Re: [PATCH] qemu: Don't use memory-backend-memfd for NVDIMMs

If guest is configured to use memfd then the function that build memory-backend-* part of command line will put memory-backend-memfd, always. Even for NVDIMMs. This is not correct, because NVDIMMs need a backing path (usually to a real host NVDIMM device). Therefore, regardless of memfd being requested, we have to stick with memory-backend-file. Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; ---

src/qemu/qemu_command.c | 3 ++- .../memfd-memory-numa.x86_64-latest.args | 6 ++++-- tests/qemuxml2argvdata/memfd-memory-numa.xml | 11 +++++++++++ tests/qemuxml2xmltest.c | 3 ++- 4 files changed, 19 insertions(+), 4 deletions(-) diff --git a/src/qemu/qemu_command.c b/src/qemu/qemu_command.c index ea513693f7..0473e7deaa 100644 --- a/src/qemu/qemu_command.c +++ b/src/qemu/qemu_command.c @@ -3052,7 +3052,8 @@ qemuBuildMemoryBackendProps(virJSONValue **backendProps, props = virJSONValueNewObject(); - if (def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_MEMFD) { + if (!mem->nvdimmPath && + def->mem.source == VIR_DOMAIN_MEMORY_SOURCE_MEMFD) { backendType = "memory-backend-memfd"; if (useHugepage) { diff --git a/tests/qemuxml2argvdata/memfd-memory-numa.x86_64-latest.args b/tests/qemuxml2argvdata/memfd-memory-numa.x86_64-latest.args index 5e54908666..3b33db3c55 100644 --- a/tests/qemuxml2argvdata/memfd-memory-numa.x86_64-latest.args +++ b/tests/qemuxml2argvdata/memfd-memory-numa.x86_64-latest.args @@ -10,13 +10,15 @@ XDG_CONFIG_HOME=/tmp/lib/domain--1-instance-00000092/.config \ -name guest=instance-00000092,debug-threads=on \ -S \ -object '{"qom-type":"secret","id":"masterKey0","format":"raw","file":"/tmp/lib/domain--1-instance-00000092/master-key.aes"}' \ --machine pc-i440fx-2.3,accel=kvm,usb=off,dump-guest-core=off \ +-machine pc-i440fx-2.3,accel=kvm,usb=off,dump-guest-core=off,nvdimm=on \ -cpu qemu64 \ --m 14336 \ +-m size=14680064k,slots=16,maxmem=1099511627776k \ -overcommit mem-lock=off \ -smp 8,sockets=1,dies=1,cores=8,threads=1 \ -object '{"qom-type":"memory-backend-memfd","id":"ram-node0","hugetlb":true,"hugetlbsize":2097152,"share":true,"prealloc":true,"size":15032385536,"host-nodes":[3],"policy":"preferred"}' \ -numa node,nodeid=0,cpus=0-7,memdev=ram-node0 \ +-object '{"qom-type":"memory-backend-file","id":"memnvdimm0","mem-path":"/tmp/nvdimm","share":true,"prealloc":true,"size":536870912,"host-nodes":[3],"policy":"preferred"}' \ +-device nvdimm,node=0,memdev=memnvdimm0,id=nvdimm0,slot=0 \ -uuid 126f2720-6f8e-45ab-a886-ec9277079a67 \ -display none \ -no-user-config \ diff --git a/tests/qemuxml2argvdata/memfd-memory-numa.xml b/tests/qemuxml2argvdata/memfd-memory-numa.xml index 3f448790a6..d9e1a9f564 100644 --- a/tests/qemuxml2argvdata/memfd-memory-numa.xml +++ b/tests/qemuxml2argvdata/memfd-memory-numa.xml @@ -1,6 +1,7 @@ <domain type='kvm'> <name>instance-00000092</name> <uuid>126f2720-6f8e-45ab-a886-ec9277079a67</uuid> + <maxMemory slots='16' unit='KiB'>1099511627776</maxMemory> <memory unit='KiB'>14680064</memory> <currentMemory unit='KiB'>14680064</currentMemory> <memoryBacking> @@ -41,5 +42,15 @@ <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </memballoon> + <memory model='nvdimm'> + <source> + <path>/tmp/nvdimm</path> + </source> + <target> + <size unit='KiB'>523264</size> + <node>0</node> + </target> + <address type='dimm' slot='0'/> + </memory> </devices> </domain> diff --git a/tests/qemuxml2xmltest.c b/tests/qemuxml2xmltest.c index 40e027aaa4..c5005d41a0 100644 --- a/tests/qemuxml2xmltest.c +++ b/tests/qemuxml2xmltest.c @@ -1305,7 +1305,8 @@ mymain(void) DO_TEST("memfd-memory-numa", QEMU_CAPS_OBJECT_MEMORY_MEMFD, QEMU_CAPS_OBJECT_MEMORY_MEMFD_HUGETLB, - QEMU_CAPS_OBJECT_MEMORY_FILE); + QEMU_CAPS_OBJECT_MEMORY_FILE, + QEMU_CAPS_DEVICE_NVDIMM); DO_TEST("memfd-memory-default-hugepage", QEMU_CAPS_OBJECT_MEMORY_MEMFD, QEMU_CAPS_OBJECT_MEMORY_MEMFD_HUGETLB,