[libvirt] [PATCH] qemu: Align memory module sizes to 2MiB

My original implementation was based on a qemu version that still did not have all the checks in place. Using sizes that would align to odd megabyte increments will produce the following error: qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,id=dimm0: backend memory size must be multiple of 0x200000 qemu-kvm: -device pc-dimm,node=0,memdev=memdimm0,id=dimm0: Device 'pc-dimm' could not be initialized Introduce an alignment retrieval function for memory devices and use it to align the devices separately and modify a test case to verify it. --- src/qemu/qemu_domain.c | 19 ++++++++++++++++++- .../qemuxml2argv-memory-hotplug-dimm.xml | 2 +- 2 files changed, 19 insertions(+), 2 deletions(-) diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c index 7d92f3a..7680c87 100644 --- a/src/qemu/qemu_domain.c +++ b/src/qemu/qemu_domain.c @@ -3376,6 +3376,21 @@ qemuDomainGetMemorySizeAlignment(virDomainDefPtr def) } +static unsigned long long +qemuDomainGetMemoryModuleSizeAlignment(const virDomainDef *def, + const virDomainMemoryDef *mem ATTRIBUTE_UNUSED) +{ + /* PPC requires the memory sizes to be rounded to 256MiB increments, so + * round them to the size always. */ + if (ARCH_IS_PPC64(def->os.arch)) + return 256 * 1024; + + /* dimm memory modules require 2MiB alignment rather than the 1MiB we are + * using elsewhere. */ + return 2048; +} + + int qemuDomainAlignMemorySizes(virDomainDefPtr def) { @@ -3402,8 +3417,10 @@ qemuDomainAlignMemorySizes(virDomainDefPtr def) def->mem.max_memory = VIR_ROUND_UP(def->mem.max_memory, align); /* Align memory module sizes */ - for (i = 0; i < def->nmems; i++) + for (i = 0; i < def->nmems; i++) { + align = qemuDomainGetMemoryModuleSizeAlignment(def, def->mems[i]); def->mems[i]->size = VIR_ROUND_UP(def->mems[i]->size, align); + } return 0; } diff --git a/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-dimm.xml b/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-dimm.xml index 3f468ec..fbcac84 100644 --- a/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-dimm.xml +++ b/tests/qemuxml2argvdata/qemuxml2argv-memory-hotplug-dimm.xml @@ -36,7 +36,7 @@ <memballoon model='virtio'/> <memory model='dimm'> <target> - <size unit='KiB'>524287</size> + <size unit='KiB'>523264</size> <node>0</node> </target> </memory> -- 2.4.5