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cd9953f720
qemu/hw/misc/ivshmem.c
Markus Armbruster cd9953f720 ivshmem: Simplify rejection of invalid peer ID from server 
ivshmem_read() processes server messages.  These are 64 bit signed
integers.  -1 is shared memory setup, 16 bit unsigned is a peer ID,
anything else is invalid.

ivshmem_read() rejects invalid negative messages right away, silently.

Invalid positive messages get rejected only in resize_peers(), and
ivshmem_read() then prints the rather cryptic message "failed to
resize peers array".

Extend the first check to cover all invalid messages, make it report
"server sent invalid message", and drop the second check.

Now resize_peers() can't fail anymore; simplify.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <1458066895-20632-23-git-send-email-armbru@redhat.com>
2016-03-21 21:29:01 +01:00

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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.
*
* Contributions after 2012-01-13 are licensed under the terms of the
* GNU GPL, version 2 or (at your option) any later version.
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/i386/pc.h"
#include "hw/pci/pci.h"
#include "hw/pci/msi.h"
#include "hw/pci/msix.h"
#include "sysemu/kvm.h"
#include "migration/migration.h"
#include "qemu/error-report.h"
#include "qemu/event_notifier.h"
#include "qemu/fifo8.h"
#include "sysemu/char.h"
#include "sysemu/hostmem.h"
#include "qapi/visitor.h"
#include "exec/ram_addr.h"
#include "hw/misc/ivshmem.h"
#include <sys/mman.h>
#define PCI_VENDOR_ID_IVSHMEM PCI_VENDOR_ID_REDHAT_QUMRANET
#define PCI_DEVICE_ID_IVSHMEM 0x1110
#define IVSHMEM_MAX_PEERS UINT16_MAX
#define IVSHMEM_IOEVENTFD 0
#define IVSHMEM_MSI 1
#define IVSHMEM_PEER 0
#define IVSHMEM_MASTER 1
#define IVSHMEM_REG_BAR_SIZE 0x100
#define IVSHMEM_DEBUG 0
#define IVSHMEM_DPRINTF(fmt, ...) \
do { \
if (IVSHMEM_DEBUG) { \
printf("IVSHMEM: " fmt, ## __VA_ARGS__); \
} \
} while (0)
#define TYPE_IVSHMEM "ivshmem"
#define IVSHMEM(obj) \
OBJECT_CHECK(IVShmemState, (obj), TYPE_IVSHMEM)
typedef struct Peer {
int nb_eventfds;
EventNotifier *eventfds;
} Peer;
typedef struct MSIVector {
PCIDevice *pdev;
int virq;
} MSIVector;
typedef struct IVShmemState {
/*< private >*/
PCIDevice parent_obj;
/*< public >*/
HostMemoryBackend *hostmem;
uint32_t intrmask;
uint32_t intrstatus;
CharDriverState *server_chr;
Fifo8 incoming_fifo;
MemoryRegion ivshmem_mmio;
/* 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;
uint64_t ivshmem_size; /* size of shared memory region */
uint32_t ivshmem_64bit;
Peer *peers;
int nb_peers; /* space in @peers[] */
int vm_id;
uint32_t vectors;
uint32_t features;
MSIVector *msi_vectors;
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 void ivshmem_update_irq(IVShmemState *s)
{
PCIDevice *d = PCI_DEVICE(s);
uint32_t isr = s->intrstatus & s->intrmask;
/* No INTx with msi=on, whether the guest enabled MSI-X or not */
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
return;
}
/* don't print ISR resets */
if (isr) {
IVSHMEM_DPRINTF("Set IRQ to %d (%04x %04x)\n",
isr ? 1 : 0, s->intrstatus, s->intrmask);
}
pci_set_irq(d, 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);
}
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);
}
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);
return ret;
}
static void ivshmem_io_write(void *opaque, hwaddr addr,
uint64_t val, unsigned size)
{
IVShmemState *s = opaque;
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->nb_peers) {
IVSHMEM_DPRINTF("Invalid destination VM ID (%d)\n", dest);
break;
}
/* check doorbell range */
if (vector < s->peers[dest].nb_eventfds) {
IVSHMEM_DPRINTF("Notifying VM %d on vector %d\n", dest, vector);
event_notifier_set(&s->peers[dest].eventfds[vector]);
} else {
IVSHMEM_DPRINTF("Invalid destination vector %d on VM %d\n",
vector, dest);
}
break;
default:
IVSHMEM_DPRINTF("Unhandled write " TARGET_FMT_plx "\n", addr);
}
}
static uint64_t ivshmem_io_read(void *opaque, hwaddr 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 (memory_region_is_mapped(&s->ivshmem)) {
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 int ivshmem_can_receive(void * opaque)
{
return sizeof(int64_t);
}
static void ivshmem_vector_notify(void *opaque)
{
MSIVector *entry = opaque;
PCIDevice *pdev = entry->pdev;
IVShmemState *s = IVSHMEM(pdev);
int vector = entry - s->msi_vectors;
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
if (!event_notifier_test_and_clear(n)) {
return;
}
IVSHMEM_DPRINTF("interrupt on vector %p %d\n", pdev, vector);
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
if (msix_enabled(pdev)) {
msix_notify(pdev, vector);
}
} else {
ivshmem_IntrStatus_write(s, 1);
}
}
static int ivshmem_vector_unmask(PCIDevice *dev, unsigned vector,
MSIMessage msg)
{
IVShmemState *s = IVSHMEM(dev);
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
MSIVector *v = &s->msi_vectors[vector];
int ret;
IVSHMEM_DPRINTF("vector unmask %p %d\n", dev, vector);
ret = kvm_irqchip_update_msi_route(kvm_state, v->virq, msg, dev);
if (ret < 0) {
return ret;
}
return kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL, v->virq);
}
static void ivshmem_vector_mask(PCIDevice *dev, unsigned vector)
{
IVShmemState *s = IVSHMEM(dev);
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
int ret;
IVSHMEM_DPRINTF("vector mask %p %d\n", dev, vector);
ret = kvm_irqchip_remove_irqfd_notifier_gsi(kvm_state, n,
s->msi_vectors[vector].virq);
if (ret != 0) {
error_report("remove_irqfd_notifier_gsi failed");
}
}
static void ivshmem_vector_poll(PCIDevice *dev,
unsigned int vector_start,
unsigned int vector_end)
{
IVShmemState *s = IVSHMEM(dev);
unsigned int vector;
IVSHMEM_DPRINTF("vector poll %p %d-%d\n", dev, vector_start, vector_end);
vector_end = MIN(vector_end, s->vectors);
for (vector = vector_start; vector < vector_end; vector++) {
EventNotifier *notifier = &s->peers[s->vm_id].eventfds[vector];
if (!msix_is_masked(dev, vector)) {
continue;
}
if (event_notifier_test_and_clear(notifier)) {
msix_set_pending(dev, vector);
}
}
}
static void watch_vector_notifier(IVShmemState *s, EventNotifier *n,
int vector)
{
int eventfd = event_notifier_get_fd(n);
assert(!s->msi_vectors[vector].pdev);
s->msi_vectors[vector].pdev = PCI_DEVICE(s);
qemu_set_fd_handler(eventfd, ivshmem_vector_notify,
NULL, &s->msi_vectors[vector]);
}
static int check_shm_size(IVShmemState *s, int fd, Error **errp)
{
/* 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;
if (fstat(fd, &buf) < 0) {
error_setg(errp, "exiting: fstat on fd %d failed: %s",
fd, strerror(errno));
return -1;
}
if (s->ivshmem_size > buf.st_size) {
error_setg(errp, "Requested memory size greater"
" than shared object size (%" PRIu64 " > %" PRIu64")",
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 int create_shared_memory_BAR(IVShmemState *s, int fd, uint8_t attr,
Error **errp)
{
void * ptr;
ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
if (ptr == MAP_FAILED) {
error_setg_errno(errp, errno, "Failed to mmap shared memory");
return -1;
}
memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2",
s->ivshmem_size, ptr);
qemu_set_ram_fd(memory_region_get_ram_addr(&s->ivshmem), fd);
vmstate_register_ram(&s->ivshmem, DEVICE(s));
memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
/* region for shared memory */
pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
return 0;
}
static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
{
memory_region_add_eventfd(&s->ivshmem_mmio,
DOORBELL,
4,
true,
(posn << 16) | i,
&s->peers[posn].eventfds[i]);
}
static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
{
memory_region_del_eventfd(&s->ivshmem_mmio,
DOORBELL,
4,
true,
(posn << 16) | i,
&s->peers[posn].eventfds[i]);
}
static void close_peer_eventfds(IVShmemState *s, int posn)
{
int i, n;
if (!ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
return;
}
if (posn < 0 || posn >= s->nb_peers) {
error_report("invalid peer %d", posn);
return;
}
n = s->peers[posn].nb_eventfds;
memory_region_transaction_begin();
for (i = 0; i < n; i++) {
ivshmem_del_eventfd(s, posn, i);
}
memory_region_transaction_commit();
for (i = 0; i < n; i++) {
event_notifier_cleanup(&s->peers[posn].eventfds[i]);
}
g_free(s->peers[posn].eventfds);
s->peers[posn].nb_eventfds = 0;
}
static void resize_peers(IVShmemState *s, int nb_peers)
{
int old_nb_peers = s->nb_peers;
int i;
assert(nb_peers > old_nb_peers);
IVSHMEM_DPRINTF("bumping storage to %d peers\n", nb_peers);
s->peers = g_realloc(s->peers, nb_peers * sizeof(Peer));
s->nb_peers = nb_peers;
for (i = old_nb_peers; i < nb_peers; i++) {
s->peers[i].eventfds = g_new0(EventNotifier, s->vectors);
s->peers[i].nb_eventfds = 0;
}
}
static bool fifo_update_and_get(IVShmemState *s, const uint8_t *buf, int size,
void *data, size_t len)
{
const uint8_t *p;
uint32_t num;
assert(len <= sizeof(int64_t)); /* limitation of the fifo */
if (fifo8_is_empty(&s->incoming_fifo) && size == len) {
memcpy(data, buf, size);
return true;
}
IVSHMEM_DPRINTF("short read of %d bytes\n", size);
num = MIN(size, sizeof(int64_t) - fifo8_num_used(&s->incoming_fifo));
fifo8_push_all(&s->incoming_fifo, buf, num);
if (fifo8_num_used(&s->incoming_fifo) < len) {
assert(num == 0);
return false;
}
size -= num;
buf += num;
p = fifo8_pop_buf(&s->incoming_fifo, len, &num);
assert(num == len);
memcpy(data, p, len);
if (size > 0) {
fifo8_push_all(&s->incoming_fifo, buf, size);
}
return true;
}
static bool fifo_update_and_get_i64(IVShmemState *s,
const uint8_t *buf, int size, int64_t *i64)
{
if (fifo_update_and_get(s, buf, size, i64, sizeof(*i64))) {
*i64 = GINT64_FROM_LE(*i64);
return true;
}
return false;
}
static int ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector)
{
PCIDevice *pdev = PCI_DEVICE(s);
MSIMessage msg = msix_get_message(pdev, vector);
int ret;
IVSHMEM_DPRINTF("ivshmem_add_kvm_msi_virq vector:%d\n", vector);
assert(!s->msi_vectors[vector].pdev);
ret = kvm_irqchip_add_msi_route(kvm_state, msg, pdev);
if (ret < 0) {
error_report("ivshmem: kvm_irqchip_add_msi_route failed");
return -1;
}
s->msi_vectors[vector].virq = ret;
s->msi_vectors[vector].pdev = pdev;
return 0;
}
static void setup_interrupt(IVShmemState *s, int vector)
{
EventNotifier *n = &s->peers[s->vm_id].eventfds[vector];
bool with_irqfd = kvm_msi_via_irqfd_enabled() &&
ivshmem_has_feature(s, IVSHMEM_MSI);
PCIDevice *pdev = PCI_DEVICE(s);
IVSHMEM_DPRINTF("setting up interrupt for vector: %d\n", vector);
if (!with_irqfd) {
IVSHMEM_DPRINTF("with eventfd\n");
watch_vector_notifier(s, n, vector);
} else if (msix_enabled(pdev)) {
IVSHMEM_DPRINTF("with irqfd\n");
if (ivshmem_add_kvm_msi_virq(s, vector) < 0) {
return;
}
if (!msix_is_masked(pdev, vector)) {
kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
s->msi_vectors[vector].virq);
}
} else {
/* it will be delayed until msix is enabled, in write_config */
IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled\n");
}
}
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
{
IVShmemState *s = opaque;
int incoming_fd;
int new_eventfd;
int64_t incoming_posn;
Error *err = NULL;
Peer *peer;
if (!fifo_update_and_get_i64(s, buf, size, &incoming_posn)) {
return;
}
incoming_fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n",
incoming_posn, incoming_fd);
if (incoming_posn < -1 || incoming_posn > IVSHMEM_MAX_PEERS) {
error_report("server sent invalid message %" PRId64,
incoming_posn);
if (incoming_fd != -1) {
close(incoming_fd);
}
return;
}
if (incoming_posn >= s->nb_peers) {
resize_peers(s, incoming_posn + 1);
}
peer = &s->peers[incoming_posn];
if (incoming_fd == -1) {
/* if posn is positive and unseen before then this is our posn*/
if (incoming_posn >= 0 && s->vm_id == -1) {
/* receive our posn */
s->vm_id = incoming_posn;
} else {
/* otherwise an fd == -1 means an existing peer has gone away */
IVSHMEM_DPRINTF("posn %" PRId64 " has gone away\n", incoming_posn);
close_peer_eventfds(s, incoming_posn);
}
return;
}
/* if the position is -1, then it's shared memory region fd */
if (incoming_posn == -1) {
void * map_ptr;
if (memory_region_is_mapped(&s->ivshmem)) {
error_report("shm already initialized");
close(incoming_fd);
return;
}
if (check_shm_size(s, incoming_fd, &err) == -1) {
error_report_err(err);
close(incoming_fd);
return;
}
/* mmap the region and map into the BAR2 */
map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
incoming_fd, 0);
if (map_ptr == MAP_FAILED) {
error_report("Failed to mmap shared memory %s", strerror(errno));
close(incoming_fd);
return;
}
memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
"ivshmem.bar2", s->ivshmem_size, map_ptr);
qemu_set_ram_fd(memory_region_get_ram_addr(&s->ivshmem),
incoming_fd);
vmstate_register_ram(&s->ivshmem, DEVICE(s));
IVSHMEM_DPRINTF("guest h/w addr = %p, size = %" PRIu64 "\n",
map_ptr, s->ivshmem_size);
memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
return;
}
/* each peer has an associated array of eventfds, and we keep
* track of how many eventfds received so far */
/* get a new eventfd: */
if (peer->nb_eventfds >= s->vectors) {
error_report("Too many eventfd received, device has %d vectors",
s->vectors);
close(incoming_fd);
return;
}
new_eventfd = peer->nb_eventfds++;
/* this is an eventfd for a particular peer VM */
IVSHMEM_DPRINTF("eventfds[%" PRId64 "][%d] = %d\n", incoming_posn,
new_eventfd, incoming_fd);
event_notifier_init_fd(&peer->eventfds[new_eventfd], incoming_fd);
fcntl_setfl(incoming_fd, O_NONBLOCK); /* msix/irqfd poll non block */
if (incoming_posn == s->vm_id) {
setup_interrupt(s, new_eventfd);
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
ivshmem_add_eventfd(s, incoming_posn, new_eventfd);
}
}
static void ivshmem_check_version(void *opaque, const uint8_t * buf, int size)
{
IVShmemState *s = opaque;
int tmp;
int64_t version;
if (!fifo_update_and_get_i64(s, buf, size, &version)) {
return;
}
tmp = qemu_chr_fe_get_msgfd(s->server_chr);
if (tmp != -1 || version != IVSHMEM_PROTOCOL_VERSION) {
fprintf(stderr, "incompatible version, you are connecting to a ivshmem-"
"server using a different protocol please check your setup\n");
qemu_chr_add_handlers(s->server_chr, NULL, NULL, NULL, s);
return;
}
IVSHMEM_DPRINTF("version check ok, switch to real chardev handler\n");
qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive, ivshmem_read,
NULL, s);
}
/* Select the MSI-X vectors used by device.
* ivshmem maps events to vectors statically, so
* we just enable all vectors on init and after reset. */
static void ivshmem_msix_vector_use(IVShmemState *s)
{
PCIDevice *d = PCI_DEVICE(s);
int i;
for (i = 0; i < s->vectors; i++) {
msix_vector_use(d, i);
}
}
static void ivshmem_reset(DeviceState *d)
{
IVShmemState *s = IVSHMEM(d);
s->intrstatus = 0;
s->intrmask = 0;
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
ivshmem_msix_vector_use(s);
}
}
static int ivshmem_setup_interrupts(IVShmemState *s)
{
/* allocate QEMU callback data for receiving interrupts */
s->msi_vectors = g_malloc0(s->vectors * sizeof(MSIVector));
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
if (msix_init_exclusive_bar(PCI_DEVICE(s), s->vectors, 1)) {
return -1;
}
IVSHMEM_DPRINTF("msix initialized (%d vectors)\n", s->vectors);
ivshmem_msix_vector_use(s);
}
return 0;
}
static void ivshmem_enable_irqfd(IVShmemState *s)
{
PCIDevice *pdev = PCI_DEVICE(s);
int i;
for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
ivshmem_add_kvm_msi_virq(s, i);
}
if (msix_set_vector_notifiers(pdev,
ivshmem_vector_unmask,
ivshmem_vector_mask,
ivshmem_vector_poll)) {
error_report("ivshmem: msix_set_vector_notifiers failed");
}
}
static void ivshmem_remove_kvm_msi_virq(IVShmemState *s, int vector)
{
IVSHMEM_DPRINTF("ivshmem_remove_kvm_msi_virq vector:%d\n", vector);
if (s->msi_vectors[vector].pdev == NULL) {
return;
}
/* it was cleaned when masked in the frontend. */
kvm_irqchip_release_virq(kvm_state, s->msi_vectors[vector].virq);
s->msi_vectors[vector].pdev = NULL;
}
static void ivshmem_disable_irqfd(IVShmemState *s)
{
PCIDevice *pdev = PCI_DEVICE(s);
int i;
for (i = 0; i < s->peers[s->vm_id].nb_eventfds; i++) {
ivshmem_remove_kvm_msi_virq(s, i);
}
msix_unset_vector_notifiers(pdev);
}
static void ivshmem_write_config(PCIDevice *pdev, uint32_t address,
uint32_t val, int len)
{
IVShmemState *s = IVSHMEM(pdev);
int is_enabled, was_enabled = msix_enabled(pdev);
pci_default_write_config(pdev, address, val, len);
is_enabled = msix_enabled(pdev);
if (kvm_msi_via_irqfd_enabled() && s->vm_id != -1) {
if (!was_enabled && is_enabled) {
ivshmem_enable_irqfd(s);
} else if (was_enabled && !is_enabled) {
ivshmem_disable_irqfd(s);
}
}
}
static void pci_ivshmem_realize(PCIDevice *dev, Error **errp)
{
IVShmemState *s = IVSHMEM(dev);
Error *err = NULL;
uint8_t *pci_conf;
uint8_t attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
PCI_BASE_ADDRESS_MEM_PREFETCH;
if (!!s->server_chr + !!s->shmobj + !!s->hostmem != 1) {
error_setg(errp,
"You must specify either 'shm', 'chardev' or 'x-memdev'");
return;
}
if (s->hostmem) {
MemoryRegion *mr;
if (s->sizearg) {
g_warning("size argument ignored with hostmem");
}
mr = host_memory_backend_get_memory(s->hostmem, &error_abort);
s->ivshmem_size = memory_region_size(mr);
} else if (s->sizearg == NULL) {
s->ivshmem_size = 4 << 20; /* 4 MB default */
} else {
char *end;
int64_t size = qemu_strtosz(s->sizearg, &end);
if (size < 0 || *end != '\0' || !is_power_of_2(size)) {
error_setg(errp, "Invalid size %s", s->sizearg);
return;
}
s->ivshmem_size = size;
}
/* IRQFD requires MSI */
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD) &&
!ivshmem_has_feature(s, IVSHMEM_MSI)) {
error_setg(errp, "ioeventfd/irqfd requires MSI");
return;
}
/* 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 {
error_setg(errp, "'role' must be 'peer' or 'master'");
return;
}
} else {
s->role_val = IVSHMEM_MASTER; /* default */
}
pci_conf = dev->config;
pci_conf[PCI_COMMAND] = PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
/*
* Note: we don't use INTx with IVSHMEM_MSI at all, so this is a
* bald-faced lie then. But it's a backwards compatible lie.
*/
pci_config_set_interrupt_pin(pci_conf, 1);
memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
"ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
/* region for registers*/
pci_register_bar(dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
&s->ivshmem_mmio);
memory_region_init(&s->bar, OBJECT(s), "ivshmem-bar2-container", s->ivshmem_size);
if (s->ivshmem_64bit) {
attr |= PCI_BASE_ADDRESS_MEM_TYPE_64;
}
if (s->hostmem != NULL) {
MemoryRegion *mr;
IVSHMEM_DPRINTF("using hostmem\n");
mr = host_memory_backend_get_memory(MEMORY_BACKEND(s->hostmem),
&error_abort);
vmstate_register_ram(mr, DEVICE(s));
memory_region_add_subregion(&s->bar, 0, mr);
pci_register_bar(PCI_DEVICE(s), 2, attr, &s->bar);
} else if (s->server_chr != NULL) {
/* FIXME do not rely on what chr drivers put into filename */
if (strncmp(s->server_chr->filename, "unix:", 5)) {
error_setg(errp, "chardev is not a unix client socket");
return;
}
/* if we get a UNIX socket as the parameter we will talk
* to the ivshmem server to receive the memory region */
IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
s->server_chr->filename);
if (ivshmem_setup_interrupts(s) < 0) {
error_setg(errp, "failed to initialize interrupts");
return;
}
/* we allocate enough space for 16 peers and grow as needed */
resize_peers(s, 16);
s->vm_id = -1;
pci_register_bar(dev, 2, attr, &s->bar);
qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive,
ivshmem_check_version, NULL, s);
} else {
/* just map the file immediately, we're not using a server */
int fd;
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) {
error_report("could not truncate shared file");
}
} else if ((fd = shm_open(s->shmobj, O_CREAT|O_RDWR,
S_IRWXU|S_IRWXG|S_IRWXO)) < 0) {
error_setg(errp, "could not open shared file");
return;
}
if (check_shm_size(s, fd, errp) == -1) {
return;
}
create_shared_memory_BAR(s, fd, attr, &err);
if (err) {
error_propagate(errp, err);
return;
}
}
fifo8_create(&s->incoming_fifo, sizeof(int64_t));
if (s->role_val == IVSHMEM_PEER) {
error_setg(&s->migration_blocker,
"Migration is disabled when using feature 'peer mode' in device 'ivshmem'");
migrate_add_blocker(s->migration_blocker);
}
}
static void pci_ivshmem_exit(PCIDevice *dev)
{
IVShmemState *s = IVSHMEM(dev);
int i;
fifo8_destroy(&s->incoming_fifo);
if (s->migration_blocker) {
migrate_del_blocker(s->migration_blocker);
error_free(s->migration_blocker);
}
if (memory_region_is_mapped(&s->ivshmem)) {
if (!s->hostmem) {
void *addr = memory_region_get_ram_ptr(&s->ivshmem);
int fd;
if (munmap(addr, s->ivshmem_size) == -1) {
error_report("Failed to munmap shared memory %s",
strerror(errno));
}
fd = qemu_get_ram_fd(memory_region_get_ram_addr(&s->ivshmem));
if (fd != -1) {
close(fd);
}
}
vmstate_unregister_ram(&s->ivshmem, DEVICE(dev));
memory_region_del_subregion(&s->bar, &s->ivshmem);
}
if (s->peers) {
for (i = 0; i < s->nb_peers; i++) {
close_peer_eventfds(s, i);
}
g_free(s->peers);
}
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
msix_uninit_exclusive_bar(dev);
}
g_free(s->msi_vectors);
}
static bool test_msix(void *opaque, int version_id)
{
IVShmemState *s = opaque;
return ivshmem_has_feature(s, IVSHMEM_MSI);
}
static bool test_no_msix(void *opaque, int version_id)
{
return !test_msix(opaque, version_id);
}
static int ivshmem_pre_load(void *opaque)
{
IVShmemState *s = opaque;
if (s->role_val == IVSHMEM_PEER) {
error_report("'peer' devices are not migratable");
return -EINVAL;
}
return 0;
}
static int ivshmem_post_load(void *opaque, int version_id)
{
IVShmemState *s = opaque;
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
ivshmem_msix_vector_use(s);
}
return 0;
}
static int ivshmem_load_old(QEMUFile *f, void *opaque, int version_id)
{
IVShmemState *s = opaque;
PCIDevice *pdev = PCI_DEVICE(s);
int ret;
IVSHMEM_DPRINTF("ivshmem_load_old\n");
if (version_id != 0) {
return -EINVAL;
}
if (s->role_val == IVSHMEM_PEER) {
error_report("'peer' devices are not migratable");
return -EINVAL;
}
ret = pci_device_load(pdev, f);
if (ret) {
return ret;
}
if (ivshmem_has_feature(s, IVSHMEM_MSI)) {
msix_load(pdev, f);
ivshmem_msix_vector_use(s);
} else {
s->intrstatus = qemu_get_be32(f);
s->intrmask = qemu_get_be32(f);
}
return 0;
}
static const VMStateDescription ivshmem_vmsd = {
.name = "ivshmem",
.version_id = 1,
.minimum_version_id = 1,
.pre_load = ivshmem_pre_load,
.post_load = ivshmem_post_load,
.fields = (VMStateField[]) {
VMSTATE_PCI_DEVICE(parent_obj, IVShmemState),
VMSTATE_MSIX_TEST(parent_obj, IVShmemState, test_msix),
VMSTATE_UINT32_TEST(intrstatus, IVShmemState, test_no_msix),
VMSTATE_UINT32_TEST(intrmask, IVShmemState, test_no_msix),
VMSTATE_END_OF_LIST()
},
.load_state_old = ivshmem_load_old,
.minimum_version_id_old = 0
};
static Property ivshmem_properties[] = {
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_UINT32("use64", IVShmemState, ivshmem_64bit, 1),
DEFINE_PROP_END_OF_LIST(),
};
static void ivshmem_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
k->realize = pci_ivshmem_realize;
k->exit = pci_ivshmem_exit;
k->config_write = ivshmem_write_config;
k->vendor_id = PCI_VENDOR_ID_IVSHMEM;
k->device_id = PCI_DEVICE_ID_IVSHMEM;
k->class_id = PCI_CLASS_MEMORY_RAM;
dc->reset = ivshmem_reset;
dc->props = ivshmem_properties;
dc->vmsd = &ivshmem_vmsd;
set_bit(DEVICE_CATEGORY_MISC, dc->categories);
dc->desc = "Inter-VM shared memory";
}
static void ivshmem_check_memdev_is_busy(Object *obj, const char *name,
Object *val, Error **errp)
{
MemoryRegion *mr;
mr = host_memory_backend_get_memory(MEMORY_BACKEND(val), &error_abort);
if (memory_region_is_mapped(mr)) {
char *path = object_get_canonical_path_component(val);
error_setg(errp, "can't use already busy memdev: %s", path);
g_free(path);
} else {
qdev_prop_allow_set_link_before_realize(obj, name, val, errp);
}
}
static void ivshmem_init(Object *obj)
{
IVShmemState *s = IVSHMEM(obj);
object_property_add_link(obj, "x-memdev", TYPE_MEMORY_BACKEND,
(Object **)&s->hostmem,
ivshmem_check_memdev_is_busy,
OBJ_PROP_LINK_UNREF_ON_RELEASE,
&error_abort);
}
static const TypeInfo ivshmem_info = {
.name = TYPE_IVSHMEM,
.parent = TYPE_PCI_DEVICE,
.instance_size = sizeof(IVShmemState),
.instance_init = ivshmem_init,
.class_init = ivshmem_class_init,
};
static void ivshmem_register_types(void)
{
type_register_static(&ivshmem_info);
}
type_init(ivshmem_register_types)
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