This patch introduces vhost_vdpa_net_load_rss() to restore the hash calculation state at device's startup.
Signed-off-by: Hawkins Jiawei <yin31...@gmail.com> --- v3: - remove the `do_rss` argument in vhost_vdpa_net_load_rss() - zero reserved fields in "cfg" manually instead of using memset() to prevent compiler "array-bounds" warning v2: https://lore.kernel.org/all/f5ffad10699001107022851e0560cb394039d6b0.1693297766.git.yin31...@gmail.com/ - resolve conflict with updated patch "vdpa: Send all CVQ state load commands in parallel" - move the `table` declaration at the beginning of the vhost_vdpa_net_load_rss() RFC: https://lore.kernel.org/all/a54ca70b12ebe2f3c391864e41241697ab1aba30.1691762906.git.yin31...@gmail.com/ net/vhost-vdpa.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c index 4b7c3b81b8..2e4bad65b4 100644 --- a/net/vhost-vdpa.c +++ b/net/vhost-vdpa.c @@ -817,6 +817,86 @@ static int vhost_vdpa_net_load_mac(VhostVDPAState *s, const VirtIONet *n, return 0; } +static int vhost_vdpa_net_load_rss(VhostVDPAState *s, const VirtIONet *n, + struct iovec *out_cursor, + struct iovec *in_cursor) +{ + struct virtio_net_rss_config cfg; + ssize_t r; + g_autofree uint16_t *table = NULL; + + /* + * According to VirtIO standard, "Initially the device has all hash + * types disabled and reports only VIRTIO_NET_HASH_REPORT_NONE.". + * + * Therefore, there is no need to send this CVQ command if the + * driver disable the all hash types, which aligns with + * the device's defaults. + * + * Note that the device's defaults can mismatch the driver's + * configuration only at live migration. + */ + if (!n->rss_data.enabled || + n->rss_data.hash_types == VIRTIO_NET_HASH_REPORT_NONE) { + return 0; + } + + table = g_malloc_n(n->rss_data.indirections_len, + sizeof(n->rss_data.indirections_table[0])); + cfg.hash_types = cpu_to_le32(n->rss_data.hash_types); + + /* + * According to VirtIO standard, "Field reserved MUST contain zeroes. + * It is defined to make the structure to match the layout of + * virtio_net_rss_config structure, defined in 5.1.6.5.7.". + * + * Therefore, we need to zero the fields in struct virtio_net_rss_config, + * which corresponds the `reserved` field in + * struct virtio_net_hash_config. + */ + cfg.indirection_table_mask = 0; + cfg.unclassified_queue = 0; + table[0] = 0; /* the actual indirection table for cfg */ + cfg.max_tx_vq = 0; + + /* + * Consider that virtio_net_handle_rss() currently does not restore the + * hash key length parsed from the CVQ command sent from the guest into + * n->rss_data and uses the maximum key length in other code, so we also + * employthe the maxium key length here. + */ + cfg.hash_key_length = sizeof(n->rss_data.key); + + const struct iovec data[] = { + { + .iov_base = &cfg, + .iov_len = offsetof(struct virtio_net_rss_config, + indirection_table), + }, { + .iov_base = table, + .iov_len = n->rss_data.indirections_len * + sizeof(n->rss_data.indirections_table[0]), + }, { + .iov_base = &cfg.max_tx_vq, + .iov_len = offsetof(struct virtio_net_rss_config, hash_key_data) - + offsetof(struct virtio_net_rss_config, max_tx_vq), + }, { + .iov_base = (void *)n->rss_data.key, + .iov_len = sizeof(n->rss_data.key), + } + }; + + r = vhost_vdpa_net_load_cmd(s, out_cursor, in_cursor, + VIRTIO_NET_CTRL_MQ, + VIRTIO_NET_CTRL_MQ_HASH_CONFIG, + data, ARRAY_SIZE(data)); + if (unlikely(r < 0)) { + return r; + } + + return 0; +} + static int vhost_vdpa_net_load_mq(VhostVDPAState *s, const VirtIONet *n, struct iovec *out_cursor, @@ -842,6 +922,15 @@ static int vhost_vdpa_net_load_mq(VhostVDPAState *s, return r; } + if (!virtio_vdev_has_feature(&n->parent_obj, VIRTIO_NET_F_HASH_REPORT)) { + return 0; + } + + r = vhost_vdpa_net_load_rss(s, n, out_cursor, in_cursor); + if (unlikely(r < 0)) { + return r; + } + return 0; } -- 2.25.1