RE: [PATCH v3 00/28] drm/i915/gvt: KVM: KVMGT fixes and page-track cleanups

[Ma, Yongwei]

> Fix a variety of found-by-inspection bugs in KVMGT, and overhaul KVM's
> page-track APIs to provide a leaner and cleaner interface.  The motivation for
> this series is to (significantly) reduce the number of KVM APIs that KVMGT
> uses, with a long-term goal of making all kvm_host.h headers KVM-internal.
> 
> As always for this series, the KVMGT changes are compile tested only.
> 
> Based on "git://git.kernel.org/pub/scm/virt/kvm/kvm.git tags/kvm-6.4-1".
> 
> v3:
>  - Collect reviewed/tested tags (I apologize if I missed any, I manually
>    gathered them this time due to a goof in my workflow). [Yan]
>  - Drop check on max KVM paging size from KVMGT. [Yan]
>  - Drop the explicit change on THP pages, and instead validate that the
>    pfns (not struct page pointers) are contiguous. [Yan]
>  - Fix buggy intel_gvt_dma_map_guest_page() usage by eliminating a helper
>    for shadowing 2MiB GTT entries. [Yan]
>  - Move kvm_arch_flush_shadow_{all,memslot}() to mmu.c instead of
> exposing
>    kvm_mmu_zap_all_fast() outside of mmu.c. [Yan]
>  - Fix an alignment goof in hlist_for_each_entry_srcu() usage. [Yan]
>  - Wrap full definition of external page track structures with
>    CONFIG_KVM_EXTERNAL_WRITE_TRACKING. [Yan]
> 
> v2:
>  - https://lore.kernel.org/all/20230311002258.852397-1-seanjc@xxxxxxxxxx
>  - Reuse vgpu_lock to protect gfn hash instead of introducing a new (and
>    buggy) mutext. [Yan]
>  - Remove a spurious return from kvm_page_track_init(). [Yan]
>  - Take @kvm directly in the inner __kvm_page_track_write(). [Yan]
>  - Delete the gfn sanity check that relies on kvm_is_visible_gfn() instead
>    of providing a dedicated interface. [Yan]
> 
> v1: https://lore.kernel.org/lkml/20221223005739.1295925-1-
> seanjc@xxxxxxxxxx
> 
> Sean Christopherson (24):
>   drm/i915/gvt: Verify pfn is "valid" before dereferencing "struct page"
>   drm/i915/gvt: Verify hugepages are contiguous in physical address
>     space
>   drm/i915/gvt: Put the page reference obtained by KVM's gfn_to_pfn()
>   drm/i915/gvt: Explicitly check that vGPU is attached before shadowing
>   drm/i915/gvt: Error out on an attempt to shadowing an unknown GTT
>     entry type
>   drm/i915/gvt: Don't rely on KVM's gfn_to_pfn() to query possible 2M
>     GTT
>   drm/i915/gvt: Use an "unsigned long" to iterate over memslot gfns
>   drm/i915/gvt: Drop unused helper intel_vgpu_reset_gtt()
>   drm/i915/gvt: Protect gfn hash table with vgpu_lock
>   KVM: x86/mmu: Move kvm_arch_flush_shadow_{all,memslot}() to mmu.c
>   KVM: x86/mmu: Don't rely on page-track mechanism to flush on memslot
>     change
>   KVM: x86/mmu: Don't bounce through page-track mechanism for guest
> PTEs
>   KVM: drm/i915/gvt: Drop @vcpu from KVM's ->track_write() hook
>   KVM: x86: Reject memslot MOVE operations if KVMGT is attached
>   drm/i915/gvt: Don't bother removing write-protection on to-be-deleted
>     slot
>   KVM: x86/mmu: Move KVM-only page-track declarations to internal header
>   KVM: x86/mmu: Use page-track notifiers iff there are external users
>   KVM: x86/mmu: Drop infrastructure for multiple page-track modes
>   KVM: x86/mmu: Rename page-track APIs to reflect the new reality
>   KVM: x86/mmu: Assert that correct locks are held for page
>     write-tracking
>   KVM: x86/mmu: Bug the VM if write-tracking is used but not enabled
>   KVM: x86/mmu: Drop @slot param from exported/external page-track APIs
>   KVM: x86/mmu: Handle KVM bookkeeping in page-track APIs, not callers
>   drm/i915/gvt: Drop final dependencies on KVM internal details
> 
> Yan Zhao (4):
>   drm/i915/gvt: remove interface intel_gvt_is_valid_gfn
>   KVM: x86: Add a new page-track hook to handle memslot deletion
>   drm/i915/gvt: switch from ->track_flush_slot() to
>     ->track_remove_region()
>   KVM: x86: Remove the unused page-track hook track_flush_slot()
> 
>  arch/x86/include/asm/kvm_host.h       |  16 +-
>  arch/x86/include/asm/kvm_page_track.h |  73 +++-----
>  arch/x86/kvm/mmu.h                    |   2 +
>  arch/x86/kvm/mmu/mmu.c                |  51 +++--
>  arch/x86/kvm/mmu/page_track.c         | 256 +++++++++++++-------------
>  arch/x86/kvm/mmu/page_track.h         |  58 ++++++
>  arch/x86/kvm/x86.c                    |  22 +--
>  drivers/gpu/drm/i915/gvt/gtt.c        | 102 ++--------
>  drivers/gpu/drm/i915/gvt/gtt.h        |   1 -
>  drivers/gpu/drm/i915/gvt/gvt.h        |   3 +-
>  drivers/gpu/drm/i915/gvt/kvmgt.c      | 117 +++++-------
>  drivers/gpu/drm/i915/gvt/page_track.c |  10 +-
>  12 files changed, 320 insertions(+), 391 deletions(-)  create mode 100644
> arch/x86/kvm/mmu/page_track.h
> 
> 
> base-commit: b3c98052d46948a8d65d2778c7f306ff38366aac
> --
> 2.40.1.606.ga4b1b128d6-goog
Verified GVT-g on Intel platform host Core(TM) i7-8559U CPU @ 2.70GHz 
 + Ubuntu22.04 LTS.

Both Linux Ubuntu 22.04 VM and Windows10 VM could boot up successfully. 
3D benchmark GLmark2 can run in the guest VM.

Tested-by: Yongwei Ma <yongwei.ma@xxxxxxxxx>

Best Regards,
Yongwei Ma