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qemu: Use predictable file names for memory-backend-file

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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 virDomainDefGetShortName().

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: John Ferlan <jferlan@redhat.com>
This commit is contained in:
Michal Privoznik 2017-11-07 15:20:12 +01:00
parent bb3de478a6
commit fec8f9c49a
10 changed files with 155 additions and 26 deletions
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2
src/qemu/qemu_command.c
View File

@ -3383,7 +3383,7 @@ 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;
}

55
src/qemu/qemu_conf.c
View File

@ -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;
}

9
src/qemu/qemu_conf.h
View File

@ -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 */

17
src/qemu/qemu_driver.c
View File

@ -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;
}

65
src/qemu/qemu_process.c
View File

@ -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,
@ -3363,33 +3393,46 @@ 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;
}

6
tests/qemuxml2argvdata/qemuxml2argv-cpu-numa-memshared.args
View File

@ -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 \

3
tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.args
View File

@ -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 \

6
tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.args
View File

@ -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 \

9
tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.args
View File

@ -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 \

9
tests/qemuxml2argvdata/qemuxml2argv-hugepages-memaccess2.args
View File

@ -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,\