diff options
Diffstat (limited to 'drivers/lguest')
| -rw-r--r-- | drivers/lguest/lguest_device.c | 68 | ||||
| -rw-r--r-- | drivers/lguest/lguest_user.c | 4 |
2 files changed, 42 insertions, 30 deletions
diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index 2bc9bf7e88e5..8080249957af 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -85,27 +85,34 @@ static unsigned desc_size(const struct lguest_device_desc *desc) + desc->config_len; } -/* This tests (and acknowleges) a feature bit. */ -static bool lg_feature(struct virtio_device *vdev, unsigned fbit) +/* This gets the device's feature bits. */ +static u32 lg_get_features(struct virtio_device *vdev) { + unsigned int i; + u32 features = 0; struct lguest_device_desc *desc = to_lgdev(vdev)->desc; - u8 *features; - - /* Obviously if they ask for a feature off the end of our feature - * bitmap, it's not set. */ - if (fbit / 8 > desc->feature_len) - return false; - - /* The feature bitmap comes after the virtqueues. */ - features = lg_features(desc); - if (!(features[fbit / 8] & (1 << (fbit % 8)))) - return false; - - /* We set the matching bit in the other half of the bitmap to tell the - * Host we want to use this feature. We don't use this yet, but we - * could in future. */ - features[desc->feature_len + fbit / 8] |= (1 << (fbit % 8)); - return true; + u8 *in_features = lg_features(desc); + + /* We do this the slow but generic way. */ + for (i = 0; i < min(desc->feature_len * 8, 32); i++) + if (in_features[i / 8] & (1 << (i % 8))) + features |= (1 << i); + + return features; +} + +static void lg_set_features(struct virtio_device *vdev, u32 features) +{ + unsigned int i; + struct lguest_device_desc *desc = to_lgdev(vdev)->desc; + /* Second half of bitmap is features we accept. */ + u8 *out_features = lg_features(desc) + desc->feature_len; + + memset(out_features, 0, desc->feature_len); + for (i = 0; i < min(desc->feature_len * 8, 32); i++) { + if (features & (1 << i)) + out_features[i / 8] |= (1 << (i % 8)); + } } /* Once they've found a field, getting a copy of it is easy. */ @@ -137,20 +144,26 @@ 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); +} + static void lg_set_status(struct virtio_device *vdev, u8 status) { BUG_ON(!status); - to_lgdev(vdev)->desc->status = status; + set_status(vdev, status); } -/* To reset the device, we (ab)use the NOTIFY hypercall, with the descriptor - * address of the device. The Host will zero the status and all the - * features. */ static void lg_reset(struct virtio_device *vdev) { - unsigned long offset = (void *)to_lgdev(vdev)->desc - lguest_devices; - - hcall(LHCALL_NOTIFY, (max_pfn<<PAGE_SHIFT) + offset, 0, 0); + set_status(vdev, 0); } /* @@ -286,7 +299,8 @@ static void lg_del_vq(struct virtqueue *vq) /* The ops structure which hooks everything together. */ static struct virtio_config_ops lguest_config_ops = { - .feature = lg_feature, + .get_features = lg_get_features, + .set_features = lg_set_features, .get = lg_get, .set = lg_set, .get_status = lg_get_status, diff --git a/drivers/lguest/lguest_user.c b/drivers/lguest/lguest_user.c index 645e6e040bfb..e73a000473cc 100644 --- a/drivers/lguest/lguest_user.c +++ b/drivers/lguest/lguest_user.c @@ -102,7 +102,7 @@ static ssize_t read(struct file *file, char __user *user, size_t size,loff_t*o) static int lg_cpu_start(struct lg_cpu *cpu, unsigned id, unsigned long start_ip) { /* We have a limited number the number of CPUs in the lguest struct. */ - if (id >= NR_CPUS) + if (id >= ARRAY_SIZE(cpu->lg->cpus)) return -EINVAL; /* Set up this CPU's id, and pointer back to the lguest struct. */ @@ -251,8 +251,6 @@ static ssize_t write(struct file *file, const char __user *in, if (!lg || (cpu_id >= lg->nr_cpus)) return -EINVAL; cpu = &lg->cpus[cpu_id]; - if (!cpu) - return -EINVAL; /* Once the Guest is dead, you can only read() why it died. */ if (lg->dead) |
