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|
/*
* vhost-user
*
* Copyright (c) 2013 Virtual Open Systems Sarl.
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include "qemu/osdep.h"
#include "qapi/error.h"
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-backend.h"
#include "hw/virtio/virtio-net.h"
#include "sysemu/char.h"
#include "sysemu/kvm.h"
#include "qemu/error-report.h"
#include "qemu/sockets.h"
#include "migration/migration.h"
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <linux/vhost.h>
#define VHOST_MEMORY_MAX_NREGIONS 8
#define VHOST_USER_F_PROTOCOL_FEATURES 30
enum VhostUserProtocolFeature {
VHOST_USER_PROTOCOL_F_MQ = 0,
VHOST_USER_PROTOCOL_F_LOG_SHMFD = 1,
VHOST_USER_PROTOCOL_F_RARP = 2,
VHOST_USER_PROTOCOL_F_REPLY_ACK = 3,
VHOST_USER_PROTOCOL_F_MAX
};
#define VHOST_USER_PROTOCOL_FEATURE_MASK ((1 << VHOST_USER_PROTOCOL_F_MAX) - 1)
typedef enum VhostUserRequest {
VHOST_USER_NONE = 0,
VHOST_USER_GET_FEATURES = 1,
VHOST_USER_SET_FEATURES = 2,
VHOST_USER_SET_OWNER = 3,
VHOST_USER_RESET_OWNER = 4,
VHOST_USER_SET_MEM_TABLE = 5,
VHOST_USER_SET_LOG_BASE = 6,
VHOST_USER_SET_LOG_FD = 7,
VHOST_USER_SET_VRING_NUM = 8,
VHOST_USER_SET_VRING_ADDR = 9,
VHOST_USER_SET_VRING_BASE = 10,
VHOST_USER_GET_VRING_BASE = 11,
VHOST_USER_SET_VRING_KICK = 12,
VHOST_USER_SET_VRING_CALL = 13,
VHOST_USER_SET_VRING_ERR = 14,
VHOST_USER_GET_PROTOCOL_FEATURES = 15,
VHOST_USER_SET_PROTOCOL_FEATURES = 16,
VHOST_USER_GET_QUEUE_NUM = 17,
VHOST_USER_SET_VRING_ENABLE = 18,
VHOST_USER_SEND_RARP = 19,
VHOST_USER_MAX
} VhostUserRequest;
typedef struct VhostUserMemoryRegion {
uint64_t guest_phys_addr;
uint64_t memory_size;
uint64_t userspace_addr;
uint64_t mmap_offset;
} VhostUserMemoryRegion;
typedef struct VhostUserMemory {
uint32_t nregions;
uint32_t padding;
VhostUserMemoryRegion regions[VHOST_MEMORY_MAX_NREGIONS];
} VhostUserMemory;
typedef struct VhostUserLog {
uint64_t mmap_size;
uint64_t mmap_offset;
} VhostUserLog;
typedef struct VhostUserMsg {
VhostUserRequest request;
#define VHOST_USER_VERSION_MASK (0x3)
#define VHOST_USER_REPLY_MASK (0x1<<2)
#define VHOST_USER_NEED_REPLY_MASK (0x1 << 3)
uint32_t flags;
uint32_t size; /* the following payload size */
union {
#define VHOST_USER_VRING_IDX_MASK (0xff)
#define VHOST_USER_VRING_NOFD_MASK (0x1<<8)
uint64_t u64;
struct vhost_vring_state state;
struct vhost_vring_addr addr;
VhostUserMemory memory;
VhostUserLog log;
} payload;
} QEMU_PACKED VhostUserMsg;
static VhostUserMsg m __attribute__ ((unused));
#define VHOST_USER_HDR_SIZE (sizeof(m.request) \
+ sizeof(m.flags) \
+ sizeof(m.size))
#define VHOST_USER_PAYLOAD_SIZE (sizeof(m) - VHOST_USER_HDR_SIZE)
/* The version of the protocol we support */
#define VHOST_USER_VERSION (0x1)
static bool ioeventfd_enabled(void)
{
return kvm_enabled() && kvm_eventfds_enabled();
}
static int vhost_user_read(struct vhost_dev *dev, VhostUserMsg *msg)
{
CharDriverState *chr = dev->opaque;
uint8_t *p = (uint8_t *) msg;
int r, size = VHOST_USER_HDR_SIZE;
r = qemu_chr_fe_read_all(chr, p, size);
if (r != size) {
error_report("Failed to read msg header. Read %d instead of %d."
" Original request %d.", r, size, msg->request);
goto fail;
}
/* validate received flags */
if (msg->flags != (VHOST_USER_REPLY_MASK | VHOST_USER_VERSION)) {
error_report("Failed to read msg header."
" Flags 0x%x instead of 0x%x.", msg->flags,
VHOST_USER_REPLY_MASK | VHOST_USER_VERSION);
goto fail;
}
/* validate message size is sane */
if (msg->size > VHOST_USER_PAYLOAD_SIZE) {
error_report("Failed to read msg header."
" Size %d exceeds the maximum %zu.", msg->size,
VHOST_USER_PAYLOAD_SIZE);
goto fail;
}
if (msg->size) {
p += VHOST_USER_HDR_SIZE;
size = msg->size;
r = qemu_chr_fe_read_all(chr, p, size);
if (r != size) {
error_report("Failed to read msg payload."
" Read %d instead of %d.", r, msg->size);
goto fail;
}
}
return 0;
fail:
return -1;
}
static int process_message_reply(struct vhost_dev *dev,
VhostUserRequest request)
{
VhostUserMsg msg;
if (vhost_user_read(dev, &msg) < 0) {
return -1;
}
if (msg.request != request) {
error_report("Received unexpected msg type."
"Expected %d received %d",
request, msg.request);
return -1;
}
return msg.payload.u64 ? -1 : 0;
}
static bool vhost_user_one_time_request(VhostUserRequest request)
{
switch (request) {
case VHOST_USER_SET_OWNER:
case VHOST_USER_RESET_OWNER:
case VHOST_USER_SET_MEM_TABLE:
case VHOST_USER_GET_QUEUE_NUM:
return true;
default:
return false;
}
}
/* most non-init callers ignore the error */
static int vhost_user_write(struct vhost_dev *dev, VhostUserMsg *msg,
int *fds, int fd_num)
{
CharDriverState *chr = dev->opaque;
int ret, size = VHOST_USER_HDR_SIZE + msg->size;
/*
* For non-vring specific requests, like VHOST_USER_SET_MEM_TABLE,
* we just need send it once in the first time. For later such
* request, we just ignore it.
*/
if (vhost_user_one_time_request(msg->request) && dev->vq_index != 0) {
return 0;
}
if (qemu_chr_fe_set_msgfds(chr, fds, fd_num) < 0) {
error_report("Failed to set msg fds.");
return -1;
}
ret = qemu_chr_fe_write_all(chr, (const uint8_t *) msg, size);
if (ret != size) {
error_report("Failed to write msg."
" Wrote %d instead of %d.", ret, size);
return -1;
}
return 0;
}
static int vhost_user_set_log_base(struct vhost_dev *dev, uint64_t base,
struct vhost_log *log)
{
int fds[VHOST_MEMORY_MAX_NREGIONS];
size_t fd_num = 0;
bool shmfd = virtio_has_feature(dev->protocol_features,
VHOST_USER_PROTOCOL_F_LOG_SHMFD);
VhostUserMsg msg = {
.request = VHOST_USER_SET_LOG_BASE,
.flags = VHOST_USER_VERSION,
.payload.log.mmap_size = log->size * sizeof(*(log->log)),
.payload.log.mmap_offset = 0,
.size = sizeof(msg.payload.log),
};
if (shmfd && log->fd != -1) {
fds[fd_num++] = log->fd;
}
if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
return -1;
}
if (shmfd) {
msg.size = 0;
if (vhost_user_read(dev, &msg) < 0) {
return -1;
}
if (msg.request != VHOST_USER_SET_LOG_BASE) {
error_report("Received unexpected msg type. "
"Expected %d received %d",
VHOST_USER_SET_LOG_BASE, msg.request);
return -1;
}
}
return 0;
}
static int vhost_user_set_mem_table(struct vhost_dev *dev,
struct vhost_memory *mem)
{
int fds[VHOST_MEMORY_MAX_NREGIONS];
int i, fd;
size_t fd_num = 0;
bool reply_supported = virtio_has_feature(dev->protocol_features,
VHOST_USER_PROTOCOL_F_REPLY_ACK);
VhostUserMsg msg = {
.request = VHOST_USER_SET_MEM_TABLE,
.flags = VHOST_USER_VERSION,
};
if (reply_supported) {
msg.flags |= VHOST_USER_NEED_REPLY_MASK;
}
for (i = 0; i < dev->mem->nregions; ++i) {
struct vhost_memory_region *reg = dev->mem->regions + i;
ram_addr_t offset;
MemoryRegion *mr;
assert((uintptr_t)reg->userspace_addr == reg->userspace_addr);
mr = memory_region_from_host((void *)(uintptr_t)reg->userspace_addr,
&offset);
fd = memory_region_get_fd(mr);
if (fd > 0) {
msg.payload.memory.regions[fd_num].userspace_addr = reg->userspace_addr;
msg.payload.memory.regions[fd_num].memory_size = reg->memory_size;
msg.payload.memory.regions[fd_num].guest_phys_addr = reg->guest_phys_addr;
msg.payload.memory.regions[fd_num].mmap_offset = offset;
assert(fd_num < VHOST_MEMORY_MAX_NREGIONS);
fds[fd_num++] = fd;
}
}
msg.payload.memory.nregions = fd_num;
if (!fd_num) {
error_report("Failed initializing vhost-user memory map, "
"consider using -object memory-backend-file share=on");
return -1;
}
msg.size = sizeof(msg.payload.memory.nregions);
msg.size += sizeof(msg.payload.memory.padding);
msg.size += fd_num * sizeof(VhostUserMemoryRegion);
if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
return -1;
}
if (reply_supported) {
return process_message_reply(dev, msg.request);
}
return 0;
}
static int vhost_user_set_vring_addr(struct vhost_dev *dev,
struct vhost_vring_addr *addr)
{
VhostUserMsg msg = {
.request = VHOST_USER_SET_VRING_ADDR,
.flags = VHOST_USER_VERSION,
.payload.addr = *addr,
.size = sizeof(msg.payload.addr),
};
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
return 0;
}
static int vhost_user_set_vring_endian(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
error_report("vhost-user trying to send unhandled ioctl");
return -1;
}
static int vhost_set_vring(struct vhost_dev *dev,
unsigned long int request,
struct vhost_vring_state *ring)
{
VhostUserMsg msg = {
.request = request,
.flags = VHOST_USER_VERSION,
.payload.state = *ring,
.size = sizeof(msg.payload.state),
};
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
return 0;
}
static int vhost_user_set_vring_num(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
return vhost_set_vring(dev, VHOST_USER_SET_VRING_NUM, ring);
}
static int vhost_user_set_vring_base(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
return vhost_set_vring(dev, VHOST_USER_SET_VRING_BASE, ring);
}
static int vhost_user_set_vring_enable(struct vhost_dev *dev, int enable)
{
int i;
if (!virtio_has_feature(dev->features, VHOST_USER_F_PROTOCOL_FEATURES)) {
return -1;
}
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_vring_state state = {
.index = dev->vq_index + i,
.num = enable,
};
vhost_set_vring(dev, VHOST_USER_SET_VRING_ENABLE, &state);
}
return 0;
}
static int vhost_user_get_vring_base(struct vhost_dev *dev,
struct vhost_vring_state *ring)
{
VhostUserMsg msg = {
.request = VHOST_USER_GET_VRING_BASE,
.flags = VHOST_USER_VERSION,
.payload.state = *ring,
.size = sizeof(msg.payload.state),
};
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
if (vhost_user_read(dev, &msg) < 0) {
return -1;
}
if (msg.request != VHOST_USER_GET_VRING_BASE) {
error_report("Received unexpected msg type. Expected %d received %d",
VHOST_USER_GET_VRING_BASE, msg.request);
return -1;
}
if (msg.size != sizeof(msg.payload.state)) {
error_report("Received bad msg size.");
return -1;
}
*ring = msg.payload.state;
return 0;
}
static int vhost_set_vring_file(struct vhost_dev *dev,
VhostUserRequest request,
struct vhost_vring_file *file)
{
int fds[VHOST_MEMORY_MAX_NREGIONS];
size_t fd_num = 0;
VhostUserMsg msg = {
.request = request,
.flags = VHOST_USER_VERSION,
.payload.u64 = file->index & VHOST_USER_VRING_IDX_MASK,
.size = sizeof(msg.payload.u64),
};
if (ioeventfd_enabled() && file->fd > 0) {
fds[fd_num++] = file->fd;
} else {
msg.payload.u64 |= VHOST_USER_VRING_NOFD_MASK;
}
if (vhost_user_write(dev, &msg, fds, fd_num) < 0) {
return -1;
}
return 0;
}
static int vhost_user_set_vring_kick(struct vhost_dev *dev,
struct vhost_vring_file *file)
{
return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_KICK, file);
}
static int vhost_user_set_vring_call(struct vhost_dev *dev,
struct vhost_vring_file *file)
{
return vhost_set_vring_file(dev, VHOST_USER_SET_VRING_CALL, file);
}
static int vhost_user_set_u64(struct vhost_dev *dev, int request, uint64_t u64)
{
VhostUserMsg msg = {
.request = request,
.flags = VHOST_USER_VERSION,
.payload.u64 = u64,
.size = sizeof(msg.payload.u64),
};
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
return 0;
}
static int vhost_user_set_features(struct vhost_dev *dev,
uint64_t features)
{
return vhost_user_set_u64(dev, VHOST_USER_SET_FEATURES, features);
}
static int vhost_user_set_protocol_features(struct vhost_dev *dev,
uint64_t features)
{
return vhost_user_set_u64(dev, VHOST_USER_SET_PROTOCOL_FEATURES, features);
}
static int vhost_user_get_u64(struct vhost_dev *dev, int request, uint64_t *u64)
{
VhostUserMsg msg = {
.request = request,
.flags = VHOST_USER_VERSION,
};
if (vhost_user_one_time_request(request) && dev->vq_index != 0) {
return 0;
}
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
if (vhost_user_read(dev, &msg) < 0) {
return -1;
}
if (msg.request != request) {
error_report("Received unexpected msg type. Expected %d received %d",
request, msg.request);
return -1;
}
if (msg.size != sizeof(msg.payload.u64)) {
error_report("Received bad msg size.");
return -1;
}
*u64 = msg.payload.u64;
return 0;
}
static int vhost_user_get_features(struct vhost_dev *dev, uint64_t *features)
{
return vhost_user_get_u64(dev, VHOST_USER_GET_FEATURES, features);
}
static int vhost_user_set_owner(struct vhost_dev *dev)
{
VhostUserMsg msg = {
.request = VHOST_USER_SET_OWNER,
.flags = VHOST_USER_VERSION,
};
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
return 0;
}
static int vhost_user_reset_device(struct vhost_dev *dev)
{
VhostUserMsg msg = {
.request = VHOST_USER_RESET_OWNER,
.flags = VHOST_USER_VERSION,
};
if (vhost_user_write(dev, &msg, NULL, 0) < 0) {
return -1;
}
return 0;
}
static int vhost_user_init(struct vhost_dev *dev, void *opaque)
{
uint64_t features;
int err;
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
dev->opaque = opaque;
err = vhost_user_get_features(dev, &features);
if (err < 0) {
return err;
}
if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) {
dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
err = vhost_user_get_u64(dev, VHOST_USER_GET_PROTOCOL_FEATURES,
&features);
if (err < 0) {
return err;
}
dev->protocol_features = features & VHOST_USER_PROTOCOL_FEATURE_MASK;
err = vhost_user_set_protocol_features(dev, dev->protocol_features);
if (err < 0) {
return err;
}
/* query the max queues we support if backend supports Multiple Queue */
if (dev->protocol_features & (1ULL << VHOST_USER_PROTOCOL_F_MQ)) {
err = vhost_user_get_u64(dev, VHOST_USER_GET_QUEUE_NUM,
&dev->max_queues);
if (err < 0) {
return err;
}
}
}
if (dev->migration_blocker == NULL &&
!virtio_has_feature(dev->protocol_features,
VHOST_USER_PROTOCOL_F_LOG_SHMFD)) {
error_setg(&dev->migration_blocker,
"Migration disabled: vhost-user backend lacks "
"VHOST_USER_PROTOCOL_F_LOG_SHMFD feature.");
}
return 0;
}
static int vhost_user_cleanup(struct vhost_dev *dev)
{
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
dev->opaque = 0;
return 0;
}
static int vhost_user_get_vq_index(struct vhost_dev *dev, int idx)
{
assert(idx >= dev->vq_index && idx < dev->vq_index + dev->nvqs);
return idx;
}
static int vhost_user_memslots_limit(struct vhost_dev *dev)
{
return VHOST_MEMORY_MAX_NREGIONS;
}
static bool vhost_user_requires_shm_log(struct vhost_dev *dev)
{
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
return virtio_has_feature(dev->protocol_features,
VHOST_USER_PROTOCOL_F_LOG_SHMFD);
}
static int vhost_user_migration_done(struct vhost_dev *dev, char* mac_addr)
{
VhostUserMsg msg = { 0 };
assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER);
/* If guest supports GUEST_ANNOUNCE do nothing */
if (virtio_has_feature(dev->acked_features, VIRTIO_NET_F_GUEST_ANNOUNCE)) {
return 0;
}
/* if backend supports VHOST_USER_PROTOCOL_F_RARP ask it to send the RARP */
if (virtio_has_feature(dev->protocol_features,
VHOST_USER_PROTOCOL_F_RARP)) {
msg.request = VHOST_USER_SEND_RARP;
msg.flags = VHOST_USER_VERSION;
memcpy((char *)&msg.payload.u64, mac_addr, 6);
msg.size = sizeof(msg.payload.u64);
return vhost_user_write(dev, &msg, NULL, 0);
}
return -1;
}
static bool vhost_user_can_merge(struct vhost_dev *dev,
uint64_t start1, uint64_t size1,
uint64_t start2, uint64_t size2)
{
ram_addr_t offset;
int mfd, rfd;
MemoryRegion *mr;
mr = memory_region_from_host((void *)(uintptr_t)start1, &offset);
mfd = memory_region_get_fd(mr);
mr = memory_region_from_host((void *)(uintptr_t)start2, &offset);
rfd = memory_region_get_fd(mr);
return mfd == rfd;
}
const VhostOps user_ops = {
.backend_type = VHOST_BACKEND_TYPE_USER,
.vhost_backend_init = vhost_user_init,
.vhost_backend_cleanup = vhost_user_cleanup,
.vhost_backend_memslots_limit = vhost_user_memslots_limit,
.vhost_set_log_base = vhost_user_set_log_base,
.vhost_set_mem_table = vhost_user_set_mem_table,
.vhost_set_vring_addr = vhost_user_set_vring_addr,
.vhost_set_vring_endian = vhost_user_set_vring_endian,
.vhost_set_vring_num = vhost_user_set_vring_num,
.vhost_set_vring_base = vhost_user_set_vring_base,
.vhost_get_vring_base = vhost_user_get_vring_base,
.vhost_set_vring_kick = vhost_user_set_vring_kick,
.vhost_set_vring_call = vhost_user_set_vring_call,
.vhost_set_features = vhost_user_set_features,
.vhost_get_features = vhost_user_get_features,
.vhost_set_owner = vhost_user_set_owner,
.vhost_reset_device = vhost_user_reset_device,
.vhost_get_vq_index = vhost_user_get_vq_index,
.vhost_set_vring_enable = vhost_user_set_vring_enable,
.vhost_requires_shm_log = vhost_user_requires_shm_log,
.vhost_migration_done = vhost_user_migration_done,
.vhost_backend_can_merge = vhost_user_can_merge,
};
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