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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 1/2] KVM: arm64: Disable KVM on systems with a VPIPT i-cache
Date: Fri, 13 Jan 2023 17:25:22 +0000	[thread overview]
Message-ID: <20230113172523.2063867-2-maz@kernel.org> (raw)
In-Reply-To: <20230113172523.2063867-1-maz@kernel.org>

Systems with a VMID-tagged PIPT i-cache have been supported for
a while by Linux and KVM. However, these systems never appeared
on our side of the multiverse.

Refuse to initialise KVM on such a machine, should then ever appear.
Following changes will drop the support from the hypervisor.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/arm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 9c5573bc4614..508deed213a2 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -2195,6 +2195,11 @@ int kvm_arch_init(void *opaque)
 	int err;
 	bool in_hyp_mode;
 
+	if (icache_is_vpipt()) {
+		kvm_info("Incompatible VPIPT I-Cache policy\n");
+		return -ENODEV;
+	}
+
 	if (!is_hyp_mode_available()) {
 		kvm_info("HYP mode not available\n");
 		return -ENODEV;
-- 
2.34.1


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  reply	other threads:[~2023-01-13 17:37 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-13 17:25 [PATCH 0/2] KVM: arm64: Drop support for VPIPT i-cache policy Marc Zyngier
2023-01-13 17:25 ` Marc Zyngier [this message]
2023-01-20 10:14   ` [PATCH 1/2] KVM: arm64: Disable KVM on systems with a VPIPT i-cache 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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