qemu-cr16/hw/i386/isapc.c
Mark Cave-Ayland 329e36af94 hw/i386/isapc.c: warn rather than reject modern x86 CPU models
Commit e1e2909f8e ("hw/i386/pc_piix.c: restrict isapc machine to 32-bit CPUs")
restricted the isapc machine to 32-bit CPUs, but subsequent concern has been
expressed as to the effect this could have on users.

The outcome of the latest discussion is that we should exercise more caution
and follow the official deprecation route, so instead of rejecting modern x86
CPUs issue a deprecation warning but allow the user to continue.

Signed-off-by: Mark Cave-Ayland <mark.caveayland@nutanix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20251023142926.964718-2-mark.caveayland@nutanix.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-10-28 14:50:07 +01:00

178 lines
5.4 KiB
C

/*
* QEMU PC System Emulator
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* SPDX-License-Identifier: MIT
*/
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "qemu/error-report.h"
#include "hw/char/parallel-isa.h"
#include "hw/dma/i8257.h"
#include "hw/i386/pc.h"
#include "hw/ide/isa.h"
#include "hw/ide/ide-bus.h"
#include "system/kvm.h"
#include "hw/i386/kvm/clock.h"
#include "hw/xen/xen-x86.h"
#include "system/xen.h"
#include "hw/rtc/mc146818rtc.h"
#include "target/i386/cpu.h"
static const int ide_iobase[MAX_IDE_BUS] = { 0x1f0, 0x170 };
static const int ide_iobase2[MAX_IDE_BUS] = { 0x3f6, 0x376 };
static const int ide_irq[MAX_IDE_BUS] = { 14, 15 };
static void pc_init_isa(MachineState *machine)
{
PCMachineState *pcms = PC_MACHINE(machine);
PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(pcms);
X86MachineState *x86ms = X86_MACHINE(machine);
MemoryRegion *system_memory = get_system_memory();
MemoryRegion *system_io = get_system_io();
ISABus *isa_bus;
uint32_t irq;
GSIState *gsi_state;
MemoryRegion *ram_memory;
DriveInfo *hd[MAX_IDE_BUS * MAX_IDE_DEVS];
int i;
bool valid_cpu_type = false;
static const char * const valid_cpu_types[] = {
X86_CPU_TYPE_NAME("486"),
X86_CPU_TYPE_NAME("athlon"),
X86_CPU_TYPE_NAME("kvm32"),
X86_CPU_TYPE_NAME("pentium"),
X86_CPU_TYPE_NAME("pentium2"),
X86_CPU_TYPE_NAME("pentium3"),
X86_CPU_TYPE_NAME("qemu32"),
};
/*
* The isapc machine is supposed to represent a legacy ISA-only PC with a
* 32-bit processor. For historical reasons the machine can still accept
* almost any valid processor, but this is now deprecated in 10.2. Emit
* a warning if anyone tries to use a deprecated CPU.
*/
for (i = 0; i < ARRAY_SIZE(valid_cpu_types); i++) {
if (!strcmp(machine->cpu_type, valid_cpu_types[i])) {
valid_cpu_type = true;
}
}
if (!valid_cpu_type) {
warn_report("cpu type %s is deprecated for isapc machine", machine->cpu_type);
}
if (machine->ram_size > 3.5 * GiB) {
error_report("Too much memory for this machine: %" PRId64 " MiB, "
"maximum 3584 MiB", machine->ram_size / MiB);
exit(1);
}
/*
* There is no RAM split for the isapc machine
*/
if (xen_enabled()) {
xen_hvm_init_pc(pcms, &ram_memory);
} else {
ram_memory = machine->ram;
pcms->max_ram_below_4g = 3.5 * GiB;
x86ms->above_4g_mem_size = 0;
x86ms->below_4g_mem_size = machine->ram_size;
}
x86_cpus_init(x86ms, pcmc->default_cpu_version);
if (kvm_enabled()) {
kvmclock_create(pcmc->kvmclock_create_always);
}
/* allocate ram and load rom/bios */
if (!xen_enabled()) {
pc_memory_init(pcms, system_memory, system_memory, 0);
} else {
assert(machine->ram_size == x86ms->below_4g_mem_size +
x86ms->above_4g_mem_size);
if (machine->kernel_filename != NULL) {
/* For xen HVM direct kernel boot, load linux here */
xen_load_linux(pcms);
}
}
gsi_state = pc_gsi_create(&x86ms->gsi, false);
isa_bus = isa_bus_new(NULL, system_memory, system_io,
&error_abort);
isa_bus_register_input_irqs(isa_bus, x86ms->gsi);
x86ms->rtc = isa_new(TYPE_MC146818_RTC);
qdev_prop_set_int32(DEVICE(x86ms->rtc), "base_year", 2000);
isa_realize_and_unref(x86ms->rtc, isa_bus, &error_fatal);
irq = object_property_get_uint(OBJECT(x86ms->rtc), "irq",
&error_fatal);
isa_connect_gpio_out(ISA_DEVICE(x86ms->rtc), 0, irq);
i8257_dma_init(OBJECT(machine), isa_bus, 0);
pcms->hpet_enabled = false;
if (x86ms->pic == ON_OFF_AUTO_ON || x86ms->pic == ON_OFF_AUTO_AUTO) {
pc_i8259_create(isa_bus, gsi_state->i8259_irq);
}
if (tcg_enabled()) {
x86_register_ferr_irq(x86ms->gsi[13]);
}
pc_vga_init(isa_bus, NULL);
/* init basic PC hardware */
pc_basic_device_init(pcms, isa_bus, x86ms->gsi, x86ms->rtc,
!MACHINE_CLASS(pcmc)->no_floppy, 0x4);
pc_nic_init(pcmc, isa_bus, NULL);
ide_drive_get(hd, ARRAY_SIZE(hd));
for (i = 0; i < MAX_IDE_BUS; i++) {
ISADevice *dev;
char busname[] = "ide.0";
dev = isa_ide_init(isa_bus, ide_iobase[i], ide_iobase2[i],
ide_irq[i],
hd[MAX_IDE_DEVS * i], hd[MAX_IDE_DEVS * i + 1]);
/*
* The ide bus name is ide.0 for the first bus and ide.1 for the
* second one.
*/
busname[4] = '0' + i;
pcms->idebus[i] = qdev_get_child_bus(DEVICE(dev), busname);
}
}
static void isapc_machine_options(MachineClass *m)
{
PCMachineClass *pcmc = PC_MACHINE_CLASS(m);
m->desc = "ISA-only PC";
m->max_cpus = 1;
m->option_rom_has_mr = true;
m->rom_file_has_mr = false;
pcmc->pci_enabled = false;
pcmc->has_acpi_build = false;
pcmc->smbios_defaults = false;
pcmc->gigabyte_align = false;
pcmc->smbios_legacy_mode = true;
pcmc->has_reserved_memory = false;
m->default_nic = "ne2k_isa";
m->default_cpu_type = X86_CPU_TYPE_NAME("486");
m->no_floppy = !module_object_class_by_name(TYPE_ISA_FDC);
m->no_parallel = !module_object_class_by_name(TYPE_ISA_PARALLEL);
}
DEFINE_PC_MACHINE(isapc, "isapc", pc_init_isa,
isapc_machine_options);