diff options
| -rw-r--r-- | Documentation/virtual/lguest/lguest.c | 25 | ||||
| -rw-r--r-- | drivers/lguest/lguest_device.c | 37 |
2 files changed, 28 insertions, 34 deletions
diff --git a/Documentation/virtual/lguest/lguest.c b/Documentation/virtual/lguest/lguest.c index e3b9bb7a644..80261d34da3 100644 --- a/Documentation/virtual/lguest/lguest.c +++ b/Documentation/virtual/lguest/lguest.c @@ -1095,9 +1095,10 @@ static void update_device_status(struct device *dev) warnx("Device %s configuration FAILED", dev->name); if (dev->running) reset_device(dev); - } else if (dev->desc->status & VIRTIO_CONFIG_S_DRIVER_OK) { - if (!dev->running) - start_device(dev); + } else { + if (dev->running) + err(1, "Device %s features finalized twice", dev->name); + start_device(dev); } } @@ -1122,25 +1123,11 @@ static void handle_output(unsigned long addr) return; } - /* - * Devices *can* be used before status is set to DRIVER_OK. - * The original plan was that they would never do this: they - * would always finish setting up their status bits before - * actually touching the virtqueues. In practice, we allowed - * them to, and they do (eg. the disk probes for partition - * tables as part of initialization). - * - * If we see this, we start the device: once it's running, we - * expect the device to catch all the notifications. - */ + /* Devices should not be used before features are finalized. */ for (vq = i->vq; vq; vq = vq->next) { if (addr != vq->config.pfn*getpagesize()) continue; - if (i->running) - errx(1, "Notification on running %s", i->name); - /* This just calls create_thread() for each virtqueue */ - start_device(i); - return; + errx(1, "Notification on %s before setup!", i->name); } } diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 69c84a1d88e..5289ffa2e50 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -109,6 +109,17 @@ static u32 lg_get_features(struct virtio_device *vdev) } /* + * To notify on reset or feature finalization, we (ab)use the NOTIFY + * hypercall, with the descriptor address of the device. + */ +static void status_notify(struct virtio_device *vdev) +{ + unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices; + + hcall(LHCALL_NOTIFY, (max_pfn << PAGE_SHIFT) + offset, 0, 0, 0); +} + +/* * The virtio core takes the features the Host offers, and copies the ones * supported by the driver into the vdev->features array. Once that's all * sorted out, this routine is called so we can tell the Host which features we @@ -135,6 +146,9 @@ static void lg_finalize_features(struct virtio_device *vdev) if (test_bit(i, vdev->features)) out_features[i / 8] |= (1 << (i % 8)); } + + /* Tell Host we've finished with this device's feature negotiation */ + status_notify(vdev); } /* Once they've found a field, getting a copy of it is easy. */ @@ -168,28 +182,21 @@ static u8 lg_get_status(struct virtio_device *vdev) return to_lgdev(vdev)->desc->status; } -/* - * To notify on status updates, we (ab)use the NOTIFY hypercall, with the - * descriptor address of the device. A zero status means "reset". - */ -static void set_status(struct virtio_device *vdev, u8 status) -{ - unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices; - - /* We set the status. */ - to_lgdev(vdev)->desc->status = status; - hcall(LHCALL_NOTIFY, (max_pfn << PAGE_SHIFT) + offset, 0, 0, 0); -} - static void lg_set_status(struct virtio_device *vdev, u8 status) { BUG_ON(!status); - set_status(vdev, status); + to_lgdev(vdev)->desc->status = status; + + /* Tell Host immediately if we failed. */ + if (status & VIRTIO_CONFIG_S_FAILED) + status_notify(vdev); } static void lg_reset(struct virtio_device *vdev) { - set_status(vdev, 0); + /* 0 status means "reset" */ + to_lgdev(vdev)->desc->status = 0; + status_notify(vdev); } /* |