From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33987) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cxskf-0008Gd-43 for qemu-devel@nongnu.org; Tue, 11 Apr 2017 06:10:22 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cxskd-0002vh-TZ for qemu-devel@nongnu.org; Tue, 11 Apr 2017 06:10:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45126) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cxskd-0002vC-Kb for qemu-devel@nongnu.org; Tue, 11 Apr 2017 06:10:19 -0400 From: Maxime Coquelin Date: Tue, 11 Apr 2017 12:10:01 +0200 Message-Id: <20170411101002.28451-2-maxime.coquelin@redhat.com> In-Reply-To: <20170411101002.28451-1-maxime.coquelin@redhat.com> References: <20170411101002.28451-1-maxime.coquelin@redhat.com> Subject: [Qemu-devel] [RFC 1/2] spec/vhost-user: Introduce secondary channel for slave initiated requests List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: mst@redhat.com, vkaplans@redhat.com, jasowang@redhat.com, wexu@redhat.com, peterx@redhat.com, yuanhan.liu@linux.intel.com, virtio-comment@lists.oasis-open.org, qemu-devel@nongnu.org Cc: Maxime Coquelin This vhost-user specification update aims at enabling the slave to send requests to the master using a dedicated socket created by the master. It can be used for example when the slave implements a device IOTLB to send cache miss requests to the master. The message types list is updated with an "Initiator" field to indicate for each type whether the master and/or slave can initiate the request. Signed-off-by: Maxime Coquelin --- docs/specs/vhost-user.txt | 38 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 38 insertions(+) diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 036890f..b365047 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. @@ -150,6 +151,11 @@ As older slaves don't support negotiating protocol features, a feature bit was dedicated for this purpose: #define VHOST_USER_F_PROTOCOL_FEATURES 30 +If the slave supports VHOST_USER_PROTOCOL_F_SLAVE_REQ protocol feature, the +master may create a secondary Unix domain socket and send its file descriptor +to the slave using VHOST_USER_SET_SLAVE_REQ_FD request. This new channel enables +the slave to send message requests and master to send message replies. + Starting and stopping rings ---------------------- Client must only process each ring when it is started. @@ -260,6 +266,7 @@ 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 ------------- @@ -268,6 +275,7 @@ Message types Id: 1 Equivalent ioctl: VHOST_GET_FEATURES + Initiator: Master Master payload: N/A Slave payload: u64 @@ -279,6 +287,7 @@ Message types Id: 2 Ioctl: VHOST_SET_FEATURES + Initiator: Master Master payload: u64 Enable features in the underlying vhost implementation using a bitmask. @@ -289,6 +298,7 @@ Message types Id: 15 Equivalent ioctl: VHOST_GET_FEATURES + Initiator: Master Master payload: N/A Slave payload: u64 @@ -302,6 +312,7 @@ Message types Id: 16 Ioctl: VHOST_SET_FEATURES + Initiator: Master Master payload: u64 Enable protocol features in the underlying vhost implementation. @@ -314,6 +325,7 @@ Message types Id: 3 Equivalent ioctl: VHOST_SET_OWNER + Initiator: Master Master payload: N/A Issued when a new connection is established. It sets the current Master @@ -323,6 +335,7 @@ Message types * VHOST_USER_RESET_OWNER Id: 4 + Initiator: Master Master payload: N/A This is no longer used. Used to be sent to request disabling @@ -335,6 +348,7 @@ Message types Id: 5 Equivalent ioctl: VHOST_SET_MEM_TABLE + Initiator: Master Master payload: memory regions description Sets the memory map regions on the slave so it can translate the vring @@ -346,6 +360,7 @@ Message types Id: 6 Equivalent ioctl: VHOST_SET_LOG_BASE + Initiator: Master Master payload: u64 Slave payload: N/A @@ -360,6 +375,7 @@ Message types Id: 7 Equivalent ioctl: VHOST_SET_LOG_FD + Initiator: Master Master payload: N/A Sets the logging file descriptor, which is passed as ancillary data. @@ -368,6 +384,7 @@ Message types Id: 8 Equivalent ioctl: VHOST_SET_VRING_NUM + Initiator: Master Master payload: vring state description Set the size of the queue. @@ -376,6 +393,7 @@ Message types Id: 9 Equivalent ioctl: VHOST_SET_VRING_ADDR + Initiator: Master Master payload: vring address description Slave payload: N/A @@ -385,6 +403,7 @@ Message types Id: 10 Equivalent ioctl: VHOST_SET_VRING_BASE + Initiator: Master Master payload: vring state description Sets the base offset in the available vring. @@ -393,6 +412,7 @@ Message types Id: 11 Equivalent ioctl: VHOST_USER_GET_VRING_BASE + Initiator: Master Master payload: vring state description Slave payload: vring state description @@ -402,6 +422,7 @@ Message types Id: 12 Equivalent ioctl: VHOST_SET_VRING_KICK + Initiator: Master Master payload: u64 Set the event file descriptor for adding buffers to the vring. It @@ -415,6 +436,7 @@ Message types Id: 13 Equivalent ioctl: VHOST_SET_VRING_CALL + Initiator: Master Master payload: u64 Set the event file descriptor to signal when buffers are used. It @@ -428,6 +450,7 @@ Message types Id: 14 Equivalent ioctl: VHOST_SET_VRING_ERR + Initiator: Master Master payload: u64 Set the event file descriptor to signal when error occurs. It @@ -440,6 +463,7 @@ Message types Id: 17 Equivalent ioctl: N/A + Initiator: Master Master payload: N/A Slave payload: u64 @@ -451,6 +475,7 @@ Message types Id: 18 Equivalent ioctl: N/A + Initiator: Master Master payload: vring state description Signal slave to enable or disable corresponding vring. @@ -461,6 +486,7 @@ Message types Id: 19 Equivalent ioctl: N/A + Initiator: Master Master payload: u64 Ask vhost user backend to broadcast a fake RARP to notify the migration @@ -475,6 +501,7 @@ Message types Id: 20 Equivalent ioctl: N/A + Initiator: Master Master payload: u64 Set host MTU value exposed to the guest. @@ -486,6 +513,17 @@ 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 + Initiator: Master + + Set the socket file descriptor for slave initiated requests. + 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. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain -- 2.9.3