Commit e54b7f52 authored by Anthony Liguori's avatar Anthony Liguori
Browse files

Merge remote branch 'amit/for-anthony' into staging

parents 1cd20f8b 37f95bf3
......@@ -20,11 +20,11 @@ typedef struct VirtConsole {
/* Callback function that's called when the guest sends us data */
static void flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)
static ssize_t flush_buf(VirtIOSerialPort *port, const uint8_t *buf, size_t len)
{
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
qemu_chr_write(vcon->chr, buf, len);
return qemu_chr_write(vcon->chr, buf, len);
}
/* Readiness of the guest to accept data on a port */
......@@ -48,34 +48,37 @@ static void chr_event(void *opaque, int event)
VirtConsole *vcon = opaque;
switch (event) {
case CHR_EVENT_OPENED: {
case CHR_EVENT_OPENED:
virtio_serial_open(&vcon->port);
break;
}
case CHR_EVENT_CLOSED:
virtio_serial_close(&vcon->port);
break;
}
}
/* Virtio Console Ports */
static int virtconsole_initfn(VirtIOSerialDevice *dev)
static int generic_port_init(VirtConsole *vcon, VirtIOSerialDevice *dev)
{
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
port->info = dev->info;
port->is_console = true;
vcon->port.info = dev->info;
if (vcon->chr) {
qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
vcon);
port->info->have_data = flush_buf;
vcon->port.info->have_data = flush_buf;
}
return 0;
}
/* Virtio Console Ports */
static int virtconsole_initfn(VirtIOSerialDevice *dev)
{
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
port->is_console = true;
return generic_port_init(vcon, dev);
}
static int virtconsole_exitfn(VirtIOSerialDevice *dev)
{
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
......@@ -115,14 +118,7 @@ static int virtserialport_initfn(VirtIOSerialDevice *dev)
VirtIOSerialPort *port = DO_UPCAST(VirtIOSerialPort, dev, &dev->qdev);
VirtConsole *vcon = DO_UPCAST(VirtConsole, port, port);
port->info = dev->info;
if (vcon->chr) {
qemu_chr_add_handlers(vcon->chr, chr_can_read, chr_read, chr_event,
vcon);
port->info->have_data = flush_buf;
}
return 0;
return generic_port_init(vcon, dev);
}
static VirtIOSerialPortInfo virtserialport_info = {
......
......@@ -113,39 +113,74 @@ static size_t write_to_port(VirtIOSerialPort *port,
return offset;
}
static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
VirtIODevice *vdev, bool discard)
static void discard_vq_data(VirtQueue *vq, VirtIODevice *vdev)
{
VirtQueueElement elem;
assert(port || discard);
while (virtqueue_pop(vq, &elem)) {
virtqueue_push(vq, &elem, 0);
}
virtio_notify(vdev, vq);
}
static void do_flush_queued_data(VirtIOSerialPort *port, VirtQueue *vq,
VirtIODevice *vdev)
{
assert(port);
assert(virtio_queue_ready(vq));
while ((discard || !port->throttled) && virtqueue_pop(vq, &elem)) {
uint8_t *buf;
size_t ret, buf_size;
while (!port->throttled) {
unsigned int i;
if (!discard) {
buf_size = iov_size(elem.out_sg, elem.out_num);
buf = qemu_malloc(buf_size);
ret = iov_to_buf(elem.out_sg, elem.out_num, buf, 0, buf_size);
/* Pop an elem only if we haven't left off a previous one mid-way */
if (!port->elem.out_num) {
if (!virtqueue_pop(vq, &port->elem)) {
break;
}
port->iov_idx = 0;
port->iov_offset = 0;
}
port->info->have_data(port, buf, ret);
qemu_free(buf);
for (i = port->iov_idx; i < port->elem.out_num; i++) {
size_t buf_size;
ssize_t ret;
buf_size = port->elem.out_sg[i].iov_len - port->iov_offset;
ret = port->info->have_data(port,
port->elem.out_sg[i].iov_base
+ port->iov_offset,
buf_size);
if (ret < 0 && ret != -EAGAIN) {
/* We don't handle any other type of errors here */
abort();
}
if (ret == -EAGAIN || (ret >= 0 && ret < buf_size)) {
virtio_serial_throttle_port(port, true);
port->iov_idx = i;
if (ret > 0) {
port->iov_offset += ret;
}
break;
}
port->iov_offset = 0;
}
virtqueue_push(vq, &elem, 0);
if (port->throttled) {
break;
}
virtqueue_push(vq, &port->elem, 0);
port->elem.out_num = 0;
}
virtio_notify(vdev, vq);
}
static void flush_queued_data(VirtIOSerialPort *port, bool discard)
static void flush_queued_data(VirtIOSerialPort *port)
{
assert(port);
if (!virtio_queue_ready(port->ovq)) {
return;
}
do_flush_queued_data(port, port->ovq, &port->vser->vdev, discard);
do_flush_queued_data(port, port->ovq, &port->vser->vdev);
}
static size_t send_control_msg(VirtIOSerialPort *port, void *buf, size_t len)
......@@ -204,7 +239,7 @@ int virtio_serial_close(VirtIOSerialPort *port)
* consume, reset the throttling flag and discard the data.
*/
port->throttled = false;
flush_queued_data(port, true);
discard_vq_data(port->ovq, &port->vser->vdev);
send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN, 0);
......@@ -258,7 +293,7 @@ void virtio_serial_throttle_port(VirtIOSerialPort *port, bool throttle)
return;
}
flush_queued_data(port, false);
flush_queued_data(port);
}
/* Guest wants to notify us of some event */
......@@ -414,11 +449,15 @@ static void handle_output(VirtIODevice *vdev, VirtQueue *vq)
discard = true;
}
if (!discard && port->throttled) {
if (discard) {
discard_vq_data(vq, vdev);
return;
}
if (port->throttled) {
return;
}
do_flush_queued_data(port, vq, vdev, discard);
do_flush_queued_data(port, vq, vdev);
}
static void handle_input(VirtIODevice *vdev, VirtQueue *vq)
......@@ -488,9 +527,24 @@ static void virtio_serial_save(QEMUFile *f, void *opaque)
* Items in struct VirtIOSerialPort.
*/
QTAILQ_FOREACH(port, &s->ports, next) {
uint32_t elem_popped;
qemu_put_be32s(f, &port->id);
qemu_put_byte(f, port->guest_connected);
qemu_put_byte(f, port->host_connected);
elem_popped = 0;
if (port->elem.out_num) {
elem_popped = 1;
}
qemu_put_be32s(f, &elem_popped);
if (elem_popped) {
qemu_put_be32s(f, &port->iov_idx);
qemu_put_be64s(f, &port->iov_offset);
qemu_put_buffer(f, (unsigned char *)&port->elem,
sizeof(port->elem));
}
}
}
......@@ -501,7 +555,7 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
uint32_t max_nr_ports, nr_active_ports, ports_map;
unsigned int i;
if (version_id > 2) {
if (version_id > 3) {
return -EINVAL;
}
......@@ -554,6 +608,29 @@ static int virtio_serial_load(QEMUFile *f, void *opaque, int version_id)
send_control_event(port, VIRTIO_CONSOLE_PORT_OPEN,
port->host_connected);
}
if (version_id > 2) {
uint32_t elem_popped;
qemu_get_be32s(f, &elem_popped);
if (elem_popped) {
qemu_get_be32s(f, &port->iov_idx);
qemu_get_be64s(f, &port->iov_offset);
qemu_get_buffer(f, (unsigned char *)&port->elem,
sizeof(port->elem));
virtqueue_map_sg(port->elem.in_sg, port->elem.in_addr,
port->elem.in_num, 1);
virtqueue_map_sg(port->elem.out_sg, port->elem.out_addr,
port->elem.out_num, 1);
/*
* Port was throttled on source machine. Let's
* unthrottle it here so data starts flowing again.
*/
virtio_serial_throttle_port(port, false);
}
}
}
return 0;
}
......@@ -634,7 +711,7 @@ static void remove_port(VirtIOSerial *vser, uint32_t port_id)
port = find_port_by_id(vser, port_id);
/* Flush out any unconsumed buffers first */
flush_queued_data(port, true);
discard_vq_data(port->ovq, &port->vser->vdev);
send_control_event(port, VIRTIO_CONSOLE_PORT_REMOVE, 1);
}
......@@ -695,6 +772,8 @@ static int virtser_port_qdev_init(DeviceState *qdev, DeviceInfo *base)
port->guest_connected = true;
}
port->elem.out_num = 0;
QTAILQ_INSERT_TAIL(&port->vser->ports, port, next);
port->ivq = port->vser->ivqs[port->id];
port->ovq = port->vser->ovqs[port->id];
......@@ -806,7 +885,7 @@ VirtIODevice *virtio_serial_init(DeviceState *dev, uint32_t max_nr_ports)
* Register for the savevm section with the virtio-console name
* to preserve backward compat
*/
register_savevm(dev, "virtio-console", -1, 2, virtio_serial_save,
register_savevm(dev, "virtio-console", -1, 3, virtio_serial_save,
virtio_serial_load, vser);
return vdev;
......
......@@ -102,6 +102,23 @@ struct VirtIOSerialPort {
*/
uint32_t id;
/*
* This is the elem that we pop from the virtqueue. A slow
* backend that consumes guest data (e.g. the file backend for
* qemu chardevs) can cause the guest to block till all the output
* is flushed. This isn't desired, so we keep a note of the last
* element popped and continue consuming it once the backend
* becomes writable again.
*/
VirtQueueElement elem;
/*
* The index and the offset into the iov buffer that was popped in
* elem above.
*/
uint32_t iov_idx;
uint64_t iov_offset;
/* Identify if this is a port that binds with hvc in the guest */
uint8_t is_console;
......@@ -137,10 +154,11 @@ struct VirtIOSerialPortInfo {
/*
* Guest wrote some data to the port. This data is handed over to
* the app via this callback. The app is supposed to consume all
* the data that is presented to it.
* the app via this callback. The app can return a size less than
* 'len'. In this case, throttling will be enabled for this port.
*/
void (*have_data)(VirtIOSerialPort *port, const uint8_t *buf, size_t len);
ssize_t (*have_data)(VirtIOSerialPort *port, const uint8_t *buf,
size_t len);
};
/* Interface to the virtio-serial bus */
......
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