Re: [PATCH v1 00/10] move memory module align to PostParse time

On 11/11/20 11:07 PM, Daniel Henrique Barboza wrote: > Hi, > > This is a work that I intended to do after pSeries NVDIMM changes > I made in commit v6.7.0-302-gd3f3c2c97f. The reasoning is that > if ppc64 NVDIMM alignment can be done in PostParse time, regular > ppc64 DIMMs alignment can also be done the same way. After that > I realized that the same logic can be applied to x86 as well, > and then I started to see where we could eliminate explicit > align calls. > > The end result is that a bug that affects pSeries the most > was found and fixed in patch 02, and now we're able to reflect > the exact memory being used by the guest in the live XML since > the alignment is now done in parse time. The series can be > fetched from: > > https://gitlab.com/danielhb/libvirt/-/tree/memory_modules_postparse_v1 > > NOTE: I worked with the x86 logic based on what I could assert > from the code itself, i.e. the aligment mechanics (2MiB align for > mem modules, 1MiB align for total memory) are related to QEMU > internals, not being hypervisor-agnostic. If someone with authority can > guarantee that the alignment restrictions for x86 are applicable > to all hypervisors (like in the pSeries case), let me know and > I'll respin the series putting the x86 code in > virDomainMemoryDefPostParse(). > > > Daniel Henrique Barboza (10): >    domain_conf.c: handle all ppc64 dimms in >      virDomainNVDimmAlignSizePseries >    qemu_domain.c: align memory modules before calculating 'initialmem' >    domain_conf.c: align pSeries mem modules in >      virDomainMemoryDefPostParse() >    qemu_domain.c: simplify qemuDomainGetMemoryModuleSizeAlignment() >    qemu_domain.c: align x86 memory module in post parse time >    qemu_domain.c: move size check for mem modules after alignment >    qemu_hotplug.c: avoid aligning the mem obj in >      qemuDomainDetachPrepMemory() >    qemu_hotplug.c: avoid aligning the mem obj in qemuDomainAttachMemory() >    qemu_domain.c: remove qemuDomainMemoryDeviceAlignSize() >    NEWS.rs: document memory alignment improvements > >   NEWS.rst                                      |  14 +++ >   src/conf/domain_conf.c                        |  25 ++++- >   src/conf/domain_conf.h                        |   2 +- >   src/libvirt_private.syms                      |   2 +- >   src/qemu/qemu_domain.c                        | 106 +++++++----------- >   src/qemu/qemu_domain.h                        |   2 - >   src/qemu/qemu_hotplug.c                       |   9 +- >   tests/qemuxml2argvdata/hugepages-nvdimm.xml   |   2 +- >   .../memory-hotplug-nvdimm-access.xml          |   2 +- >   .../memory-hotplug-nvdimm-align.xml           |   2 +- >   .../memory-hotplug-nvdimm-label.xml           |   2 +- >   .../memory-hotplug-nvdimm-pmem.xml            |   2 +- >   .../memory-hotplug-nvdimm-readonly.xml        |   2 +- >   .../memory-hotplug-nvdimm.xml                 |   2 +- >   .../memory-hotplug-ppc64-nonuma.args          |   2 +- >   tests/qemuxml2argvdata/pages-dimm-discard.xml |   2 +- >   .../memory-hotplug-dimm.xml                   |   4 +- >   17 files changed, 92 insertions(+), 90 deletions(-) > Reviewed-by: Michal Privoznik <mprivozn(a)redhat.com&gt;

but perhaps you want Andrea to look into it too.

Michal