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From: Quentin Perret <qperret@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
	 Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	 Oliver Upton <oliver.upton@linux.dev>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>
Cc: kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org,
	kvmarm@lists.cs.columbia.edu,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH] KVM: arm64: Use correct accessor to parse stage-1 PTEs
Date: Tue, 25 Oct 2022 14:51:56 +0000	[thread overview]
Message-ID: <20221025145156.855308-1-qperret@google.com> (raw)

hyp_get_page_state() is used with pKVM to retrieve metadata about a page
by parsing a hypervisor stage-1 PTE. However, it incorrectly uses a
helper which parses *stage-2* mappings. Ouch.

Luckily, pkvm_getstate() only looks at the software bits, which happen
to be in the same place for stage-1 and stage-2 PTEs, and this all ends
up working correctly by accident. But clearly, we should do better.

Fix hyp_get_page_state() to use the correct helper.

Fixes: e82edcc75c4e ("KVM: arm64: Implement do_share() helper for sharing memory")
Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 1e78acf9662e..07f9dc9848ef 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -516,7 +516,7 @@ static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte)
 	if (!kvm_pte_valid(pte))
 		return PKVM_NOPAGE;
 
-	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
+	return pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte));
 }
 
 static int __hyp_check_page_state_range(u64 addr, u64 size,
-- 
2.38.0.135.g90850a2211-goog

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

WARNING: multiple messages have this Message-ID (diff)
From: Quentin Perret <qperret@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
	 Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	 Oliver Upton <oliver.upton@linux.dev>,
	Catalin Marinas <catalin.marinas@arm.com>,
	 Will Deacon <will@kernel.org>
Cc: Quentin Perret <qperret@google.com>,
	linux-arm-kernel@lists.infradead.org,  kvmarm@lists.linux.dev,
	kvmarm@lists.cs.columbia.edu,  linux-kernel@vger.kernel.org
Subject: [PATCH] KVM: arm64: Use correct accessor to parse stage-1 PTEs
Date: Tue, 25 Oct 2022 14:51:56 +0000	[thread overview]
Message-ID: <20221025145156.855308-1-qperret@google.com> (raw)
Message-ID: <20221025145156.ic0Tzhjun8lk11-pa6bYMOmDQ95EeYvzROBlrp3yx4g@z> (raw)

hyp_get_page_state() is used with pKVM to retrieve metadata about a page
by parsing a hypervisor stage-1 PTE. However, it incorrectly uses a
helper which parses *stage-2* mappings. Ouch.

Luckily, pkvm_getstate() only looks at the software bits, which happen
to be in the same place for stage-1 and stage-2 PTEs, and this all ends
up working correctly by accident. But clearly, we should do better.

Fix hyp_get_page_state() to use the correct helper.

Fixes: e82edcc75c4e ("KVM: arm64: Implement do_share() helper for sharing memory")
Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 1e78acf9662e..07f9dc9848ef 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -516,7 +516,7 @@ static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte)
 	if (!kvm_pte_valid(pte))
 		return PKVM_NOPAGE;
 
-	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
+	return pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte));
 }
 
 static int __hyp_check_page_state_range(u64 addr, u64 size,
-- 
2.38.0.135.g90850a2211-goog


WARNING: multiple messages have this Message-ID (diff)
From: Quentin Perret <qperret@google.com>
To: Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
	 Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	 Oliver Upton <oliver.upton@linux.dev>,
	Catalin Marinas <catalin.marinas@arm.com>,
	 Will Deacon <will@kernel.org>
Cc: Quentin Perret <qperret@google.com>,
	linux-arm-kernel@lists.infradead.org,  kvmarm@lists.linux.dev,
	kvmarm@lists.cs.columbia.edu,  linux-kernel@vger.kernel.org
Subject: [PATCH] KVM: arm64: Use correct accessor to parse stage-1 PTEs
Date: Tue, 25 Oct 2022 14:51:56 +0000	[thread overview]
Message-ID: <20221025145156.855308-1-qperret@google.com> (raw)

hyp_get_page_state() is used with pKVM to retrieve metadata about a page
by parsing a hypervisor stage-1 PTE. However, it incorrectly uses a
helper which parses *stage-2* mappings. Ouch.

Luckily, pkvm_getstate() only looks at the software bits, which happen
to be in the same place for stage-1 and stage-2 PTEs, and this all ends
up working correctly by accident. But clearly, we should do better.

Fix hyp_get_page_state() to use the correct helper.

Fixes: e82edcc75c4e ("KVM: arm64: Implement do_share() helper for sharing memory")
Signed-off-by: Quentin Perret <qperret@google.com>
---
 arch/arm64/kvm/hyp/nvhe/mem_protect.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 1e78acf9662e..07f9dc9848ef 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -516,7 +516,7 @@ static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte)
 	if (!kvm_pte_valid(pte))
 		return PKVM_NOPAGE;
 
-	return pkvm_getstate(kvm_pgtable_stage2_pte_prot(pte));
+	return pkvm_getstate(kvm_pgtable_hyp_pte_prot(pte));
 }
 
 static int __hyp_check_page_state_range(u64 addr, u64 size,
-- 
2.38.0.135.g90850a2211-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

             reply	other threads:[~2022-10-25 14:52 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-10-25 14:51 Quentin Perret [this message]
2022-10-25 14:51 ` [PATCH] KVM: arm64: Use correct accessor to parse stage-1 PTEs Quentin Perret
2022-10-25 14:51 ` Quentin Perret
2022-10-25 15:30 ` Marc Zyngier
2022-10-25 15:30   ` Marc Zyngier
2022-10-25 15:30   ` Marc Zyngier

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