static void blk_handle_requests(struct XenBlkDev *blkdev)
{
RING_IDX rc, rp;
struct ioreq *ioreq;
blkdev->more_work = 0;
rc = blkdev->rings.common.req_cons;
rp = blkdev->rings.common.sring->req_prod;
xen_rmb(); /* Ensure we see queued requests up to 'rp'. */
blk_send_response_all(blkdev);
while (rc != rp) {
/* pull request from ring */
if (RING_REQUEST_CONS_OVERFLOW(&blkdev->rings.common, rc)) {
break;
}
ioreq = ioreq_start(blkdev);
if (ioreq == NULL) {
blkdev->more_work++;
break;
}
blk_get_request(blkdev, ioreq, rc);
blkdev->rings.common.req_cons = ++rc;
/* parse them */
if (ioreq_parse(ioreq) != 0) {
switch (ioreq->req.operation) {
case BLKIF_OP_READ:
block_acct_invalid(blk_get_stats(blkdev->blk),
BLOCK_ACCT_READ);
break;
case BLKIF_OP_WRITE:
block_acct_invalid(blk_get_stats(blkdev->blk),
BLOCK_ACCT_WRITE);
break;
case BLKIF_OP_FLUSH_DISKCACHE:
block_acct_invalid(blk_get_stats(blkdev->blk),
BLOCK_ACCT_FLUSH);
default:
break;
};
if (blk_send_response_one(ioreq)) {
xen_pv_send_notify(&blkdev->xendev);
}
ioreq_release(ioreq, false);
continue;
}
ioreq_runio_qemu_aio(ioreq);
}
if (blkdev->more_work && blkdev->requests_inflight < blkdev->max_requests) {
qemu_bh_schedule(blkdev->bh);
}
}
static void input_event(struct XenDevice *xendev)
{
struct XenInput *xenfb = container_of(xendev, struct XenInput, c.xendev);
struct xenkbd_page *page = xenfb->c.page;
/* We don't understand any keyboard events, so just ignore them. */
if (page->out_prod == page->out_cons)
return;
page->out_cons = page->out_prod;
xen_pv_send_notify(&xenfb->c.xendev);
}
/* walk finished list, send outstanding responses, free requests */
static void blk_send_response_all(struct XenBlkDev *blkdev)
{
struct ioreq *ioreq;
int send_notify = 0;
while (!QLIST_EMPTY(&blkdev->finished)) {
ioreq = QLIST_FIRST(&blkdev->finished);
send_notify += blk_send_response_one(ioreq);
ioreq_release(ioreq, true);
}
if (send_notify) {
xen_pv_send_notify(&blkdev->xendev);
}
}
static void buffer_append(struct XenConsole *con)
{
struct buffer *buffer = &con->buffer;
XENCONS_RING_IDX cons, prod, size;
struct xencons_interface *intf = con->sring;
cons = intf->out_cons;
prod = intf->out_prod;
xen_mb();
size = prod - cons;
if ((size == 0) || (size > sizeof(intf->out)))
return;
if ((buffer->capacity - buffer->size) < size) {
buffer->capacity += (size + 1024);
buffer->data = g_realloc(buffer->data, buffer->capacity);
}
while (cons != prod)
buffer->data[buffer->size++] = intf->out[
MASK_XENCONS_IDX(cons++, intf->out)];
xen_mb();
intf->out_cons = cons;
xen_pv_send_notify(&con->xendev);
if (buffer->max_capacity &&
buffer->size > buffer->max_capacity) {
/* Discard the middle of the data. */
size_t over = buffer->size - buffer->max_capacity;
uint8_t *maxpos = buffer->data + buffer->max_capacity;
memmove(maxpos - over, maxpos, over);
buffer->data = g_realloc(buffer->data, buffer->max_capacity);
buffer->size = buffer->capacity = buffer->max_capacity;
if (buffer->consumed > buffer->max_capacity - over)
buffer->consumed = buffer->max_capacity - over;
}
}
static void xencons_receive(void *opaque, const uint8_t *buf, int len)
{
struct XenConsole *con = opaque;
struct xencons_interface *intf = con->sring;
XENCONS_RING_IDX prod;
int i, max;
max = ring_free_bytes(con);
/* The can_receive() func limits this, but check again anyway */
if (max < len)
len = max;
prod = intf->in_prod;
for (i = 0; i < len; i++) {
intf->in[MASK_XENCONS_IDX(prod++, intf->in)] =
buf[i];
}
xen_wmb();
intf->in_prod = prod;
xen_pv_send_notify(&con->xendev);
}
/* Send an event to the keyboard frontend driver */
static int xenfb_kbd_event(struct XenInput *xenfb,
union xenkbd_in_event *event)
{
struct xenkbd_page *page = xenfb->c.page;
uint32_t prod;
if (xenfb->c.xendev.be_state != XenbusStateConnected)
return 0;
if (!page)
return 0;
prod = page->in_prod;
if (prod - page->in_cons == XENKBD_IN_RING_LEN) {
errno = EAGAIN;
return -1;
}
xen_mb(); /* ensure ring space available */
XENKBD_IN_RING_REF(page, prod) = *event;
xen_wmb(); /* ensure ring contents visible */
page->in_prod = prod + 1;
return xen_pv_send_notify(&xenfb->c.xendev);
}
