Re: [libvirt] [PATCH v2 20/20] qemu: ensure that memory 'discard' is used if specified in XML

On 08/09/2018 02:38 PM, Pavel Hrdina wrote: > Signed-off-by: Pavel Hrdina <phrdina(a)redhat.com&gt; > --- > src/qemu/qemu_command.c | 4 +++- > .../pages-discard-hugepages.args | 11 +++++++---- > tests/qemuxml2argvdata/pages-discard.args | 18 ++++++++++++++---- > 3 files changed, 24 insertions(+), 9 deletions(-) > > diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c > index dbeb3a54f6..a7859feae6 100644 > --- a/src/qemu/qemu_command.c > +++ b/src/qemu/qemu_command.c > @@ -3147,6 +3147,7 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps, > return -1; > > if (useHugepage || mem->nvdimmPath || memAccess || > + discard == VIR_TRISTATE_BOOL_YES || > def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_FILE) { > > if (useHugepage) { > @@ -3228,7 +3229,8 @@ qemuBuildMemoryBackendProps(virJSONValuePtr *backendProps, > if (!needHugepage && !mem->sourceNodes && !nodeSpecified && > !mem->nvdimmPath && > memAccess == VIR_DOMAIN_MEMORY_ACCESS_DEFAULT && > - def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force) { > + def->mem.source != VIR_DOMAIN_MEMORY_SOURCE_FILE && !force && > + discard != VIR_TRISTATE_BOOL_YES) { > /* report back that using the new backend is not necessary > * to achieve the desired configuration */ > ret = 1; > diff --git a/tests/qemuxml2argvdata/pages-discard-hugepages.args b/tests/qemuxml2argvdata/pages-discard-hugepages.args > index 2dfacefe4a..d859480c26 100644 > --- a/tests/qemuxml2argvdata/pages-discard-hugepages.args > +++ b/tests/qemuxml2argvdata/pages-discard-hugepages.args > @@ -10,10 +10,13 @@ QEMU_AUDIO_DRV=none \ > -machine pc,accel=tcg,usb=off,dump-guest-core=off \ > -m 1024 \ > -smp 2,sockets=2,cores=1,threads=1 \ > --mem-prealloc \ > --mem-path /dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu \ > --numa node,nodeid=0,cpus=0,mem=256 \ > --numa node,nodeid=1,cpus=1,mem=768 \ > +-object memory-backend-file,id=ram-node0,prealloc=yes,\ > +mem-path=/dev/hugepages2M/libvirt/qemu/-1-SomeDummyHugepagesGu,size=268435456 \ > +-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-SomeDummyHugepagesGu,\ > +discard-data=yes,size=805306368 \ > +-numa node,nodeid=1,cpus=1,memdev=ram-node1 \ This will break migration. But at the same time, it's very unlikely that anybody is using discard without hugepages.

Michal -- libvir-list mailing list libvir-list(a)redhat.com https://www.redhat.com/mailman/listinfo/libvir-list