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vhost-user: introduce vhost-user API

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Add vhost_user.c and vhost_user.h that define the functions needed
to implement vhost-user backend.

Signed-off-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Laurent Vivier 2024-11-22 17:43:30 +01:00 committed by Stefano Brivio
parent 7d1cd4dbf5
commit 31117b27c6
4 changed files with 1181 additions and 2 deletions
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4
Makefile
View File

@ -37,7 +37,7 @@ FLAGS += -DDUAL_STACK_SOCKETS=$(DUAL_STACK_SOCKETS)
PASST_SRCS = arch.c arp.c checksum.c conf.c dhcp.c dhcpv6.c flow.c fwd.c \
icmp.c igmp.c inany.c iov.c ip.c isolation.c lineread.c log.c mld.c \
ndp.c netlink.c packet.c passt.c pasta.c pcap.c pif.c tap.c tcp.c \
tcp_buf.c tcp_splice.c udp.c udp_flow.c util.c virtio.c
tcp_buf.c tcp_splice.c udp.c udp_flow.c util.c vhost_user.c virtio.c
QRAP_SRCS = qrap.c
SRCS = $(PASST_SRCS) $(QRAP_SRCS)
@ -47,7 +47,7 @@ PASST_HEADERS = arch.h arp.h checksum.h conf.h dhcp.h dhcpv6.h flow.h fwd.h \
flow_table.h icmp.h icmp_flow.h inany.h iov.h ip.h isolation.h \
lineread.h log.h ndp.h netlink.h packet.h passt.h pasta.h pcap.h pif.h \
siphash.h tap.h tcp.h tcp_buf.h tcp_conn.h tcp_internal.h tcp_splice.h \
udp.h udp_flow.h util.h virtio.h
udp.h udp_flow.h util.h vhost_user.h virtio.h
HEADERS = $(PASST_HEADERS) seccomp.h
C := \#include <sys/random.h>\nint main(){int a=getrandom(0, 0, 0);}

970
vhost_user.c Normal file
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@ -0,0 +1,970 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* vhost-user API, command management and virtio interface
*
* Copyright Red Hat
* Author: Laurent Vivier <lvivier@redhat.com>
*
* Some parts from QEMU subprojects/libvhost-user/libvhost-user.c
* licensed under the following terms:
*
* Copyright IBM, Corp. 2007
* Copyright (c) 2016 Red Hat, Inc.
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
* Marc-André Lureau <mlureau@redhat.com>
* Victor Kaplansky <victork@redhat.com>
*
* 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 <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include <assert.h>
#include <stdbool.h>
#include <inttypes.h>
#include <time.h>
#include <net/ethernet.h>
#include <netinet/in.h>
#include <sys/epoll.h>
#include <sys/eventfd.h>
#include <sys/mman.h>
#include <linux/vhost_types.h>
#include <linux/virtio_net.h>
#include "util.h"
#include "passt.h"
#include "tap.h"
#include "vhost_user.h"
#include "pcap.h"
/* vhost-user version we are compatible with */
#define VHOST_USER_VERSION 1
/**
* vu_print_capabilities() - print vhost-user capabilities
* this is part of the vhost-user backend
* convention.
*/
/* cppcheck-suppress unusedFunction */
void vu_print_capabilities(void)
{
info("{");
info(" \"type\": \"net\"");
info("}");
exit(EXIT_SUCCESS);
}
/**
* vu_request_to_string() - convert a vhost-user request number to its name
* @req: request number
*
* Return: the name of request number
*/
static const char *vu_request_to_string(unsigned int req)
{
if (req < VHOST_USER_MAX) {
#define REQ(req) [req] = #req
static const char * const vu_request_str[VHOST_USER_MAX] = {
REQ(VHOST_USER_NONE),
REQ(VHOST_USER_GET_FEATURES),
REQ(VHOST_USER_SET_FEATURES),
REQ(VHOST_USER_SET_OWNER),
REQ(VHOST_USER_RESET_OWNER),
REQ(VHOST_USER_SET_MEM_TABLE),
REQ(VHOST_USER_SET_LOG_BASE),
REQ(VHOST_USER_SET_LOG_FD),
REQ(VHOST_USER_SET_VRING_NUM),
REQ(VHOST_USER_SET_VRING_ADDR),
REQ(VHOST_USER_SET_VRING_BASE),
REQ(VHOST_USER_GET_VRING_BASE),
REQ(VHOST_USER_SET_VRING_KICK),
REQ(VHOST_USER_SET_VRING_CALL),
REQ(VHOST_USER_SET_VRING_ERR),
REQ(VHOST_USER_GET_PROTOCOL_FEATURES),
REQ(VHOST_USER_SET_PROTOCOL_FEATURES),
REQ(VHOST_USER_GET_QUEUE_NUM),
REQ(VHOST_USER_SET_VRING_ENABLE),
REQ(VHOST_USER_SEND_RARP),
REQ(VHOST_USER_NET_SET_MTU),
REQ(VHOST_USER_SET_BACKEND_REQ_FD),
REQ(VHOST_USER_IOTLB_MSG),
REQ(VHOST_USER_SET_VRING_ENDIAN),
REQ(VHOST_USER_GET_CONFIG),
REQ(VHOST_USER_SET_CONFIG),
REQ(VHOST_USER_POSTCOPY_ADVISE),
REQ(VHOST_USER_POSTCOPY_LISTEN),
REQ(VHOST_USER_POSTCOPY_END),
REQ(VHOST_USER_GET_INFLIGHT_FD),
REQ(VHOST_USER_SET_INFLIGHT_FD),
REQ(VHOST_USER_GPU_SET_SOCKET),
REQ(VHOST_USER_VRING_KICK),
REQ(VHOST_USER_GET_MAX_MEM_SLOTS),
REQ(VHOST_USER_ADD_MEM_REG),
REQ(VHOST_USER_REM_MEM_REG),
};
#undef REQ
return vu_request_str[req];
}
return "unknown";
}
/**
* qva_to_va() - Translate front-end (QEMU) virtual address to our virtual
* address
* @dev: vhost-user device
* @qemu_addr: front-end userspace address
*
* Return: the memory address in our process virtual address space.
*/
static void *qva_to_va(struct vu_dev *dev, uint64_t qemu_addr)
{
unsigned int i;
/* Find matching memory region. */
for (i = 0; i < dev->nregions; i++) {
const struct vu_dev_region *r = &dev->regions[i];
if ((qemu_addr >= r->qva) && (qemu_addr < (r->qva + r->size))) {
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
return (void *)(qemu_addr - r->qva + r->mmap_addr +
r->mmap_offset);
}
}
return NULL;
}
/**
* vmsg_close_fds() - Close all file descriptors of a given message
* @vmsg: vhost-user message with the list of the file descriptors
*/
static void vmsg_close_fds(const struct vhost_user_msg *vmsg)
{
int i;
for (i = 0; i < vmsg->fd_num; i++)
close(vmsg->fds[i]);
}
/**
* vu_remove_watch() - Remove a file descriptor from our passt epoll
* file descriptor
* @vdev: vhost-user device
* @fd: file descriptor to remove
*/
static void vu_remove_watch(const struct vu_dev *vdev, int fd)
{
/* Placeholder to add passt related code */
(void)vdev;
(void)fd;
}
/**
* vmsg_set_reply_u64() - Set reply payload.u64 and clear request flags
* and fd_num
* @vmsg: vhost-user message
* @val: 64-bit value to reply
*/
static void vmsg_set_reply_u64(struct vhost_user_msg *vmsg, uint64_t val)
{
vmsg->hdr.flags = 0; /* defaults will be set by vu_send_reply() */
vmsg->hdr.size = sizeof(vmsg->payload.u64);
vmsg->payload.u64 = val;
vmsg->fd_num = 0;
}
/**
* vu_message_read_default() - Read incoming vhost-user message from the
* front-end
* @conn_fd: vhost-user command socket
* @vmsg: vhost-user message
*
* Return: 0 if recvmsg() has been interrupted or if there's no data to read,
* 1 if a message has been received
*/
static int vu_message_read_default(int conn_fd, struct vhost_user_msg *vmsg)
{
char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS *
sizeof(int))] = { 0 };
struct iovec iov = {
.iov_base = (char *)vmsg,
.iov_len = VHOST_USER_HDR_SIZE,
};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = control,
.msg_controllen = sizeof(control),
};
ssize_t ret, sz_payload;
struct cmsghdr *cmsg;
ret = recvmsg(conn_fd, &msg, MSG_DONTWAIT);
if (ret < 0) {
if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
return 0;
die_perror("vhost-user message receive (recvmsg)");
}
vmsg->fd_num = 0;
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (cmsg->cmsg_level == SOL_SOCKET &&
cmsg->cmsg_type == SCM_RIGHTS) {
size_t fd_size;
ASSERT(cmsg->cmsg_len >= CMSG_LEN(0));
fd_size = cmsg->cmsg_len - CMSG_LEN(0);
ASSERT(fd_size <= sizeof(vmsg->fds));
vmsg->fd_num = fd_size / sizeof(int);
memcpy(vmsg->fds, CMSG_DATA(cmsg), fd_size);
break;
}
}
sz_payload = vmsg->hdr.size;
if ((size_t)sz_payload > sizeof(vmsg->payload)) {
die("vhost-user message request too big: %d,"
" size: vmsg->size: %zd, "
"while sizeof(vmsg->payload) = %zu",
vmsg->hdr.request, sz_payload, sizeof(vmsg->payload));
}
if (sz_payload) {
do
ret = recv(conn_fd, &vmsg->payload, sz_payload, 0);
while (ret < 0 && errno == EINTR);
if (ret < 0)
die_perror("vhost-user message receive");
if (ret == 0)
die("EOF on vhost-user message receive");
if (ret < sz_payload)
die("Short-read on vhost-user message receive");
}
return 1;
}
/**
* vu_message_write() - Send a message to the front-end
* @conn_fd: vhost-user command socket
* @vmsg: vhost-user message
*
* #syscalls:vu sendmsg
*/
static void vu_message_write(int conn_fd, struct vhost_user_msg *vmsg)
{
char control[CMSG_SPACE(VHOST_MEMORY_BASELINE_NREGIONS * sizeof(int))] = { 0 };
struct iovec iov = {
.iov_base = (char *)vmsg,
.iov_len = VHOST_USER_HDR_SIZE + vmsg->hdr.size,
};
struct msghdr msg = {
.msg_iov = &iov,
.msg_iovlen = 1,
.msg_control = control,
};
int rc;
ASSERT(vmsg->fd_num <= VHOST_MEMORY_BASELINE_NREGIONS);
if (vmsg->fd_num > 0) {
size_t fdsize = vmsg->fd_num * sizeof(int);
struct cmsghdr *cmsg;
msg.msg_controllen = CMSG_SPACE(fdsize);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(fdsize);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
memcpy(CMSG_DATA(cmsg), vmsg->fds, fdsize);
}
do
rc = sendmsg(conn_fd, &msg, 0);
while (rc < 0 && errno == EINTR);
if (rc < 0)
die_perror("vhost-user message send");
if ((uint32_t)rc < VHOST_USER_HDR_SIZE + vmsg->hdr.size)
die("EOF on vhost-user message send");
}
/**
* vu_send_reply() - Update message flags and send it to front-end
* @conn_fd: vhost-user command socket
* @vmsg: vhost-user message
*/
static void vu_send_reply(int conn_fd, struct vhost_user_msg *msg)
{
msg->hdr.flags &= ~VHOST_USER_VERSION_MASK;
msg->hdr.flags |= VHOST_USER_VERSION;
msg->hdr.flags |= VHOST_USER_REPLY_MASK;
vu_message_write(conn_fd, msg);
}
/**
* vu_get_features_exec() - Provide back-end features bitmask to front-end
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: True as a reply is requested
*/
static bool vu_get_features_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
uint64_t features =
1ULL << VIRTIO_F_VERSION_1 |
1ULL << VIRTIO_NET_F_MRG_RXBUF |
1ULL << VHOST_USER_F_PROTOCOL_FEATURES;
(void)vdev;
vmsg_set_reply_u64(msg, features);
debug("Sending back to guest u64: 0x%016"PRIx64, msg->payload.u64);
return true;
}
/**
* vu_set_enable_all_rings() - Enable/disable all the virtqueues
* @vdev: vhost-user device
* @enable: New virtqueues state
*/
static void vu_set_enable_all_rings(struct vu_dev *vdev, bool enable)
{
uint16_t i;
for (i = 0; i < VHOST_USER_MAX_QUEUES; i++)
vdev->vq[i].enable = enable;
}
/**
* vu_set_features_exec() - Enable features of the back-end
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_features_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
debug("u64: 0x%016"PRIx64, msg->payload.u64);
vdev->features = msg->payload.u64;
/* We only support devices conforming to VIRTIO 1.0 or
* later
*/
if (!vu_has_feature(vdev, VIRTIO_F_VERSION_1))
die("virtio legacy devices aren't supported by passt");
if (!vu_has_feature(vdev, VHOST_USER_F_PROTOCOL_FEATURES))
vu_set_enable_all_rings(vdev, true);
return false;
}
/**
* vu_set_owner_exec() - Session start flag, do nothing in our case
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_owner_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
(void)vdev;
(void)msg;
return false;
}
/**
* map_ring() - Convert ring front-end (QEMU) addresses to our process
* virtual address space.
* @vdev: vhost-user device
* @vq: Virtqueue
*
* Return: True if ring cannot be mapped to our address space
*/
static bool map_ring(struct vu_dev *vdev, struct vu_virtq *vq)
{
vq->vring.desc = qva_to_va(vdev, vq->vra.desc_user_addr);
vq->vring.used = qva_to_va(vdev, vq->vra.used_user_addr);
vq->vring.avail = qva_to_va(vdev, vq->vra.avail_user_addr);
debug("Setting virtq addresses:");
debug(" vring_desc at %p", (void *)vq->vring.desc);
debug(" vring_used at %p", (void *)vq->vring.used);
debug(" vring_avail at %p", (void *)vq->vring.avail);
return !(vq->vring.desc && vq->vring.used && vq->vring.avail);
}
/**
* vu_set_mem_table_exec() - Sets the memory map regions to be able to
* translate the vring addresses.
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*
* #syscalls:vu mmap munmap
*/
static bool vu_set_mem_table_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
struct vhost_user_memory m = msg->payload.memory, *memory = &m;
unsigned int i;
for (i = 0; i < vdev->nregions; i++) {
const struct vu_dev_region *r = &vdev->regions[i];
if (r->mmap_addr) {
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
munmap((void *)r->mmap_addr, r->size + r->mmap_offset);
}
}
vdev->nregions = memory->nregions;
debug("vhost-user nregions: %u", memory->nregions);
for (i = 0; i < vdev->nregions; i++) {
struct vhost_user_memory_region *msg_region = &memory->regions[i];
struct vu_dev_region *dev_region = &vdev->regions[i];
void *mmap_addr;
debug("vhost-user region %d", i);
debug(" guest_phys_addr: 0x%016"PRIx64,
msg_region->guest_phys_addr);
debug(" memory_size: 0x%016"PRIx64,
msg_region->memory_size);
debug(" userspace_addr 0x%016"PRIx64,
msg_region->userspace_addr);
debug(" mmap_offset 0x%016"PRIx64,
msg_region->mmap_offset);
dev_region->gpa = msg_region->guest_phys_addr;
dev_region->size = msg_region->memory_size;
dev_region->qva = msg_region->userspace_addr;
dev_region->mmap_offset = msg_region->mmap_offset;
/* We don't use offset argument of mmap() since the
* mapped address has to be page aligned.
*/
mmap_addr = mmap(0, dev_region->size + dev_region->mmap_offset,
PROT_READ | PROT_WRITE, MAP_SHARED |
MAP_NORESERVE, msg->fds[i], 0);
if (mmap_addr == MAP_FAILED)
die_perror("vhost-user region mmap error");
dev_region->mmap_addr = (uint64_t)(uintptr_t)mmap_addr;
debug(" mmap_addr: 0x%016"PRIx64,
dev_region->mmap_addr);
close(msg->fds[i]);
}
for (i = 0; i < VHOST_USER_MAX_QUEUES; i++) {
if (vdev->vq[i].vring.desc) {
if (map_ring(vdev, &vdev->vq[i]))
die("remapping queue %d during setmemtable", i);
}
}
return false;
}
/**
* vu_set_vring_num_exec() - Set the size of the queue (vring size)
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_num_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
unsigned int idx = msg->payload.state.index;
unsigned int num = msg->payload.state.num;
debug("State.index: %u", idx);
debug("State.num: %u", num);
vdev->vq[idx].vring.num = num;
return false;
}
/**
* vu_set_vring_addr_exec() - Set the addresses of the vring
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_addr_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
/* We need to copy the payload to vhost_vring_addr structure
* to access index because address of msg->payload.addr
* can be unaligned as it is packed.
*/
struct vhost_vring_addr addr = msg->payload.addr;
struct vu_virtq *vq = &vdev->vq[addr.index];
debug("vhost_vring_addr:");
debug(" index: %d", addr.index);
debug(" flags: %d", addr.flags);
debug(" desc_user_addr: 0x%016" PRIx64,
(uint64_t)addr.desc_user_addr);
debug(" used_user_addr: 0x%016" PRIx64,
(uint64_t)addr.used_user_addr);
debug(" avail_user_addr: 0x%016" PRIx64,
(uint64_t)addr.avail_user_addr);
debug(" log_guest_addr: 0x%016" PRIx64,
(uint64_t)addr.log_guest_addr);
vq->vra = msg->payload.addr;
vq->vring.flags = addr.flags;
vq->vring.log_guest_addr = addr.log_guest_addr;
if (map_ring(vdev, vq))
die("Invalid vring_addr message");
vq->used_idx = le16toh(vq->vring.used->idx);
if (vq->last_avail_idx != vq->used_idx) {
debug("Last avail index != used index: %u != %u",
vq->last_avail_idx, vq->used_idx);
}
return false;
}
/**
* vu_set_vring_base_exec() - Sets the next index to use for descriptors
* in this vring
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_base_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
unsigned int idx = msg->payload.state.index;
unsigned int num = msg->payload.state.num;
debug("State.index: %u", idx);
debug("State.num: %u", num);
vdev->vq[idx].shadow_avail_idx = vdev->vq[idx].last_avail_idx = num;
return false;
}
/**
* vu_get_vring_base_exec() - Stops the vring and returns the current
* descriptor index or indices
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: True as a reply is requested
*/
static bool vu_get_vring_base_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
unsigned int idx = msg->payload.state.index;
debug("State.index: %u", idx);
msg->payload.state.num = vdev->vq[idx].last_avail_idx;
msg->hdr.size = sizeof(msg->payload.state);
vdev->vq[idx].started = false;
if (vdev->vq[idx].call_fd != -1) {
close(vdev->vq[idx].call_fd);
vdev->vq[idx].call_fd = -1;
}
if (vdev->vq[idx].kick_fd != -1) {
vu_remove_watch(vdev, vdev->vq[idx].kick_fd);
close(vdev->vq[idx].kick_fd);
vdev->vq[idx].kick_fd = -1;
}
return true;
}
/**
* vu_set_watch() - Add a file descriptor to the passt epoll file descriptor
* @vdev: vhost-user device
* @idx: queue index of the file descriptor to add
*/
static void vu_set_watch(const struct vu_dev *vdev, int idx)
{
/* Placeholder to add passt related code */
(void)vdev;
(void)idx;
}
/**
* vu_check_queue_msg_file() - Check if a message is valid,
* close fds if NOFD bit is set
* @vmsg: vhost-user message
*/
static void vu_check_queue_msg_file(struct vhost_user_msg *msg)
{
bool nofd = msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
int idx = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
if (idx >= VHOST_USER_MAX_QUEUES)
die("Invalid vhost-user queue index: %u", idx);
if (nofd) {
vmsg_close_fds(msg);
return;
}
if (msg->fd_num != 1)
die("Invalid fds in vhost-user request: %d", msg->hdr.request);
}
/**
* vu_set_vring_kick_exec() - Set the event file descriptor for adding buffers
* to the vring
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_kick_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
bool nofd = msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
int idx = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
debug("u64: 0x%016"PRIx64, msg->payload.u64);
vu_check_queue_msg_file(msg);
if (vdev->vq[idx].kick_fd != -1) {
vu_remove_watch(vdev, vdev->vq[idx].kick_fd);
close(vdev->vq[idx].kick_fd);
vdev->vq[idx].kick_fd = -1;
}
if (!nofd)
vdev->vq[idx].kick_fd = msg->fds[0];
debug("Got kick_fd: %d for vq: %d", vdev->vq[idx].kick_fd, idx);
vdev->vq[idx].started = true;
if (vdev->vq[idx].kick_fd != -1 && VHOST_USER_IS_QUEUE_TX(idx)) {
vu_set_watch(vdev, idx);
debug("Waiting for kicks on fd: %d for vq: %d",
vdev->vq[idx].kick_fd, idx);
}
return false;
}
/**
* vu_set_vring_call_exec() - Set the event file descriptor to signal when
* buffers are used
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_call_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
bool nofd = msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
int idx = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
debug("u64: 0x%016"PRIx64, msg->payload.u64);
vu_check_queue_msg_file(msg);
if (vdev->vq[idx].call_fd != -1) {
close(vdev->vq[idx].call_fd);
vdev->vq[idx].call_fd = -1;
}
if (!nofd)
vdev->vq[idx].call_fd = msg->fds[0];
/* in case of I/O hang after reconnecting */
if (vdev->vq[idx].call_fd != -1)
eventfd_write(msg->fds[0], 1);
debug("Got call_fd: %d for vq: %d", vdev->vq[idx].call_fd, idx);
return false;
}
/**
* vu_set_vring_err_exec() - Set the event file descriptor to signal when
* error occurs
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_err_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
bool nofd = msg->payload.u64 & VHOST_USER_VRING_NOFD_MASK;
int idx = msg->payload.u64 & VHOST_USER_VRING_IDX_MASK;
debug("u64: 0x%016"PRIx64, msg->payload.u64);
vu_check_queue_msg_file(msg);
if (vdev->vq[idx].err_fd != -1) {
close(vdev->vq[idx].err_fd);
vdev->vq[idx].err_fd = -1;
}
if (!nofd)
vdev->vq[idx].err_fd = msg->fds[0];
return false;
}
/**
* vu_get_protocol_features_exec() - Provide the protocol (vhost-user) features
* to the front-end
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: True as a reply is requested
*/
static bool vu_get_protocol_features_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
uint64_t features = 1ULL << VHOST_USER_PROTOCOL_F_REPLY_ACK;
(void)vdev;
vmsg_set_reply_u64(msg, features);
return true;
}
/**
* vu_set_protocol_features_exec() - Enable protocol (vhost-user) features
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_protocol_features_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
uint64_t features = msg->payload.u64;
debug("u64: 0x%016"PRIx64, features);
vdev->protocol_features = msg->payload.u64;
return false;
}
/**
* vu_get_queue_num_exec() - Tell how many queues we support
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: True as a reply is requested
*/
static bool vu_get_queue_num_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
(void)vdev;
vmsg_set_reply_u64(msg, VHOST_USER_MAX_QUEUES);
return true;
}
/**
* vu_set_vring_enable_exec() - Enable or disable corresponding vring
* @vdev: vhost-user device
* @vmsg: vhost-user message
*
* Return: False as no reply is requested
*/
static bool vu_set_vring_enable_exec(struct vu_dev *vdev,
struct vhost_user_msg *msg)
{
unsigned int enable = msg->payload.state.num;
unsigned int idx = msg->payload.state.index;
debug("State.index: %u", idx);
debug("State.enable: %u", enable);
if (idx >= VHOST_USER_MAX_QUEUES)
die("Invalid vring_enable index: %u", idx);
vdev->vq[idx].enable = enable;
return false;
}
/**
* vu_init() - Initialize vhost-user device structure
* @c: execution context
* @vdev: vhost-user device
*/
/* cppcheck-suppress unusedFunction */
void vu_init(struct ctx *c, struct vu_dev *vdev)
{
int i;
vdev->context = c;
for (i = 0; i < VHOST_USER_MAX_QUEUES; i++) {
vdev->vq[i] = (struct vu_virtq){
.call_fd = -1,
.kick_fd = -1,
.err_fd = -1,
.notification = true,
};
}
}
/**
* vu_cleanup() - Reset vhost-user device
* @vdev: vhost-user device
*/
/* cppcheck-suppress unusedFunction */
void vu_cleanup(struct vu_dev *vdev)
{
unsigned int i;
for (i = 0; i < VHOST_USER_MAX_QUEUES; i++) {
struct vu_virtq *vq = &vdev->vq[i];
vq->started = false;
vq->notification = true;
if (vq->call_fd != -1) {
close(vq->call_fd);
vq->call_fd = -1;
}
if (vq->err_fd != -1) {
close(vq->err_fd);
vq->err_fd = -1;
}
if (vq->kick_fd != -1) {
vu_remove_watch(vdev, vq->kick_fd);
close(vq->kick_fd);
vq->kick_fd = -1;
}
vq->vring.desc = 0;
vq->vring.used = 0;
vq->vring.avail = 0;
}
for (i = 0; i < vdev->nregions; i++) {
const struct vu_dev_region *r = &vdev->regions[i];
if (r->mmap_addr) {
/* NOLINTNEXTLINE(performance-no-int-to-ptr) */
munmap((void *)r->mmap_addr, r->size + r->mmap_offset);
}
}
vdev->nregions = 0;
}
/**
* vu_sock_reset() - Reset connection socket
* @vdev: vhost-user device
*/
static void vu_sock_reset(struct vu_dev *vdev)
{
/* Placeholder to add passt related code */
(void)vdev;
}
static bool (*vu_handle[VHOST_USER_MAX])(struct vu_dev *vdev,
struct vhost_user_msg *msg) = {
[VHOST_USER_GET_FEATURES] = vu_get_features_exec,
[VHOST_USER_SET_FEATURES] = vu_set_features_exec,
[VHOST_USER_GET_PROTOCOL_FEATURES] = vu_get_protocol_features_exec,
[VHOST_USER_SET_PROTOCOL_FEATURES] = vu_set_protocol_features_exec,
[VHOST_USER_GET_QUEUE_NUM] = vu_get_queue_num_exec,
[VHOST_USER_SET_OWNER] = vu_set_owner_exec,
[VHOST_USER_SET_MEM_TABLE] = vu_set_mem_table_exec,
[VHOST_USER_SET_VRING_NUM] = vu_set_vring_num_exec,
[VHOST_USER_SET_VRING_ADDR] = vu_set_vring_addr_exec,
[VHOST_USER_SET_VRING_BASE] = vu_set_vring_base_exec,
[VHOST_USER_GET_VRING_BASE] = vu_get_vring_base_exec,
[VHOST_USER_SET_VRING_KICK] = vu_set_vring_kick_exec,
[VHOST_USER_SET_VRING_CALL] = vu_set_vring_call_exec,
[VHOST_USER_SET_VRING_ERR] = vu_set_vring_err_exec,
[VHOST_USER_SET_VRING_ENABLE] = vu_set_vring_enable_exec,
};
/**
* vu_control_handler() - Handle control commands for vhost-user
* @vdev: vhost-user device
* @fd: vhost-user message socket
* @events: epoll events
*/
/* cppcheck-suppress unusedFunction */
void vu_control_handler(struct vu_dev *vdev, int fd, uint32_t events)
{
struct vhost_user_msg msg = { 0 };
bool need_reply, reply_requested;
int ret;
if (events & (EPOLLRDHUP | EPOLLHUP | EPOLLERR)) {
vu_sock_reset(vdev);
return;
}
ret = vu_message_read_default(fd, &msg);
if (ret == 0) {
vu_sock_reset(vdev);
return;
}
debug("================ Vhost user message ================");
debug("Request: %s (%d)", vu_request_to_string(msg.hdr.request),
msg.hdr.request);
debug("Flags: 0x%x", msg.hdr.flags);
debug("Size: %u", msg.hdr.size);
need_reply = msg.hdr.flags & VHOST_USER_NEED_REPLY_MASK;
if (msg.hdr.request >= 0 && msg.hdr.request < VHOST_USER_MAX &&
vu_handle[msg.hdr.request])
reply_requested = vu_handle[msg.hdr.request](vdev, &msg);
else
die("Unhandled request: %d", msg.hdr.request);
/* cppcheck-suppress legacyUninitvar */
if (!reply_requested && need_reply) {
msg.payload.u64 = 0;
msg.hdr.flags = 0;
msg.hdr.size = sizeof(msg.payload.u64);
msg.fd_num = 0;
reply_requested = true;
}
if (reply_requested)
vu_send_reply(fd, &msg);
}

208
vhost_user.h Normal file
View File

@ -0,0 +1,208 @@
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* vhost-user API, command management and virtio interface
*
* Copyright Red Hat
* Author: Laurent Vivier <lvivier@redhat.com>
*/
/* some parts from subprojects/libvhost-user/libvhost-user.h */
#ifndef VHOST_USER_H
#define VHOST_USER_H
#include "virtio.h"
#include "iov.h"
#define VHOST_USER_F_PROTOCOL_FEATURES 30
#define VHOST_MEMORY_BASELINE_NREGIONS 8
/**
* enum vhost_user_protocol_feature - List of available vhost-user features
*/
enum vhost_user_protocol_feature {
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_NET_MTU = 4,
VHOST_USER_PROTOCOL_F_BACKEND_REQ = 5,
VHOST_USER_PROTOCOL_F_CROSS_ENDIAN = 6,
VHOST_USER_PROTOCOL_F_CRYPTO_SESSION = 7,
VHOST_USER_PROTOCOL_F_PAGEFAULT = 8,
VHOST_USER_PROTOCOL_F_CONFIG = 9,
VHOST_USER_PROTOCOL_F_SLAVE_SEND_FD = 10,
VHOST_USER_PROTOCOL_F_HOST_NOTIFIER = 11,
VHOST_USER_PROTOCOL_F_INFLIGHT_SHMFD = 12,
VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS = 14,
VHOST_USER_PROTOCOL_F_CONFIGURE_MEM_SLOTS = 15,
VHOST_USER_PROTOCOL_F_MAX
};
/**
* enum vhost_user_request - List of available vhost-user requests
*/
enum vhost_user_request {
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_NET_SET_MTU = 20,
VHOST_USER_SET_BACKEND_REQ_FD = 21,
VHOST_USER_IOTLB_MSG = 22,
VHOST_USER_SET_VRING_ENDIAN = 23,
VHOST_USER_GET_CONFIG = 24,
VHOST_USER_SET_CONFIG = 25,
VHOST_USER_CREATE_CRYPTO_SESSION = 26,
VHOST_USER_CLOSE_CRYPTO_SESSION = 27,
VHOST_USER_POSTCOPY_ADVISE = 28,
VHOST_USER_POSTCOPY_LISTEN = 29,
VHOST_USER_POSTCOPY_END = 30,
VHOST_USER_GET_INFLIGHT_FD = 31,
VHOST_USER_SET_INFLIGHT_FD = 32,
VHOST_USER_GPU_SET_SOCKET = 33,
VHOST_USER_VRING_KICK = 35,
VHOST_USER_GET_MAX_MEM_SLOTS = 36,
VHOST_USER_ADD_MEM_REG = 37,
VHOST_USER_REM_MEM_REG = 38,
VHOST_USER_MAX
};
/**
* struct vhost_user_header - vhost-user message header
* @request: Request type of the message
* @flags: Request flags
* @size: The following payload size
*/
struct vhost_user_header {
enum vhost_user_request 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;
} __attribute__ ((__packed__));
/**
* struct vhost_user_memory_region - Front-end shared memory region information
* @guest_phys_addr: Guest physical address of the region
* @memory_size: Memory size
* @userspace_addr: front-end (QEMU) userspace address
* @mmap_offset: region offset in the shared memory area
*/
struct vhost_user_memory_region {
uint64_t guest_phys_addr;
uint64_t memory_size;
uint64_t userspace_addr;
uint64_t mmap_offset;
};
/**
* struct vhost_user_memory - List of all the shared memory regions
* @nregions: Number of memory regions
* @padding: Padding
* @regions: Memory regions list
*/
struct vhost_user_memory {
uint32_t nregions;
uint32_t padding;
struct vhost_user_memory_region regions[VHOST_MEMORY_BASELINE_NREGIONS];
};
/**
* union vhost_user_payload - vhost-user message payload
* @u64: 64-bit payload
* @state: vring state payload
* @addr: vring addresses payload
* vhost_user_memory: Memory regions information payload
*/
union vhost_user_payload {
#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;
struct vhost_user_memory memory;
};
/**
* struct vhost_user_msg - vhost-use message
* @hdr: Message header
* @payload: Message payload
* @fds: File descriptors associated with the message
* in the ancillary data.
* (shared memory or event file descriptors)
* @fd_num: Number of file descriptors
*/
struct vhost_user_msg {
struct vhost_user_header hdr;
union vhost_user_payload payload;
int fds[VHOST_MEMORY_BASELINE_NREGIONS];
int fd_num;
} __attribute__ ((__packed__));
#define VHOST_USER_HDR_SIZE sizeof(struct vhost_user_header)
/* index of the RX virtqueue */
#define VHOST_USER_RX_QUEUE 0
/* index of the TX virtqueue */
#define VHOST_USER_TX_QUEUE 1
/* in case of multiqueue, the RX and TX queues are interleaved */
#define VHOST_USER_IS_QUEUE_TX(n) (n % 2)
#define VHOST_USER_IS_QUEUE_RX(n) (!(n % 2))
/* Default virtio-net header for passt */
#define VU_HEADER ((struct virtio_net_hdr){ \
.flags = VIRTIO_NET_HDR_F_DATA_VALID, \
.gso_type = VIRTIO_NET_HDR_GSO_NONE, \
})
/**
* vu_queue_enabled - Return state of a virtqueue
* @vq: virtqueue to check
*
* Return: true if the virqueue is enabled, false otherwise
*/
/* cppcheck-suppress unusedFunction */
static inline bool vu_queue_enabled(const struct vu_virtq *vq)
{
return vq->enable;
}
/**
* vu_queue_started - Return state of a virtqueue
* @vq: virtqueue to check
*
* Return: true if the virqueue is started, false otherwise
*/
/* cppcheck-suppress unusedFunction */
static inline bool vu_queue_started(const struct vu_virtq *vq)
{
return vq->started;
}
void vu_print_capabilities(void);
void vu_init(struct ctx *c, struct vu_dev *vdev);
void vu_cleanup(struct vu_dev *vdev);
void vu_control_handler(struct vu_dev *vdev, int fd, uint32_t events);
#endif /* VHOST_USER_H */

1
virtio.h
View File

@ -105,6 +105,7 @@ struct vu_dev_region {
* @protocol_features: Vhost-user protocol features
*/
struct vu_dev {
struct ctx *context;
uint32_t nregions;
struct vu_dev_region regions[VHOST_USER_MAX_RAM_SLOTS];
struct vu_virtq vq[VHOST_USER_MAX_QUEUES];