[libvirt] [PATCH v3 4/5] qemu: Use predictable file names for memory-backend-file

In some cases management application needs to allocate memory for qemu upfront and then just let qemu use that. Since we don't want to expose path for memory-backend-file anywhere in the domain XML, we can generate predictable paths. In this case: $memoryBackingDir/libvirt/qemu/$shortName/$alias where $shortName is result of virDomainObjGetShortName(). Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_command.c | 2 +- src/qemu/qemu_conf.c | 55 +++++++++++++++++- src/qemu/qemu_conf.h | 9 ++- src/qemu/qemu_driver.c | 17 ++++++ src/qemu/qemu_process.c | 65 ++++++++++++++++++---- .../qemuxml2argv-cpu-numa-memshared.args | 6 +- .../qemuxml2argv-fd-memory-numa-topology.args | 3 +- .../qemuxml2argv-fd-memory-numa-topology2.args | 6 +- .../qemuxml2argv-fd-memory-numa-topology3.args | 9 ++- .../qemuxml2argv-hugepages-memaccess2.args | 9 ++- 10 files changed, 155 insertions(+), 26 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index c949afe90..c12cfec7a 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3419,7 +3419,7 @@ qemuBuildMemoryBackendStr(virJSONValuePtr *backendProps, } else { /* We can have both pagesize and mem source. If that's the case, * prefer hugepages as those are more specific. */ - if (qemuGetMemoryBackingPath(cfg, &memPath) < 0) + if (qemuGetMemoryBackingPath(def, cfg, mem->info.alias, &memPath) < 0) goto cleanup; } diff --git a/src/qemu/qemu_conf.c b/src/qemu/qemu_conf.c index f3cff1503..af503d31c 100644 --- a/src/qemu/qemu_conf.c +++ b/src/qemu/qemu_conf.c @@ -1750,9 +1750,41 @@ qemuGetDomainHupageMemPath(const virDomainDef *def, } +int +qemuGetMemoryBackingBasePath(virQEMUDriverConfigPtr cfg, + char **path) +{ + return virAsprintf(path, "%s/libvirt/qemu", cfg->memoryBackingDir); +} + + +int +qemuGetMemoryBackingDomainPath(const virDomainDef *def, + virQEMUDriverConfigPtr cfg, + char **path) +{ + char *shortName = NULL; + char *base = NULL; + int ret = -1; + + if (!(shortName = virDomainDefGetShortName(def)) || + qemuGetMemoryBackingBasePath(cfg, &base) < 0 || + virAsprintf(path, "%s/%s", base, shortName) < 0) + goto cleanup; + + ret = 0; + cleanup: + VIR_FREE(base); + VIR_FREE(shortName); + return ret; +} + + /** * qemuGetMemoryBackingPath: + * @def: domain definition * @cfg: the driver config + * @alias: memory object alias * @memPath: constructed path * * Constructs path to memory backing dir and stores it at @memPath. @@ -1761,8 +1793,27 @@ qemuGetDomainHupageMemPath(const virDomainDef *def, * -1 otherwise (with error reported). */ int -qemuGetMemoryBackingPath(virQEMUDriverConfigPtr cfg, +qemuGetMemoryBackingPath(const virDomainDef *def, + virQEMUDriverConfigPtr cfg, + const char *alias, char **memPath) { - return VIR_STRDUP(*memPath, cfg->memoryBackingDir); + char *domainPath = NULL; + int ret = -1; + + if (!alias) { + /* This should never happen (TM) */ + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("memory device alias is not assigned")); + goto cleanup; + } + + if (qemuGetMemoryBackingDomainPath(def, cfg, &domainPath) < 0 || + virAsprintf(memPath, "%s/%s", domainPath, alias) < 0) + goto cleanup; + + ret = 0; + cleanup: + VIR_FREE(domainPath); + return ret; } diff --git a/src/qemu/qemu_conf.h b/src/qemu/qemu_conf.h index 9d6866816..a553e30e2 100644 --- a/src/qemu/qemu_conf.h +++ b/src/qemu/qemu_conf.h @@ -364,6 +364,13 @@ int qemuGetDomainHupageMemPath(const virDomainDef *def, unsigned long long pagesize, char **memPath); -int qemuGetMemoryBackingPath(virQEMUDriverConfigPtr cfg, +int qemuGetMemoryBackingBasePath(virQEMUDriverConfigPtr cfg, + char **path); +int qemuGetMemoryBackingDomainPath(const virDomainDef *def, + virQEMUDriverConfigPtr cfg, + char **path); +int qemuGetMemoryBackingPath(const virDomainDef *def, + virQEMUDriverConfigPtr cfg, + const char *alias, char **memPath); #endif /* __QEMUD_CONF_H */ diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index bb53d78ea..47f85b9bf 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -631,6 +631,7 @@ qemuStateInitialize(bool privileged, uid_t run_uid = -1; gid_t run_gid = -1; char *hugepagePath = NULL; + char *memoryBackingPath = NULL; size_t i; if (VIR_ALLOC(qemu_driver) < 0) @@ -889,6 +890,21 @@ qemuStateInitialize(bool privileged, VIR_FREE(hugepagePath); } + if (qemuGetMemoryBackingBasePath(cfg, &memoryBackingPath) < 0) + goto error; + + if (virFileMakePath(memoryBackingPath) < 0) { + virReportSystemError(errno, + _("unable to create memory backing path %s"), + memoryBackingPath); + goto error; + } + + if (privileged && + virFileUpdatePerm(memoryBackingPath, + 0, S_IXGRP | S_IXOTH) < 0) + goto error; + if (!(qemu_driver->closeCallbacks = virCloseCallbacksNew())) goto error; @@ -946,6 +962,7 @@ qemuStateInitialize(bool privileged, virObjectUnref(conn); VIR_FREE(driverConf); VIR_FREE(hugepagePath); + VIR_FREE(memoryBackingPath); qemuStateCleanup(); return -1; } diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 8eef2794e..eca41261a 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -3324,6 +3324,36 @@ qemuProcessNeedHugepagesPath(virDomainDefPtr def, } +static bool +qemuProcessNeedMemoryBackingPath(virDomainDefPtr def, + virDomainMemoryDefPtr mem) +{ + size_t i; + size_t numaNodes; + + if (def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE || + def->mem.access != VIR_DOMAIN_MEMORY_ACCESS_DEFAULT) + return true; + + numaNodes = virDomainNumaGetNodeCount(def->numa); + for (i = 0; i < numaNodes; i++) { + if (virDomainNumaGetNodeMemoryAccessMode(def->numa, i) + != VIR_DOMAIN_MEMORY_ACCESS_DEFAULT) + return true; + } + + if (mem && + mem->model == VIR_DOMAIN_MEMORY_MODEL_DIMM && + (mem->access != VIR_DOMAIN_MEMORY_ACCESS_DEFAULT || + (mem->targetNode >= 0 && + virDomainNumaGetNodeMemoryAccessMode(def->numa, mem->targetNode) + != VIR_DOMAIN_MEMORY_ACCESS_DEFAULT))) + return true; + + return false; +} + + static int qemuProcessBuildDestroyMemoryPathsImpl(virQEMUDriverPtr driver, virDomainDefPtr def, @@ -3365,33 +3395,46 @@ qemuProcessBuildDestroyMemoryPaths(virQEMUDriverPtr driver, bool build) { virQEMUDriverConfigPtr cfg = virQEMUDriverGetConfig(driver); - char *hugepagePath = NULL; + char *path = NULL; size_t i; - bool shouldBuild = false; + bool shouldBuildHP = false; + bool shouldBuildMB = false; int ret = -1; - if (build) - shouldBuild = qemuProcessNeedHugepagesPath(vm->def, mem); + if (build) { + shouldBuildHP = qemuProcessNeedHugepagesPath(vm->def, mem); + shouldBuildMB = qemuProcessNeedMemoryBackingPath(vm->def, mem); + } - if (!build || shouldBuild) { + if (!build || shouldBuildHP) { for (i = 0; i < cfg->nhugetlbfs; i++) { - VIR_FREE(hugepagePath); - hugepagePath = qemuGetDomainHugepagePath(vm->def, &cfg->hugetlbfs[i]); + path = qemuGetDomainHugepagePath(vm->def, &cfg->hugetlbfs[i]); - if (!hugepagePath) + if (!path) goto cleanup; if (qemuProcessBuildDestroyMemoryPathsImpl(driver, vm->def, - hugepagePath, build) < 0) + path, build) < 0) goto cleanup; - VIR_FREE(hugepagePath); + VIR_FREE(path); } } + if (!build || shouldBuildMB) { + if (qemuGetMemoryBackingDomainPath(vm->def, cfg, &path) < 0) + goto cleanup; + + if (qemuProcessBuildDestroyMemoryPathsImpl(driver, vm->def, + path, build) < 0) + goto cleanup; + + VIR_FREE(path); + } + ret = 0; cleanup: - VIR_FREE(hugepagePath); + VIR_FREE(path); virObjectUnref(cfg); return ret; } diff --git a/tests/qemuxml2argvdata/qemuxml2argv-cpu-numa-memshared.args b/tests/qemuxml2argvdata/qemuxml2argv-cpu-numa-memshared.args index 5700c3413..352819429 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-cpu-numa-memshared.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-cpu-numa-memshared.args @@ -10,10 +10,12 @@ QEMU_AUDIO_DRV=none \ -M pc \ -m 214 \ -smp 16,sockets=2,cores=4,threads=2 \ --object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node0,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node0,\ share=yes,size=112197632 \ -numa node,nodeid=0,cpus=0-7,memdev=ram-node0 \ --object memory-backend-file,id=ram-node1,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node1,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node1,\ share=no,size=112197632 \ -numa node,nodeid=1,cpus=8-15,memdev=ram-node1 \ -uuid c7a5fdbd-edaf-9455-926a-d65c16db1809 \ diff --git a/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.args b/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.args index 12f3d8ab8..fa1353259 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.args @@ -11,7 +11,8 @@ QEMU_AUDIO_DRV=none \ -m 14336 \ -mem-prealloc \ -smp 8,sockets=1,cores=8,threads=1 \ --object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node0,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node0,\ share=yes,size=15032385536 \ -numa node,nodeid=0,cpus=0-7,memdev=ram-node0 \ -uuid 126f2720-6f8e-45ab-a886-ec9277079a67 \ diff --git a/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.args b/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.args index 585e4d506..6f73a1b99 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.args @@ -11,10 +11,12 @@ QEMU_AUDIO_DRV=none \ -m 28672 \ -mem-prealloc \ -smp 20,sockets=1,cores=8,threads=1 \ --object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node0,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node0,\ share=no,size=15032385536 \ -numa node,nodeid=0,cpus=0-7,memdev=ram-node0 \ --object memory-backend-file,id=ram-node1,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node1,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node1,\ share=yes,size=15032385536 \ -numa node,nodeid=1,cpus=8-15,memdev=ram-node1 \ -uuid 126f2720-6f8e-45ab-a886-ec9277079a67 \ diff --git a/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.args b/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.args index e9a57a69e..3c352fe03 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.args @@ -11,13 +11,16 @@ QEMU_AUDIO_DRV=none \ -m 43008 \ -mem-prealloc \ -smp 32,sockets=1,cores=24,threads=1 \ --object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node0,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node0,\ share=yes,size=15032385536 \ -numa node,nodeid=0,cpus=0-1,memdev=ram-node0 \ --object memory-backend-file,id=ram-node1,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node1,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node1,\ share=yes,size=15032385536 \ -numa node,nodeid=1,cpus=2-3,memdev=ram-node1 \ --object memory-backend-file,id=ram-node2,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node2,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-instance-00000092/ram-node2,\ share=no,size=15032385536 \ -numa node,nodeid=2,cpus=4-5,memdev=ram-node2 \ -uuid 126f2720-6f8e-45ab-a886-ec9277079a67 \ diff --git a/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args index 55db49171..d8e506c19 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args +++ b/tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args @@ -10,17 +10,20 @@ QEMU_AUDIO_DRV=none \ -M pc \ -m size=4194304k,slots=16,maxmem=8388608k \ -smp 4,sockets=4,cores=1,threads=1 \ --object memory-backend-file,id=ram-node0,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node0,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node0,\ share=no,size=1073741824,host-nodes=0-3,policy=bind \ -numa node,nodeid=0,cpus=0,memdev=ram-node0 \ -object memory-backend-file,id=ram-node1,prealloc=yes,\ mem-path=/dev/hugepages2M/libvirt/qemu/-1-QEMUGuest1,share=yes,size=1073741824,\ host-nodes=0-3,policy=bind \ -numa node,nodeid=1,cpus=1,memdev=ram-node1 \ --object memory-backend-file,id=ram-node2,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node2,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node2,\ share=no,size=1073741824,host-nodes=0-3,policy=bind \ -numa node,nodeid=2,cpus=2,memdev=ram-node2 \ --object memory-backend-file,id=ram-node3,mem-path=/var/lib/libvirt/qemu/ram,\ +-object memory-backend-file,id=ram-node3,\ +mem-path=/var/lib/libvirt/qemu/ram/libvirt/qemu/-1-QEMUGuest1/ram-node3,\ share=no,size=1073741824,host-nodes=3,policy=bind \ -numa node,nodeid=3,cpus=3,memdev=ram-node3 \ -object memory-backend-file,id=memdimm0,prealloc=yes,\ -- 2.13.6