From d74c30c81159d703fb4e1caa0ec6772ff89dd02f Mon Sep 17 00:00:00 2001 From: Daniil Tatianin Date: Tue, 6 Sep 2022 10:31:07 +0300 Subject: 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 Message-Id: <20220906073111.353245-2-d-tatianin@yandex-team.ru> Reviewed-by: Raphael Norwitz Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/block/virtio-blk.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) (limited to 'hw/block') diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index e9ba752..10c47c2 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -49,13 +49,11 @@ static const VirtIOFeature feature_sizes[] = { {} }; -static void virtio_blk_set_config_size(VirtIOBlock *s, uint64_t host_features) -{ - s->config_size = MAX(VIRTIO_BLK_CFG_SIZE, - virtio_feature_get_config_size(feature_sizes, host_features)); - - assert(s->config_size <= sizeof(struct virtio_blk_config)); -} +static const VirtIOConfigSizeParams cfg_size_params = { + .min_size = VIRTIO_BLK_CFG_SIZE, + .max_size = sizeof(struct virtio_blk_config), + .feature_sizes = feature_sizes +}; static void virtio_blk_init_request(VirtIOBlock *s, VirtQueue *vq, VirtIOBlockReq *req) @@ -1204,8 +1202,8 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) return; } - virtio_blk_set_config_size(s, s->host_features); - + s->config_size = virtio_get_config_size(&cfg_size_params, + s->host_features); virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size); s->blk = conf->conf.blk; -- cgit v1.1