On Wed, 18 Oct 2023 at 08:56, Michael S. Tsirkin <m...@redhat.com> wrote: > > From: Hawkins Jiawei <yin31...@gmail.com> > > This patch introduces vhost_vdpa_net_load_rss() to restore > the hash calculation state at device's startup. > > Note that vhost_vdpa_net_load_rss() has `do_rss` argument, > which allows future code to reuse this function to restore > the receive-side scaling state when the VIRTIO_NET_F_RSS > feature is enabled in SVQ. Currently, vhost_vdpa_net_load_rss() > could only be invoked when `do_rss` is set to false. > > Signed-off-by: Hawkins Jiawei <yin31...@gmail.com> > Message-Id: > <f5ffad10699001107022851e0560cb394039d6b0.1693297766.git.yin31...@gmail.com> > Reviewed-by: Michael S. Tsirkin <m...@redhat.com> > Signed-off-by: Michael S. Tsirkin <m...@redhat.com> > --- > net/vhost-vdpa.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 91 insertions(+) > > diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c > index 4b7c3b81b8..40d0bcbc0b 100644 > --- a/net/vhost-vdpa.c > +++ b/net/vhost-vdpa.c > @@ -817,6 +817,88 @@ 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, bool do_rss) > +{ > + 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; > + } > + > + 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. > + */ > + memset(&cfg.indirection_table_mask, 0, > + sizeof_field(struct virtio_net_hash_config, reserved));
Please take a look at the following CI failure: In file included from /usr/include/string.h:495, from /home/gitlab-runner/builds/-LCfcJ2T/0/qemu-project/qemu/include/qemu/osdep.h:116, from ../net/vhost-vdpa.c:12: In function ‘memset’, inlined from ‘vhost_vdpa_net_load_rss’ at ../net/vhost-vdpa.c:874:9: /usr/include/s390x-linux-gnu/bits/string_fortified.h:71:10: error: ‘__builtin_memset’ offset [7, 12] from the object at ‘cfg’ is out of the bounds of referenced subobject ‘indirection_table_mask’ with type ‘short unsigned int’ at offset 4 [-Werror=array-bounds] 71 | return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest)); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors https://gitlab.com/qemu-project/qemu/-/jobs/5329820077 > + > + table = g_malloc_n(n->rss_data.indirections_len, > + sizeof(n->rss_data.indirections_table[0])); > + for (int i = 0; i < n->rss_data.indirections_len; ++i) { > + table[i] = cpu_to_le16(n->rss_data.indirections_table[i]); > + } > + > + /* > + * 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 +924,15 @@ 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, false); > + if (unlikely(r < 0)) { > + return r; > + } > + > return 0; > } > > -- > MST > >