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xemu/hw/ivshmem.c
Hongyong Zang ff51a738cf ivshmem: fix PCI BAR2 registration during initialization 
Ivshmem cannot work, and the command lspci cannot show ivshmem BAR2 in the guest.
As for pci_register_bar(), parameter MemoryRegion should be s->bar instead of s->ivshmem.

Reviewed-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Hongyong Zang <zanghongyong@huawei.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2011-11-21 15:05:59 -06:00

790 lines
22 KiB
C
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/*
* Inter-VM Shared Memory PCI device.
*
* Author:
* Cam Macdonell <cam@cs.ualberta.ca>
*
* Based On: cirrus_vga.c
* Copyright (c) 2004 Fabrice Bellard
* Copyright (c) 2004 Makoto Suzuki (suzu)
*
* and rtl8139.c
* Copyright (c) 2006 Igor Kovalenko
*
* This code is licensed under the GNU GPL v2.
*/
#include "hw.h"
#include "pc.h"
#include "pci.h"
#include "msix.h"
#include "kvm.h"
#include "migration.h"
#include "qerror.h"
#include <sys/mman.h>
#include <sys/types.h>
#define IVSHMEM_IOEVENTFD 0
#define IVSHMEM_MSI 1
#define IVSHMEM_PEER 0
#define IVSHMEM_MASTER 1
#define IVSHMEM_REG_BAR_SIZE 0x100
//#define DEBUG_IVSHMEM
#ifdef DEBUG_IVSHMEM
#define IVSHMEM_DPRINTF(fmt, ...) \
do {printf("IVSHMEM: " fmt, ## __VA_ARGS__); } while (0)
#else
#define IVSHMEM_DPRINTF(fmt, ...)
#endif
typedef struct Peer {
int nb_eventfds;
int *eventfds;
} Peer;
typedef struct EventfdEntry {
PCIDevice *pdev;
int vector;
} EventfdEntry;
typedef struct IVShmemState {
PCIDevice dev;
uint32_t intrmask;
uint32_t intrstatus;
uint32_t doorbell;
CharDriverState **eventfd_chr;
CharDriverState *server_chr;
MemoryRegion ivshmem_mmio;
pcibus_t mmio_addr;
/* We might need to register the BAR before we actually have the memory.
* So prepare a container MemoryRegion for the BAR immediately and
* add a subregion when we have the memory.
*/
MemoryRegion bar;
MemoryRegion ivshmem;
MemoryRegion msix_bar;
uint64_t ivshmem_size; /* size of shared memory region */
int shm_fd; /* shared memory file descriptor */
Peer *peers;
int nb_peers; /* how many guests we have space for */
int max_peer; /* maximum numbered peer */
int vm_id;
uint32_t vectors;
uint32_t features;
EventfdEntry *eventfd_table;
Error *migration_blocker;
char * shmobj;
char * sizearg;
char * role;
int role_val; /* scalar to avoid multiple string comparisons */
} IVShmemState;
/* registers for the Inter-VM shared memory device */
enum ivshmem_registers {
INTRMASK = 0,
INTRSTATUS = 4,
IVPOSITION = 8,
DOORBELL = 12,
};
static inline uint32_t ivshmem_has_feature(IVShmemState *ivs,
unsigned int feature) {
return (ivs->features & (1 << feature));
}
static inline bool is_power_of_two(uint64_t x) {
return (x & (x - 1)) == 0;
}
/* accessing registers - based on rtl8139 */
static void ivshmem_update_irq(IVShmemState *s, int val)
{
int isr;
isr = (s->intrstatus & s->intrmask) & 0xffffffff;
/* don't print ISR resets */
if (isr) {
IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
isr ? 1 : 0, s->intrstatus, s->intrmask);
}
qemu_set_irq(s->dev.irq[0], (isr != 0));
}
static void ivshmem_IntrMask_write(IVShmemState *s, uint32_t val)
{
IVSHMEM_DPRINTF("IntrMask write(w) val = 0x%04x\n", val);
s->intrmask = val;
ivshmem_update_irq(s, val);
}
static uint32_t ivshmem_IntrMask_read(IVShmemState *s)
{
uint32_t ret = s->intrmask;
IVSHMEM_DPRINTF("intrmask read(w) val = 0x%04x\n", ret);
return ret;
}
static void ivshmem_IntrStatus_write(IVShmemState *s, uint32_t val)
{
IVSHMEM_DPRINTF("IntrStatus write(w) val = 0x%04x\n", val);
s->intrstatus = val;
ivshmem_update_irq(s, val);
return;
}
static uint32_t ivshmem_IntrStatus_read(IVShmemState *s)
{
uint32_t ret = s->intrstatus;
/* reading ISR clears all interrupts */
s->intrstatus = 0;
ivshmem_update_irq(s, 0);
return ret;
}
static void ivshmem_io_write(void *opaque, target_phys_addr_t addr,
uint64_t val, unsigned size)
{
IVShmemState *s = opaque;
uint64_t write_one = 1;
uint16_t dest = val >> 16;
uint16_t vector = val & 0xff;
addr &= 0xfc;
IVSHMEM_DPRINTF("writing to addr " TARGET_FMT_plx "\n", addr);
switch (addr)
{
case INTRMASK:
ivshmem_IntrMask_write(s, val);
break;
case INTRSTATUS:
ivshmem_IntrStatus_write(s, val);
break;
case DOORBELL:
/* check that dest VM ID is reasonable */
if (dest > s->max_peer) {
IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
break;
}
/* check doorbell range */
if (vector < s->peers[dest].nb_eventfds) {
IVSHMEM_DPRINTF("Writing %" PRId64 " to VM %d on vector %d\n",
write_one, dest, vector);
if (write(s->peers[dest].eventfds[vector],
&(write_one), 8) != 8) {
IVSHMEM_DPRINTF("error writing to eventfd\n");
}
}
break;
default:
IVSHMEM_DPRINTF("Invalid VM Doorbell VM %d\n", dest);
}
}
static uint64_t ivshmem_io_read(void *opaque, target_phys_addr_t addr,
unsigned size)
{
IVShmemState *s = opaque;
uint32_t ret;
switch (addr)
{
case INTRMASK:
ret = ivshmem_IntrMask_read(s);
break;
case INTRSTATUS:
ret = ivshmem_IntrStatus_read(s);
break;
case IVPOSITION:
/* return my VM ID if the memory is mapped */
if (s->shm_fd > 0) {
ret = s->vm_id;
} else {
ret = -1;
}
break;
default:
IVSHMEM_DPRINTF("why are we reading " TARGET_FMT_plx "\n", addr);
ret = 0;
}
return ret;
}
static const MemoryRegionOps ivshmem_mmio_ops = {
.read = ivshmem_io_read,
.write = ivshmem_io_write,
.endianness = DEVICE_NATIVE_ENDIAN,
.impl = {
.min_access_size = 4,
.max_access_size = 4,
},
};
static void ivshmem_receive(void *opaque, const uint8_t *buf, int size)
{
IVShmemState *s = opaque;
ivshmem_IntrStatus_write(s, *buf);
IVSHMEM_DPRINTF("ivshmem_receive 0x%02x\n", *buf);
}
static int ivshmem_can_receive(void * opaque)
{
return 8;
}
static void ivshmem_event(void *opaque, int event)
{
IVSHMEM_DPRINTF("ivshmem_event %d\n", event);
}
static void fake_irqfd(void *opaque, const uint8_t *buf, int size) {
EventfdEntry *entry = opaque;
PCIDevice *pdev = entry->pdev;
IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, entry->vector);
msix_notify(pdev, entry->vector);
}
static CharDriverState* create_eventfd_chr_device(void * opaque, int eventfd,
int vector)
{
/* create a event character device based on the passed eventfd */
IVShmemState *s = opaque;
CharDriverState * chr;
chr = qemu_chr_open_eventfd(eventfd);
if (chr == NULL) {
fprintf(stderr, "creating eventfd for eventfd %d failed\n", eventfd);
exit(-1);
}
/* if MSI is supported we need multiple interrupts */
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
s->eventfd_table[vector].pdev = &s->dev;
s->eventfd_table[vector].vector = vector;
qemu_chr_add_handlers(chr, ivshmem_can_receive, fake_irqfd,
ivshmem_event, &s->eventfd_table[vector]);
} else {
qemu_chr_add_handlers(chr, ivshmem_can_receive, ivshmem_receive,
ivshmem_event, s);
}
return chr;
}
static int check_shm_size(IVShmemState *s, int fd) {
/* check that the guest isn't going to try and map more memory than the
* the object has allocated return -1 to indicate error */
struct stat buf;
fstat(fd, &buf);
if (s->ivshmem_size > buf.st_size) {
fprintf(stderr,
"IVSHMEM ERROR: Requested memory size greater"
" than shared object size (%" PRIu64 " > %" PRIu64")\n",
s->ivshmem_size, (uint64_t)buf.st_size);
return -1;
} else {
return 0;
}
}
/* create the shared memory BAR when we are not using the server, so we can
* create the BAR and map the memory immediately */
static void create_shared_memory_BAR(IVShmemState *s, int fd) {
void * ptr;
s->shm_fd = fd;
ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
memory_region_init_ram_ptr(&s->ivshmem, &s->dev.qdev, "ivshmem.bar2",
s->ivshmem_size, ptr);
memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
/* region for shared memory */
pci_register_bar(&s->dev, 2, PCI_BASE_ADDRESS_SPACE_MEMORY, &s->bar);
}
static void close_guest_eventfds(IVShmemState *s, int posn)
{
int i, guest_curr_max;
guest_curr_max = s->peers[posn].nb_eventfds;
for (i = 0; i < guest_curr_max; i++) {
kvm_set_ioeventfd_mmio_long(s->peers[posn].eventfds[i],
s->mmio_addr + DOORBELL, (posn << 16) | i, 0);
close(s->peers[posn].eventfds[i]);
}
g_free(s->peers[posn].eventfds);
s->peers[posn].nb_eventfds = 0;
}
static void setup_ioeventfds(IVShmemState *s) {
int i, j;
for (i = 0; i <= s->max_peer; i++) {
for (j = 0; j < s->peers[i].nb_eventfds; j++) {
memory_region_add_eventfd(&s->ivshmem_mmio,
DOORBELL,
4,
true,
(i << 16) | j,
s->peers[i].eventfds[j]);
}
}
}
/* this function increase the dynamic storage need to store data about other
* guests */
static void increase_dynamic_storage(IVShmemState *s, int new_min_size) {
int j, old_nb_alloc;
old_nb_alloc = s->nb_peers;
while (new_min_size >= s->nb_peers)
s->nb_peers = s->nb_peers * 2;
IVSHMEM_DPRINTF("bumping storage to %d guests\n", s->nb_peers);
s->peers = g_realloc(s->peers, s->nb_peers * sizeof(Peer));
/* zero out new pointers */
for (j = old_nb_alloc; j < s->nb_peers; j++) {
s->peers[j].eventfds = NULL;
s->peers[j].nb_eventfds = 0;
}
}
static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
{
IVShmemState *s = opaque;
int incoming_fd, tmp_fd;
int guest_max_eventfd;
long incoming_posn;
memcpy(&incoming_posn, buf, sizeof(long));
/* pick off s->server_chr->msgfd and store it, posn should accompany msg */
tmp_fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %ld, fd is %d\n", incoming_posn, tmp_fd);
/* make sure we have enough space for this guest */
if (incoming_posn >= s->nb_peers) {
increase_dynamic_storage(s, incoming_posn);
}
if (tmp_fd == -1) {
/* if posn is positive and unseen before then this is our posn*/
if ((incoming_posn >= 0) &&
(s->peers[incoming_posn].eventfds == NULL)) {
/* receive our posn */
s->vm_id = incoming_posn;
return;
} else {
/* otherwise an fd == -1 means an existing guest has gone away */
IVSHMEM_DPRINTF("posn %ld has gone away\n", incoming_posn);
close_guest_eventfds(s, incoming_posn);
return;
}
}
/* because of the implementation of get_msgfd, we need a dup */
incoming_fd = dup(tmp_fd);
if (incoming_fd == -1) {
fprintf(stderr, "could not allocate file descriptor %s\n",
strerror(errno));
return;
}
/* if the position is -1, then it's shared memory region fd */
if (incoming_posn == -1) {
void * map_ptr;
s->max_peer = 0;
if (check_shm_size(s, incoming_fd) == -1) {
exit(-1);
}
/* mmap the region and map into the BAR2 */
map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
incoming_fd, 0);
memory_region_init_ram_ptr(&s->ivshmem, &s->dev.qdev,
"ivshmem.bar2", s->ivshmem_size, map_ptr);
IVSHMEM_DPRINTF("guest h/w addr = %" PRIu64 ", size = %" PRIu64 "\n",
s->ivshmem_offset, s->ivshmem_size);
memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
/* only store the fd if it is successfully mapped */
s->shm_fd = incoming_fd;
return;
}
/* each guest has an array of eventfds, and we keep track of how many
* guests for each VM */
guest_max_eventfd = s->peers[incoming_posn].nb_eventfds;
if (guest_max_eventfd == 0) {
/* one eventfd per MSI vector */
s->peers[incoming_posn].eventfds = (int *) g_malloc(s->vectors *
sizeof(int));
}
/* this is an eventfd for a particular guest VM */
IVSHMEM_DPRINTF("eventfds[%ld][%d] = %d\n", incoming_posn,
guest_max_eventfd, incoming_fd);
s->peers[incoming_posn].eventfds[guest_max_eventfd] = incoming_fd;
/* increment count for particular guest */
s->peers[incoming_posn].nb_eventfds++;
/* keep track of the maximum VM ID */
if (incoming_posn > s->max_peer) {
s->max_peer = incoming_posn;
}
if (incoming_posn == s->vm_id) {
s->eventfd_chr[guest_max_eventfd] = create_eventfd_chr_device(s,
s->peers[s->vm_id].eventfds[guest_max_eventfd],
guest_max_eventfd);
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
if (kvm_set_ioeventfd_mmio_long(incoming_fd, s->mmio_addr + DOORBELL,
(incoming_posn << 16) | guest_max_eventfd, 1) < 0) {
fprintf(stderr, "ivshmem: ioeventfd not available\n");
}
}
return;
}
static void ivshmem_reset(DeviceState *d)
{
IVShmemState *s = DO_UPCAST(IVShmemState, dev.qdev, d);
s->intrstatus = 0;
return;
}
static uint64_t ivshmem_get_size(IVShmemState * s) {
uint64_t value;
char *ptr;
value = strtoull(s->sizearg, &ptr, 10);
switch (*ptr) {
case 0: case 'M': case 'm':
value <<= 20;
break;
case 'G': case 'g':
value <<= 30;
break;
default:
fprintf(stderr, "qemu: invalid ram size: %s\n", s->sizearg);
exit(1);
}
/* BARs must be a power of 2 */
if (!is_power_of_two(value)) {
fprintf(stderr, "ivshmem: size must be power of 2\n");
exit(1);
}
return value;
}
static void ivshmem_setup_msi(IVShmemState * s) {
int i;
/* allocate the MSI-X vectors */
memory_region_init(&s->msix_bar, "ivshmem-msix", 4096);
if (!msix_init(&s->dev, s->vectors, &s->msix_bar, 1, 0)) {
pci_register_bar(&s->dev, 1, PCI_BASE_ADDRESS_SPACE_MEMORY,
&s->msix_bar);
IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
} else {
IVSHMEM_DPRINTF("msix initialization failed\n");
exit(1);
}
/* 'activate' the vectors */
for (i = 0; i < s->vectors; i++) {
msix_vector_use(&s->dev, i);
}
/* allocate Qemu char devices for receiving interrupts */
s->eventfd_table = g_malloc0(s->vectors * sizeof(EventfdEntry));
}
static void ivshmem_save(QEMUFile* f, void *opaque)
{
IVShmemState *proxy = opaque;
IVSHMEM_DPRINTF("ivshmem_save\n");
pci_device_save(&proxy->dev, f);
if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
msix_save(&proxy->dev, f);
} else {
qemu_put_be32(f, proxy->intrstatus);
qemu_put_be32(f, proxy->intrmask);
}
}
static int ivshmem_load(QEMUFile* f, void *opaque, int version_id)
{
IVSHMEM_DPRINTF("ivshmem_load\n");
IVShmemState *proxy = opaque;
int ret, i;
if (version_id > 0) {
return -EINVAL;
}
if (proxy->role_val == IVSHMEM_PEER) {
fprintf(stderr, "ivshmem: 'peer' devices are not migratable\n");
return -EINVAL;
}
ret = pci_device_load(&proxy->dev, f);
if (ret) {
return ret;
}
if (ivshmem_has_feature(proxy, IVSHMEM_MSI)) {
msix_load(&proxy->dev, f);
for (i = 0; i < proxy->vectors; i++) {
msix_vector_use(&proxy->dev, i);
}
} else {
proxy->intrstatus = qemu_get_be32(f);
proxy->intrmask = qemu_get_be32(f);
}
return 0;
}
static int pci_ivshmem_init(PCIDevice *dev)
{
IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
uint8_t *pci_conf;
if (s->sizearg == NULL)
s->ivshmem_size = 4 << 20; /* 4 MB default */
else {
s->ivshmem_size = ivshmem_get_size(s);
}
register_savevm(&s->dev.qdev, "ivshmem", 0, 0, ivshmem_save, ivshmem_load,
dev);
/* IRQFD requires MSI */
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
!ivshmem_has_feature(s, IVSHMEM_MSI)) {
fprintf(stderr, "ivshmem: ioeventfd/irqfd requires MSI\n");
exit(1);
}
/* check that role is reasonable */
if (s->role) {
if (strncmp(s->role, "peer", 5) == 0) {
s->role_val = IVSHMEM_PEER;
} else if (strncmp(s->role, "master", 7) == 0) {
s->role_val = IVSHMEM_MASTER;
} else {
fprintf(stderr, "ivshmem: 'role' must be 'peer' or 'master'\n");
exit(1);
}
} else {
s->role_val = IVSHMEM_MASTER; /* default */
}
if (s->role_val == IVSHMEM_PEER) {
error_set(&s->migration_blocker, QERR_DEVICE_FEATURE_BLOCKS_MIGRATION, "ivshmem", "peer mode");
migrate_add_blocker(s->migration_blocker);
}
pci_conf = s->dev.config;
pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
pci_config_set_interrupt_pin(pci_conf, 1);
s->shm_fd = 0;
memory_region_init_io(&s->ivshmem_mmio, &ivshmem_mmio_ops, s,
"ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
setup_ioeventfds(s);
}
/* region for registers*/
pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
&s->ivshmem_mmio);
memory_region_init(&s->bar, "ivshmem-bar2-container", s->ivshmem_size);
if ((s->server_chr != NULL) &&
(strncmp(s->server_chr->filename, "unix:", 5) == 0)) {
/* if we get a UNIX socket as the parameter we will talk
* to the ivshmem server to receive the memory region */
if (s->shmobj != NULL) {
fprintf(stderr, "WARNING: do not specify both 'chardev' "
"and 'shm' with ivshmem\n");
}
IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
s->server_chr->filename);
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
ivshmem_setup_msi(s);
}
/* we allocate enough space for 16 guests and grow as needed */
s->nb_peers = 16;
s->vm_id = -1;
/* allocate/initialize space for interrupt handling */
s->peers = g_malloc0(s->nb_peers * sizeof(Peer));
pci_register_bar(&s->dev, 2,
PCI_BASE_ADDRESS_SPACE_MEMORY, &s->bar);
s->eventfd_chr = g_malloc0(s->vectors * sizeof(CharDriverState *));
qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
ivshmem_event, s);
} else {
/* just map the file immediately, we're not using a server */
int fd;
if (s->shmobj == NULL) {
fprintf(stderr, "Must specify 'chardev' or 'shm' to ivshmem\n");
}
IVSHMEM_DPRINTF("using shm_open (shm object = %s)\n", s->shmobj);
/* try opening with O_EXCL and if it succeeds zero the memory
* by truncating to 0 */
if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR|O_EXCL,
S_IRWXU|S_IRWXG|S_IRWXO)) > 0) {
/* truncate file to length PCI device's memory */
if (ftruncate(fd, s->ivshmem_size) != 0) {
fprintf(stderr, "ivshmem: could not truncate shared file\n");
}
} else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
fprintf(stderr, "ivshmem: could not open shared file\n");
exit(-1);
}
if (check_shm_size(s, fd) == -1) {
exit(-1);
}
create_shared_memory_BAR(s, fd);
}
return 0;
}
static int pci_ivshmem_uninit(PCIDevice *dev)
{
IVShmemState *s = DO_UPCAST(IVShmemState, dev, dev);
if (s->migration_blocker) {
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
}
memory_region_destroy(&s->ivshmem_mmio);
memory_region_del_subregion(&s->bar, &s->ivshmem);
memory_region_destroy(&s->ivshmem);
memory_region_destroy(&s->bar);
unregister_savevm(&dev->qdev, "ivshmem", s);
return 0;
}
static PCIDeviceInfo ivshmem_info = {
.qdev.name = "ivshmem",
.qdev.size = sizeof(IVShmemState),
.qdev.reset = ivshmem_reset,
.init = pci_ivshmem_init,
.exit = pci_ivshmem_uninit,
.vendor_id = PCI_VENDOR_ID_REDHAT_QUMRANET,
.device_id = 0x1110,
.class_id = PCI_CLASS_MEMORY_RAM,
.qdev.props = (Property[]) {
DEFINE_PROP_CHR("chardev", IVShmemState, server_chr),
DEFINE_PROP_STRING("size", IVShmemState, sizearg),
DEFINE_PROP_UINT32("vectors", IVShmemState, vectors, 1),
DEFINE_PROP_BIT("ioeventfd", IVShmemState, features, IVSHMEM_IOEVENTFD, false),
DEFINE_PROP_BIT("msi", IVShmemState, features, IVSHMEM_MSI, true),
DEFINE_PROP_STRING("shm", IVShmemState, shmobj),
DEFINE_PROP_STRING("role", IVShmemState, role),
DEFINE_PROP_END_OF_LIST(),
}
};
static void ivshmem_register_devices(void)
{
pci_qdev_register(&ivshmem_info);
}
device_init(ivshmem_register_devices)
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