| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * |
| * Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> |
| * Copyright 2011 David Gibson, IBM Corporation <dwg@au1.ibm.com> |
| * Copyright 2016 Alexey Kardashevskiy, IBM Corporation <aik@au1.ibm.com> |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/string.h> |
| #include <linux/kvm.h> |
| #include <linux/kvm_host.h> |
| #include <linux/highmem.h> |
| #include <linux/gfp.h> |
| #include <linux/slab.h> |
| #include <linux/sched/signal.h> |
| #include <linux/hugetlb.h> |
| #include <linux/list.h> |
| #include <linux/anon_inodes.h> |
| #include <linux/iommu.h> |
| #include <linux/file.h> |
| #include <linux/mm.h> |
| |
| #include <asm/kvm_ppc.h> |
| #include <asm/kvm_book3s.h> |
| #include <asm/book3s/64/mmu-hash.h> |
| #include <asm/hvcall.h> |
| #include <asm/synch.h> |
| #include <asm/ppc-opcode.h> |
| #include <asm/udbg.h> |
| #include <asm/iommu.h> |
| #include <asm/tce.h> |
| #include <asm/mmu_context.h> |
| |
| static struct kvmppc_spapr_tce_table *kvmppc_find_table(struct kvm *kvm, |
| unsigned long liobn) |
| { |
| struct kvmppc_spapr_tce_table *stt; |
| |
| list_for_each_entry_lockless(stt, &kvm->arch.spapr_tce_tables, list) |
| if (stt->liobn == liobn) |
| return stt; |
| |
| return NULL; |
| } |
| |
| static unsigned long kvmppc_tce_pages(unsigned long iommu_pages) |
| { |
| return ALIGN(iommu_pages * sizeof(u64), PAGE_SIZE) / PAGE_SIZE; |
| } |
| |
| static unsigned long kvmppc_stt_pages(unsigned long tce_pages) |
| { |
| unsigned long stt_bytes = sizeof(struct kvmppc_spapr_tce_table) + |
| (tce_pages * sizeof(struct page *)); |
| |
| return tce_pages + ALIGN(stt_bytes, PAGE_SIZE) / PAGE_SIZE; |
| } |
| |
| static void kvm_spapr_tce_iommu_table_free(struct rcu_head *head) |
| { |
| struct kvmppc_spapr_tce_iommu_table *stit = container_of(head, |
| struct kvmppc_spapr_tce_iommu_table, rcu); |
| |
| iommu_tce_table_put(stit->tbl); |
| |
| kfree(stit); |
| } |
| |
| static void kvm_spapr_tce_liobn_put(struct kref *kref) |
| { |
| struct kvmppc_spapr_tce_iommu_table *stit = container_of(kref, |
| struct kvmppc_spapr_tce_iommu_table, kref); |
| |
| list_del_rcu(&stit->next); |
| |
| call_rcu(&stit->rcu, kvm_spapr_tce_iommu_table_free); |
| } |
| |
| void kvm_spapr_tce_release_iommu_group(struct kvm *kvm, |
| struct iommu_group *grp) |
| { |
| int i; |
| struct kvmppc_spapr_tce_table *stt; |
| struct kvmppc_spapr_tce_iommu_table *stit, *tmp; |
| struct iommu_table_group *table_group = NULL; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) { |
| |
| table_group = iommu_group_get_iommudata(grp); |
| if (WARN_ON(!table_group)) |
| continue; |
| |
| list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) { |
| for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { |
| if (table_group->tables[i] != stit->tbl) |
| continue; |
| |
| kref_put(&stit->kref, kvm_spapr_tce_liobn_put); |
| } |
| } |
| cond_resched_rcu(); |
| } |
| rcu_read_unlock(); |
| } |
| |
| long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, |
| struct iommu_group *grp) |
| { |
| struct kvmppc_spapr_tce_table *stt = NULL; |
| bool found = false; |
| struct iommu_table *tbl = NULL; |
| struct iommu_table_group *table_group; |
| long i; |
| struct kvmppc_spapr_tce_iommu_table *stit; |
| struct fd f; |
| |
| f = fdget(tablefd); |
| if (!f.file) |
| return -EBADF; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) { |
| if (stt == f.file->private_data) { |
| found = true; |
| break; |
| } |
| } |
| rcu_read_unlock(); |
| |
| fdput(f); |
| |
| if (!found) |
| return -EINVAL; |
| |
| table_group = iommu_group_get_iommudata(grp); |
| if (WARN_ON(!table_group)) |
| return -EFAULT; |
| |
| for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { |
| struct iommu_table *tbltmp = table_group->tables[i]; |
| |
| if (!tbltmp) |
| continue; |
| /* Make sure hardware table parameters are compatible */ |
| if ((tbltmp->it_page_shift <= stt->page_shift) && |
| (tbltmp->it_offset << tbltmp->it_page_shift == |
| stt->offset << stt->page_shift) && |
| (tbltmp->it_size << tbltmp->it_page_shift >= |
| stt->size << stt->page_shift)) { |
| /* |
| * Reference the table to avoid races with |
| * add/remove DMA windows. |
| */ |
| tbl = iommu_tce_table_get(tbltmp); |
| break; |
| } |
| } |
| if (!tbl) |
| return -EINVAL; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(stit, &stt->iommu_tables, next) { |
| if (tbl != stit->tbl) |
| continue; |
| |
| if (!kref_get_unless_zero(&stit->kref)) { |
| /* stit is being destroyed */ |
| iommu_tce_table_put(tbl); |
| rcu_read_unlock(); |
| return -ENOTTY; |
| } |
| /* |
| * The table is already known to this KVM, we just increased |
| * its KVM reference counter and can return. |
| */ |
| rcu_read_unlock(); |
| return 0; |
| } |
| rcu_read_unlock(); |
| |
| stit = kzalloc(sizeof(*stit), GFP_KERNEL); |
| if (!stit) { |
| iommu_tce_table_put(tbl); |
| return -ENOMEM; |
| } |
| |
| stit->tbl = tbl; |
| kref_init(&stit->kref); |
| |
| list_add_rcu(&stit->next, &stt->iommu_tables); |
| |
| return 0; |
| } |
| |
| static void release_spapr_tce_table(struct rcu_head *head) |
| { |
| struct kvmppc_spapr_tce_table *stt = container_of(head, |
| struct kvmppc_spapr_tce_table, rcu); |
| unsigned long i, npages = kvmppc_tce_pages(stt->size); |
| |
| for (i = 0; i < npages; i++) |
| if (stt->pages[i]) |
| __free_page(stt->pages[i]); |
| |
| kfree(stt); |
| } |
| |
| static struct page *kvm_spapr_get_tce_page(struct kvmppc_spapr_tce_table *stt, |
| unsigned long sttpage) |
| { |
| struct page *page = stt->pages[sttpage]; |
| |
| if (page) |
| return page; |
| |
| mutex_lock(&stt->alloc_lock); |
| page = stt->pages[sttpage]; |
| if (!page) { |
| page = alloc_page(GFP_KERNEL | __GFP_ZERO); |
| WARN_ON_ONCE(!page); |
| if (page) |
| stt->pages[sttpage] = page; |
| } |
| mutex_unlock(&stt->alloc_lock); |
| |
| return page; |
| } |
| |
| static vm_fault_t kvm_spapr_tce_fault(struct vm_fault *vmf) |
| { |
| struct kvmppc_spapr_tce_table *stt = vmf->vma->vm_file->private_data; |
| struct page *page; |
| |
| if (vmf->pgoff >= kvmppc_tce_pages(stt->size)) |
| return VM_FAULT_SIGBUS; |
| |
| page = kvm_spapr_get_tce_page(stt, vmf->pgoff); |
| if (!page) |
| return VM_FAULT_OOM; |
| |
| get_page(page); |
| vmf->page = page; |
| return 0; |
| } |
| |
| static const struct vm_operations_struct kvm_spapr_tce_vm_ops = { |
| .fault = kvm_spapr_tce_fault, |
| }; |
| |
| static int kvm_spapr_tce_mmap(struct file *file, struct vm_area_struct *vma) |
| { |
| vma->vm_ops = &kvm_spapr_tce_vm_ops; |
| return 0; |
| } |
| |
| static int kvm_spapr_tce_release(struct inode *inode, struct file *filp) |
| { |
| struct kvmppc_spapr_tce_table *stt = filp->private_data; |
| struct kvmppc_spapr_tce_iommu_table *stit, *tmp; |
| struct kvm *kvm = stt->kvm; |
| |
| mutex_lock(&kvm->lock); |
| list_del_rcu(&stt->list); |
| mutex_unlock(&kvm->lock); |
| |
| list_for_each_entry_safe(stit, tmp, &stt->iommu_tables, next) { |
| WARN_ON(!kref_read(&stit->kref)); |
| while (1) { |
| if (kref_put(&stit->kref, kvm_spapr_tce_liobn_put)) |
| break; |
| } |
| } |
| |
| account_locked_vm(kvm->mm, |
| kvmppc_stt_pages(kvmppc_tce_pages(stt->size)), false); |
| |
| kvm_put_kvm(stt->kvm); |
| |
| call_rcu(&stt->rcu, release_spapr_tce_table); |
| |
| return 0; |
| } |
| |
| static const struct file_operations kvm_spapr_tce_fops = { |
| .mmap = kvm_spapr_tce_mmap, |
| .release = kvm_spapr_tce_release, |
| }; |
| |
| int kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm, |
| struct kvm_create_spapr_tce_64 *args) |
| { |
| struct kvmppc_spapr_tce_table *stt = NULL; |
| struct kvmppc_spapr_tce_table *siter; |
| struct mm_struct *mm = kvm->mm; |
| unsigned long npages; |
| int ret; |
| |
| if (!args->size || args->page_shift < 12 || args->page_shift > 34 || |
| (args->offset + args->size > (ULLONG_MAX >> args->page_shift))) |
| return -EINVAL; |
| |
| npages = kvmppc_tce_pages(args->size); |
| ret = account_locked_vm(mm, kvmppc_stt_pages(npages), true); |
| if (ret) |
| return ret; |
| |
| ret = -ENOMEM; |
| stt = kzalloc(struct_size(stt, pages, npages), GFP_KERNEL | __GFP_NOWARN); |
| if (!stt) |
| goto fail_acct; |
| |
| stt->liobn = args->liobn; |
| stt->page_shift = args->page_shift; |
| stt->offset = args->offset; |
| stt->size = args->size; |
| stt->kvm = kvm; |
| mutex_init(&stt->alloc_lock); |
| INIT_LIST_HEAD_RCU(&stt->iommu_tables); |
| |
| mutex_lock(&kvm->lock); |
| |
| /* Check this LIOBN hasn't been previously allocated */ |
| ret = 0; |
| list_for_each_entry(siter, &kvm->arch.spapr_tce_tables, list) { |
| if (siter->liobn == args->liobn) { |
| ret = -EBUSY; |
| break; |
| } |
| } |
| |
| kvm_get_kvm(kvm); |
| if (!ret) |
| ret = anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops, |
| stt, O_RDWR | O_CLOEXEC); |
| |
| if (ret >= 0) |
| list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables); |
| else |
| kvm_put_kvm_no_destroy(kvm); |
| |
| mutex_unlock(&kvm->lock); |
| |
| if (ret >= 0) |
| return ret; |
| |
| kfree(stt); |
| fail_acct: |
| account_locked_vm(mm, kvmppc_stt_pages(npages), false); |
| return ret; |
| } |
| |
| static long kvmppc_tce_to_ua(struct kvm *kvm, unsigned long tce, |
| unsigned long *ua) |
| { |
| unsigned long gfn = tce >> PAGE_SHIFT; |
| struct kvm_memory_slot *memslot; |
| |
| memslot = __gfn_to_memslot(kvm_memslots(kvm), gfn); |
| if (!memslot) |
| return -EINVAL; |
| |
| *ua = __gfn_to_hva_memslot(memslot, gfn) | |
| (tce & ~(PAGE_MASK | TCE_PCI_READ | TCE_PCI_WRITE)); |
| |
| return 0; |
| } |
| |
| static long kvmppc_tce_validate(struct kvmppc_spapr_tce_table *stt, |
| unsigned long tce) |
| { |
| unsigned long gpa = tce & ~(TCE_PCI_READ | TCE_PCI_WRITE); |
| enum dma_data_direction dir = iommu_tce_direction(tce); |
| struct kvmppc_spapr_tce_iommu_table *stit; |
| unsigned long ua = 0; |
| |
| /* Allow userspace to poison TCE table */ |
| if (dir == DMA_NONE) |
| return H_SUCCESS; |
| |
| if (iommu_tce_check_gpa(stt->page_shift, gpa)) |
| return H_TOO_HARD; |
| |
| if (kvmppc_tce_to_ua(stt->kvm, tce, &ua)) |
| return H_TOO_HARD; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(stit, &stt->iommu_tables, next) { |
| unsigned long hpa = 0; |
| struct mm_iommu_table_group_mem_t *mem; |
| long shift = stit->tbl->it_page_shift; |
| |
| mem = mm_iommu_lookup(stt->kvm->mm, ua, 1ULL << shift); |
| if (!mem || mm_iommu_ua_to_hpa(mem, ua, shift, &hpa)) { |
| rcu_read_unlock(); |
| return H_TOO_HARD; |
| } |
| } |
| rcu_read_unlock(); |
| |
| return H_SUCCESS; |
| } |
| |
| /* |
| * Handles TCE requests for emulated devices. |
| * Puts guest TCE values to the table and expects user space to convert them. |
| * Cannot fail so kvmppc_tce_validate must be called before it. |
| */ |
| static void kvmppc_tce_put(struct kvmppc_spapr_tce_table *stt, |
| unsigned long idx, unsigned long tce) |
| { |
| struct page *page; |
| u64 *tbl; |
| unsigned long sttpage; |
| |
| idx -= stt->offset; |
| sttpage = idx / TCES_PER_PAGE; |
| page = stt->pages[sttpage]; |
| |
| if (!page) { |
| /* We allow any TCE, not just with read|write permissions */ |
| if (!tce) |
| return; |
| |
| page = kvm_spapr_get_tce_page(stt, sttpage); |
| if (!page) |
| return; |
| } |
| tbl = page_to_virt(page); |
| |
| tbl[idx % TCES_PER_PAGE] = tce; |
| } |
| |
| static void kvmppc_clear_tce(struct mm_struct *mm, struct kvmppc_spapr_tce_table *stt, |
| struct iommu_table *tbl, unsigned long entry) |
| { |
| unsigned long i; |
| unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift); |
| unsigned long io_entry = entry << (stt->page_shift - tbl->it_page_shift); |
| |
| for (i = 0; i < subpages; ++i) { |
| unsigned long hpa = 0; |
| enum dma_data_direction dir = DMA_NONE; |
| |
| iommu_tce_xchg_no_kill(mm, tbl, io_entry + i, &hpa, &dir); |
| } |
| } |
| |
| static long kvmppc_tce_iommu_mapped_dec(struct kvm *kvm, |
| struct iommu_table *tbl, unsigned long entry) |
| { |
| struct mm_iommu_table_group_mem_t *mem = NULL; |
| const unsigned long pgsize = 1ULL << tbl->it_page_shift; |
| __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry); |
| |
| if (!pua) |
| return H_SUCCESS; |
| |
| mem = mm_iommu_lookup(kvm->mm, be64_to_cpu(*pua), pgsize); |
| if (!mem) |
| return H_TOO_HARD; |
| |
| mm_iommu_mapped_dec(mem); |
| |
| *pua = cpu_to_be64(0); |
| |
| return H_SUCCESS; |
| } |
| |
| static long kvmppc_tce_iommu_do_unmap(struct kvm *kvm, |
| struct iommu_table *tbl, unsigned long entry) |
| { |
| enum dma_data_direction dir = DMA_NONE; |
| unsigned long hpa = 0; |
| long ret; |
| |
| if (WARN_ON_ONCE(iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, |
| &dir))) |
| return H_TOO_HARD; |
| |
| if (dir == DMA_NONE) |
| return H_SUCCESS; |
| |
| ret = kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry); |
| if (ret != H_SUCCESS) |
| iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, &dir); |
| |
| return ret; |
| } |
| |
| static long kvmppc_tce_iommu_unmap(struct kvm *kvm, |
| struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl, |
| unsigned long entry) |
| { |
| unsigned long i, ret = H_SUCCESS; |
| unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift); |
| unsigned long io_entry = entry * subpages; |
| |
| for (i = 0; i < subpages; ++i) { |
| ret = kvmppc_tce_iommu_do_unmap(kvm, tbl, io_entry + i); |
| if (ret != H_SUCCESS) |
| break; |
| } |
| |
| iommu_tce_kill(tbl, io_entry, subpages); |
| |
| return ret; |
| } |
| |
| static long kvmppc_tce_iommu_do_map(struct kvm *kvm, struct iommu_table *tbl, |
| unsigned long entry, unsigned long ua, |
| enum dma_data_direction dir) |
| { |
| long ret; |
| unsigned long hpa; |
| __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry); |
| struct mm_iommu_table_group_mem_t *mem; |
| |
| if (!pua) |
| /* it_userspace allocation might be delayed */ |
| return H_TOO_HARD; |
| |
| mem = mm_iommu_lookup(kvm->mm, ua, 1ULL << tbl->it_page_shift); |
| if (!mem) |
| /* This only handles v2 IOMMU type, v1 is handled via ioctl() */ |
| return H_TOO_HARD; |
| |
| if (WARN_ON_ONCE(mm_iommu_ua_to_hpa(mem, ua, tbl->it_page_shift, &hpa))) |
| return H_TOO_HARD; |
| |
| if (mm_iommu_mapped_inc(mem)) |
| return H_TOO_HARD; |
| |
| ret = iommu_tce_xchg_no_kill(kvm->mm, tbl, entry, &hpa, &dir); |
| if (WARN_ON_ONCE(ret)) { |
| mm_iommu_mapped_dec(mem); |
| return H_TOO_HARD; |
| } |
| |
| if (dir != DMA_NONE) |
| kvmppc_tce_iommu_mapped_dec(kvm, tbl, entry); |
| |
| *pua = cpu_to_be64(ua); |
| |
| return 0; |
| } |
| |
| static long kvmppc_tce_iommu_map(struct kvm *kvm, |
| struct kvmppc_spapr_tce_table *stt, struct iommu_table *tbl, |
| unsigned long entry, unsigned long ua, |
| enum dma_data_direction dir) |
| { |
| unsigned long i, pgoff, ret = H_SUCCESS; |
| unsigned long subpages = 1ULL << (stt->page_shift - tbl->it_page_shift); |
| unsigned long io_entry = entry * subpages; |
| |
| for (i = 0, pgoff = 0; i < subpages; |
| ++i, pgoff += IOMMU_PAGE_SIZE(tbl)) { |
| |
| ret = kvmppc_tce_iommu_do_map(kvm, tbl, |
| io_entry + i, ua + pgoff, dir); |
| if (ret != H_SUCCESS) |
| break; |
| } |
| |
| iommu_tce_kill(tbl, io_entry, subpages); |
| |
| return ret; |
| } |
| |
| long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn, |
| unsigned long ioba, unsigned long tce) |
| { |
| struct kvmppc_spapr_tce_table *stt; |
| long ret, idx; |
| struct kvmppc_spapr_tce_iommu_table *stit; |
| unsigned long entry, ua = 0; |
| enum dma_data_direction dir; |
| |
| /* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */ |
| /* liobn, ioba, tce); */ |
| |
| stt = kvmppc_find_table(vcpu->kvm, liobn); |
| if (!stt) |
| return H_TOO_HARD; |
| |
| ret = kvmppc_ioba_validate(stt, ioba, 1); |
| if (ret != H_SUCCESS) |
| return ret; |
| |
| idx = srcu_read_lock(&vcpu->kvm->srcu); |
| |
| ret = kvmppc_tce_validate(stt, tce); |
| if (ret != H_SUCCESS) |
| goto unlock_exit; |
| |
| dir = iommu_tce_direction(tce); |
| |
| if ((dir != DMA_NONE) && kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) { |
| ret = H_PARAMETER; |
| goto unlock_exit; |
| } |
| |
| entry = ioba >> stt->page_shift; |
| |
| list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { |
| if (dir == DMA_NONE) |
| ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt, |
| stit->tbl, entry); |
| else |
| ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, stit->tbl, |
| entry, ua, dir); |
| |
| |
| if (ret != H_SUCCESS) { |
| kvmppc_clear_tce(vcpu->kvm->mm, stt, stit->tbl, entry); |
| goto unlock_exit; |
| } |
| } |
| |
| kvmppc_tce_put(stt, entry, tce); |
| |
| unlock_exit: |
| srcu_read_unlock(&vcpu->kvm->srcu, idx); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(kvmppc_h_put_tce); |
| |
| long kvmppc_h_put_tce_indirect(struct kvm_vcpu *vcpu, |
| unsigned long liobn, unsigned long ioba, |
| unsigned long tce_list, unsigned long npages) |
| { |
| struct kvmppc_spapr_tce_table *stt; |
| long i, ret = H_SUCCESS, idx; |
| unsigned long entry, ua = 0; |
| u64 __user *tces; |
| u64 tce; |
| struct kvmppc_spapr_tce_iommu_table *stit; |
| |
| stt = kvmppc_find_table(vcpu->kvm, liobn); |
| if (!stt) |
| return H_TOO_HARD; |
| |
| entry = ioba >> stt->page_shift; |
| /* |
| * SPAPR spec says that the maximum size of the list is 512 TCEs |
| * so the whole table fits in 4K page |
| */ |
| if (npages > 512) |
| return H_PARAMETER; |
| |
| if (tce_list & (SZ_4K - 1)) |
| return H_PARAMETER; |
| |
| ret = kvmppc_ioba_validate(stt, ioba, npages); |
| if (ret != H_SUCCESS) |
| return ret; |
| |
| idx = srcu_read_lock(&vcpu->kvm->srcu); |
| if (kvmppc_tce_to_ua(vcpu->kvm, tce_list, &ua)) { |
| ret = H_TOO_HARD; |
| goto unlock_exit; |
| } |
| tces = (u64 __user *) ua; |
| |
| for (i = 0; i < npages; ++i) { |
| if (get_user(tce, tces + i)) { |
| ret = H_TOO_HARD; |
| goto unlock_exit; |
| } |
| tce = be64_to_cpu(tce); |
| |
| ret = kvmppc_tce_validate(stt, tce); |
| if (ret != H_SUCCESS) |
| goto unlock_exit; |
| } |
| |
| for (i = 0; i < npages; ++i) { |
| /* |
| * This looks unsafe, because we validate, then regrab |
| * the TCE from userspace which could have been changed by |
| * another thread. |
| * |
| * But it actually is safe, because the relevant checks will be |
| * re-executed in the following code. If userspace tries to |
| * change this dodgily it will result in a messier failure mode |
| * but won't threaten the host. |
| */ |
| if (get_user(tce, tces + i)) { |
| ret = H_TOO_HARD; |
| goto unlock_exit; |
| } |
| tce = be64_to_cpu(tce); |
| |
| if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) { |
| ret = H_PARAMETER; |
| goto unlock_exit; |
| } |
| |
| list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { |
| ret = kvmppc_tce_iommu_map(vcpu->kvm, stt, |
| stit->tbl, entry + i, ua, |
| iommu_tce_direction(tce)); |
| |
| if (ret != H_SUCCESS) { |
| kvmppc_clear_tce(vcpu->kvm->mm, stt, stit->tbl, |
| entry + i); |
| goto unlock_exit; |
| } |
| } |
| |
| kvmppc_tce_put(stt, entry + i, tce); |
| } |
| |
| unlock_exit: |
| srcu_read_unlock(&vcpu->kvm->srcu, idx); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(kvmppc_h_put_tce_indirect); |
| |
| long kvmppc_h_stuff_tce(struct kvm_vcpu *vcpu, |
| unsigned long liobn, unsigned long ioba, |
| unsigned long tce_value, unsigned long npages) |
| { |
| struct kvmppc_spapr_tce_table *stt; |
| long i, ret; |
| struct kvmppc_spapr_tce_iommu_table *stit; |
| |
| stt = kvmppc_find_table(vcpu->kvm, liobn); |
| if (!stt) |
| return H_TOO_HARD; |
| |
| ret = kvmppc_ioba_validate(stt, ioba, npages); |
| if (ret != H_SUCCESS) |
| return ret; |
| |
| /* Check permission bits only to allow userspace poison TCE for debug */ |
| if (tce_value & (TCE_PCI_WRITE | TCE_PCI_READ)) |
| return H_PARAMETER; |
| |
| list_for_each_entry_lockless(stit, &stt->iommu_tables, next) { |
| unsigned long entry = ioba >> stt->page_shift; |
| |
| for (i = 0; i < npages; ++i) { |
| ret = kvmppc_tce_iommu_unmap(vcpu->kvm, stt, |
| stit->tbl, entry + i); |
| |
| if (ret == H_SUCCESS) |
| continue; |
| |
| if (ret == H_TOO_HARD) |
| return ret; |
| |
| WARN_ON_ONCE(1); |
| kvmppc_clear_tce(vcpu->kvm->mm, stt, stit->tbl, entry + i); |
| } |
| } |
| |
| for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift)) |
| kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce); |
| |
| long kvmppc_h_get_tce(struct kvm_vcpu *vcpu, unsigned long liobn, |
| unsigned long ioba) |
| { |
| struct kvmppc_spapr_tce_table *stt; |
| long ret; |
| unsigned long idx; |
| struct page *page; |
| u64 *tbl; |
| |
| stt = kvmppc_find_table(vcpu->kvm, liobn); |
| if (!stt) |
| return H_TOO_HARD; |
| |
| ret = kvmppc_ioba_validate(stt, ioba, 1); |
| if (ret != H_SUCCESS) |
| return ret; |
| |
| idx = (ioba >> stt->page_shift) - stt->offset; |
| page = stt->pages[idx / TCES_PER_PAGE]; |
| if (!page) { |
| kvmppc_set_gpr(vcpu, 4, 0); |
| return H_SUCCESS; |
| } |
| tbl = (u64 *)page_address(page); |
| |
| kvmppc_set_gpr(vcpu, 4, tbl[idx % TCES_PER_PAGE]); |
| |
| return H_SUCCESS; |
| } |
| EXPORT_SYMBOL_GPL(kvmppc_h_get_tce); |