From: Will Deacon <will@kernel.org>
To: kvmarm@lists.cs.columbia.edu
Cc: kernel-team@android.com, Gavin Shan <gshan@redhat.com>,
Suzuki Poulose <suzuki.poulose@arm.com>,
Marc Zyngier <maz@kernel.org>,
Quentin Perret <qperret@google.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
James Morse <james.morse@arm.com>,
Andrew Scull <ascull@google.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH v5 03/21] KVM: arm64: Add support for creating kernel-agnostic stage-1 page tables
Date: Fri, 11 Sep 2020 14:25:11 +0100 [thread overview]
Message-ID: <20200911132529.19844-4-will@kernel.org> (raw)
In-Reply-To: <20200911132529.19844-1-will@kernel.org>
The generic page-table walker is pretty useless as it stands, because it
doesn't understand enough to allocate anything. Teach it about stage-1
page-tables, and hook up an API for allocating these for the hypervisor
at EL2.
Cc: Marc Zyngier <maz@kernel.org>
Cc: Quentin Perret <qperret@google.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/kvm_pgtable.h | 40 ++++++++
arch/arm64/kvm/hyp/pgtable.c | 133 +++++++++++++++++++++++++++
2 files changed, 173 insertions(+)
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index 9423e5d609f1..d0a207d095e6 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -77,6 +77,46 @@ struct kvm_pgtable_walker {
const enum kvm_pgtable_walk_flags flags;
};
+/**
+ * kvm_pgtable_hyp_init() - Initialise a hypervisor stage-1 page-table.
+ * @pgt: Uninitialised page-table structure to initialise.
+ * @va_bits: Maximum virtual address bits.
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits);
+
+/**
+ * kvm_pgtable_hyp_destroy() - Destroy an unused hypervisor stage-1 page-table.
+ * @pgt: Page-table structure initialised by kvm_pgtable_hyp_init().
+ *
+ * The page-table is assumed to be unreachable by any hardware walkers prior
+ * to freeing and therefore no TLB invalidation is performed.
+ */
+void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt);
+
+/**
+ * kvm_pgtable_hyp_map() - Install a mapping in a hypervisor stage-1 page-table.
+ * @pgt: Page-table structure initialised by kvm_pgtable_hyp_init().
+ * @addr: Virtual address at which to place the mapping.
+ * @size: Size of the mapping.
+ * @phys: Physical address of the memory to map.
+ * @prot: Permissions and attributes for the mapping.
+ *
+ * The offset of @addr within a page is ignored, @size is rounded-up to
+ * the next page boundary and @phys is rounded-down to the previous page
+ * boundary.
+ *
+ * If device attributes are not explicitly requested in @prot, then the
+ * mapping will be normal, cacheable. Attempts to install a new mapping
+ * for a virtual address that is already mapped will be rejected with an
+ * error and a WARN().
+ *
+ * Return: 0 on success, negative error code on failure.
+ */
+int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
+ enum kvm_pgtable_prot prot);
+
/**
* kvm_pgtable_walk() - Walk a page-table.
* @pgt: Page-table structure initialised by kvm_pgtable_*_init().
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 3fb9d1949a3f..23a1006aa4ef 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -24,8 +24,18 @@
#define KVM_PTE_LEAF_ATTR_LO GENMASK(11, 2)
+#define KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX GENMASK(4, 2)
+#define KVM_PTE_LEAF_ATTR_LO_S1_AP GENMASK(7, 6)
+#define KVM_PTE_LEAF_ATTR_LO_S1_AP_RO 3
+#define KVM_PTE_LEAF_ATTR_LO_S1_AP_RW 1
+#define KVM_PTE_LEAF_ATTR_LO_S1_SH GENMASK(9, 8)
+#define KVM_PTE_LEAF_ATTR_LO_S1_SH_IS 3
+#define KVM_PTE_LEAF_ATTR_LO_S1_AF BIT(10)
+
#define KVM_PTE_LEAF_ATTR_HI GENMASK(63, 51)
+#define KVM_PTE_LEAF_ATTR_HI_S1_XN BIT(54)
+
struct kvm_pgtable_walk_data {
struct kvm_pgtable *pgt;
struct kvm_pgtable_walker *walker;
@@ -283,3 +293,126 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
return _kvm_pgtable_walk(&walk_data);
}
+
+struct hyp_map_data {
+ u64 phys;
+ kvm_pte_t attr;
+};
+
+static int hyp_map_set_prot_attr(enum kvm_pgtable_prot prot,
+ struct hyp_map_data *data)
+{
+ bool device = prot & KVM_PGTABLE_PROT_DEVICE;
+ u32 mtype = device ? MT_DEVICE_nGnRE : MT_NORMAL;
+ kvm_pte_t attr = FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX, mtype);
+ u32 sh = KVM_PTE_LEAF_ATTR_LO_S1_SH_IS;
+ u32 ap = (prot & KVM_PGTABLE_PROT_W) ? KVM_PTE_LEAF_ATTR_LO_S1_AP_RW :
+ KVM_PTE_LEAF_ATTR_LO_S1_AP_RO;
+
+ if (!(prot & KVM_PGTABLE_PROT_R))
+ return -EINVAL;
+
+ if (prot & KVM_PGTABLE_PROT_X) {
+ if (prot & KVM_PGTABLE_PROT_W)
+ return -EINVAL;
+
+ if (device)
+ return -EINVAL;
+ } else {
+ attr |= KVM_PTE_LEAF_ATTR_HI_S1_XN;
+ }
+
+ attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_AP, ap);
+ attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh);
+ attr |= KVM_PTE_LEAF_ATTR_LO_S1_AF;
+ data->attr = attr;
+ return 0;
+}
+
+static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
+ kvm_pte_t *ptep, struct hyp_map_data *data)
+{
+ u64 granule = kvm_granule_size(level), phys = data->phys;
+
+ if (!kvm_block_mapping_supported(addr, end, phys, level))
+ return false;
+
+ WARN_ON(!kvm_set_valid_leaf_pte(ptep, phys, data->attr, level));
+ data->phys += granule;
+ return true;
+}
+
+static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
+ enum kvm_pgtable_walk_flags flag, void * const arg)
+{
+ kvm_pte_t *childp;
+
+ if (hyp_map_walker_try_leaf(addr, end, level, ptep, arg))
+ return 0;
+
+ if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1))
+ return -EINVAL;
+
+ childp = (kvm_pte_t *)get_zeroed_page(GFP_KERNEL);
+ if (!childp)
+ return -ENOMEM;
+
+ kvm_set_table_pte(ptep, childp);
+ return 0;
+}
+
+int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
+ enum kvm_pgtable_prot prot)
+{
+ int ret;
+ struct hyp_map_data map_data = {
+ .phys = ALIGN_DOWN(phys, PAGE_SIZE),
+ };
+ struct kvm_pgtable_walker walker = {
+ .cb = hyp_map_walker,
+ .flags = KVM_PGTABLE_WALK_LEAF,
+ .arg = &map_data,
+ };
+
+ ret = hyp_map_set_prot_attr(prot, &map_data);
+ if (ret)
+ return ret;
+
+ ret = kvm_pgtable_walk(pgt, addr, size, &walker);
+ dsb(ishst);
+ isb();
+ return ret;
+}
+
+int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits)
+{
+ u64 levels = ARM64_HW_PGTABLE_LEVELS(va_bits);
+
+ pgt->pgd = (kvm_pte_t *)get_zeroed_page(GFP_KERNEL);
+ if (!pgt->pgd)
+ return -ENOMEM;
+
+ pgt->ia_bits = va_bits;
+ pgt->start_level = KVM_PGTABLE_MAX_LEVELS - levels;
+ pgt->mmu = NULL;
+ return 0;
+}
+
+static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
+ enum kvm_pgtable_walk_flags flag, void * const arg)
+{
+ free_page((unsigned long)kvm_pte_follow(*ptep));
+ return 0;
+}
+
+void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
+{
+ struct kvm_pgtable_walker walker = {
+ .cb = hyp_free_walker,
+ .flags = KVM_PGTABLE_WALK_TABLE_POST,
+ };
+
+ WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
+ free_page((unsigned long)pgt->pgd);
+ pgt->pgd = NULL;
+}
--
2.28.0.618.gf4bc123cb7-goog
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next prev parent reply other threads:[~2020-09-11 13:27 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 13:25 [PATCH v5 00/21] KVM: arm64: Rewrite page-table code and fault handling Will Deacon
2020-09-11 13:25 ` [PATCH v5 01/21] KVM: arm64: Remove kvm_mmu_free_memory_caches() Will Deacon
2020-09-11 13:25 ` [PATCH v5 02/21] KVM: arm64: Add stand-alone page-table walker infrastructure Will Deacon
2020-09-11 13:25 ` Will Deacon [this message]
2020-09-11 13:25 ` [PATCH v5 04/21] KVM: arm64: Use generic allocator for hyp stage-1 page-tables Will Deacon
2020-09-11 13:25 ` [PATCH v5 05/21] KVM: arm64: Add support for creating kernel-agnostic stage-2 page tables Will Deacon
2020-09-11 13:25 ` [PATCH v5 06/21] KVM: arm64: Add support for stage-2 map()/unmap() in generic page-table Will Deacon
2020-09-15 10:47 ` Alexandru Elisei
2020-09-11 13:25 ` [PATCH v5 07/21] KVM: arm64: Convert kvm_phys_addr_ioremap() to generic page-table API Will Deacon
2020-09-11 13:25 ` [PATCH v5 08/21] KVM: arm64: Convert kvm_set_spte_hva() " Will Deacon
2020-09-11 13:25 ` [PATCH v5 09/21] KVM: arm64: Convert unmap_stage2_range() " Will Deacon
2020-09-15 10:57 ` Alexandru Elisei
2020-09-11 13:25 ` [PATCH v5 10/21] KVM: arm64: Add support for stage-2 page-aging in generic page-table Will Deacon
2020-09-11 13:25 ` [PATCH v5 11/21] KVM: arm64: Convert page-aging and access faults to generic page-table API Will Deacon
2020-09-11 13:25 ` [PATCH v5 12/21] KVM: arm64: Add support for stage-2 write-protect in generic page-table Will Deacon
2020-09-11 13:25 ` [PATCH v5 13/21] KVM: arm64: Convert write-protect operation to generic page-table API Will Deacon
2020-09-11 13:25 ` [PATCH v5 14/21] KVM: arm64: Add support for stage-2 cache flushing in generic page-table Will Deacon
2020-09-11 13:25 ` [PATCH v5 15/21] KVM: arm64: Convert memslot cache-flushing code to generic page-table API Will Deacon
2020-09-11 13:25 ` [PATCH v5 16/21] KVM: arm64: Add support for relaxing stage-2 perms in generic page-table code Will Deacon
2020-09-15 16:16 ` Alexandru Elisei
2020-09-11 13:25 ` [PATCH v5 17/21] KVM: arm64: Convert user_mem_abort() to generic page-table API Will Deacon
2020-09-11 13:25 ` [PATCH v5 18/21] KVM: arm64: Check the pgt instead of the pgd when modifying page-table Will Deacon
2020-09-11 13:25 ` [PATCH v5 19/21] KVM: arm64: Remove unused page-table code Will Deacon
2020-09-11 13:25 ` [PATCH v5 20/21] KVM: arm64: Remove unused 'pgd' field from 'struct kvm_s2_mmu' Will Deacon
2020-09-11 13:25 ` [PATCH v5 21/21] KVM: arm64: Don't constrain maximum IPA size based on host configuration Will Deacon
2020-09-11 15:04 ` [PATCH v5 00/21] KVM: arm64: Rewrite page-table code and fault handling Marc Zyngier
2020-10-01 10:21 ` Alexandru Elisei
2020-10-01 12:28 ` Will Deacon
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