From: Quentin Perret <qperret@google.com>
To: maz@kernel.org, james.morse@arm.com, alexandru.elisei@arm.com,
suzuki.poulose@arm.com, catalin.marinas@arm.com, will@kernel.org
Cc: linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
ardb@kernel.org, qwandor@google.com, tabba@google.com,
dbrazdil@google.com, kernel-team@android.com,
Quentin Perret <qperret@google.com>
Subject: [PATCH v2 13/16] KVM: arm64: Enable retrieving protections attributes of PTEs
Date: Mon, 26 Jul 2021 10:29:02 +0100 [thread overview]
Message-ID: <20210726092905.2198501-14-qperret@google.com> (raw)
In-Reply-To: <20210726092905.2198501-1-qperret@google.com>
Introduce helper functions in the KVM stage-2 and stage-1 page-table
manipulation library allowing to retrieve the enum kvm_pgtable_prot of a
PTE. This will be useful to implement custom walkers outside of
pgtable.c.
Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/include/asm/kvm_pgtable.h | 20 +++++++++++++++
arch/arm64/kvm/hyp/pgtable.c | 37 ++++++++++++++++++++++++++++
2 files changed, 57 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 0be9f83974ad..f253fb5bcee2 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -492,4 +492,24 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
*/
int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
kvm_pte_t *ptep, u32 *level);
+
+/**
+ * kvm_pgtable_stage2_pte_prot() - Retrieve the protection attributes of a
+ * stage-2 Page-Table Entry.
+ * @pte: Page-table entry
+ *
+ * Return: protection attributes of the page-table entry in the enum
+ * kvm_pgtable_prot format.
+ */
+enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte);
+
+/**
+ * kvm_pgtable_hyp_pte_prot() - Retrieve the protection attributes of a stage-1
+ * Page-Table Entry.
+ * @pte: Page-table entry
+ *
+ * Return: protection attributes of the page-table entry in the enum
+ * kvm_pgtable_prot format.
+ */
+enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte);
#endif /* __ARM64_KVM_PGTABLE_H__ */
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index bd409d524dea..fb80d3019cff 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -376,6 +376,26 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
return 0;
}
+enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte)
+{
+ enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW;
+ u32 ap;
+
+ if (!kvm_pte_valid(pte))
+ return prot;
+
+ if (!(pte & KVM_PTE_LEAF_ATTR_HI_S1_XN))
+ prot |= KVM_PGTABLE_PROT_X;
+
+ ap = FIELD_GET(KVM_PTE_LEAF_ATTR_LO_S1_AP, pte);
+ if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RO)
+ prot |= KVM_PGTABLE_PROT_R;
+ else if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RW)
+ prot |= KVM_PGTABLE_PROT_R | KVM_PGTABLE_PROT_W;
+
+ return prot;
+}
+
static bool hyp_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
{
/*
@@ -578,6 +598,23 @@ static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot p
return 0;
}
+enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte)
+{
+ enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW;
+
+ if (!kvm_pte_valid(pte))
+ return prot;
+
+ if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R)
+ prot |= KVM_PGTABLE_PROT_R;
+ if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W)
+ prot |= KVM_PGTABLE_PROT_W;
+ if (!(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN))
+ prot |= KVM_PGTABLE_PROT_X;
+
+ return prot;
+}
+
static bool stage2_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
{
if (!kvm_pte_valid(old) || !kvm_pte_valid(new))
--
2.32.0.432.gabb21c7263-goog
next prev parent reply other threads:[~2021-07-26 9:30 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-26 9:28 [PATCH v2 00/16] Track shared pages at EL2 in protected mode Quentin Perret
2021-07-26 9:28 ` [PATCH v2 01/16] KVM: arm64: Introduce helper to retrieve a PTE and its level Quentin Perret
2021-07-26 9:28 ` [PATCH v2 02/16] KVM: arm64: Provide the host_stage2_try() helper macro Quentin Perret
2021-07-26 9:28 ` [PATCH v2 03/16] KVM: arm64: Expose page-table helpers Quentin Perret
2021-07-26 9:28 ` [PATCH v2 04/16] KVM: arm64: Optimize host memory aborts Quentin Perret
2021-07-26 10:35 ` Marc Zyngier
2021-07-26 13:13 ` Quentin Perret
2021-07-26 13:24 ` Marc Zyngier
2021-07-26 9:28 ` [PATCH v2 05/16] KVM: arm64: Rename KVM_PTE_LEAF_ATTR_S2_IGNORED Quentin Perret
2021-07-26 9:28 ` [PATCH v2 06/16] KVM: arm64: Don't overwrite software bits with owner id Quentin Perret
2021-07-26 9:28 ` [PATCH v2 07/16] KVM: arm64: Tolerate re-creating hyp mappings to set software bits Quentin Perret
2021-07-26 9:28 ` [PATCH v2 08/16] KVM: arm64: Enable forcing page-level stage-2 mappings Quentin Perret
2021-07-26 9:28 ` [PATCH v2 09/16] KVM: arm64: Allow populating software bits Quentin Perret
2021-07-26 9:28 ` [PATCH v2 10/16] KVM: arm64: Add helpers to tag shared pages in SW bits Quentin Perret
2021-07-26 9:29 ` [PATCH v2 11/16] KVM: arm64: Introduce and export host_stage2_idmap_locked() Quentin Perret
2021-07-26 9:29 ` [PATCH v2 12/16] KVM: arm64: Mark host bss and rodata section as shared Quentin Perret
2021-07-28 12:14 ` Quentin Perret
2021-07-26 9:29 ` Quentin Perret [this message]
2021-07-26 9:29 ` [PATCH v2 14/16] KVM: arm64: Refactor protected nVHE stage-1 locking Quentin Perret
2021-07-26 9:29 ` [PATCH v2 15/16] KVM: arm64: Restrict EL2 stage-1 changes in protected mode Quentin Perret
2021-07-26 11:27 ` Marc Zyngier
2021-07-26 12:55 ` Quentin Perret
2021-07-26 9:29 ` [PATCH v2 16/16] KVM: arm64: Make __pkvm_create_mappings static Quentin Perret
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