Message-ID: <20230306224127.1689967-1-vipinsh@google.com>
Date:   Mon,  6 Mar 2023 14:41:09 -0800
From:   Vipin Sharma <vipinsh@...gle.com>
To:     seanjc@...gle.com, pbonzini@...hat.com, bgardon@...gle.com,
        dmatlack@...gle.com
Cc:     jmattson@...gle.com, mizhang@...gle.com, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Vipin Sharma <vipinsh@...gle.com>
Subject: [Patch v4 00/18] NUMA aware page table allocation

Hi,

This series build up based on the feedback on v3.

Biggest change in features is to enable NUMA aware page table per VM
basis instead of using a module parameter for all VMs on a host. This
was decided based on an internal discussion to avoid forcing all VMs to
be NUMA aware on a host. We need to collect more data to see how much
performance degradation a VM can get in negative testing, where vCPUs in
VM are always accessing remote NUMA nodes memory instead of staying
local compared to a VM which is not NUMA aware.

There are other changes which are mentioned in the change log below for
v4.

Thanks
Vipin

v4:
- Removed module parameter for enabling NUMA aware page table.
- Added new capability KVM_CAP_NUMA_AWARE_PAGE_TABLE to enable this
  feature per VM.
- Added documentation for the new capability.
- Holding mutex just before the top up and releasing it after the
  fault/split is addressed. Previous version were using spinlocks two
  times, first time for topup and second time fetching the page from
  cache.
- Using the existing slots_lock for split_shadow_page_cache operations.
- KVM MMU shrinker will also shrink mm_shadow_info_cache besides
  split_shadow_page_cache and mmu_shadow_page_cache.
- Reduced cache default size to 4.
- Split patches into smaller ones.

v3: https://lore.kernel.org/lkml/20221222023457.1764-1-vipinsh@google.com/
- Split patches into smaller ones.
- Repurposed KVM MMU shrinker to free cache pages instead of oldest page table
  pages
- Reduced cache size from 40 to 5
- Removed __weak function and initializing node value in all architectures.
- Some name changes.

v2: https://lore.kernel.org/lkml/20221201195718.1409782-1-vipinsh@google.com/
- All page table pages will be allocated on underlying physical page's
  NUMA node.
- Introduced module parameter, numa_aware_pagetable, to disable this
  feature.
- Using kvm_pfn_to_refcounted_page to get page from a pfn.

v1: https://lore.kernel.org/all/20220801151928.270380-1-vipinsh@google.com/

Vipin Sharma (18):
  KVM: x86/mmu: Change KVM mmu shrinker to no-op
  KVM: x86/mmu: Remove zapped_obsolete_pages from struct kvm_arch{}
  KVM: x86/mmu: Track count of pages in KVM MMU page caches globally
  KVM: x86/mmu: Shrink shadow page caches via MMU shrinker
  KVM: x86/mmu: Add split_shadow_page_cache pages to global count of MMU
    cache pages
  KVM: x86/mmu: Shrink split_shadow_page_cache via MMU shrinker
  KVM: x86/mmu: Unconditionally count allocations from MMU page caches
  KVM: x86/mmu: Track unused mmu_shadowed_info_cache pages count via
    global counter
  KVM: x86/mmu: Shrink mmu_shadowed_info_cache via MMU shrinker
  KVM: x86/mmu: Add per VM NUMA aware page table capability
  KVM: x86/mmu: Add documentation of NUMA aware page table capability
  KVM: x86/mmu: Allocate NUMA aware page tables on TDP huge page splits
  KVM: mmu: Add common initialization logic for struct
    kvm_mmu_memory_cache{}
  KVM: mmu: Initialize kvm_mmu_memory_cache.gfp_zero to __GFP_ZERO by
    default
  KVM: mmu: Add NUMA node support in struct kvm_mmu_memory_cache{}
  KVM: x86/mmu: Allocate numa aware page tables during page fault
  KVM: x86/mmu: Allocate shadow mmu page table on huge page split on the
    same NUMA node
  KVM: x86/mmu: Reduce default mmu memory cache size

 Documentation/virt/kvm/api.rst   |  29 +++
 arch/arm64/kvm/arm.c             |   2 +-
 arch/arm64/kvm/mmu.c             |   2 +-
 arch/mips/kvm/mips.c             |   3 +
 arch/riscv/kvm/mmu.c             |   8 +-
 arch/riscv/kvm/vcpu.c            |   2 +-
 arch/x86/include/asm/kvm_host.h  |  17 +-
 arch/x86/include/asm/kvm_types.h |   6 +-
 arch/x86/kvm/mmu/mmu.c           | 319 +++++++++++++++++++------------
 arch/x86/kvm/mmu/mmu_internal.h  |  38 ++++
 arch/x86/kvm/mmu/paging_tmpl.h   |  29 +--
 arch/x86/kvm/mmu/tdp_mmu.c       |  23 ++-
 arch/x86/kvm/x86.c               |  18 +-
 include/linux/kvm_host.h         |   2 +
 include/linux/kvm_types.h        |  21 ++
 include/uapi/linux/kvm.h         |   1 +
 virt/kvm/kvm_main.c              |  24 ++-
 17 files changed, 386 insertions(+), 158 deletions(-)

-- 
2.40.0.rc0.216.gc4246ad0f0-goog

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