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>
---
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.yin31149@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.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 | 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;
+
+ /*
+ * 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;
}
--
2.25.1On Wed, Oct 25, 2023 at 3:02 AM Hawkins Jiawei <yin31149@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 <yin31149@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.yin31149@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.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 | 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 <eperezma@redhat.com>
[1] https://patchwork.kernel.org/project/qemu-devel/patch/cf5b78a16ed0318982ceffb195f2227f6aad4ac1.1698195059.git.yin31149@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
>
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