aboutsummaryrefslogtreecommitdiff
path: root/hw/virtio
diff options
context:
space:
mode:
authorDaniil Tatianin <d-tatianin@yandex-team.ru>2022-09-06 10:31:07 +0300
committerMichael S. Tsirkin <mst@redhat.com>2022-10-07 09:41:51 -0400
commitd74c30c81159d703fb4e1caa0ec6772ff89dd02f (patch)
treec8f36550406c81c0ce8925b55eabc45d083c8773 /hw/virtio
parent8fcfc8235e43649cd4045c815abdaac078cff9c2 (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.c10
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;
}