Re: [Qemu-devel] [PATCH V3 00/10] Add support for binding guest numa nodes to host numa nodes

[Wanlong Gao <gaowanlong@cn.fujitsu.com>]

Hi,

who can pick this set up?

Thanks,
Wanlong Gao

> As you know, QEMU can't direct it's memory allocation now, this may cause
> guest cross node access performance regression.
> And, the worse thing is that if PCI-passthrough is used,
> direct-attached-device uses DMA transfer between device and qemu process.
> All pages of the guest will be pinned by get_user_pages().
> 
> KVM_ASSIGN_PCI_DEVICE ioctl
>   kvm_vm_ioctl_assign_device()
>     =>kvm_assign_device()
>       => kvm_iommu_map_memslots()
>         => kvm_iommu_map_pages()
>            => kvm_pin_pages()
> 
> So, with direct-attached-device, all guest page's page count will be +1 and
> any page migration will not work. AutoNUMA won't too.
> 
> So, we should set the guest nodes memory allocation policy before
> the pages are really mapped.
> 
> According to this patch set, we are able to set guest nodes memory policy
> like following:
> 
>  -numa node,nodeid=0,mem=1024,cpus=0,mem-policy=membind,mem-hostnode=0-1
>  -numa node,nodeid=1,mem=1024,cpus=1,mem-policy=interleave,mem-hostnode=1
> 
> This supports "mem-policy={membind|interleave|preferred},mem-hostnode=[+|!]{all|N-N}" like format.
> 
> And patch 8/10 adds a QMP command "set-mpol" to set the memory policy for every
> guest nodes:
>     set-mpol nodeid=0 mem-policy=membind mem-hostnode=0-1
> 
> And patch 9/10 adds a monitor command "set-mpol" whose format like:
>     set-mpol 0 mem-policy=membind,mem-hostnode=0-1
> 
> And with patch 10/10, we can get the current memory policy of each guest node
> using monitor command "info numa", for example:
> 
>     (qemu) info numa
>     2 nodes
>     node 0 cpus: 0
>     node 0 size: 1024 MB
>     node 0 mempolicy: membind=0,1
>     node 1 cpus: 1
>     node 1 size: 1024 MB
>     node 1 mempolicy: interleave=1
> 
> 
> V1->V2:
>     change to use QemuOpts in numa options (Paolo)
>     handle Error in mpol parser (Paolo)
>     change qmp command format to mem-policy=membind,mem-hostnode=0-1 like (Paolo)
> V2->V3:
>     also handle Error in cpus parser (5/10)
>     split out common parser from cpus and hostnode parser (Bandan 6/10)
> 
> 
> Bandan Das (1):
>   NUMA: Support multiple CPU ranges on -numa option
> 
> Wanlong Gao (9):
>   NUMA: Add numa_info structure to contain numa nodes info
>   NUMA: Add Linux libnuma detection
>   NUMA: parse guest numa nodes memory policy
>   NUMA: handle Error in cpus, mpol and hostnode parser
>   NUMA: split out the common range parser
>   NUMA: set guest numa nodes memory policy
>   NUMA: add qmp command set-mpol to set memory policy for NUMA node
>   NUMA: add hmp command set-mpol
>   NUMA: show host memory policy info in info numa command
> 
>  configure               |  32 ++++++
>  cpus.c                  | 143 +++++++++++++++++++++++-
>  hmp-commands.hx         |  16 +++
>  hmp.c                   |  35 ++++++
>  hmp.h                   |   1 +
>  hw/i386/pc.c            |   4 +-
>  hw/net/eepro100.c       |   1 -
>  include/sysemu/sysemu.h |  20 +++-
>  monitor.c               |  44 +++++++-
>  qapi-schema.json        |  15 +++
>  qemu-options.hx         |   3 +-
>  qmp-commands.hx         |  35 ++++++
>  vl.c                    | 285 +++++++++++++++++++++++++++++++++++-------------
>  13 files changed, 553 insertions(+), 81 deletions(-)
>