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/net/virtio-net.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'hw/net/virtio-net.c') diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c index 63a8332..e9f696b 100644 --- a/hw/net/virtio-net.c +++ b/hw/net/virtio-net.c @@ -106,6 +106,12 @@ static const VirtIOFeature feature_sizes[] = { {} }; +static const VirtIOConfigSizeParams cfg_size_params = { + .min_size = endof(struct virtio_net_config, mac), + .max_size = sizeof(struct virtio_net_config), + .feature_sizes = feature_sizes +}; + static VirtIONetQueue *virtio_net_get_subqueue(NetClientState *nc) { VirtIONet *n = qemu_get_nic_opaque(nc); @@ -3241,8 +3247,7 @@ static void virtio_net_set_config_size(VirtIONet *n, uint64_t host_features) { virtio_add_feature(&host_features, VIRTIO_NET_F_MAC); - n->config_size = virtio_feature_get_config_size(feature_sizes, - host_features); + n->config_size = virtio_get_config_size(&cfg_size_params, host_features); } void virtio_net_set_netclient_name(VirtIONet *n, const char *name, -- cgit v1.1