From dcb10c000cdd4d14f5ac4f07b04fb666494ef4a8 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 23 Sep 2015 12:19:56 +0800 Subject: vhost-user: add protocol feature negotiation Support a separate bitmask for vhost-user protocol features, and messages to get/set protocol features. Invoke them at init. No features are defined yet. [ leverage vhost_user_call for request handling -- Yuanhan Liu ] Signed-off-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Reviewed-by: Marcel Apfelbaum Tested-by: Marcel Apfelbaum --- docs/specs/vhost-user.txt | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) (limited to 'docs') diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 650bb18..70da3b1 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -113,6 +113,7 @@ message replies. Most of the requests don't require replies. Here is a list of the ones that do: * VHOST_GET_FEATURES + * VHOST_GET_PROTOCOL_FEATURES * VHOST_GET_VRING_BASE There are several messages that the master sends with file descriptors passed @@ -127,6 +128,13 @@ in the ancillary data: 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. +Any protocol extensions are gated by protocol feature bits, +which allows full backwards compatibility on both master +and slave. +As older slaves don't support negotiating protocol features, +a feature bit was dedicated for this purpose: +#define VHOST_USER_F_PROTOCOL_FEATURES 30 + Message types ------------- @@ -138,6 +146,8 @@ Message types Slave payload: u64 Get from the underlying vhost implementation the features bitmask. + Feature bit VHOST_USER_F_PROTOCOL_FEATURES signals slave support for + VHOST_USER_GET_PROTOCOL_FEATURES and VHOST_USER_SET_PROTOCOL_FEATURES. * VHOST_USER_SET_FEATURES @@ -146,6 +156,33 @@ Message types Master payload: u64 Enable features in the underlying vhost implementation using a bitmask. + Feature bit VHOST_USER_F_PROTOCOL_FEATURES signals slave support for + VHOST_USER_GET_PROTOCOL_FEATURES and VHOST_USER_SET_PROTOCOL_FEATURES. + + * VHOST_USER_GET_PROTOCOL_FEATURES + + Id: 15 + Equivalent ioctl: VHOST_GET_FEATURES + Master payload: N/A + Slave payload: u64 + + Get the protocol feature bitmask from the underlying vhost implementation. + Only legal if feature bit VHOST_USER_F_PROTOCOL_FEATURES is present in + VHOST_USER_GET_FEATURES. + Note: slave that reported VHOST_USER_F_PROTOCOL_FEATURES must support + this message even before VHOST_USER_SET_FEATURES was called. + + * VHOST_USER_SET_PROTOCOL_FEATURES + + Id: 16 + Ioctl: VHOST_SET_FEATURES + Master payload: u64 + + Enable protocol features in the underlying vhost implementation. + Only legal if feature bit VHOST_USER_F_PROTOCOL_FEATURES is present in + VHOST_USER_GET_FEATURES. + Note: slave that reported VHOST_USER_F_PROTOCOL_FEATURES must support + this message even before VHOST_USER_SET_FEATURES was called. * VHOST_USER_SET_OWNER -- cgit v1.1 From d1f8b30ec8dde0318fd1b98d24a64926feae9625 Mon Sep 17 00:00:00 2001 From: Yuanhan Liu Date: Wed, 23 Sep 2015 12:19:57 +0800 Subject: vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE Quote from Michael: We really should rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE. Suggested-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Reviewed-by: Marcel Apfelbaum Tested-by: Marcel Apfelbaum --- docs/specs/vhost-user.txt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'docs') diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 70da3b1..ccbbcbb 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -194,10 +194,10 @@ Message types as an owner of the session. This can be used on the Slave as a "session start" flag. - * VHOST_USER_RESET_OWNER + * VHOST_USER_RESET_DEVICE Id: 4 - Equivalent ioctl: VHOST_RESET_OWNER + Equivalent ioctl: VHOST_RESET_DEVICE Master payload: N/A Issued when a new connection is about to be closed. The Master will no -- cgit v1.1 From e2051e9e004649b53af4db34f78c689fb44e075b Mon Sep 17 00:00:00 2001 From: Yuanhan Liu Date: Wed, 23 Sep 2015 12:19:58 +0800 Subject: vhost-user: add VHOST_USER_GET_QUEUE_NUM message This is for querying how many queues the backend supports if it has mq support(when VHOST_USER_PROTOCOL_F_MQ flag is set from the quried protocol features). vhost_net_get_max_queues() is the interface to export that value, and to tell if the backend supports # of queues user requested, which is done in the following patch. Signed-off-by: Yuanhan Liu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Tested-by: Marcel Apfelbaum --- docs/specs/vhost-user.txt | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'docs') diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index ccbbcbb..43db9b4 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -301,3 +301,14 @@ Message types Bits (0-7) of the payload contain the vring index. Bit 8 is the invalid FD flag. This flag is set when there is no file descriptor in the ancillary data. + + * VHOST_USER_GET_QUEUE_NUM + + Id: 17 + Equivalent ioctl: N/A + Master payload: N/A + Slave payload: u64 + + Query how many queues the backend supports. This request should be + sent only when VHOST_USER_PROTOCOL_F_MQ is set in quried protocol + features by VHOST_USER_GET_PROTOCOL_FEATURES. -- cgit v1.1 From b931bfbf042983f311b3b09894d8030b2755a638 Mon Sep 17 00:00:00 2001 From: Changchun Ouyang Date: Wed, 23 Sep 2015 12:20:00 +0800 Subject: vhost-user: add multiple queue support This patch is initially based a patch from Nikolay Nikolaev. This patch adds vhost-user multiple queue support, by creating a nc and vhost_net pair for each queue. Qemu exits if find that the backend can't support the number of requested queues (by providing queues=# option). The max number is queried by a new message, VHOST_USER_GET_QUEUE_NUM, and is sent only when protocol feature VHOST_USER_PROTOCOL_F_MQ is present first. The max queue check is done at vhost-user initiation stage. We initiate one queue first, which, in the meantime, also gets the max_queues the backend supports. In older version, it was reported that some messages are sent more times than necessary. Here we came an agreement with Michael that we could categorize vhost user messages to 2 types: non-vring specific messages, which should be sent only once, and vring specific messages, which should be sent per queue. Here I introduced a helper function vhost_user_one_time_request(), which lists following messages as non-vring specific messages: VHOST_USER_SET_OWNER VHOST_USER_RESET_DEVICE VHOST_USER_SET_MEM_TABLE VHOST_USER_GET_QUEUE_NUM For above messages, we simply ignore them when they are not sent the first time. Signed-off-by: Nikolay Nikolaev Signed-off-by: Changchun Ouyang Signed-off-by: Yuanhan Liu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Reviewed-by: Jason Wang Tested-by: Marcel Apfelbaum --- docs/specs/vhost-user.txt | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'docs') diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index 43db9b4..cfc9d41 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -135,6 +135,21 @@ As older slaves don't support negotiating protocol features, a feature bit was dedicated for this purpose: #define VHOST_USER_F_PROTOCOL_FEATURES 30 +Multiple queue support +---------------------- + +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: +#define VHOST_USER_PROTOCOL_F_MQ 0 + +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 +requested queues is bigger than that. + +As all queues share one connection, the master uses a unique index for each +queue in the sent message to identify a specified queue. + Message types ------------- -- cgit v1.1 From 7263a0ad7899994b719ebed736a1119cc2e08110 Mon Sep 17 00:00:00 2001 From: Changchun Ouyang Date: Wed, 23 Sep 2015 12:20:01 +0800 Subject: vhost-user: add a new message to disable/enable a specific virt queue. Add a new message, VHOST_USER_SET_VRING_ENABLE, to enable or disable a specific virt queue, which is similar to attach/detach queue for tap device. virtio driver on guest doesn't have to use max virt queue pair, it could enable any number of virt queue ranging from 1 to max virt queue pair. Signed-off-by: Changchun Ouyang Signed-off-by: Yuanhan Liu Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Signed-off-by: Yuanhan Liu Reviewed-by: Jason Wang Tested-by: Marcel Apfelbaum --- docs/specs/vhost-user.txt | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) (limited to 'docs') diff --git a/docs/specs/vhost-user.txt b/docs/specs/vhost-user.txt index cfc9d41..4eadad1 100644 --- a/docs/specs/vhost-user.txt +++ b/docs/specs/vhost-user.txt @@ -148,7 +148,9 @@ VHOST_USER_GET_PROTOCOL_FEATURES. 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 -queue in the sent message to identify a specified queue. +queue in the sent message to identify a specified queue. One queue pair +is enabled initially. More queues are enabled dynamically, by sending +message VHOST_USER_SET_VRING_ENABLE. Message types ------------- @@ -327,3 +329,11 @@ Message types Query how many queues the backend supports. This request should be sent only when VHOST_USER_PROTOCOL_F_MQ is set in quried protocol features by VHOST_USER_GET_PROTOCOL_FEATURES. + + * VHOST_USER_SET_VRING_ENABLE + + Id: 18 + Equivalent ioctl: N/A + Master payload: vring state description + + Signal slave to enable or disable corresponding vring. -- cgit v1.1