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#include <sys/epoll.h>
#include <sys/ioctl.h>
#include <pthread.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <linux/kernel.h>
#include <linux/kvm.h>
#include <linux/types.h>
#include "kvm/ioeventfd.h"
#include "kvm/kvm.h"
#include "kvm/util.h"
#define IOEVENTFD_MAX_EVENTS 20
static struct epoll_event events[IOEVENTFD_MAX_EVENTS];
static int epoll_fd, epoll_stop_fd;
static LIST_HEAD(used_ioevents);
static bool ioeventfd_avail;
static void *ioeventfd__thread(void *param)
{
u64 tmp = 1;
kvm__set_thread_name("ioeventfd-worker");
for (;;) {
int nfds, i;
nfds = epoll_wait(epoll_fd, events, IOEVENTFD_MAX_EVENTS, -1);
for (i = 0; i < nfds; i++) {
struct ioevent *ioevent;
if (events[i].data.fd == epoll_stop_fd)
goto done;
ioevent = events[i].data.ptr;
if (read(ioevent->fd, &tmp, sizeof(tmp)) < 0)
die("Failed reading event");
ioevent->fn(ioevent->fn_kvm, ioevent->fn_ptr);
}
}
done:
tmp = write(epoll_stop_fd, &tmp, sizeof(tmp));
return NULL;
}
static int ioeventfd__start(void)
{
pthread_t thread;
if (!ioeventfd_avail)
return -ENOSYS;
return pthread_create(&thread, NULL, ioeventfd__thread, NULL);
}
int ioeventfd__init(struct kvm *kvm)
{
struct epoll_event epoll_event = {.events = EPOLLIN};
int r;
ioeventfd_avail = kvm__supports_extension(kvm, KVM_CAP_IOEVENTFD);
if (!ioeventfd_avail)
return 1; /* Not fatal, but let caller determine no-go. */
epoll_fd = epoll_create(IOEVENTFD_MAX_EVENTS);
if (epoll_fd < 0)
return -errno;
epoll_stop_fd = eventfd(0, 0);
epoll_event.data.fd = epoll_stop_fd;
r = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, epoll_stop_fd, &epoll_event);
if (r < 0)
goto cleanup;
r = ioeventfd__start();
if (r < 0)
goto cleanup;
r = 0;
return r;
cleanup:
close(epoll_stop_fd);
close(epoll_fd);
return r;
}
base_init(ioeventfd__init);
int ioeventfd__exit(struct kvm *kvm)
{
u64 tmp = 1;
int r;
if (!ioeventfd_avail)
return 0;
r = write(epoll_stop_fd, &tmp, sizeof(tmp));
if (r < 0)
return r;
r = read(epoll_stop_fd, &tmp, sizeof(tmp));
if (r < 0)
return r;
close(epoll_fd);
close(epoll_stop_fd);
return 0;
}
base_exit(ioeventfd__exit);
int ioeventfd__add_event(struct ioevent *ioevent, int flags)
{
struct kvm_ioeventfd kvm_ioevent;
struct epoll_event epoll_event;
struct ioevent *new_ioevent;
int event, r;
if (!ioeventfd_avail)
return -ENOSYS;
new_ioevent = malloc(sizeof(*new_ioevent));
if (new_ioevent == NULL)
return -ENOMEM;
*new_ioevent = *ioevent;
event = new_ioevent->fd;
kvm_ioevent = (struct kvm_ioeventfd) {
.addr = ioevent->io_addr,
.len = ioevent->io_len,
.datamatch = ioevent->datamatch,
.fd = event,
.flags = KVM_IOEVENTFD_FLAG_DATAMATCH,
};
if (flags & IOEVENTFD_FLAG_PIO)
kvm_ioevent.flags |= KVM_IOEVENTFD_FLAG_PIO;
r = ioctl(ioevent->fn_kvm->vm_fd, KVM_IOEVENTFD, &kvm_ioevent);
if (r) {
r = -errno;
goto cleanup;
}
if (!(flags & IOEVENTFD_FLAG_USER_POLL))
return 0;
epoll_event = (struct epoll_event) {
.events = EPOLLIN,
.data.ptr = new_ioevent,
};
r = epoll_ctl(epoll_fd, EPOLL_CTL_ADD, event, &epoll_event);
if (r) {
r = -errno;
goto cleanup;
}
list_add_tail(&new_ioevent->list, &used_ioevents);
return 0;
cleanup:
free(new_ioevent);
return r;
}
int ioeventfd__del_event(u64 addr, u64 datamatch)
{
struct kvm_ioeventfd kvm_ioevent;
struct ioevent *ioevent;
u8 found = 0;
if (!ioeventfd_avail)
return -ENOSYS;
list_for_each_entry(ioevent, &used_ioevents, list) {
if (ioevent->io_addr == addr) {
found = 1;
break;
}
}
if (found == 0 || ioevent == NULL)
return -ENOENT;
kvm_ioevent = (struct kvm_ioeventfd) {
.addr = ioevent->io_addr,
.len = ioevent->io_len,
.datamatch = ioevent->datamatch,
.flags = KVM_IOEVENTFD_FLAG_PIO
| KVM_IOEVENTFD_FLAG_DEASSIGN
| KVM_IOEVENTFD_FLAG_DATAMATCH,
};
ioctl(ioevent->fn_kvm->vm_fd, KVM_IOEVENTFD, &kvm_ioevent);
epoll_ctl(epoll_fd, EPOLL_CTL_DEL, ioevent->fd, NULL);
list_del(&ioevent->list);
close(ioevent->fd);
free(ioevent);
return 0;
}
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