diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_64_vio.c')
-rw-r--r-- | arch/powerpc/kvm/book3s_64_vio.c | 756 |
1 files changed, 756 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c new file mode 100644 index 000000000..c640053ab --- /dev/null +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -0,0 +1,756 @@ +// 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 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); +} + +extern 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(); +} + +extern 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, +}; + +long 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, size = args->size; + 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(size); + ret = account_locked_vm(mm, kvmppc_stt_pages(npages), true); + if (ret) + return ret; + + ret = -ENOMEM; + stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *), + GFP_KERNEL); + if (!stt) + goto fail_acct; + + stt->liobn = args->liobn; + stt->page_shift = args->page_shift; + stt->offset = args->offset; + stt->size = 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 = search_memslots(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); |