linux/arch/powerpc/kvm/book3s_64_vio.c

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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright 2010 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
* Copyright 2011 David Gibson, IBM Corporation <dwg@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/hugetlb.h>
#include <linux/list.h>
#include <linux/anon_inodes.h>
#include <asm/tlbflush.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
#include <asm/mmu-hash64.h>
#include <asm/hvcall.h>
#include <asm/synch.h>
#include <asm/ppc-opcode.h>
#include <asm/kvm_host.h>
#include <asm/udbg.h>
#define TCES_PER_PAGE (PAGE_SIZE / sizeof(u64))
static unsigned long kvmppc_tce_pages(unsigned long window_size)
{
return ALIGN((window_size >> SPAPR_TCE_SHIFT)
* 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 long kvmppc_account_memlimit(unsigned long stt_pages, bool inc)
{
long ret = 0;
if (!current || !current->mm)
return ret; /* process exited */
down_write(&current->mm->mmap_sem);
if (inc) {
unsigned long locked, lock_limit;
locked = current->mm->locked_vm + stt_pages;
lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
if (locked > lock_limit && !capable(CAP_IPC_LOCK))
ret = -ENOMEM;
else
current->mm->locked_vm += stt_pages;
} else {
if (WARN_ON_ONCE(stt_pages > current->mm->locked_vm))
stt_pages = current->mm->locked_vm;
current->mm->locked_vm -= stt_pages;
}
pr_debug("[%d] RLIMIT_MEMLOCK KVM %c%ld %ld/%ld%s\n", current->pid,
inc ? '+' : '-',
stt_pages << PAGE_SHIFT,
current->mm->locked_vm << PAGE_SHIFT,
rlimit(RLIMIT_MEMLOCK),
ret ? " - exceeded" : "");
up_write(&current->mm->mmap_sem);
return ret;
}
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);
int i;
unsigned long npages = kvmppc_tce_pages(stt->window_size);
for (i = 0; i < npages; i++)
__free_page(stt->pages[i]);
kfree(stt);
}
static int kvm_spapr_tce_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct kvmppc_spapr_tce_table *stt = vma->vm_file->private_data;
struct page *page;
if (vmf->pgoff >= kvmppc_tce_pages(stt->window_size))
return VM_FAULT_SIGBUS;
page = stt->pages[vmf->pgoff];
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;
list_del_rcu(&stt->list);
kvm_put_kvm(stt->kvm);
kvmppc_account_memlimit(
kvmppc_stt_pages(kvmppc_tce_pages(stt->window_size)), false);
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 *args)
{
struct kvmppc_spapr_tce_table *stt = NULL;
unsigned long npages;
int ret = -ENOMEM;
int i;
/* Check this LIOBN hasn't been previously allocated */
list_for_each_entry(stt, &kvm->arch.spapr_tce_tables, list) {
if (stt->liobn == args->liobn)
return -EBUSY;
}
npages = kvmppc_tce_pages(args->window_size);
ret = kvmppc_account_memlimit(kvmppc_stt_pages(npages), true);
if (ret) {
stt = NULL;
goto fail;
}
stt = kzalloc(sizeof(*stt) + npages * sizeof(struct page *),
GFP_KERNEL);
if (!stt)
goto fail;
stt->liobn = args->liobn;
stt->window_size = args->window_size;
stt->kvm = kvm;
for (i = 0; i < npages; i++) {
stt->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
if (!stt->pages[i])
goto fail;
}
kvm_get_kvm(kvm);
mutex_lock(&kvm->lock);
list_add_rcu(&stt->list, &kvm->arch.spapr_tce_tables);
mutex_unlock(&kvm->lock);
return anon_inode_getfd("kvm-spapr-tce", &kvm_spapr_tce_fops,
stt, O_RDWR | O_CLOEXEC);
fail:
if (stt) {
for (i = 0; i < npages; i++)
if (stt->pages[i])
__free_page(stt->pages[i]);
kfree(stt);
}
return ret;
}