From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
kvm@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Oliver Upton <oliver.upton@linux.dev>,
Zenghui Yu <yuzenghui@huawei.com>,
James Clark <james.clark@arm.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Mark Brown <broonie@kernel.org>
Subject: [PATCH 0/5] KVM: arm64: Move host-specific data out of kvm_vcpu_arch
Date: Sat, 2 Mar 2024 11:19:30 +0000 [thread overview]
Message-ID: <20240302111935.129994-1-maz@kernel.org> (raw)
It appears that over the years, we have accumulated a lot of cruft in
the kvm_vcpu_arch structure. Part of the gunk is data that is strictly
host CPU specific, and this result in two main problems:
- the structure itself is stupidly large, over 8kB. With the
arch-agnostic kvm_vcpu, we're above 10kB, which is insane. This has
some ripple effects, as we need physically contiguous allocation to
be able to map it at EL2 for !VHE. There is more to it though, as
some data structures, although per-vcpu, could be allocated
separately.
- We lose track of the life-cycle of this data, because we're
guaranteed that it will be around forever and we start relying on
wrong assumptions. This is becoming a maintenance burden.
This series rectifies some of these things, starting with the two main
offenders: debug and FP, a lot of which gets pushed out to the per-CPU
host structure. Indeed, their lifetime really isn't that of the vcpu,
but tied to the physical CPU the vpcu runs on.
This results in a small reduction of the vcpu size, but mainly a much
clearer understanding of the life-cycle of these structures.
Patches against v6.8-rc6.
Marc Zyngier (5):
KVM: arm64: Add accessor for per-CPU state
KVM: arm64: Exclude host_debug_data from vcpu_arch
KVM: arm64: Exclude mdcr_el2_host from kvm_vcpu_arch
KVM: arm64: Exclude host_fpsimd_state pointer from kvm_vcpu_arch
KVM: arm64: Exclude FP ownership from kvm_vcpu_arch
arch/arm64/include/asm/kvm_emulate.h | 4 +-
arch/arm64/include/asm/kvm_host.h | 65 ++++++++++++++---------
arch/arm64/kvm/arm.c | 8 +--
arch/arm64/kvm/fpsimd.c | 13 +++--
arch/arm64/kvm/hyp/include/hyp/debug-sr.h | 8 +--
arch/arm64/kvm/hyp/include/hyp/switch.h | 23 ++++----
arch/arm64/kvm/hyp/nvhe/debug-sr.c | 8 +--
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 --
arch/arm64/kvm/hyp/nvhe/psci-relay.c | 2 +-
arch/arm64/kvm/hyp/nvhe/setup.c | 3 +-
arch/arm64/kvm/hyp/nvhe/switch.c | 6 +--
arch/arm64/kvm/hyp/vhe/switch.c | 6 +--
arch/arm64/kvm/hyp/vhe/sysreg-sr.c | 4 +-
arch/arm64/kvm/pmu.c | 2 +-
14 files changed, 79 insertions(+), 76 deletions(-)
--
2.39.2
next reply other threads:[~2024-03-02 11:19 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-02 11:19 Marc Zyngier [this message]
2024-03-02 11:19 ` [PATCH 1/5] KVM: arm64: Add accessor for per-CPU state Marc Zyngier
2024-03-04 12:05 ` Suzuki K Poulose
2024-03-09 13:00 ` Marc Zyngier
2024-03-11 4:50 ` Dongli Zhang
2024-03-11 17:13 ` Marc Zyngier
2024-03-02 11:19 ` [PATCH 2/5] KVM: arm64: Exclude host_debug_data from vcpu_arch Marc Zyngier
2024-03-02 11:19 ` [PATCH 3/5] KVM: arm64: Exclude mdcr_el2_host from kvm_vcpu_arch Marc Zyngier
2024-03-02 11:19 ` [PATCH 4/5] KVM: arm64: Exclude host_fpsimd_state pointer " Marc Zyngier
2024-03-04 20:45 ` Mark Brown
2024-03-02 11:19 ` [PATCH 5/5] KVM: arm64: Exclude FP ownership " Marc Zyngier
2024-03-04 19:10 ` Mark Brown
2024-03-06 9:43 ` Marc Zyngier
2024-03-06 22:19 ` Mark Brown
2024-03-07 11:10 ` Marc Zyngier
2024-03-07 14:26 ` Mark Brown
2024-03-09 11:01 ` Marc Zyngier
2024-03-11 18:42 ` Mark Brown
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