mem-path' (and '-mem-prealloc') parameter here if * the hugepages and no numa node is specified. */ if (!virDomainNumaGetNodeCount(def->numa) && - qemuBuildMemPathStr(cfg, def, cmd) < 0) + qemuBuildMemPathStr(cfg, def, cmd, priv) < 0) return -1; if (def->mem.locked && !virQEMUCapsGet(qemuCaps, QEMU_CAPS_REALTIME_MLOCK)) { @@ -7613,7 +7628,7 @@ qemuBuildNumaArgStr(virQEMUDriverConfigPtr cfg, } if (!needBackend && - qemuBuildMemPathStr(cfg, def, cmd) < 0) + qemuBuildMemPathStr(cfg, def, cmd, priv) < 0) goto cleanup; for (i = 0; i < ncells; i++) { @@ -10250,7 +10265,7 @@ qemuBuildCommandLine(virQEMUDriverPtr driver, if (!migrateURI && !snapshot && qemuDomainAlignMemorySizes(def) < 0) goto error; - if (qemuBuildMemCommandLine(cmd, cfg, def, qemuCaps) < 0) + if (qemuBuildMemCommandLine(cmd, cfg, def, qemuCaps, priv) < 0) goto error; if (qemuBuildSmpCommandLine(cmd, def) < 0) diff --git a/src/qemu/qemu_command.h b/src/qemu/qemu_command.h index 98d4ac90b5..656479ac45 100644 --- a/src/qemu/qemu_command.h +++ b/src/qemu/qemu_command.h @@ -129,6 +129,7 @@ int qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps, virDomainDefPtr def, virDomainMemoryDefPtr mem, virBitmapPtr autoNodeset, + bool forbidPrealloc, bool force); char *qemuBuildMemoryDeviceStr(virDomainMemoryDefPtr mem); diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index ba3fff607a..0307acfe6a 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -1944,6 +1944,8 @@ qemuDomainObjPrivateDataClear(qemuDomainObjPrivatePtr priv) VIR_FREE(priv->libDir); VIR_FREE(priv->channelTargetDir); + priv->memPrealloc = false; + /* remove automatic pinning data */ virBitmapFree(priv->autoNodeset); priv->autoNodeset = NULL; diff --git a/src/qemu/qemu_domain.h b/src/qemu/qemu_domain.h index 80bd4bde91..7ccbff8d26 100644 --- a/src/qemu/qemu_domain.h +++ b/src/qemu/qemu_domain.h @@ -370,6 +370,9 @@ struct _qemuDomainObjPrivate { /* qemuProcessStartCPUs stores the reason for starting vCPUs here for the * RESUME event handler to use it */ virDomainRunningReason runningReason; + + /* true if global -mem-prealloc appears on cmd line */ + bool memPrealloc; }; # define QEMU_DOMAIN_PRIVATE(vm) \ diff --git a/src/qemu/qemu_hotplug.c b/src/qemu/qemu_hotplug.c index 0a63741b9e..6ead926f09 100644 --- a/src/qemu/qemu_hotplug.c +++ b/src/qemu/qemu_hotplug.c @@ -2458,7 +2458,8 @@ qemuDomainAttachMemory(virQEMUDriverPtr driver, goto cleanup; if (qemuBuildMemoryBackendProps(&props, objalias, cfg, - priv->qemuCaps, vm->def, mem, NULL, true) < 0) + priv->qemuCaps, vm->def, mem, NULL, + priv->memPrealloc, true) < 0) goto cleanup; if (qemuProcessBuildDestroyMemoryPaths(driver, vm, mem, true) < 0) diff --git a/tests/qemuxml2argvdata/hugepages-numa-default-dimm.args b/tests/qemuxml2argvdata/hugepages-numa-default-dimm.args index 143d8b041f..df90f7aad9 100644 --- a/tests/qemuxml2argvdata/hugepages-numa-default-dimm.args +++ b/tests/qemuxml2argvdata/hugepages-numa-default-dimm.args @@ -13,7 +13,7 @@ QEMU_AUDIO_DRV=none \ -mem-prealloc \ -mem-path /dev/hugepages2M/libvirt/qemu/-1-fedora \ -numa node,nodeid=0,cpus=0-1,mem=1024 \ --object memory-backend-file,id=memdimm0,prealloc=yes,\ +-object memory-backend-file,id=memdimm0,\ mem-path=/dev/hugepages1G/libvirt/qemu/-1-fedora,size=1073741824,\ host-nodes=1-3,policy=bind \ -device pc-dimm,node=0,memdev=memdimm0,id=dimm0,slot=0 \ -- 2.18.1