From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Marc Zyngier <maz@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
kvmarm@lists.cs.columbia.edu
Subject: [PATCH 4/5] KVM: arm64: Prevent re-finalisation of pKVM for a given CPU
Date: Thu, 23 Sep 2021 12:22:55 +0100 [thread overview]
Message-ID: <20210923112256.15767-5-will@kernel.org> (raw)
In-Reply-To: <20210923112256.15767-1-will@kernel.org>
__pkvm_prot_finalize() completes the deprivilege of the host when pKVM
is in use by installing a stage-2 translation table for the calling CPU.
Issuing the hypercall multiple times for a given CPU makes little sense,
but in such a case just return early with -EPERM rather than go through
the whole page-table dance again.
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index bacd493a4eac..cafe17e5fa8f 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -123,6 +123,9 @@ int __pkvm_prot_finalize(void)
struct kvm_s2_mmu *mmu = &host_kvm.arch.mmu;
struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
+ if (params->hcr_el2 & HCR_VM)
+ return -EPERM;
+
params->vttbr = kvm_get_vttbr(mmu);
params->vtcr = host_kvm.arch.vtcr;
params->hcr_el2 |= HCR_VM;
--
2.33.0.464.g1972c5931b-goog
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https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Will Deacon <will@kernel.org>
To: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Quentin Perret <qperret@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
kvmarm@lists.cs.columbia.edu
Subject: [PATCH 4/5] KVM: arm64: Prevent re-finalisation of pKVM for a given CPU
Date: Thu, 23 Sep 2021 12:22:55 +0100 [thread overview]
Message-ID: <20210923112256.15767-5-will@kernel.org> (raw)
In-Reply-To: <20210923112256.15767-1-will@kernel.org>
__pkvm_prot_finalize() completes the deprivilege of the host when pKVM
is in use by installing a stage-2 translation table for the calling CPU.
Issuing the hypercall multiple times for a given CPU makes little sense,
but in such a case just return early with -EPERM rather than go through
the whole page-table dance again.
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index bacd493a4eac..cafe17e5fa8f 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -123,6 +123,9 @@ int __pkvm_prot_finalize(void)
struct kvm_s2_mmu *mmu = &host_kvm.arch.mmu;
struct kvm_nvhe_init_params *params = this_cpu_ptr(&kvm_init_params);
+ if (params->hcr_el2 & HCR_VM)
+ return -EPERM;
+
params->vttbr = kvm_get_vttbr(mmu);
params->vtcr = host_kvm.arch.vtcr;
params->hcr_el2 |= HCR_VM;
--
2.33.0.464.g1972c5931b-goog
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next prev parent reply other threads:[~2021-09-23 11:23 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-23 11:22 [PATCH 0/5] KVM: arm64: Restrict host hypercalls when pKVM is enabled Will Deacon
2021-09-23 11:22 ` Will Deacon
2021-09-23 11:22 ` [PATCH 1/5] arm64: Prevent kexec and hibernation if is_protected_kvm_enabled() Will Deacon
2021-09-23 11:22 ` Will Deacon
2021-09-23 11:45 ` Mark Rutland
2021-09-23 11:45 ` Mark Rutland
2021-09-23 12:29 ` Will Deacon
2021-09-23 12:29 ` Will Deacon
2021-09-23 11:22 ` [PATCH 2/5] KVM: arm64: Reject stub hypercalls after pKVM has been initialised Will Deacon
2021-09-23 11:22 ` Will Deacon
2021-09-29 13:37 ` Quentin Perret
2021-09-29 13:37 ` Quentin Perret
2021-09-23 11:22 ` [PATCH 3/5] KVM: arm64: Propagate errors from __pkvm_prot_finalize hypercall Will Deacon
2021-09-23 11:22 ` Will Deacon
2021-09-29 13:36 ` Quentin Perret
2021-09-29 13:36 ` Quentin Perret
2021-10-05 11:30 ` Will Deacon
2021-10-05 11:30 ` Will Deacon
2021-09-23 11:22 ` Will Deacon [this message]
2021-09-23 11:22 ` [PATCH 4/5] KVM: arm64: Prevent re-finalisation of pKVM for a given CPU Will Deacon
2021-09-29 13:41 ` Quentin Perret
2021-09-29 13:41 ` Quentin Perret
2021-09-23 11:22 ` [PATCH 5/5] KVM: arm64: Disable privileged hypercalls after pKVM finalisation Will Deacon
2021-09-23 11:22 ` Will Deacon
2021-09-23 12:56 ` Marc Zyngier
2021-09-23 12:56 ` Marc Zyngier
2021-09-23 13:02 ` Will Deacon
2021-09-23 13:02 ` Will Deacon
2021-09-23 13:11 ` Marc Zyngier
2021-09-23 13:11 ` Marc Zyngier
2021-09-23 12:58 ` Will Deacon
2021-09-23 12:58 ` Will Deacon
2021-09-23 12:21 ` [PATCH 0/5] KVM: arm64: Restrict host hypercalls when pKVM is enabled Marc Zyngier
2021-09-23 12:21 ` Marc Zyngier
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