From: Oliver Upton <oliver.upton@linux.dev>
To: kvmarm@lists.linux.dev
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH 5/8] KVM: arm64: Prevent NV feature flag on systems w/o nested virt
Date: Wed, 20 Sep 2023 19:50:33 +0000 [thread overview]
Message-ID: <20230920195036.1169791-6-oliver.upton@linux.dev> (raw)
In-Reply-To: <20230920195036.1169791-1-oliver.upton@linux.dev>
It would appear that userspace can select the NV feature flag regardless
of whether the system actually supports the feature. Obviously a nested
guest isn't getting far in this situation; let's reject the flag
instead.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/arm.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e40f3bfcb0a1..ef92c2f2de70 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1208,6 +1208,9 @@ static unsigned long system_supported_vcpu_features(void)
clear_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, &features);
}
+ if (!cpus_have_const_cap(ARM64_HAS_NESTED_VIRT))
+ clear_bit(KVM_ARM_VCPU_HAS_EL2, &features);
+
return features;
}
--
2.42.0.515.g380fc7ccd1-goog
next prev parent reply other threads:[~2023-09-20 19:50 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-20 19:50 [PATCH 0/8] KVM: arm64: Cleanup + fix to vCPU reset, feature flags Oliver Upton
2023-09-20 19:50 ` [PATCH 1/8] KVM: arm64: Add generic check for system-supported vCPU features Oliver Upton
2023-09-21 8:30 ` Marc Zyngier
2023-09-21 12:47 ` Philippe Mathieu-Daudé
2023-09-20 19:50 ` [PATCH 2/8] KVM: arm64: Hoist PMUv3 check into KVM_ARM_VCPU_INIT ioctl handler Oliver Upton
2023-09-21 12:48 ` Philippe Mathieu-Daudé
2023-09-20 19:50 ` [PATCH 3/8] KVM: arm64: Hoist SVE " Oliver Upton
2023-09-20 19:50 ` [PATCH 4/8] KVM: arm64: Hoist PAuth checks into KVM_ARM_VCPU_INIT ioctl Oliver Upton
2023-09-20 19:50 ` Oliver Upton [this message]
2023-09-21 8:25 ` [PATCH 5/8] KVM: arm64: Prevent NV feature flag on systems w/o nested virt Marc Zyngier
2023-09-20 19:50 ` [PATCH 6/8] KVM: arm64: Hoist NV+SVE check into KVM_ARM_VCPU_INIT ioctl handler Oliver Upton
2023-09-20 19:50 ` [PATCH 7/8] KVM: arm64: Remove unused return value from kvm_reset_vcpu() Oliver Upton
2023-09-20 19:50 ` [PATCH 8/8] KVM: arm64: Get rid of vCPU-scoped feature bitmap Oliver Upton
2023-09-21 8:49 ` [PATCH 0/8] KVM: arm64: Cleanup + fix to vCPU reset, feature flags Marc Zyngier
2023-09-21 18:18 ` Oliver Upton
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