/******************************************************************************
 * arch/x86/hvm/grant_table.c
 *
 * Grant table interfaces for HVM guests
 *
 * Copyright (C) 2017 Wei Liu <wei.liu2@citrix.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#include <xen/types.h>

#include <public/grant_table.h>

#include <asm/p2m.h>

int create_grant_p2m_mapping(uint64_t addr, mfn_t frame,
                             unsigned int flags,
                             unsigned int cache_flags)
{
    p2m_type_t p2mt;
    int rc;

    if ( cache_flags || (flags & ~GNTMAP_readonly) != GNTMAP_host_map )
        return GNTST_general_error;

    if ( flags & GNTMAP_readonly )
        p2mt = p2m_grant_map_ro;
    else
        p2mt = p2m_grant_map_rw;
    rc = guest_physmap_add_entry(current->domain,
                                 _gfn(addr >> PAGE_SHIFT),
                                 frame, PAGE_ORDER_4K, p2mt);
    if ( rc )
        return GNTST_general_error;
    else
        return GNTST_okay;
}

int replace_grant_p2m_mapping(uint64_t addr, mfn_t frame,
                              uint64_t new_addr, unsigned int flags)
{
    unsigned long gfn = (unsigned long)(addr >> PAGE_SHIFT);
    p2m_type_t type;
    mfn_t old_mfn;
    struct domain *d = current->domain;

    if ( new_addr != 0 || (flags & GNTMAP_contains_pte) )
        return GNTST_general_error;

    old_mfn = get_gfn_query(d, gfn, &type);
    if ( !p2m_is_grant(type) || !mfn_eq(old_mfn, frame) )
    {
        put_gfn(d, gfn);
        gdprintk(XENLOG_WARNING,
                 "old mapping invalid (type %d, mfn %" PRI_mfn ", frame %"PRI_mfn")\n",
                 type, mfn_x(old_mfn), mfn_x(frame));
        return GNTST_general_error;
    }
    if ( guest_physmap_remove_page(d, _gfn(gfn), frame, PAGE_ORDER_4K) )
    {
        put_gfn(d, gfn);
        return GNTST_general_error;
    }

    put_gfn(d, gfn);
    return GNTST_okay;
}

/*
 * Local variables:
 * mode: C
 * c-file-style: "BSD"
 * c-basic-offset: 4
 * tab-width: 4
 * indent-tabs-mode: nil
 * End:
 */
