From 4c3e257b5e6ccba6bd34f780fab8008e0d79680a Mon Sep 17 00:00:00 2001 From: Changpeng Liu Date: Thu, 4 Jan 2018 09:53:31 +0800 Subject: vhost-user: add new vhost user messages to support virtio config space Add VHOST_USER_GET_CONFIG/VHOST_USER_SET_CONFIG messages which can be used for live migration of vhost user devices, also vhost user devices can benefit from the messages to get/set virtio config space from/to the I/O target. For the purpose to support virtio config space change, VHOST_USER_SLAVE_CONFIG_CHANGE_MSG message is added as the event notifier in case virtio config space change in the slave I/O target. Signed-off-by: Changpeng Liu Reviewed-by: Marc-André Lureau Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/interop/vhost-user.txt | 55 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'docs') diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index d49444e037..0875ef4ec3 100644 --- a/docs/interop/vhost-user.txt +++ b/docs/interop/vhost-user.txt @@ -119,6 +119,19 @@ Depending on the request type, payload can be: - 3: IOTLB invalidate - 4: IOTLB access fail + * Virtio device config space + ----------------------------------- + | offset | size | flags | payload | + ----------------------------------- + + Offset: a 32-bit offset of virtio device's configuration space + Size: a 32-bit configuration space access size in bytes + Flags: a 32-bit value: + - 0: Vhost master messages used for writeable fields + - 1: Vhost master messages used for live migration + Payload: Size bytes array holding the contents of the virtio + device's configuration space + In QEMU the vhost-user message is implemented with the following struct: typedef struct VhostUserMsg { @@ -132,6 +145,7 @@ typedef struct VhostUserMsg { VhostUserMemory memory; VhostUserLog log; struct vhost_iotlb_msg iotlb; + VhostUserConfig config; }; } QEMU_PACKED VhostUserMsg; @@ -623,6 +637,32 @@ Master message types and expect this message once (per VQ) during device configuration (ie. before the master starts the VQ). + * VHOST_USER_GET_CONFIG + + Id: 24 + Equivalent ioctl: N/A + Master payload: virtio device config space + Slave payload: virtio device config space + + Submitted by the vhost-user master to fetch the contents of the virtio + device configuration space, vhost-user slave's payload size MUST match + master's request, vhost-user slave uses zero length of payload to + indicate an error to vhost-user master. The vhost-user master may + cache the contents to avoid repeated VHOST_USER_GET_CONFIG calls. + +* VHOST_USER_SET_CONFIG + + Id: 25 + Equivalent ioctl: N/A + Master payload: virtio device config space + Slave payload: N/A + + Submitted by the vhost-user master when the Guest changes the virtio + device configuration space and also can be used for live migration + on the destination host. The vhost-user slave must check the flags + field, and slaves MUST NOT accept SET_CONFIG for read-only + configuration space fields unless the live migration bit is set. + Slave message types ------------------- @@ -641,6 +681,21 @@ Slave message types This request should be send only when VIRTIO_F_IOMMU_PLATFORM feature has been successfully negotiated. +* VHOST_USER_SLAVE_CONFIG_CHANGE_MSG + + Id: 2 + Equivalent ioctl: N/A + Slave payload: N/A + Master payload: N/A + + Vhost-user slave sends such messages to notify that the virtio device's + configuration space has changed, for those host devices which can support + such feature, host driver can send VHOST_USER_GET_CONFIG message to slave + to get the latest content. If VHOST_USER_PROTOCOL_F_REPLY_ACK is + negotiated, and slave set the VHOST_USER_NEED_REPLY flag, master must + respond with zero when operation is successfully completed, or non-zero + otherwise. + VHOST_USER_PROTOCOL_F_REPLY_ACK: ------------------------------- The original vhost-user specification only demands replies for certain -- cgit v1.2.3-55-g7522 From 7de22778e1e25d974bad61fbd00757296e3e421e Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Fri, 12 Jan 2018 15:56:55 +0100 Subject: vhost-user: fix multiple queue specification The number of queues supported by the slave is queried with message VHOST_USER_GET_QUEUE_NUM, not with message VHOST_USER_GET_PROTOCOL_FEATURES. Signed-off-by: Maxime Coquelin Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- docs/interop/vhost-user.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'docs') diff --git a/docs/interop/vhost-user.txt b/docs/interop/vhost-user.txt index 0875ef4ec3..9fcf48d611 100644 --- a/docs/interop/vhost-user.txt +++ b/docs/interop/vhost-user.txt @@ -228,8 +228,8 @@ Multiple queue is treated as a protocol extension, hence the slave has to implement protocol features first. The multiple queues feature is supported only when the protocol feature VHOST_USER_PROTOCOL_F_MQ (bit 0) is set. -The max number of queues the slave supports can be queried with message -VHOST_USER_GET_PROTOCOL_FEATURES. Master should stop when the number of +The max number of queue pairs the slave supports can be queried with message +VHOST_USER_GET_QUEUE_NUM. Master should stop when the number of requested queues is bigger than that. As all queues share one connection, the master uses a unique index for each -- cgit v1.2.3-55-g7522