platform.c

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/*
 * Bareflank Hypervisor
 *
 * Copyright (C) 2015 Assured Information Security, Inc.
 * Author: Rian Quinn        <quinnr@ainfosec.com>
 * Author: Brendan Kerrigan  <kerriganb@ainfosec.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <debug.h>
#include <platform.h>
#include <bfelf_loader.h>

#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/version.h>
#include <linux/cpumask.h>
#include <linux/sched.h>
#include <linux/kallsyms.h>

#include <asm/tlbflush.h>

typedef long (*set_affinity_fn)(pid_t, const struct cpumask *);
set_affinity_fn set_cpu_affinity = 0;

void *
platform_alloc_rw(uint64_t len)
{
    void *addr = NULL;

    if (len == 0)
    {
        ALERT("platform_alloc_rw: invalid length\n");
        return addr;
    }

    addr = vmalloc(len);

    if (addr == NULL)
        ALERT("platform_alloc_rw: failed to vmalloc mem: %lld\n", len);

    return addr;
}

void *
platform_alloc_rwe(uint64_t len)
{
    void *addr = NULL;

    if (len == 0)
    {
        ALERT("platform_alloc_rwe: invalid length\n");
        return addr;
    }

    addr = __vmalloc(len, GFP_KERNEL, PAGE_KERNEL_EXEC);

    if (addr == NULL)
        ALERT("platform_alloc_rwe: failed to vmalloc executable mem: %lld\n", len);

    return addr;
}

void
platform_free_rw(void *addr, uint64_t len)
{
    (void) len;

    if (addr == NULL)
    {
        ALERT("platform_free_rw: invalid address %p\n", addr);
        return;
    }

    vfree(addr);
}

void
platform_free_rwe(void *addr, uint64_t len)
{
    (void) len;

    if (addr == NULL)
    {
        ALERT("platform_free_rwe: invalid address %p\n", addr);
        return;
    }

    vfree(addr);
}

void *
platform_virt_to_phys(void *virt)
{
    if (is_vmalloc_addr(virt))
        return (void *)page_to_phys(vmalloc_to_page(virt));
    else
        return (void *)virt_to_phys(virt);
}

void
platform_memset(void *ptr, char value, uint64_t num)
{
    if (!ptr)
        return;

    memset(ptr, value, num);
}

void
platform_memcpy(void *dst, const void *src, uint64_t num)
{
    if (!dst || !src)
        return;

    memcpy(dst, src, num);
}

void
platform_start(void)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0)
    cr4_init_shadow();
#endif
}

void
platform_stop(void)
{
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,0,0)
    cr4_init_shadow();
#endif
}

int64_t
platform_num_cpus(void)
{
    int64_t num_cpus = num_online_cpus();

    if (num_cpus < 0)
        return 0;

    return num_cpus;
}

int64_t
platform_set_affinity(int64_t affinity)
{
    if (!set_cpu_affinity)
    {
        set_cpu_affinity = (set_affinity_fn)kallsyms_lookup_name("sched_setaffinity");
        if (set_cpu_affinity == NULL)
        {
            ALERT("Failed to locate sched_setaffinity\n");
            return BF_ERROR_UNKNOWN;
        }
    }

    if (set_cpu_affinity(current->pid, cpumask_of(affinity)) != 0)
        return BF_ERROR_UNKNOWN;

    return affinity;
}

void
platform_restore_affinity(int64_t affinity)
{
    (void) affinity;
}