diff options
author | Daniil Tatianin <d-tatianin@yandex-team.ru> | 2022-09-06 10:31:07 +0300 |
---|---|---|
committer | Michael S. Tsirkin <mst@redhat.com> | 2022-10-07 09:41:51 -0400 |
commit | d74c30c81159d703fb4e1caa0ec6772ff89dd02f (patch) | |
tree | c8f36550406c81c0ce8925b55eabc45d083c8773 /hw/virtio | |
parent | 8fcfc8235e43649cd4045c815abdaac078cff9c2 (diff) |
virtio: introduce VirtIOConfigSizeParams & virtio_get_config_size
This is the first step towards moving all device config size calculation
logic into the virtio core code. In particular, this adds a struct that
contains all the necessary information for common virtio code to be able
to calculate the final config size for a device. This is expected to be
used with the new virtio_get_config_size helper, which calculates the
final length based on the provided host features.
This builds on top of already existing code like VirtIOFeature and
virtio_feature_get_config_size(), but adds additional fields, as well as
sanity checking so that device-specifc code doesn't have to duplicate it.
An example usage would be:
static const VirtIOFeature dev_features[] = {
{.flags = 1ULL << FEATURE_1_BIT,
.end = endof(struct virtio_dev_config, feature_1)},
{.flags = 1ULL << FEATURE_2_BIT,
.end = endof(struct virtio_dev_config, feature_2)},
{}
};
static const VirtIOConfigSizeParams dev_cfg_size_params = {
.min_size = DEV_BASE_CONFIG_SIZE,
.max_size = sizeof(struct virtio_dev_config),
.feature_sizes = dev_features
};
// code inside my_dev_device_realize()
size_t config_size = virtio_get_config_size(&dev_cfg_size_params,
host_features);
virtio_init(vdev, VIRTIO_ID_MYDEV, config_size);
Currently every device is expected to write its own boilerplate from the
example above in device_realize(), however, the next step of this
transition is moving VirtIOConfigSizeParams into VirtioDeviceClass,
so that it can be done automatically by the virtio initialization code.
All of the users of virtio_feature_get_config_size have been converted
to use virtio_get_config_size so it's no longer needed and is removed
with this commit.
Signed-off-by: Daniil Tatianin <d-tatianin@yandex-team.ru>
Message-Id: <20220906073111.353245-2-d-tatianin@yandex-team.ru>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'hw/virtio')
-rw-r--r-- | hw/virtio/virtio.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 97a6307c0f..2cc1d7d24a 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -3006,11 +3006,12 @@ int virtio_set_features(VirtIODevice *vdev, uint64_t val) return ret; } -size_t virtio_feature_get_config_size(const VirtIOFeature *feature_sizes, - uint64_t host_features) +size_t virtio_get_config_size(const VirtIOConfigSizeParams *params, + uint64_t host_features) { - size_t config_size = 0; - int i; + size_t config_size = params->min_size; + const VirtIOFeature *feature_sizes = params->feature_sizes; + size_t i; for (i = 0; feature_sizes[i].flags != 0; i++) { if (host_features & feature_sizes[i].flags) { @@ -3018,6 +3019,7 @@ size_t virtio_feature_get_config_size(const VirtIOFeature *feature_sizes, } } + assert(config_size <= params->max_size); return config_size; } |