qemu-patch-raspberry4/hw/s390x/s390-virtio.c
Christian Borntraeger cb927b8aee s390-virtio: Accommodate guests using virtqueues too early
Feature updates are not a synchronuous operation for the legacy
s390-virtio transport. This transport syncs the guest feature bits
(those from finalize) on the set_status hypercall. Before that qemu
thinks that features are zero, which means QEMU will misbehave, e.g.
it will not write the event index, even if the guest asks for it.

Let's detect the case where a kick happens before the driver is ready
and force sync the features.
With this workaround, it is now safe to switch to the common feature
bit handling code as used by all other transports.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
2015-05-08 10:36:02 +02:00

368 lines
10 KiB
C

/*
* QEMU S390 virtio target
*
* Copyright (c) 2009 Alexander Graf <agraf@suse.de>
* Copyright IBM Corp 2012
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* Contributions after 2012-10-29 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*
* You should have received a copy of the GNU (Lesser) General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "hw/hw.h"
#include "sysemu/block-backend.h"
#include "sysemu/blockdev.h"
#include "sysemu/sysemu.h"
#include "net/net.h"
#include "hw/boards.h"
#include "monitor/monitor.h"
#include "hw/loader.h"
#include "hw/virtio/virtio.h"
#include "hw/sysbus.h"
#include "sysemu/kvm.h"
#include "exec/address-spaces.h"
#include "hw/s390x/s390-virtio-bus.h"
#include "hw/s390x/sclp.h"
#include "hw/s390x/s390_flic.h"
#include "hw/s390x/s390-virtio.h"
#include "cpu.h"
//#define DEBUG_S390
#ifdef DEBUG_S390
#define DPRINTF(fmt, ...) \
do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) \
do { } while (0)
#endif
#define MAX_BLK_DEVS 10
#define ZIPL_FILENAME "s390-zipl.rom"
#define TYPE_S390_MACHINE "s390-machine"
#define S390_TOD_CLOCK_VALUE_MISSING 0x00
#define S390_TOD_CLOCK_VALUE_PRESENT 0x01
static VirtIOS390Bus *s390_bus;
static S390CPU **ipi_states;
S390CPU *s390_cpu_addr2state(uint16_t cpu_addr)
{
if (cpu_addr >= smp_cpus) {
return NULL;
}
return ipi_states[cpu_addr];
}
static int s390_virtio_hcall_notify(const uint64_t *args)
{
uint64_t mem = args[0];
int r = 0, i;
if (mem > ram_size) {
VirtIOS390Device *dev = s390_virtio_bus_find_vring(s390_bus, mem, &i);
if (dev) {
/*
* Older kernels will use the virtqueue before setting DRIVER_OK.
* In this case the feature bits are not yet up to date, meaning
* that several funny things can happen, e.g. the guest thinks
* EVENT_IDX is on and QEMU thinks it is off. Let's force a feature
* and status sync.
*/
if (!(dev->vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
s390_virtio_device_update_status(dev);
}
virtio_queue_notify(dev->vdev, i);
} else {
r = -EINVAL;
}
} else {
/* Early printk */
}
return r;
}
static int s390_virtio_hcall_reset(const uint64_t *args)
{
uint64_t mem = args[0];
VirtIOS390Device *dev;
dev = s390_virtio_bus_find_mem(s390_bus, mem);
if (dev == NULL) {
return -EINVAL;
}
virtio_reset(dev->vdev);
address_space_stb(&address_space_memory,
dev->dev_offs + VIRTIO_DEV_OFFS_STATUS, 0,
MEMTXATTRS_UNSPECIFIED, NULL);
s390_virtio_device_sync(dev);
s390_virtio_reset_idx(dev);
return 0;
}
static int s390_virtio_hcall_set_status(const uint64_t *args)
{
uint64_t mem = args[0];
int r = 0;
VirtIOS390Device *dev;
dev = s390_virtio_bus_find_mem(s390_bus, mem);
if (dev) {
s390_virtio_device_update_status(dev);
} else {
r = -EINVAL;
}
return r;
}
static void s390_virtio_register_hcalls(void)
{
s390_register_virtio_hypercall(KVM_S390_VIRTIO_NOTIFY,
s390_virtio_hcall_notify);
s390_register_virtio_hypercall(KVM_S390_VIRTIO_RESET,
s390_virtio_hcall_reset);
s390_register_virtio_hypercall(KVM_S390_VIRTIO_SET_STATUS,
s390_virtio_hcall_set_status);
}
void s390_init_ipl_dev(const char *kernel_filename,
const char *kernel_cmdline,
const char *initrd_filename,
const char *firmware,
bool enforce_bios)
{
DeviceState *dev;
dev = qdev_create(NULL, "s390-ipl");
if (kernel_filename) {
qdev_prop_set_string(dev, "kernel", kernel_filename);
}
if (initrd_filename) {
qdev_prop_set_string(dev, "initrd", initrd_filename);
}
qdev_prop_set_string(dev, "cmdline", kernel_cmdline);
qdev_prop_set_string(dev, "firmware", firmware);
qdev_prop_set_bit(dev, "enforce_bios", enforce_bios);
object_property_add_child(qdev_get_machine(), "s390-ipl",
OBJECT(dev), NULL);
qdev_init_nofail(dev);
}
void s390_init_cpus(const char *cpu_model, uint8_t *storage_keys)
{
int i;
if (cpu_model == NULL) {
cpu_model = "host";
}
ipi_states = g_malloc(sizeof(S390CPU *) * smp_cpus);
for (i = 0; i < smp_cpus; i++) {
S390CPU *cpu;
CPUState *cs;
cpu = cpu_s390x_init(cpu_model);
cs = CPU(cpu);
ipi_states[i] = cpu;
cs->halted = 1;
cs->exception_index = EXCP_HLT;
cpu->env.storage_keys = storage_keys;
}
}
void s390_create_virtio_net(BusState *bus, const char *name)
{
int i;
for (i = 0; i < nb_nics; i++) {
NICInfo *nd = &nd_table[i];
DeviceState *dev;
if (!nd->model) {
nd->model = g_strdup("virtio");
}
if (strcmp(nd->model, "virtio")) {
fprintf(stderr, "S390 only supports VirtIO nics\n");
exit(1);
}
dev = qdev_create(bus, name);
qdev_set_nic_properties(dev, nd);
qdev_init_nofail(dev);
}
}
void gtod_save(QEMUFile *f, void *opaque)
{
uint64_t tod_low;
uint8_t tod_high;
int r;
r = s390_get_clock(&tod_high, &tod_low);
if (r) {
fprintf(stderr, "WARNING: Unable to get guest clock for migration. "
"Error code %d. Guest clock will not be migrated "
"which could cause the guest to hang.\n", r);
qemu_put_byte(f, S390_TOD_CLOCK_VALUE_MISSING);
return;
}
qemu_put_byte(f, S390_TOD_CLOCK_VALUE_PRESENT);
qemu_put_byte(f, tod_high);
qemu_put_be64(f, tod_low);
}
int gtod_load(QEMUFile *f, void *opaque, int version_id)
{
uint64_t tod_low;
uint8_t tod_high;
int r;
if (qemu_get_byte(f) == S390_TOD_CLOCK_VALUE_MISSING) {
fprintf(stderr, "WARNING: Guest clock was not migrated. This could "
"cause the guest to hang.\n");
return 0;
}
tod_high = qemu_get_byte(f);
tod_low = qemu_get_be64(f);
r = s390_set_clock(&tod_high, &tod_low);
if (r) {
fprintf(stderr, "WARNING: Unable to set guest clock value. "
"s390_get_clock returned error %d. This could cause "
"the guest to hang.\n", r);
}
return 0;
}
/* PC hardware initialisation */
static void s390_init(MachineState *machine)
{
ram_addr_t my_ram_size = machine->ram_size;
MemoryRegion *sysmem = get_system_memory();
MemoryRegion *ram = g_new(MemoryRegion, 1);
int increment_size = 20;
uint8_t *storage_keys;
void *virtio_region;
hwaddr virtio_region_len;
hwaddr virtio_region_start;
/*
* The storage increment size is a multiple of 1M and is a power of 2.
* The number of storage increments must be MAX_STORAGE_INCREMENTS or
* fewer.
*/
while ((my_ram_size >> increment_size) > MAX_STORAGE_INCREMENTS) {
increment_size++;
}
my_ram_size = my_ram_size >> increment_size << increment_size;
/* let's propagate the changed ram size into the global variable. */
ram_size = my_ram_size;
/* get a BUS */
s390_bus = s390_virtio_bus_init(&my_ram_size);
s390_sclp_init();
s390_init_ipl_dev(machine->kernel_filename, machine->kernel_cmdline,
machine->initrd_filename, ZIPL_FILENAME, false);
s390_flic_init();
/* register hypercalls */
s390_virtio_register_hcalls();
/* allocate RAM */
memory_region_init_ram(ram, NULL, "s390.ram", my_ram_size, &error_abort);
vmstate_register_ram_global(ram);
memory_region_add_subregion(sysmem, 0, ram);
/* clear virtio region */
virtio_region_len = my_ram_size - ram_size;
virtio_region_start = ram_size;
virtio_region = cpu_physical_memory_map(virtio_region_start,
&virtio_region_len, true);
memset(virtio_region, 0, virtio_region_len);
cpu_physical_memory_unmap(virtio_region, virtio_region_len, 1,
virtio_region_len);
/* allocate storage keys */
storage_keys = g_malloc0(my_ram_size / TARGET_PAGE_SIZE);
/* init CPUs */
s390_init_cpus(machine->cpu_model, storage_keys);
/* Create VirtIO network adapters */
s390_create_virtio_net((BusState *)s390_bus, "virtio-net-s390");
/* Register savevm handler for guest TOD clock */
register_savevm(NULL, "todclock", 0, 1, gtod_save, gtod_load, NULL);
}
void s390_nmi(NMIState *n, int cpu_index, Error **errp)
{
CPUState *cs = qemu_get_cpu(cpu_index);
if (s390_cpu_restart(S390_CPU(cs))) {
error_set(errp, QERR_UNSUPPORTED);
}
}
static void s390_machine_class_init(ObjectClass *oc, void *data)
{
MachineClass *mc = MACHINE_CLASS(oc);
NMIClass *nc = NMI_CLASS(oc);
mc->name = "s390-virtio";
mc->alias = "s390";
mc->desc = "VirtIO based S390 machine";
mc->init = s390_init;
mc->block_default_type = IF_VIRTIO;
mc->max_cpus = 255;
mc->no_serial = 1;
mc->no_parallel = 1;
mc->use_virtcon = 1;
mc->no_floppy = 1;
mc->no_cdrom = 1;
mc->no_sdcard = 1;
mc->is_default = 1;
nc->nmi_monitor_handler = s390_nmi;
}
static const TypeInfo s390_machine_info = {
.name = TYPE_S390_MACHINE,
.parent = TYPE_MACHINE,
.class_init = s390_machine_class_init,
.interfaces = (InterfaceInfo[]) {
{ TYPE_NMI },
{ }
},
};
static void s390_machine_register_types(void)
{
type_register_static(&s390_machine_info);
}
type_init(s390_machine_register_types)