--- /dev/null
+/*
+ * fake_mem.c
+ *
+ * Copyright (C) 2015 FUJITSU LIMITED
+ * Author: Taku Izumi <izumi.taku@jp.fujitsu.com>
+ *
+ * This code introduces new boot option named "efi_fake_mem"
+ * By specifying this parameter, you can add arbitrary attribute to
+ * specific memory range by updating original (firmware provided) EFI
+ * memmap.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/>.
+ *
+ * The full GNU General Public License is included in this distribution in
+ * the file called "COPYING".
+ */
+
+#include <linux/kernel.h>
+#include <linux/efi.h>
+#include <linux/init.h>
+#include <linux/memblock.h>
+#include <linux/types.h>
+#include <linux/sort.h>
+#include <asm/efi.h>
+
+#define EFI_MAX_FAKEMEM CONFIG_EFI_MAX_FAKE_MEM
+
+struct fake_mem {
+ struct range range;
+ u64 attribute;
+};
+static struct fake_mem fake_mems[EFI_MAX_FAKEMEM];
+static int nr_fake_mem;
+
+static int __init cmp_fake_mem(const void *x1, const void *x2)
+{
+ const struct fake_mem *m1 = x1;
+ const struct fake_mem *m2 = x2;
+
+ if (m1->range.start < m2->range.start)
+ return -1;
+ if (m1->range.start > m2->range.start)
+ return 1;
+ return 0;
+}
+
+void __init efi_fake_memmap(void)
+{
+ u64 start, end, m_start, m_end, m_attr;
+ int new_nr_map = memmap.nr_map;
+ efi_memory_desc_t *md;
+ phys_addr_t new_memmap_phy;
+ void *new_memmap;
+ void *old, *new;
+ int i;
+
+ if (!nr_fake_mem || !efi_enabled(EFI_MEMMAP))
+ return;
+
+ /* count up the number of EFI memory descriptor */
+ for (old = memmap.map; old < memmap.map_end; old += memmap.desc_size) {
+ md = old;
+ start = md->phys_addr;
+ end = start + (md->num_pages << EFI_PAGE_SHIFT) - 1;
+
+ for (i = 0; i < nr_fake_mem; i++) {
+ /* modifying range */
+ m_start = fake_mems[i].range.start;
+ m_end = fake_mems[i].range.end;
+
+ if (m_start <= start) {
+ /* split into 2 parts */
+ if (start < m_end && m_end < end)
+ new_nr_map++;
+ }
+ if (start < m_start && m_start < end) {
+ /* split into 3 parts */
+ if (m_end < end)
+ new_nr_map += 2;
+ /* split into 2 parts */
+ if (end <= m_end)
+ new_nr_map++;
+ }
+ }
+ }
+
+ /* allocate memory for new EFI memmap */
+ new_memmap_phy = memblock_alloc(memmap.desc_size * new_nr_map,
+ PAGE_SIZE);
+ if (!new_memmap_phy)
+ return;
+
+ /* create new EFI memmap */
+ new_memmap = early_memremap(new_memmap_phy,
+ memmap.desc_size * new_nr_map);
+ if (!new_memmap) {
+ memblock_free(new_memmap_phy, memmap.desc_size * new_nr_map);
+ return;
+ }
+
+ for (old = memmap.map, new = new_memmap;
+ old < memmap.map_end;
+ old += memmap.desc_size, new += memmap.desc_size) {
+
+ /* copy original EFI memory descriptor */
+ memcpy(new, old, memmap.desc_size);
+ md = new;
+ start = md->phys_addr;
+ end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT) - 1;
+
+ for (i = 0; i < nr_fake_mem; i++) {
+ /* modifying range */
+ m_start = fake_mems[i].range.start;
+ m_end = fake_mems[i].range.end;
+ m_attr = fake_mems[i].attribute;
+
+ if (m_start <= start && end <= m_end)
+ md->attribute |= m_attr;
+
+ if (m_start <= start &&
+ (start < m_end && m_end < end)) {
+ /* first part */
+ md->attribute |= m_attr;
+ md->num_pages = (m_end - md->phys_addr + 1) >>
+ EFI_PAGE_SHIFT;
+ /* latter part */
+ new += memmap.desc_size;
+ memcpy(new, old, memmap.desc_size);
+ md = new;
+ md->phys_addr = m_end + 1;
+ md->num_pages = (end - md->phys_addr + 1) >>
+ EFI_PAGE_SHIFT;
+ }
+
+ if ((start < m_start && m_start < end) && m_end < end) {
+ /* first part */
+ md->num_pages = (m_start - md->phys_addr) >>
+ EFI_PAGE_SHIFT;
+ /* middle part */
+ new += memmap.desc_size;
+ memcpy(new, old, memmap.desc_size);
+ md = new;
+ md->attribute |= m_attr;
+ md->phys_addr = m_start;
+ md->num_pages = (m_end - m_start + 1) >>
+ EFI_PAGE_SHIFT;
+ /* last part */
+ new += memmap.desc_size;
+ memcpy(new, old, memmap.desc_size);
+ md = new;
+ md->phys_addr = m_end + 1;
+ md->num_pages = (end - m_end) >>
+ EFI_PAGE_SHIFT;
+ }
+
+ if ((start < m_start && m_start < end) &&
+ (end <= m_end)) {
+ /* first part */
+ md->num_pages = (m_start - md->phys_addr) >>
+ EFI_PAGE_SHIFT;
+ /* latter part */
+ new += memmap.desc_size;
+ memcpy(new, old, memmap.desc_size);
+ md = new;
+ md->phys_addr = m_start;
+ md->num_pages = (end - md->phys_addr + 1) >>
+ EFI_PAGE_SHIFT;
+ md->attribute |= m_attr;
+ }
+ }
+ }
+
+ /* swap into new EFI memmap */
+ efi_unmap_memmap();
+ memmap.map = new_memmap;
+ memmap.phys_map = new_memmap_phy;
+ memmap.nr_map = new_nr_map;
+ memmap.map_end = memmap.map + memmap.nr_map * memmap.desc_size;
+ set_bit(EFI_MEMMAP, &efi.flags);
+
+ /* print new EFI memmap */
+ efi_print_memmap();
+}
+
+static int __init setup_fake_mem(char *p)
+{
+ u64 start = 0, mem_size = 0, attribute = 0;
+ int i;
+
+ if (!p)
+ return -EINVAL;
+
+ while (*p != '\0') {
+ mem_size = memparse(p, &p);
+ if (*p == '@')
+ start = memparse(p+1, &p);
+ else
+ break;
+
+ if (*p == ':')
+ attribute = simple_strtoull(p+1, &p, 0);
+ else
+ break;
+
+ if (nr_fake_mem >= EFI_MAX_FAKEMEM)
+ break;
+
+ fake_mems[nr_fake_mem].range.start = start;
+ fake_mems[nr_fake_mem].range.end = start + mem_size - 1;
+ fake_mems[nr_fake_mem].attribute = attribute;
+ nr_fake_mem++;
+
+ if (*p == ',')
+ p++;
+ }
+
+ sort(fake_mems, nr_fake_mem, sizeof(struct fake_mem),
+ cmp_fake_mem, NULL);
+
+ for (i = 0; i < nr_fake_mem; i++)
+ pr_info("efi_fake_mem: add attr=0x%016llx to [mem 0x%016llx-0x%016llx]",
+ fake_mems[i].attribute, fake_mems[i].range.start,
+ fake_mems[i].range.end);
+
+ return *p == '\0' ? 0 : -EINVAL;
+}
+
+early_param("efi_fake_mem", setup_fake_mem);
Code Review / kvmfornfv.git / blobdiff