cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
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page-vary-common.c (1668B)

      1/*
      2 * Variable page size handling -- target independent part.
      3 *
      4 *  Copyright (c) 2003 Fabrice Bellard
      5 *
      6 * This library is free software; you can redistribute it and/or
      7 * modify it under the terms of the GNU Lesser General Public
      8 * License as published by the Free Software Foundation; either
      9 * version 2.1 of the License, or (at your option) any later version.
     10 *
     11 * This library is distributed in the hope that it will be useful,
     12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
     13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     14 * Lesser General Public License for more details.
     15 *
     16 * You should have received a copy of the GNU Lesser General Public
     17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
     18 */
     19
     20#define IN_PAGE_VARY 1
     21
     22#include "qemu/osdep.h"
     23#include "qemu-common.h"
     24#include "exec/page-vary.h"
     25
     26/* WARNING: This file must *not* be complied with -flto. */
     27
     28TargetPageBits target_page;
     29
     30bool set_preferred_target_page_bits_common(int bits)
     31{
     32    /*
     33     * The target page size is the lowest common denominator for all
     34     * the CPUs in the system, so we can only make it smaller, never
     35     * larger. And we can't make it smaller once we've committed to
     36     * a particular size.
     37     */
     38    if (target_page.bits == 0 || target_page.bits > bits) {
     39        if (target_page.decided) {
     40            return false;
     41        }
     42        target_page.bits = bits;
     43    }
     44    return true;
     45}
     46
     47void finalize_target_page_bits_common(int min)
     48{
     49    if (target_page.bits == 0) {
     50        target_page.bits = min;
     51    }
     52    target_page.mask = -1ull << target_page.bits;
     53    target_page.decided = true;
     54}