diff options
Diffstat (limited to 'arch/arm64/kvm/mmu.c')
| -rw-r--r-- | arch/arm64/kvm/mmu.c | 150 |
1 files changed, 137 insertions, 13 deletions
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index e65acf35cee3..bc2aba953299 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -239,6 +239,9 @@ void free_hyp_pgds(void) static bool kvm_host_owns_hyp_mappings(void) { + if (is_kernel_in_hyp_mode()) + return false; + if (static_branch_likely(&kvm_protected_mode_initialized)) return false; @@ -281,14 +284,117 @@ static phys_addr_t kvm_kaddr_to_phys(void *kaddr) } } -static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end) +struct hyp_shared_pfn { + u64 pfn; + int count; + struct rb_node node; +}; + +static DEFINE_MUTEX(hyp_shared_pfns_lock); +static struct rb_root hyp_shared_pfns = RB_ROOT; + +static struct hyp_shared_pfn *find_shared_pfn(u64 pfn, struct rb_node ***node, + struct rb_node **parent) { - phys_addr_t addr; + struct hyp_shared_pfn *this; + + *node = &hyp_shared_pfns.rb_node; + *parent = NULL; + while (**node) { + this = container_of(**node, struct hyp_shared_pfn, node); + *parent = **node; + if (this->pfn < pfn) + *node = &((**node)->rb_left); + else if (this->pfn > pfn) + *node = &((**node)->rb_right); + else + return this; + } + + return NULL; +} + +static int share_pfn_hyp(u64 pfn) +{ + struct rb_node **node, *parent; + struct hyp_shared_pfn *this; + int ret = 0; + + mutex_lock(&hyp_shared_pfns_lock); + this = find_shared_pfn(pfn, &node, &parent); + if (this) { + this->count++; + goto unlock; + } + + this = kzalloc(sizeof(*this), GFP_KERNEL); + if (!this) { + ret = -ENOMEM; + goto unlock; + } + + this->pfn = pfn; + this->count = 1; + rb_link_node(&this->node, parent, node); + rb_insert_color(&this->node, &hyp_shared_pfns); + ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, pfn, 1); +unlock: + mutex_unlock(&hyp_shared_pfns_lock); + + return ret; +} + +static int unshare_pfn_hyp(u64 pfn) +{ + struct rb_node **node, *parent; + struct hyp_shared_pfn *this; + int ret = 0; + + mutex_lock(&hyp_shared_pfns_lock); + this = find_shared_pfn(pfn, &node, &parent); + if (WARN_ON(!this)) { + ret = -ENOENT; + goto unlock; + } + + this->count--; + if (this->count) + goto unlock; + + rb_erase(&this->node, &hyp_shared_pfns); + kfree(this); + ret = kvm_call_hyp_nvhe(__pkvm_host_unshare_hyp, pfn, 1); +unlock: + mutex_unlock(&hyp_shared_pfns_lock); + + return ret; +} + +int kvm_share_hyp(void *from, void *to) +{ + phys_addr_t start, end, cur; + u64 pfn; int ret; - for (addr = ALIGN_DOWN(start, PAGE_SIZE); addr < end; addr += PAGE_SIZE) { - ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, - __phys_to_pfn(addr)); + if (is_kernel_in_hyp_mode()) + return 0; + + /* + * The share hcall maps things in the 'fixed-offset' region of the hyp + * VA space, so we can only share physically contiguous data-structures + * for now. + */ + if (is_vmalloc_or_module_addr(from) || is_vmalloc_or_module_addr(to)) + return -EINVAL; + + if (kvm_host_owns_hyp_mappings()) + return create_hyp_mappings(from, to, PAGE_HYP); + + start = ALIGN_DOWN(__pa(from), PAGE_SIZE); + end = PAGE_ALIGN(__pa(to)); + for (cur = start; cur < end; cur += PAGE_SIZE) { + pfn = __phys_to_pfn(cur); + ret = share_pfn_hyp(pfn); if (ret) return ret; } @@ -296,6 +402,22 @@ static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end) return 0; } +void kvm_unshare_hyp(void *from, void *to) +{ + phys_addr_t start, end, cur; + u64 pfn; + + if (is_kernel_in_hyp_mode() || kvm_host_owns_hyp_mappings() || !from) + return; + + start = ALIGN_DOWN(__pa(from), PAGE_SIZE); + end = PAGE_ALIGN(__pa(to)); + for (cur = start; cur < end; cur += PAGE_SIZE) { + pfn = __phys_to_pfn(cur); + WARN_ON(unshare_pfn_hyp(pfn)); + } +} + /** * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode * @from: The virtual kernel start address of the range @@ -316,12 +438,8 @@ int create_hyp_mappings(void *from, void *to, enum kvm_pgtable_prot prot) if (is_kernel_in_hyp_mode()) return 0; - if (!kvm_host_owns_hyp_mappings()) { - if (WARN_ON(prot != PAGE_HYP)) - return -EPERM; - return pkvm_share_hyp(kvm_kaddr_to_phys(from), - kvm_kaddr_to_phys(to)); - } + if (!kvm_host_owns_hyp_mappings()) + return -EPERM; start = start & PAGE_MASK; end = PAGE_ALIGN(end); @@ -407,6 +525,9 @@ int create_hyp_io_mappings(phys_addr_t phys_addr, size_t size, unsigned long addr; int ret; + if (is_protected_kvm_enabled()) + return -EPERM; + *kaddr = ioremap(phys_addr, size); if (!*kaddr) return -ENOMEM; @@ -516,7 +637,8 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu) if (!pgt) return -ENOMEM; - err = kvm_pgtable_stage2_init(pgt, &kvm->arch, &kvm_s2_mm_ops); + mmu->arch = &kvm->arch; + err = kvm_pgtable_stage2_init(pgt, mmu, &kvm_s2_mm_ops); if (err) goto out_free_pgtable; @@ -529,7 +651,6 @@ int kvm_init_stage2_mmu(struct kvm *kvm, struct kvm_s2_mmu *mmu) for_each_possible_cpu(cpu) *per_cpu_ptr(mmu->last_vcpu_ran, cpu) = -1; - mmu->arch = &kvm->arch; mmu->pgt = pgt; mmu->pgd_phys = __pa(pgt->pgd); WRITE_ONCE(mmu->vmid.vmid_gen, 0); @@ -650,6 +771,9 @@ int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa, KVM_PGTABLE_PROT_R | (writable ? KVM_PGTABLE_PROT_W : 0); + if (is_protected_kvm_enabled()) + return -EPERM; + size += offset_in_page(guest_ipa); guest_ipa &= PAGE_MASK; |