diff options
Diffstat (limited to 'drivers/lguest/lguest_device.c')
| -rw-r--r-- | drivers/lguest/lguest_device.c | 70 |
1 files changed, 47 insertions, 23 deletions
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 69c84a1d88e..d0a1d8a45c8 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -15,6 +15,7 @@ #include <linux/interrupt.h> #include <linux/virtio_ring.h> #include <linux/err.h> +#include <linux/export.h> #include <linux/slab.h> #include <asm/io.h> #include <asm/paravirt.h> @@ -109,6 +110,17 @@ 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 +147,9 @@ 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 +183,21 @@ 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); } /* @@ -221,7 +229,7 @@ struct lguest_vq_info { * make a hypercall. We hand the physical address of the virtqueue so the Host * knows which virtqueue we're talking about. */ -static void lg_notify(struct virtqueue *vq) +static bool lg_notify(struct virtqueue *vq) { /* * We store our virtqueue information in the "priv" pointer of the @@ -230,10 +238,11 @@ static void lg_notify(struct virtqueue *vq) struct lguest_vq_info *lvq = vq->priv; hcall(LHCALL_NOTIFY, lvq->config.pfn << PAGE_SHIFT, 0, 0, 0); + return true; } /* An extern declaration inside a C file is bad form. Don't do it. */ -extern void lguest_setup_irq(unsigned int irq); +extern int lguest_setup_irq(unsigned int irq); /* * This routine finds the Nth virtqueue described in the configuration of @@ -255,6 +264,9 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, struct virtqueue *vq; int err; + if (!name) + return NULL; + /* We must have this many virtqueues. */ if (index >= ldev->desc->num_vq) return ERR_PTR(-ENOENT); @@ -284,17 +296,21 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, /* * OK, tell virtio_ring.c to set up a virtqueue now we know its size - * and we've got a pointer to its pages. + * and we've got a pointer to its pages. Note that we set weak_barriers + * to 'true': the host just a(nother) SMP CPU, so we only need inter-cpu + * barriers. */ - vq = vring_new_virtqueue(lvq->config.num, LGUEST_VRING_ALIGN, - vdev, lvq->pages, lg_notify, callback, name); + vq = vring_new_virtqueue(index, lvq->config.num, LGUEST_VRING_ALIGN, vdev, + true, lvq->pages, lg_notify, callback, name); if (!vq) { err = -ENOMEM; goto unmap; } /* Make sure the interrupt is allocated. */ - lguest_setup_irq(lvq->config.irq); + err = lguest_setup_irq(lvq->config.irq); + if (err) + goto destroy_vring; /* * Tell the interrupt for this virtqueue to go to the virtio_ring @@ -307,7 +323,7 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, err = request_irq(lvq->config.irq, vring_interrupt, IRQF_SHARED, dev_name(&vdev->dev), vq); if (err) - goto destroy_vring; + goto free_desc; /* * Last of all we hook up our 'struct lguest_vq_info" to the @@ -316,6 +332,8 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, vq->priv = lvq; return vq; +free_desc: + irq_free_desc(lvq->config.irq); destroy_vring: vring_del_virtqueue(vq); unmap: @@ -373,8 +391,13 @@ error: return PTR_ERR(vqs[i]); } +static const char *lg_bus_name(struct virtio_device *vdev) +{ + return ""; +} + /* The ops structure which hooks everything together. */ -static struct virtio_config_ops lguest_config_ops = { +static const struct virtio_config_ops lguest_config_ops = { .get_features = lg_get_features, .finalize_features = lg_finalize_features, .get = lg_get, @@ -384,6 +407,7 @@ static struct virtio_config_ops lguest_config_ops = { .reset = lg_reset, .find_vqs = lg_find_vqs, .del_vqs = lg_del_vqs, + .bus_name = lg_bus_name, }; /* |