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5503e28504
qemu/hw/misc/ivshmem.c
Markus Armbruster 5503e28504 ivshmem: Implement shm=... with a memory backend 
ivshmem has its very own code to create and map shared memory.
Replace that with an implicitly created memory backend.  Reduces the
number of ways we create BAR 2 from three to two.

The memory-backend-file is currently available only with CONFIG_LINUX,
so this adds a second Linuxism to ivshmem (the other one is eventfd).
Should we ever need to make it portable to systems where
memory-backend-file can't be made to serve, we could create a
memory-backend-shmem that allocates memory with shm_open().

Bonus fix: shared memory files are now created with permissions 0655
instead of 0777.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1458066895-20632-32-git-send-email-armbru@redhat.com>
2016-03-21 21:29:02 +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 "qom/object_interfaces.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;
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;
size_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;
uint64_t msg_buf; /* buffer for receiving server messages */
int msg_buffered_bytes; /* #bytes in @msg_buf */
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:
ret = s->vm_id;
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_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 (%zu > %" PRIu64")",
s->ivshmem_size, (uint64_t)buf.st_size);
return -1;
} else {
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;
assert(posn >= 0 && posn < s->nb_peers);
n = s->peers[posn].nb_eventfds;
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
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 void ivshmem_add_kvm_msi_virq(IVShmemState *s, int vector,
Error **errp)
{
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_setg(errp, "kvm_irqchip_add_msi_route failed");
return;
}
s->msi_vectors[vector].virq = ret;
s->msi_vectors[vector].pdev = pdev;
}
static void setup_interrupt(IVShmemState *s, int vector, Error **errp)
{
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);
Error *err = NULL;
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");
ivshmem_add_kvm_msi_virq(s, vector, &err);
if (err) {
error_propagate(errp, err);
return;
}
if (!msix_is_masked(pdev, vector)) {
kvm_irqchip_add_irqfd_notifier_gsi(kvm_state, n, NULL,
s->msi_vectors[vector].virq);
/* TODO handle error */
}
} else {
/* it will be delayed until msix is enabled, in write_config */
IVSHMEM_DPRINTF("with irqfd, delayed until msix enabled\n");
}
}
static void process_msg_shmem(IVShmemState *s, int fd, Error **errp)
{
Error *err = NULL;
void *ptr;
if (memory_region_is_mapped(&s->ivshmem)) {
error_setg(errp, "server sent unexpected shared memory message");
close(fd);
return;
}
if (check_shm_size(s, fd, &err) == -1) {
error_propagate(errp, err);
close(fd);
return;
}
/* mmap the region and map into the BAR2 */
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");
close(fd);
return;
}
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);
}
static void process_msg_disconnect(IVShmemState *s, uint16_t posn,
Error **errp)
{
IVSHMEM_DPRINTF("posn %d has gone away\n", posn);
if (posn >= s->nb_peers || posn == s->vm_id) {
error_setg(errp, "invalid peer %d", posn);
return;
}
close_peer_eventfds(s, posn);
}
static void process_msg_connect(IVShmemState *s, uint16_t posn, int fd,
Error **errp)
{
Peer *peer = &s->peers[posn];
int vector;
/*
* The N-th connect message for this peer comes with the file
* descriptor for vector N-1. Count messages to find the vector.
*/
if (peer->nb_eventfds >= s->vectors) {
error_setg(errp, "Too many eventfd received, device has %d vectors",
s->vectors);
close(fd);
return;
}
vector = peer->nb_eventfds++;
IVSHMEM_DPRINTF("eventfds[%d][%d] = %d\n", posn, vector, fd);
event_notifier_init_fd(&peer->eventfds[vector], fd);
fcntl_setfl(fd, O_NONBLOCK); /* msix/irqfd poll non block */
if (posn == s->vm_id) {
setup_interrupt(s, vector, errp);
/* TODO do we need to handle the error? */
}
if (ivshmem_has_feature(s, IVSHMEM_IOEVENTFD)) {
ivshmem_add_eventfd(s, posn, vector);
}
}
static void process_msg(IVShmemState *s, int64_t msg, int fd, Error **errp)
{
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
if (msg < -1 || msg > IVSHMEM_MAX_PEERS) {
error_setg(errp, "server sent invalid message %" PRId64, msg);
close(fd);
return;
}
if (msg == -1) {
process_msg_shmem(s, fd, errp);
return;
}
if (msg >= s->nb_peers) {
resize_peers(s, msg + 1);
}
if (fd >= 0) {
process_msg_connect(s, msg, fd, errp);
} else {
process_msg_disconnect(s, msg, errp);
}
}
static int ivshmem_can_receive(void *opaque)
{
IVShmemState *s = opaque;
assert(s->msg_buffered_bytes < sizeof(s->msg_buf));
return sizeof(s->msg_buf) - s->msg_buffered_bytes;
}
static void ivshmem_read(void *opaque, const uint8_t *buf, int size)
{
IVShmemState *s = opaque;
Error *err = NULL;
int fd;
int64_t msg;
assert(size >= 0 && s->msg_buffered_bytes + size <= sizeof(s->msg_buf));
memcpy((unsigned char *)&s->msg_buf + s->msg_buffered_bytes, buf, size);
s->msg_buffered_bytes += size;
if (s->msg_buffered_bytes < sizeof(s->msg_buf)) {
return;
}
msg = le64_to_cpu(s->msg_buf);
s->msg_buffered_bytes = 0;
fd = qemu_chr_fe_get_msgfd(s->server_chr);
IVSHMEM_DPRINTF("posn is %" PRId64 ", fd is %d\n", msg, fd);
process_msg(s, msg, fd, &err);
if (err) {
error_report_err(err);
}
}
static int64_t ivshmem_recv_msg(IVShmemState *s, int *pfd, Error **errp)
{
int64_t msg;
int n, ret;
n = 0;
do {
ret = qemu_chr_fe_read_all(s->server_chr, (uint8_t *)&msg + n,
sizeof(msg) - n);
if (ret < 0 && ret != -EINTR) {
error_setg_errno(errp, -ret, "read from server failed");
return INT64_MIN;
}
n += ret;
} while (n < sizeof(msg));
*pfd = qemu_chr_fe_get_msgfd(s->server_chr);
return msg;
}
static void ivshmem_recv_setup(IVShmemState *s, Error **errp)
{
Error *err = NULL;
int64_t msg;
int fd;
msg = ivshmem_recv_msg(s, &fd, &err);
if (err) {
error_propagate(errp, err);
return;
}
if (msg != IVSHMEM_PROTOCOL_VERSION) {
error_setg(errp, "server sent version %" PRId64 ", expecting %d",
msg, IVSHMEM_PROTOCOL_VERSION);
return;
}
if (fd != -1) {
error_setg(errp, "server sent invalid version message");
return;
}
/*
* ivshmem-server sends the remaining initial messages in a fixed
* order, but the device has always accepted them in any order.
* Stay as compatible as practical, just in case people use
* servers that behave differently.
*/
/*
* ivshmem_device_spec.txt has always required the ID message
* right here, and ivshmem-server has always complied. However,
* older versions of the device accepted it out of order, but
* broke when an interrupt setup message arrived before it.
*/
msg = ivshmem_recv_msg(s, &fd, &err);
if (err) {
error_propagate(errp, err);
return;
}
if (fd != -1 || msg < 0 || msg > IVSHMEM_MAX_PEERS) {
error_setg(errp, "server sent invalid ID message");
return;
}
s->vm_id = msg;
/*
* Receive more messages until we got shared memory.
*/
do {
msg = ivshmem_recv_msg(s, &fd, &err);
if (err) {
error_propagate(errp, err);
return;
}
process_msg(s, msg, fd, &err);
if (err) {
error_propagate(errp, err);
return;
}
} while (msg != -1);
/*
* This function must either map the shared memory or fail. The
* loop above ensures that: it terminates normally only after it
* successfully processed the server's shared memory message.
* Assert that actually mapped the shared memory:
*/
assert(memory_region_is_mapped(&s->ivshmem));
}
/* 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++) {
Error *err = NULL;
ivshmem_add_kvm_msi_virq(s, i, &err);
if (err) {
error_report_err(err);
/* TODO do we need to handle the error? */
}
}
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()) {
if (!was_enabled && is_enabled) {
ivshmem_enable_irqfd(s);
} else if (was_enabled && !is_enabled) {
ivshmem_disable_irqfd(s);
}
}
}
static void desugar_shm(IVShmemState *s)
{
Object *obj;
char *path;
obj = object_new("memory-backend-file");
path = g_strdup_printf("/dev/shm/%s", s->shmobj);
object_property_set_str(obj, path, "mem-path", &error_abort);
g_free(path);
object_property_set_int(obj, s->ivshmem_size, "size", &error_abort);
object_property_set_bool(obj, true, "share", &error_abort);
object_property_add_child(OBJECT(s), "internal-shm-backend", obj,
&error_abort);
user_creatable_complete(obj, &error_abort);
s->hostmem = MEMORY_BACKEND(obj);
}
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 || (size_t)size != size || *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->shmobj) {
desugar_shm(s);
}
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 {
IVSHMEM_DPRINTF("using shared memory server (socket = %s)\n",
s->server_chr->filename);
/* we allocate enough space for 16 peers and grow as needed */
resize_peers(s, 16);
pci_register_bar(dev, 2, attr, &s->bar);
/*
* Receive setup messages from server synchronously.
* Older versions did it asynchronously, but that creates a
* number of entertaining race conditions.
*/
ivshmem_recv_setup(s, &err);
if (err) {
error_propagate(errp, err);
return;
}
qemu_chr_add_handlers(s->server_chr, ivshmem_can_receive,
ivshmem_read, NULL, s);
if (ivshmem_setup_interrupts(s) < 0) {
error_setg(errp, "failed to initialize interrupts");
return;
}
}
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;
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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