[libvirt] [PATCHv4 3/3] qemu: Add args generation for file memory backing
Safka, JaroslavX
jaroslavx.safka at intel.com
Mon Jan 30 08:07:15 UTC 2017
Comments inside
> -----Original Message-----
> From: Michal Privoznik [mailto:mprivozn at redhat.com]
> Sent: Saturday, January 28, 2017 3:03 PM
> To: Safka, JaroslavX <jaroslavx.safka at intel.com>; libvir-list at redhat.com
> Cc: Mooney, Sean K <sean.k.mooney at intel.com>; Ptacek, MichalX
> <michalx.ptacek at intel.com>
> Subject: Re: [libvirt] [PATCHv4 3/3] qemu: Add args generation for file memory
> backing
>
> On 13.12.2016 13:12, Jaroslav Safka wrote:
> > This patch add support for file memory backing on numa topology.
> >
> > The specified access mode in memoryBacking can be overriden by
> > specifying token memAccess in numa cell.
> > ---
> > src/qemu/qemu_command.c | 113 ++++++++++++++-------
> > .../qemuxml2argv-fd-memory-no-numa-topology.args | 21 ++++
> > .../qemuxml2argv-fd-memory-no-numa-topology.xml | 27 +++++
> > .../qemuxml2argv-fd-memory-numa-topology.args | 24 +++++
> > .../qemuxml2argv-fd-memory-numa-topology.xml | 30 ++++++
> > .../qemuxml2argv-fd-memory-numa-topology2.args | 26 +++++
> > .../qemuxml2argv-fd-memory-numa-topology2.xml | 31 ++++++
> > .../qemuxml2argv-fd-memory-numa-topology3.args | 30 ++++++
> > .../qemuxml2argv-fd-memory-numa-topology3.xml | 32 ++++++
> > tests/qemuxml2argvtest.c | 12 ++-
> > tests/qemuxml2xmltest.c | 1 -
> > 11 files changed, 308 insertions(+), 39 deletions(-) create mode
> > 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-no-numa-topology.args
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-no-numa-topology.xml
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.args
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology.xml
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.args
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology2.xml
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.args
> > create mode 100644
> > tests/qemuxml2argvdata/qemuxml2argv-fd-memory-numa-topology3.xml
>
> A lot of tests. Impressive.
>
> >
> > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index
> > 7d186d2..a897ed5 100644
> > --- a/src/qemu/qemu_command.c
> > +++ b/src/qemu/qemu_command.c
> > @@ -3315,15 +3315,11 @@ qemuBuildMemoryBackendStr(unsigned long
> long size,
> > if (!(props = virJSONValueNewObject()))
> > return -1;
> >
> > - if (pagesize) {
> > - if (qemuGetDomainHupageMemPath(def, cfg, pagesize, &mem_path) <
> 0)
> > - goto cleanup;
> > -
> > + if (def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) {
> > *backendType = "memory-backend-file";
> >
> > if (virJSONValueObjectAdd(props,
> > - "b:prealloc", true,
> > - "s:mem-path", mem_path,
> > + "s:mem-path", cfg->libDir,
>
> Really? cfg->libDir should stay intact. Should QEMU need to create a file,
> something cfg->stateDir based is probably more suitable. Or even some /tmp/
> based path. Or am I misunderstanding something?
>
[Jarek] You are right, I was not fully sure about this path. I will use the stateDir then.
> > NULL) < 0)
> > goto cleanup;
> >
> > @@ -3339,18 +3335,54 @@ qemuBuildMemoryBackendStr(unsigned long
> long size,
> > break;
> >
> > case VIR_DOMAIN_MEMORY_ACCESS_DEFAULT:
> > + if (def->mem.access == VIR_DOMAIN_MEMORY_ACCESS_SHARED) {
> > + if (virJSONValueObjectAdd(props, "b:share", true, NULL) < 0)
> > + goto cleanup;
> > + }
> > + break;
> > +
> > case VIR_DOMAIN_MEMORY_ACCESS_LAST:
> > break;
> > }
> > +
> > + force = true;
> > } else {
> > - if (memAccess) {
> > - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
> > - _("Shared memory mapping is supported "
> > - "only with hugepages"));
> > - goto cleanup;
>
> Is this right? What if we are starting a domain that doesn't have hugepages nor
> def->mem.source = file set? I think this should be kept in. Moreover, because
> you removed this bit, you also had to remove the test from qemuxml2argv.
> Please don't remove tests that are failing after your change - they are failing
> for a very good reason.
>
[Jarek] I will check it
> > - }
> > + if (pagesize) {
> > + if (qemuGetDomainHupageMemPath(def, cfg, pagesize,
> &mem_path) < 0)
> > + goto cleanup;
> >
> > - *backendType = "memory-backend-ram";
> > + *backendType = "memory-backend-file";
> > +
> > + if (virJSONValueObjectAdd(props,
> > + "b:prealloc", true,
> > + "s:mem-path", mem_path,
> > + NULL) < 0)
> > + goto cleanup;
> > +
> > + switch (memAccess) {
> > + case VIR_DOMAIN_MEMORY_ACCESS_SHARED:
> > + if (virJSONValueObjectAdd(props, "b:share", true, NULL) < 0)
> > + goto cleanup;
> > + break;
> > +
> > + case VIR_DOMAIN_MEMORY_ACCESS_PRIVATE:
> > + if (virJSONValueObjectAdd(props, "b:share", false, NULL) < 0)
> > + goto cleanup;
> > + break;
> > +
> > + case VIR_DOMAIN_MEMORY_ACCESS_DEFAULT:
> > + if (def->mem.access ==
> VIR_DOMAIN_MEMORY_ACCESS_SHARED) {
> > + if (virJSONValueObjectAdd(props, "b:share", true, NULL) < 0)
> > + goto cleanup;
> > + }
> > + break;
> > +
> > + case VIR_DOMAIN_MEMORY_ACCESS_LAST:
> > + break;
> > + }
> > + } else {
> > + *backendType = "memory-backend-ram";
> > + }
> > }
>
> Oh, this is just a 1:1 copy of what is already there and what you know use for
> def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE case. I think these
> to branches can be merged together and all that you need to special case (i.e.
> mem_path and 'force = true;' can be special cased in the body:
>
> if (pagesize ||
> def->mem.source ...) {
> if (pagesize) {
> /* use qemuGetDomainHupageMemPath to look up mem-path */
> } else {
> VIR_STRDUP(mem_path, /* some per-domain? path */
> }
> *backendType = file;
> ...
> if (def->mem.source..)
> force = true;
> } else {
> *backendType = ram;
> }
>
[Jarek] I will try to change it. Thanks
> >
> > if (virJSONValueObjectAdd(props, "U:size", size * 1024, NULL) <
> > 0) @@ -7250,31 +7282,37 @@
> qemuBuildMemPathStr(virQEMUDriverConfigPtr cfg,
> > const long system_page_size = virGetSystemPageSizeKB();
> > char *mem_path = NULL;
> >
> > - /*
> > - * No-op if hugepages were not requested.
> > - */
> > - if (!def->mem.nhugepages)
> > - return 0;
> > + if (def->mem.nhugepages) {
> >
> > - /* There is one special case: if user specified "huge"
> > - * pages of regular system pages size.
> > - * And there is nothing to do in this case.
> > - */
> > - if (def->mem.hugepages[0].size == system_page_size)
> > - return 0;
> > + /* There is one special case: if user specified "huge"
> > + * pages of regular system pages size.
> > + * And there is nothing to do in this case.
> > + */
> > + if (def->mem.hugepages[0].size == system_page_size)
> > + return 0;
> >
> > - if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MEM_PATH)) {
> > - virReportError(VIR_ERR_INTERNAL_ERROR,
> > - _("hugepage backing not supported by '%s'"),
> > - def->emulator);
> > - return -1;
> > - }
> > + if (!virQEMUCapsGet(qemuCaps, QEMU_CAPS_MEM_PATH)) {
> > + virReportError(VIR_ERR_INTERNAL_ERROR,
> > + _("hugepage backing not supported by '%s'"),
> > + def->emulator);
> > + return -1;
> > + }
> >
> > - if (qemuGetDomainHupageMemPath(def, cfg, def-
> >mem.hugepages[0].size, &mem_path) < 0)
> > - return -1;
> > + if (qemuGetDomainHupageMemPath(def, cfg, def-
> >mem.hugepages[0].size, &mem_path) < 0)
> > + return -1;
> > +
> > + if (def->mem.allocation !=
> VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE)
> > + virCommandAddArgList(cmd, "-mem-prealloc", NULL);
> > +
> > + virCommandAddArgList(cmd, "-mem-path", mem_path, NULL);
> > + VIR_FREE(mem_path);
> > + } else {
> > + /*
> > + * No-op if hugepages or immediate allocation were not requested.
> > + */
> > + return 0;
> > + }
> >
> > - virCommandAddArgList(cmd, "-mem-prealloc", "-mem-path", mem_path,
> NULL);
> > - VIR_FREE(mem_path);
> >
> > return 0;
> > }
>
> Again, a lot of useless changes because you have changed one condition.
> I mean, this function is still no-op if no hugepages are requested, but instead of
> returning early, the actual return for the negative case is here. This would be
> so tiny, easy peasy change had you not inverted the condition.
>
[Jarek] oki, I will change it
> > @@ -7303,9 +7341,12 @@ qemuBuildMemCommandLine(virCommandPtr
> cmd,
> > virDomainDefGetMemoryInitial(def) / 1024);
> > }
> >
> > + if (def->mem.allocation ==
> VIR_DOMAIN_MEMORY_ALLOCATION_IMMEDIATE)
> > + virCommandAddArgList(cmd, "-mem-prealloc", NULL);
> > +
> > /*
> > - * Add '-mem-path' (and '-mem-prealloc') parameter here only if
> > - * there is no numa node specified.
> > + * Add '-mem-path' (and '-mem-prealloc') parameter here if
> > + * the hugepages and no numa node is specified.
> > */
> > if (!virDomainNumaGetNodeCount(def->numa) &&
> > qemuBuildMemPathStr(cfg, def, qemuCaps, cmd) < 0)
>
>
> > diff --git a/tests/qemuxml2argvtest.c b/tests/qemuxml2argvtest.c index
> > 81c62ac..babff8f 100644
> > --- a/tests/qemuxml2argvtest.c
> > +++ b/tests/qemuxml2argvtest.c
> > @@ -1500,8 +1500,6 @@ mymain(void)
> > DO_TEST_PARSE_ERROR("cpu-numa3", NONE);
> > DO_TEST_FAILURE("cpu-numa-disjoint", NONE);
> > DO_TEST("cpu-numa-disjoint", QEMU_CAPS_NUMA);
> > - DO_TEST_FAILURE("cpu-numa-memshared",
> QEMU_CAPS_OBJECT_MEMORY_RAM);
> > - DO_TEST_FAILURE("cpu-numa-memshared", NONE);
>
>
> NACK to this chunk.
>
> > DO_TEST("cpu-host-model", NONE);
> > DO_TEST("cpu-host-model-vendor", NONE);
> > skipLegacyCPUs = true;
> > @@ -2415,6 +2413,16 @@ mymain(void)
> >
> > DO_TEST("cpu-hotplug-startup",
> > QEMU_CAPS_QUERY_HOTPLUGGABLE_CPUS);
> >
> > + DO_TEST("fd-memory-numa-topology", QEMU_CAPS_MEM_PATH,
> QEMU_CAPS_OBJECT_MEMORY_FILE,
> > + QEMU_CAPS_KVM);
> > + DO_TEST("fd-memory-numa-topology2", QEMU_CAPS_MEM_PATH,
> QEMU_CAPS_OBJECT_MEMORY_FILE,
> > + QEMU_CAPS_KVM);
> > + DO_TEST("fd-memory-numa-topology3", QEMU_CAPS_MEM_PATH,
> QEMU_CAPS_OBJECT_MEMORY_FILE,
> > + QEMU_CAPS_KVM);
> > +
> > + DO_TEST("fd-memory-no-numa-topology", QEMU_CAPS_MEM_PATH,
> QEMU_CAPS_OBJECT_MEMORY_FILE,
> > + QEMU_CAPS_KVM);
> > +
> > qemuTestDriverFree(&driver);
> >
> > return ret == 0 ? EXIT_SUCCESS : EXIT_FAILURE; diff --git
> > a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c index
> > e4d011f..ae6a873 100644
> > --- a/tests/qemuxml2xmltest.c
> > +++ b/tests/qemuxml2xmltest.c
> > @@ -939,7 +939,6 @@ mymain(void)
> > DO_TEST("cpu-numa-no-memory-element", NONE);
> > DO_TEST("cpu-numa-disordered", NONE);
> > DO_TEST("cpu-numa-disjoint", NONE);
> > - DO_TEST("cpu-numa-memshared", NONE);
>
> NACK to this chunk. Removing tests because they are failing after a change
> is/should be no-no.
>
> >
> > DO_TEST("numatune-auto-prefer", NONE);
> > DO_TEST("numatune-memnode", NONE);
> >
>
> Otherwise looking good.
>
> Michal
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