[libvirt] [PATCH v3 4/5] qemu: Use predictable file names for memory-backend-file
John Ferlan
jferlan at redhat.com
Wed Nov 8 02:15:45 UTC 2017
On 11/07/2017 10:51 AM, Michal Privoznik wrote:
> 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().
Just realized the s/Obj/Def/ from my previous review was missed.
John
>
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
> 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,\
>
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