From bb0e92cbbcd1f91411d0a7241f8febe2c8c5b078 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 11 Sep 2020 14:25:11 +0100 Subject: KVM: arm64: Add support for creating kernel-agnostic stage-1 page tables 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. Signed-off-by: Will Deacon Signed-off-by: Marc Zyngier Reviewed-by: Gavin Shan Cc: Marc Zyngier Cc: Quentin Perret Link: https://lore.kernel.org/r/20200911132529.19844-4-will@kernel.org --- arch/arm64/kvm/hyp/pgtable.c | 133 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) (limited to 'arch/arm64/kvm/hyp/pgtable.c') 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; +} -- cgit v1.2.3