Re: [Qemu-devel] [PATCH 1/5] migration: create a dedicated connection for rdma return path
* Lidong Chen (jemmy858...@gmail.com) wrote:
> If start a RDMA migration with postcopy enabled, the source qemu
> establish a dedicated connection for return path.
>
> Signed-off-by: Lidong Chen
OK, I think that'll work.
Signed-off-by: Dr. David Alan Gilbert
> ---
> migration/rdma.c | 94
> ++--
> 1 file changed, 91 insertions(+), 3 deletions(-)
>
> diff --git a/migration/rdma.c b/migration/rdma.c
> index da474fc..230bd97 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -387,6 +387,10 @@ typedef struct RDMAContext {
> uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX];
>
> GHashTable *blockmap;
> +
> +/* the RDMAContext for return path */
> +struct RDMAContext *return_path;
> +bool is_return_path;
> } RDMAContext;
>
> #define TYPE_QIO_CHANNEL_RDMA "qio-channel-rdma"
> @@ -2329,10 +2333,22 @@ static void qemu_rdma_cleanup(RDMAContext *rdma)
> rdma_destroy_id(rdma->cm_id);
> rdma->cm_id = NULL;
> }
> +
> +/* the destination side, listen_id and channel is shared */
> if (rdma->listen_id) {
> -rdma_destroy_id(rdma->listen_id);
> +if (!rdma->is_return_path) {
> +rdma_destroy_id(rdma->listen_id);
> +}
> rdma->listen_id = NULL;
> +
> +if (rdma->channel) {
> +if (!rdma->is_return_path) {
> +rdma_destroy_event_channel(rdma->channel);
> +}
> +rdma->channel = NULL;
> +}
> }
> +
> if (rdma->channel) {
> rdma_destroy_event_channel(rdma->channel);
> rdma->channel = NULL;
> @@ -2561,6 +2577,25 @@ err_dest_init_create_listen_id:
>
> }
>
> +static void qemu_rdma_return_path_dest_init(RDMAContext *rdma_return_path,
> +RDMAContext *rdma)
> +{
> +int idx;
> +
> +for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
> +rdma_return_path->wr_data[idx].control_len = 0;
> +rdma_return_path->wr_data[idx].control_curr = NULL;
> +}
> +
> +/*the CM channel and CM id is shared*/
> +rdma_return_path->channel = rdma->channel;
> +rdma_return_path->listen_id = rdma->listen_id;
> +
> +rdma->return_path = rdma_return_path;
> +rdma_return_path->return_path = rdma;
> +rdma_return_path->is_return_path = true;
> +}
> +
> static void *qemu_rdma_data_init(const char *host_port, Error **errp)
> {
> RDMAContext *rdma = NULL;
> @@ -3014,6 +3049,8 @@ err:
> return ret;
> }
>
> +static void rdma_accept_incoming_migration(void *opaque);
> +
> static int qemu_rdma_accept(RDMAContext *rdma)
> {
> RDMACapabilities cap;
> @@ -3108,7 +3145,14 @@ static int qemu_rdma_accept(RDMAContext *rdma)
> }
> }
>
> -qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL);
> +/* Accept the second connection request for return path */
> +if (migrate_postcopy() && !rdma->is_return_path) {
> +qemu_set_fd_handler(rdma->channel->fd,
> rdma_accept_incoming_migration,
> +NULL,
> +(void *)(intptr_t)rdma->return_path);
> +} else {
> +qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL);
> +}
>
> ret = rdma_accept(rdma->cm_id, &conn_param);
> if (ret) {
> @@ -3681,6 +3725,10 @@ static void rdma_accept_incoming_migration(void
> *opaque)
>
> trace_qemu_rdma_accept_incoming_migration_accepted();
>
> +if (rdma->is_return_path) {
> +return;
> +}
> +
> f = qemu_fopen_rdma(rdma, "rb");
> if (f == NULL) {
> ERROR(errp, "could not qemu_fopen_rdma!");
> @@ -3695,7 +3743,7 @@ static void rdma_accept_incoming_migration(void *opaque)
> void rdma_start_incoming_migration(const char *host_port, Error **errp)
> {
> int ret;
> -RDMAContext *rdma;
> +RDMAContext *rdma, *rdma_return_path;
> Error *local_err = NULL;
>
> trace_rdma_start_incoming_migration();
> @@ -3722,12 +3770,24 @@ void rdma_start_incoming_migration(const char
> *host_port, Error **errp)
>
> trace_rdma_start_incoming_migration_after_rdma_listen();
>
> +/* initialize the RDMAContext for return path */
> +if (migrate_postcopy()) {
> +rdma_return_path = qemu_rdma_data_init(host_port, &local_err);
> +
> +if (rdma_return_path == NULL) {
> +goto err;
> +}
> +
> +qemu_rdma_return_path_dest_init(rdma_return_path, rdma);
> +}
> +
> qemu_set_fd_handler(rdma->channel->fd, rdma_accept_incoming_migration,
> NULL, (void *)(intptr_t)rdma);
> return;
> err:
> error_propagate(errp, local_err);
> g_free(rdma);
> +g_free(rdma_return_path);
> }
>
> void rdma_start_outgoing_migration(void *opaque,
> @@ -3735,6 +3795,7 @@ void rdma_start_outgoing_migration(void *opaque,
> {
> MigrationState *s = opaque;
> RDMAContext *rdma = qemu_rdma_data_init(host_po
[Qemu-devel] [PATCH 1/5] migration: create a dedicated connection for rdma return path
If start a RDMA migration with postcopy enabled, the source qemu
establish a dedicated connection for return path.
Signed-off-by: Lidong Chen
---
migration/rdma.c | 94 ++--
1 file changed, 91 insertions(+), 3 deletions(-)
diff --git a/migration/rdma.c b/migration/rdma.c
index da474fc..230bd97 100644
--- a/migration/rdma.c
+++ b/migration/rdma.c
@@ -387,6 +387,10 @@ typedef struct RDMAContext {
uint64_t unregistrations[RDMA_SIGNALED_SEND_MAX];
GHashTable *blockmap;
+
+/* the RDMAContext for return path */
+struct RDMAContext *return_path;
+bool is_return_path;
} RDMAContext;
#define TYPE_QIO_CHANNEL_RDMA "qio-channel-rdma"
@@ -2329,10 +2333,22 @@ static void qemu_rdma_cleanup(RDMAContext *rdma)
rdma_destroy_id(rdma->cm_id);
rdma->cm_id = NULL;
}
+
+/* the destination side, listen_id and channel is shared */
if (rdma->listen_id) {
-rdma_destroy_id(rdma->listen_id);
+if (!rdma->is_return_path) {
+rdma_destroy_id(rdma->listen_id);
+}
rdma->listen_id = NULL;
+
+if (rdma->channel) {
+if (!rdma->is_return_path) {
+rdma_destroy_event_channel(rdma->channel);
+}
+rdma->channel = NULL;
+}
}
+
if (rdma->channel) {
rdma_destroy_event_channel(rdma->channel);
rdma->channel = NULL;
@@ -2561,6 +2577,25 @@ err_dest_init_create_listen_id:
}
+static void qemu_rdma_return_path_dest_init(RDMAContext *rdma_return_path,
+RDMAContext *rdma)
+{
+int idx;
+
+for (idx = 0; idx < RDMA_WRID_MAX; idx++) {
+rdma_return_path->wr_data[idx].control_len = 0;
+rdma_return_path->wr_data[idx].control_curr = NULL;
+}
+
+/*the CM channel and CM id is shared*/
+rdma_return_path->channel = rdma->channel;
+rdma_return_path->listen_id = rdma->listen_id;
+
+rdma->return_path = rdma_return_path;
+rdma_return_path->return_path = rdma;
+rdma_return_path->is_return_path = true;
+}
+
static void *qemu_rdma_data_init(const char *host_port, Error **errp)
{
RDMAContext *rdma = NULL;
@@ -3014,6 +3049,8 @@ err:
return ret;
}
+static void rdma_accept_incoming_migration(void *opaque);
+
static int qemu_rdma_accept(RDMAContext *rdma)
{
RDMACapabilities cap;
@@ -3108,7 +3145,14 @@ static int qemu_rdma_accept(RDMAContext *rdma)
}
}
-qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL);
+/* Accept the second connection request for return path */
+if (migrate_postcopy() && !rdma->is_return_path) {
+qemu_set_fd_handler(rdma->channel->fd, rdma_accept_incoming_migration,
+NULL,
+(void *)(intptr_t)rdma->return_path);
+} else {
+qemu_set_fd_handler(rdma->channel->fd, NULL, NULL, NULL);
+}
ret = rdma_accept(rdma->cm_id, &conn_param);
if (ret) {
@@ -3681,6 +3725,10 @@ static void rdma_accept_incoming_migration(void *opaque)
trace_qemu_rdma_accept_incoming_migration_accepted();
+if (rdma->is_return_path) {
+return;
+}
+
f = qemu_fopen_rdma(rdma, "rb");
if (f == NULL) {
ERROR(errp, "could not qemu_fopen_rdma!");
@@ -3695,7 +3743,7 @@ static void rdma_accept_incoming_migration(void *opaque)
void rdma_start_incoming_migration(const char *host_port, Error **errp)
{
int ret;
-RDMAContext *rdma;
+RDMAContext *rdma, *rdma_return_path;
Error *local_err = NULL;
trace_rdma_start_incoming_migration();
@@ -3722,12 +3770,24 @@ void rdma_start_incoming_migration(const char
*host_port, Error **errp)
trace_rdma_start_incoming_migration_after_rdma_listen();
+/* initialize the RDMAContext for return path */
+if (migrate_postcopy()) {
+rdma_return_path = qemu_rdma_data_init(host_port, &local_err);
+
+if (rdma_return_path == NULL) {
+goto err;
+}
+
+qemu_rdma_return_path_dest_init(rdma_return_path, rdma);
+}
+
qemu_set_fd_handler(rdma->channel->fd, rdma_accept_incoming_migration,
NULL, (void *)(intptr_t)rdma);
return;
err:
error_propagate(errp, local_err);
g_free(rdma);
+g_free(rdma_return_path);
}
void rdma_start_outgoing_migration(void *opaque,
@@ -3735,6 +3795,7 @@ void rdma_start_outgoing_migration(void *opaque,
{
MigrationState *s = opaque;
RDMAContext *rdma = qemu_rdma_data_init(host_port, errp);
+RDMAContext *rdma_return_path = NULL;
int ret = 0;
if (rdma == NULL) {
@@ -3755,6 +3816,32 @@ void rdma_start_outgoing_migration(void *opaque,
goto err;
}
+/* RDMA postcopy need a seprate queue pair for return path */
+if (migrate_postcopy()) {
+rdma_return_path = qemu_rdma_data_init(host_port, errp);
+
+if (rdma_return_path == NULL) {
+
