qemu/hw/i386/e820_memory_layout.c
Ani Sinha 4ad08e8a57 hw/i386/e820: remove legacy reserved entries for e820
e820 reserved entries were used before the dynamic entries with fw config files
were intoduced. Please see the following change:
7d67110f2d9a6("pc: add etc/e820 fw_cfg file")

Identical support was introduced into seabios as well with the following commit:
ce39bd4031820 ("Add support for etc/e820 fw_cfg file")

Both the above commits are now quite old. QEMU machines 1.7 and newer no longer
use the reserved entries. Seabios uses fw config files and
dynamic e820 entries by default and only falls back to using reserved entries
when it has to work with old qemu (versions earlier than 1.7). Please see
functions qemu_cfg_e820() and qemu_early_e820(). It is safe to remove legacy
FW_CFG_E820_TABLE and associated code now as QEMU 7.0 has deprecated i440fx
machines 1.7 and older. It would be incredibly rare to run the latest qemu
version with a very old version of seabios that did not support fw config files
for e820.

As far as I could see, edk2/ovfm never supported reserved entries and uses fw
config files from the beginning. So there should be no incompatibilities with
ovfm as well.

CC: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Ani Sinha <ani@anisinha.ca>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Message-Id: <20220831045311.33083-1-ani@anisinha.ca>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2022-11-02 06:56:31 -04:00

42 lines
1 KiB
C

/*
* QEMU BIOS e820 routines
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* SPDX-License-Identifier: MIT
*/
#include "qemu/osdep.h"
#include "qemu/bswap.h"
#include "e820_memory_layout.h"
static size_t e820_entries;
struct e820_entry *e820_table;
int e820_add_entry(uint64_t address, uint64_t length, uint32_t type)
{
/* new "etc/e820" file -- include ram and reserved entries */
e820_table = g_renew(struct e820_entry, e820_table, e820_entries + 1);
e820_table[e820_entries].address = cpu_to_le64(address);
e820_table[e820_entries].length = cpu_to_le64(length);
e820_table[e820_entries].type = cpu_to_le32(type);
e820_entries++;
return e820_entries;
}
int e820_get_num_entries(void)
{
return e820_entries;
}
bool e820_get_entry(int idx, uint32_t type, uint64_t *address, uint64_t *length)
{
if (idx < e820_entries && e820_table[idx].type == cpu_to_le32(type)) {
*address = le64_to_cpu(e820_table[idx].address);
*length = le64_to_cpu(e820_table[idx].length);
return true;
}
return false;
}