diff options
Diffstat (limited to 'Documentation/lguest')
| -rw-r--r-- | Documentation/lguest/lguest.c | 41 |
1 files changed, 22 insertions, 19 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 5470b8ed2149..84c471b07c27 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -551,6 +551,21 @@ static unsigned next_desc(struct virtqueue *vq, unsigned int i) return next; } +/* This actually sends the interrupt for this virtqueue */ +static void trigger_irq(struct virtqueue *vq) +{ + unsigned long buf[] = { LHREQ_IRQ, vq->config.irq }; + + /* If they don't want an interrupt, don't send one, unless empty. */ + if ((vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) + && lg_last_avail(vq) != vq->vring.avail->idx) + return; + + /* Send the Guest an interrupt tell them we used something up. */ + if (write(lguest_fd, buf, sizeof(buf)) != 0) + err(1, "Triggering irq %i", vq->config.irq); +} + /* This looks in the virtqueue and for the first available buffer, and converts * it to an iovec for convenient access. Since descriptors consist of some * number of output then some number of input descriptors, it's actually two @@ -567,6 +582,9 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq, while (last_avail == vq->vring.avail->idx) { u64 event; + /* OK, tell Guest about progress up to now. */ + trigger_irq(vq); + /* Nothing new? Wait for eventfd to tell us they refilled. */ if (read(vq->eventfd, &event, sizeof(event)) != sizeof(event)) errx(1, "Event read failed?"); @@ -631,21 +649,6 @@ static void add_used(struct virtqueue *vq, unsigned int head, int len) vq->vring.used->idx++; } -/* This actually sends the interrupt for this virtqueue */ -static void trigger_irq(struct virtqueue *vq) -{ - unsigned long buf[] = { LHREQ_IRQ, vq->config.irq }; - - /* If they don't want an interrupt, don't send one, unless empty. */ - if ((vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) - && lg_last_avail(vq) != vq->vring.avail->idx) - return; - - /* Send the Guest an interrupt tell them we used something up. */ - if (write(lguest_fd, buf, sizeof(buf)) != 0) - err(1, "Triggering irq %i", vq->config.irq); -} - /* And here's the combo meal deal. Supersize me! */ static void add_used_and_trigger(struct virtqueue *vq, unsigned head, int len) { @@ -730,7 +733,7 @@ static void console_output(struct virtqueue *vq) err(1, "Write to stdout gave %i", len); iov_consume(iov, out, len); } - add_used_and_trigger(vq, head, 0); + add_used(vq, head, 0); } /* @@ -754,7 +757,7 @@ static void net_output(struct virtqueue *vq) errx(1, "Input buffers in net output queue?"); if (writev(net_info->tunfd, iov, out) < 0) errx(1, "Write to tun failed?"); - add_used_and_trigger(vq, head, 0); + add_used(vq, head, 0); } /* This is where we handle packets coming in from the tun device to our @@ -1422,7 +1425,7 @@ static void blk_request(struct virtqueue *vq) if (out->type & VIRTIO_BLK_T_BARRIER) fdatasync(vblk->fd); - add_used_and_trigger(vq, head, wlen); + add_used(vq, head, wlen); } /*L:198 This actually sets up a virtual block device. */ @@ -1496,7 +1499,7 @@ static void rng_input(struct virtqueue *vq) } /* Tell the Guest about the new input. */ - add_used_and_trigger(vq, head, totlen); + add_used(vq, head, totlen); } /* And this creates a "hardware" random number device for the Guest. */ |