From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org,
kvm@vger.kernel.org
Cc: Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Mark Rutland <mark.rutland@arm.com>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Oliver Upton <oliver.upton@linux.dev>,
Zenghui Yu <yuzenghui@huawei.com>
Subject: [PATCH 0/2] KVM: arm64: Drop support for VPIPT i-cache policy
Date: Fri, 13 Jan 2023 17:25:21 +0000 [thread overview]
Message-ID: <20230113172523.2063867-1-maz@kernel.org> (raw)
ARMv8.2 introduced support for VPIPT i-caches, the V standing for
VMID-tagged. Although this looks like a reasonable idea, no
implementation has ever made it into the wild.
Linux has supported this for almost 6 years (amusingly, just as the
architecture was dropping support for AVIVT i-caches), but we have no
way to even test it, and it is likely that this code is just
bit-rotting. This isn't great.
Since this only impacts KVM, let's drop the support from the
hypervisor. The kernel itself can still work as a guest on such a
system, assuming that there is HW and a hypervisor that supports this
architecture variation.
On the other hand, if you are aware of such an implementation and can
actively test KVM on this setup, please shout!
M.
Marc Zyngier (2):
KVM: arm64: Disable KVM on systems with a VPIPT i-cache
KVM: arm64: Remove VPIPT I-cache handling
arch/arm64/include/asm/kvm_mmu.h | 3 +--
arch/arm64/kvm/arm.c | 5 +++++
arch/arm64/kvm/hyp/nvhe/tlb.c | 35 --------------------------------
arch/arm64/kvm/hyp/vhe/tlb.c | 13 ------------
4 files changed, 6 insertions(+), 50 deletions(-)
--
2.34.1
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next reply other threads:[~2023-01-13 17:36 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-13 17:25 Marc Zyngier [this message]
2023-01-13 17:25 ` [PATCH 1/2] KVM: arm64: Disable KVM on systems with a VPIPT i-cache Marc Zyngier
2023-01-20 10:14 ` Will Deacon
2023-01-20 11:49 ` Marc Zyngier
2023-01-13 17:25 ` [PATCH 2/2] KVM: arm64: Remove VPIPT I-cache handling Marc Zyngier
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