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| author | Marc-André Lureau | 2017-06-02 12:18:30 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin | 2017-06-02 17:57:17 +0200 |
| commit | 4bbeeba023f22c117d7a4c561354b91a0bf62e42 (patch) | |
| tree | 1567b50c019cd1f40be26d06eff46b93cf4beec7 /docs | |
| parent | vhost-user: add vhost_user to hold the chr (diff) | |
| download | qemu-4bbeeba023f22c117d7a4c561354b91a0bf62e42.tar.gz qemu-4bbeeba023f22c117d7a4c561354b91a0bf62e42.tar.xz qemu-4bbeeba023f22c117d7a4c561354b91a0bf62e42.zip | |
vhost-user: add slave-req-fd support
Learn to give a socket to the slave to let him make requests to the
master.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/specs/vhost-user.txt | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 036890feb0..5fa7016cc1 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -139,6 +139,7 @@ in the ancillary data: * VHOST_USER_SET_VRING_KICK * VHOST_USER_SET_VRING_CALL * VHOST_USER_SET_VRING_ERR + * VHOST_USER_SET_SLAVE_REQ_FD If Master is unable to send the full message or receives a wrong reply it will close the connection. An optional reconnection mechanism can be implemented. @@ -252,6 +253,18 @@ Once the source has finished migration, rings will be stopped by the source. No further update must be done before rings are restarted. +Slave communication +------------------- + +An optional communication channel is provided if the slave declares +VHOST_USER_PROTOCOL_F_SLAVE_REQ protocol feature, to allow the slave to make +requests to the master. + +The fd is provided via VHOST_USER_SET_SLAVE_REQ_FD ancillary data. + +A slave may then send VHOST_USER_SLAVE_* messages to the master +using this fd communication channel. + Protocol features ----------------- @@ -260,9 +273,10 @@ Protocol features #define VHOST_USER_PROTOCOL_F_RARP 2 #define VHOST_USER_PROTOCOL_F_REPLY_ACK 3 #define VHOST_USER_PROTOCOL_F_MTU 4 +#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5 -Message types -------------- +Master message types +-------------------- * VHOST_USER_GET_FEATURES @@ -486,6 +500,20 @@ Message types If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond with zero in case the specified MTU is valid, or non-zero otherwise. + * VHOST_USER_SET_SLAVE_REQ_FD + + Id: 21 + Equivalent ioctl: N/A + Master payload: N/A + + Set the socket file descriptor for slave initiated requests. It is passed + in the ancillary data. + This request should be sent only when VHOST_USER_F_PROTOCOL_FEATURES + has been negotiated, and protocol feature bit VHOST_USER_PROTOCOL_F_SLAVE_REQ + bit is present in VHOST_USER_GET_PROTOCOL_FEATURES. + If VHOST_USER_PROTOCOL_F_REPLY_ACK is negotiated, slave must respond + with zero for success, non-zero otherwise. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain |