diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/nvhe/mm.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/mm.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/nvhe/mm.c b/arch/arm64/kvm/hyp/nvhe/mm.c new file mode 100644 index 000000000..96193cb31 --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/mm.c @@ -0,0 +1,215 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Google LLC + * Author: Quentin Perret <qperret@google.com> + */ + +#include <linux/kvm_host.h> +#include <asm/kvm_hyp.h> +#include <asm/kvm_mmu.h> +#include <asm/kvm_pgtable.h> +#include <asm/kvm_pkvm.h> +#include <asm/spectre.h> + +#include <nvhe/early_alloc.h> +#include <nvhe/gfp.h> +#include <nvhe/memory.h> +#include <nvhe/mm.h> +#include <nvhe/spinlock.h> + +struct kvm_pgtable pkvm_pgtable; +hyp_spinlock_t pkvm_pgd_lock; + +struct memblock_region hyp_memory[HYP_MEMBLOCK_REGIONS]; +unsigned int hyp_memblock_nr; + +static u64 __io_map_base; + +static int __pkvm_create_mappings(unsigned long start, unsigned long size, + unsigned long phys, enum kvm_pgtable_prot prot) +{ + int err; + + hyp_spin_lock(&pkvm_pgd_lock); + err = kvm_pgtable_hyp_map(&pkvm_pgtable, start, size, phys, prot); + hyp_spin_unlock(&pkvm_pgd_lock); + + return err; +} + +/** + * pkvm_alloc_private_va_range - Allocates a private VA range. + * @size: The size of the VA range to reserve. + * @haddr: The hypervisor virtual start address of the allocation. + * + * The private virtual address (VA) range is allocated above __io_map_base + * and aligned based on the order of @size. + * + * Return: 0 on success or negative error code on failure. + */ +int pkvm_alloc_private_va_range(size_t size, unsigned long *haddr) +{ + unsigned long base, addr; + int ret = 0; + + hyp_spin_lock(&pkvm_pgd_lock); + + /* Align the allocation based on the order of its size */ + addr = ALIGN(__io_map_base, PAGE_SIZE << get_order(size)); + + /* The allocated size is always a multiple of PAGE_SIZE */ + base = addr + PAGE_ALIGN(size); + + /* Are we overflowing on the vmemmap ? */ + if (!addr || base > __hyp_vmemmap) + ret = -ENOMEM; + else { + __io_map_base = base; + *haddr = addr; + } + + hyp_spin_unlock(&pkvm_pgd_lock); + + return ret; +} + +int __pkvm_create_private_mapping(phys_addr_t phys, size_t size, + enum kvm_pgtable_prot prot, + unsigned long *haddr) +{ + unsigned long addr; + int err; + + size = PAGE_ALIGN(size + offset_in_page(phys)); + err = pkvm_alloc_private_va_range(size, &addr); + if (err) + return err; + + err = __pkvm_create_mappings(addr, size, phys, prot); + if (err) + return err; + + *haddr = addr + offset_in_page(phys); + return err; +} + +int pkvm_create_mappings_locked(void *from, void *to, enum kvm_pgtable_prot prot) +{ + unsigned long start = (unsigned long)from; + unsigned long end = (unsigned long)to; + unsigned long virt_addr; + phys_addr_t phys; + + hyp_assert_lock_held(&pkvm_pgd_lock); + + start = start & PAGE_MASK; + end = PAGE_ALIGN(end); + + for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) { + int err; + + phys = hyp_virt_to_phys((void *)virt_addr); + err = kvm_pgtable_hyp_map(&pkvm_pgtable, virt_addr, PAGE_SIZE, + phys, prot); + if (err) + return err; + } + + return 0; +} + +int pkvm_create_mappings(void *from, void *to, enum kvm_pgtable_prot prot) +{ + int ret; + + hyp_spin_lock(&pkvm_pgd_lock); + ret = pkvm_create_mappings_locked(from, to, prot); + hyp_spin_unlock(&pkvm_pgd_lock); + + return ret; +} + +int hyp_back_vmemmap(phys_addr_t phys, unsigned long size, phys_addr_t back) +{ + unsigned long start, end; + + hyp_vmemmap_range(phys, size, &start, &end); + + return __pkvm_create_mappings(start, end - start, back, PAGE_HYP); +} + +static void *__hyp_bp_vect_base; +int pkvm_cpu_set_vector(enum arm64_hyp_spectre_vector slot) +{ + void *vector; + + switch (slot) { + case HYP_VECTOR_DIRECT: { + vector = __kvm_hyp_vector; + break; + } + case HYP_VECTOR_SPECTRE_DIRECT: { + vector = __bp_harden_hyp_vecs; + break; + } + case HYP_VECTOR_INDIRECT: + case HYP_VECTOR_SPECTRE_INDIRECT: { + vector = (void *)__hyp_bp_vect_base; + break; + } + default: + return -EINVAL; + } + + vector = __kvm_vector_slot2addr(vector, slot); + *this_cpu_ptr(&kvm_hyp_vector) = (unsigned long)vector; + + return 0; +} + +int hyp_map_vectors(void) +{ + phys_addr_t phys; + unsigned long bp_base; + int ret; + + if (!kvm_system_needs_idmapped_vectors()) { + __hyp_bp_vect_base = __bp_harden_hyp_vecs; + return 0; + } + + phys = __hyp_pa(__bp_harden_hyp_vecs); + ret = __pkvm_create_private_mapping(phys, __BP_HARDEN_HYP_VECS_SZ, + PAGE_HYP_EXEC, &bp_base); + if (ret) + return ret; + + __hyp_bp_vect_base = (void *)bp_base; + + return 0; +} + +int hyp_create_idmap(u32 hyp_va_bits) +{ + unsigned long start, end; + + start = hyp_virt_to_phys((void *)__hyp_idmap_text_start); + start = ALIGN_DOWN(start, PAGE_SIZE); + + end = hyp_virt_to_phys((void *)__hyp_idmap_text_end); + end = ALIGN(end, PAGE_SIZE); + + /* + * One half of the VA space is reserved to linearly map portions of + * memory -- see va_layout.c for more details. The other half of the VA + * space contains the trampoline page, and needs some care. Split that + * second half in two and find the quarter of VA space not conflicting + * with the idmap to place the IOs and the vmemmap. IOs use the lower + * half of the quarter and the vmemmap the upper half. + */ + __io_map_base = start & BIT(hyp_va_bits - 2); + __io_map_base ^= BIT(hyp_va_bits - 2); + __hyp_vmemmap = __io_map_base | BIT(hyp_va_bits - 3); + + return __pkvm_create_mappings(start, end - start, start, PAGE_HYP_EXEC); +} |