linux-kernel - Re: [PATCH v3 00/18] KVM: arm64: Non-protected guest stage-2 support for pKVM

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Message-ID: <CA+EHjTz7=dRz5X-CjjniJgwd87Q4DQbRdXzi0on4C21urYnhOQ@mail.gmail.com>
Date: Tue, 17 Dec 2024 09:25:52 +0000
From: Fuad Tabba <tabba@...gle.com>
To: Quentin Perret <qperret@...gle.com>
Cc: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>, 
	Joey Gouly <joey.gouly@....com>, Suzuki K Poulose <suzuki.poulose@....com>, 
	Zenghui Yu <yuzenghui@...wei.com>, Catalin Marinas <catalin.marinas@....com>, 
	Will Deacon <will@...nel.org>, Vincent Donnefort <vdonnefort@...gle.com>, 
	Sebastian Ene <sebastianene@...gle.com>, linux-arm-kernel@...ts.infradead.org, 
	kvmarm@...ts.linux.dev, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 00/18] KVM: arm64: Non-protected guest stage-2 support
 for pKVM

On Mon, 16 Dec 2024 at 17:58, Quentin Perret <qperret@...gle.com> wrote:
>
> Hi all,
>
> This is the v3 of the series adding support for non-protected guests
> stage-2 to pKVM. Please refer to v1 for all the context:

For the series:

Tested-by: Fuad Tabba <tabba@...gle.com>

Cheers,
/fuad



>
>   https://lore.kernel.org/kvmarm/20241104133204.85208-1-qperret@google.com/
>
> The series is organized as follows:
>
>  - Patches 01 to 04 move the host ownership state tracking from the
>    host's stage-2 page-table to the hypervisor's vmemmap. This avoids
>    fragmenting the host stage-2 for shared pages, which is only needed
>    to store an annotation in the SW bits of the corresponding PTE. All
>    pages mapped into non-protected guests are shared from pKVM's PoV,
>    so the cost of stage-2 fragmentation will increase massively as we
>    start tracking that at EL2. Note that these patches also help with
>    the existing sharing for e.g. FF-A, so they could possibly be merged
>    separately from the rest of the series.
>
>  - Patches 05 to 07 implement a minor refactoring of the pgtable code to
>    ease the integration of the pKVM MMU later on.
>
>  - Patches 08 to 16 introduce all the infrastructure needed on the pKVM
>    side for handling guest stage-2 page-tables at EL2.
>
>  - Patches 17 and 18 plumb the newly introduced pKVM support into
>    KVM/arm64.
>
> Patches based on 6.13-rc3, tested on Pixel 6 and Qemu.
>
> Changes in v3:
>  - Rebased on 6.13-rc3
>  - Applied Marc's rework of the for_each_mapping_in_range() macro mess
>  - Removed mappings_lock in favor the mmu_lock
>  - Dropped BUG_ON() from pkvm_mkstate()
>  - Renamed range_is_allowed_memory() and clarified the comment inside it
>  - Explicitly bail out when using host_stage2_set_owner_locked() on
>    non-memory regions
>  - Check PKVM_NOPAGE state as an equality rather than a bitwise
>    operator
>  - Reworked __pkvm_host_share_guest() to return -EPERM in case of
>    illegal multi-sharing
>  - Added get_np_pkvm_hyp_vm() to simplify HVC error handling in
>    hyp-main.c
>  - Cosmetic changes and improved coding consitency thoughout the series
>
> Changes in v2:
>  - Rebased on 6.13-rc1 (small conflicts with 2362506f7cff ("KVM: arm64:
>    Don't mark "struct page" accessed when making SPTE young") in
>    particular)
>  - Fixed kerneldoc breakage for __unmap_stage2_range()
>  - Fixed pkvm_pgtable_test_clear_young() to use correct HVC
>  - Folded guest_get_valid_pte() into __check_host_unshare_guest() for
>    clarity
>
> Thanks,
> Quentin
>
> Marc Zyngier (1):
>   KVM: arm64: Introduce __pkvm_vcpu_{load,put}()
>
> Quentin Perret (17):
>   KVM: arm64: Change the layout of enum pkvm_page_state
>   KVM: arm64: Move enum pkvm_page_state to memory.h
>   KVM: arm64: Make hyp_page::order a u8
>   KVM: arm64: Move host page ownership tracking to the hyp vmemmap
>   KVM: arm64: Pass walk flags to kvm_pgtable_stage2_mkyoung
>   KVM: arm64: Pass walk flags to kvm_pgtable_stage2_relax_perms
>   KVM: arm64: Make kvm_pgtable_stage2_init() a static inline function
>   KVM: arm64: Add {get,put}_pkvm_hyp_vm() helpers
>   KVM: arm64: Introduce __pkvm_host_share_guest()
>   KVM: arm64: Introduce __pkvm_host_unshare_guest()
>   KVM: arm64: Introduce __pkvm_host_relax_guest_perms()
>   KVM: arm64: Introduce __pkvm_host_wrprotect_guest()
>   KVM: arm64: Introduce __pkvm_host_test_clear_young_guest()
>   KVM: arm64: Introduce __pkvm_host_mkyoung_guest()
>   KVM: arm64: Introduce __pkvm_tlb_flush_vmid()
>   KVM: arm64: Introduce the EL1 pKVM MMU
>   KVM: arm64: Plumb the pKVM MMU in KVM
>
>  arch/arm64/include/asm/kvm_asm.h              |   9 +
>  arch/arm64/include/asm/kvm_host.h             |   4 +
>  arch/arm64/include/asm/kvm_mmu.h              |  16 +
>  arch/arm64/include/asm/kvm_pgtable.h          |  38 ++-
>  arch/arm64/include/asm/kvm_pkvm.h             |  23 ++
>  arch/arm64/kvm/arm.c                          |  23 +-
>  arch/arm64/kvm/hyp/include/nvhe/gfp.h         |   6 +-
>  arch/arm64/kvm/hyp/include/nvhe/mem_protect.h |  38 +--
>  arch/arm64/kvm/hyp/include/nvhe/memory.h      |  42 ++-
>  arch/arm64/kvm/hyp/include/nvhe/pkvm.h        |  16 +
>  arch/arm64/kvm/hyp/nvhe/hyp-main.c            | 201 ++++++++++-
>  arch/arm64/kvm/hyp/nvhe/mem_protect.c         | 320 ++++++++++++++++--
>  arch/arm64/kvm/hyp/nvhe/page_alloc.c          |  14 +-
>  arch/arm64/kvm/hyp/nvhe/pkvm.c                |  68 ++++
>  arch/arm64/kvm/hyp/nvhe/setup.c               |   7 +-
>  arch/arm64/kvm/hyp/pgtable.c                  |  13 +-
>  arch/arm64/kvm/mmu.c                          | 113 +++++--
>  arch/arm64/kvm/pkvm.c                         | 198 +++++++++++
>  arch/arm64/kvm/vgic/vgic-v3.c                 |   6 +-
>  19 files changed, 1010 insertions(+), 145 deletions(-)
>
> --
> 2.47.1.613.gc27f4b7a9f-goog
>