Move pKVM ownership state to hyp

From:		Quentin Perret <qperret-AT-google.com>
To:		Marc Zyngier <maz-AT-kernel.org>, Oliver Upton <oliver.upton-AT-linux.dev>, Joey Gouly <joey.gouly-AT-arm.com>, Suzuki K Poulose <suzuki.poulose-AT-arm.com>, Zenghui Yu <yuzenghui-AT-huawei.com>, Catalin Marinas <catalin.marinas-AT-arm.com>, Will Deacon <will-AT-kernel.org>
Subject:		[PATCH 0/6] Move pKVM ownership state to hyp_vmemmap
Date:		Thu, 27 Feb 2025 00:33:04 +0000
Message-ID:		<20250227003310.367350-1-qperret@google.com>
Cc:		Vincent Donnefort <vdonnefort-AT-google.com>, Quentin Perret <qperret-AT-google.com>, linux-arm-kernel-AT-lists.infradead.org, kvmarm-AT-lists.linux.dev, linux-kernel-AT-vger.kernel.org
Archive-link:		Article

Hi all,

This series moves the hypervisor's ownership state to the hyp_vmemmap,
as discussed in [1]. The two main benefits are:

 1. much cheaper hyp state lookups, since we can avoid the hyp stage-1
    page-table walk;

 2. de-correlates the hyp state from the presence of a mapping in the
    linear map range of the hypervisor; which enables a bunch of
    clean-ups in the existing code and will simplify the introduction of
    other features in the future (hyp tracing, ...)

Patch 01 is a self-sufficient cleanup that I found thanks to patch 05.
Patches 02-04 implement the aforementioned migration of the hyp state
to the vmemmap. Patches 05 and 06 are cleanups enabled by that
migration.

Patches based on 6.14-rc4, tested on Qemu.

Thanks!
Quentin

[1] https://lore.kernel.org/kvmarm/Z79ZJVOHtNu6YsVt@google.com/

Fuad Tabba (1):
  KVM: arm64: Track SVE state in the hypervisor vcpu structure

Quentin Perret (5):
  KVM: arm64: Use 0b11 for encoding PKVM_NOPAGE
  KVM: arm64: Introduce {get,set}_host_state() helpers
  KVM: arm64: Move hyp state to hyp_vmemmap
  KVM: arm64: Defer EL2 stage-1 mapping on share
  KVM: arm64: Unconditionally cross check hyp state

 arch/arm64/include/asm/kvm_host.h        |  12 +--
 arch/arm64/kvm/hyp/include/nvhe/memory.h |  35 ++++++--
 arch/arm64/kvm/hyp/nvhe/hyp-main.c       |   4 -
 arch/arm64/kvm/hyp/nvhe/mem_protect.c    | 106 ++++++++++++-----------
 arch/arm64/kvm/hyp/nvhe/pkvm.c           |  54 ++++++++++--
 arch/arm64/kvm/hyp/nvhe/setup.c          |  10 ++-
 6 files changed, 147 insertions(+), 74 deletions(-)

-- 
2.48.1.658.g4767266eb4-goog

Move pKVM ownership state to hyp_vmemmap