On Wed, Oct 25, 2023 at 3:02 AM Hawkins Jiawei <yin31...@gmail.com> wrote: > > 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> > --- > v4: > - fix some typos pointed out by Michael > - zero the `cfg` fields at the definition suggested by Michael > > v3: > https://patchwork.kernel.org/project/qemu-devel/patch/b7cd0c8d6a58b16b086f11714d2908ad35c67caa.1697902949.git.yin31...@gmail.com/ > - 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 | 91 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 91 insertions(+) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 7a226c93bc..e59d40b8ae 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -818,6 +818,88 @@ 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;
Nitpick, I think the table should actually be introduced in [1], not here. Otherwise, it adds unneeded complexity to review it. However I think it is fine if both series get merged one after another, so: Acked-by: Eugenio Pérez <epere...@redhat.com> [1] https://patchwork.kernel.org/project/qemu-devel/patch/cf5b78a16ed0318982ceffb195f2227f6aad4ac1.1698195059.git.yin31...@gmail.com/ > + > + /* > + * 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 disables 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 to the > + * `reserved` field in struct virtio_net_hash_config. > + * > + * Note that all other fields are zeroed at their definitions, > + * except for the `indirection_table` field, where the actual data > + * is stored in the `table` variable to ensure compatibility > + * with RSS case. Therefore, we need to zero the `table` variable here. > + */ > + table[0] = 0; > + > + /* > + * Considering 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 employ the maximum 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, > @@ -843,6 +925,15 @@ 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 >
