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[PATCH v3 1/2] vdpa: Restore hash calculation state
From: |
Hawkins Jiawei |
Subject: |
[PATCH v3 1/2] vdpa: Restore hash calculation state |
Date: |
Sun, 22 Oct 2023 10:00:48 +0800 |
This patch introduces vhost_vdpa_net_load_rss() to restore
the hash calculation state at device's startup.
Signed-off-by: Hawkins Jiawei <yin31149@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.yin31149@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.yin31149@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