blob: 6365087f3160243c1c058c280ef7b14dc6506f33 [file] [log] [blame]
// 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 = __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 iommu_table *tbl,
unsigned long entry)
{
unsigned long hpa = 0;
enum dma_data_direction dir = DMA_NONE;
iommu_tce_xchg_no_kill(mm, tbl, entry, &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;
}
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;
}
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);
iommu_tce_kill(stit->tbl, entry, 1);
if (ret != H_SUCCESS) {
kvmppc_clear_tce(vcpu->kvm->mm, 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 invalidate_exit;
}
tce = be64_to_cpu(tce);
if (kvmppc_tce_to_ua(vcpu->kvm, tce, &ua)) {
ret = H_PARAMETER;
goto invalidate_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, stit->tbl,
entry);
goto invalidate_exit;
}
}
kvmppc_tce_put(stt, entry + i, tce);
}
invalidate_exit:
list_for_each_entry_lockless(stit, &stt->iommu_tables, next)
iommu_tce_kill(stit->tbl, entry, npages);
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)
goto invalidate_exit;
WARN_ON_ONCE(1);
kvmppc_clear_tce(vcpu->kvm->mm, stit->tbl, entry);
}
}
for (i = 0; i < npages; ++i, ioba += (1ULL << stt->page_shift))
kvmppc_tce_put(stt, ioba >> stt->page_shift, tce_value);
invalidate_exit:
list_for_each_entry_lockless(stit, &stt->iommu_tables, next)
iommu_tce_kill(stit->tbl, ioba >> stt->page_shift, npages);
return ret;
}
EXPORT_SYMBOL_GPL(kvmppc_h_stuff_tce);