linux-imx

/*

 * kvm asynchronous fault support

 *

 * Copyright 2010 Red Hat, Inc.

 *

 * Author:

 *      Gleb Natapov <gleb@redhat.com>

 *

 * This file is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License

 * 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,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.

 */

​

#include <linux/kvm_host.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/mmu_context.h>

#include <linux/sched/mm.h>

​

#include "async_pf.h"

#include <trace/events/kvm.h>

​

static inline void kvm_async_page_present_sync(struct kvm_vcpu *vcpu,

                           struct kvm_async_pf *work)

{

#ifdef CONFIG_KVM_ASYNC_PF_SYNC

    kvm_arch_async_page_present(vcpu, work);

#endif

}

static inline void kvm_async_page_present_async(struct kvm_vcpu *vcpu,

                        struct kvm_async_pf *work)

{

#ifndef CONFIG_KVM_ASYNC_PF_SYNC

    kvm_arch_async_page_present(vcpu, work);

#endif

}

​

static struct kmem_cache *async_pf_cache;

​

int kvm_async_pf_init(void)

{

    async_pf_cache = KMEM_CACHE(kvm_async_pf, 0);

​

    if (!async_pf_cache)

        return -ENOMEM;

​

    return 0;

}

​

void kvm_async_pf_deinit(void)

{

    kmem_cache_destroy(async_pf_cache);

    async_pf_cache = NULL;

}

​

void kvm_async_pf_vcpu_init(struct kvm_vcpu *vcpu)

{

    INIT_LIST_HEAD(&vcpu->async_pf.done);

    INIT_LIST_HEAD(&vcpu->async_pf.queue);

    spin_lock_init(&vcpu->async_pf.lock);

}

​

static void async_pf_execute(struct work_struct *work)

{

    struct kvm_async_pf *apf =

        container_of(work, struct kvm_async_pf, work);

    struct mm_struct *mm = apf->mm;

    struct kvm_vcpu *vcpu = apf->vcpu;

    unsigned long addr = apf->addr;

    gva_t gva = apf->gva;

    int locked = 1;

​

    might_sleep();

​

    /*

     * This work is run asynchronously to the task which owns

     * mm and might be done in another context, so we must

     * access remotely.

     */

    down_read(&mm->mmap_sem);

    get_user_pages_remote(NULL, mm, addr, 1, FOLL_WRITE, NULL, NULL,

            &locked);

    if (locked)