From 3f8f2a92c10af2e44d2b1c7cc610960ff634739a Mon Sep 17 00:00:00 2001 From: Marcel Apfelbaum Date: Thu, 24 Sep 2015 17:04:03 +0200 Subject: [PATCH 08/13] vhost-user: add protocol feature negotiation Message-id: <1443114248-18614-7-git-send-email-marcel@redhat.com> Patchwork-id: 67939 O-Subject: [RHEL-7.2 qemu-kvm-rhev PATCH 06/11] vhost-user: add protocol feature negotiation Bugzilla: 1207687 RH-Acked-by: Victor Kaplansky RH-Acked-by: Xiao Wang RH-Acked-by: Michael S. Tsirkin From: "Michael S. Tsirkin" 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 (cherry picked from commit dcb10c000cdd4d14f5ac4f07b04fb666494ef4a8) Signed-off-by: Marcel Apfelbaum Signed-off-by: Miroslav Rezanina --- docs/specs/vhost-user.txt | 37 +++++++++++++++++++++++++++++++++++++ hw/net/vhost_net.c | 2 ++ hw/virtio/vhost-user.c | 31 +++++++++++++++++++++++++++++++ include/hw/virtio/vhost.h | 1 + 4 files changed, 71 insertions(+) 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 diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index 1d76b94..9d32d76 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -152,8 +152,10 @@ struct vhost_net *vhost_net_init(VhostNetOptions *options) net->dev.backend_features = qemu_has_vnet_hdr(options->net_backend) ? 0 : (1ULL << VHOST_NET_F_VIRTIO_NET_HDR); net->backend = r; + net->dev.protocol_features = 0; } else { net->dev.backend_features = 0; + net->dev.protocol_features = 0; net->backend = -1; } net->nc = options->net_backend; diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c index 78c5c0d..87198a4 100644 --- a/hw/virtio/vhost-user.c +++ b/hw/virtio/vhost-user.c @@ -24,6 +24,8 @@ #include #define VHOST_MEMORY_MAX_NREGIONS 8 +#define VHOST_USER_F_PROTOCOL_FEATURES 30 +#define VHOST_USER_PROTOCOL_FEATURE_MASK 0x0ULL typedef enum VhostUserRequest { VHOST_USER_NONE = 0, @@ -41,6 +43,8 @@ typedef enum VhostUserRequest { VHOST_USER_SET_VRING_KICK = 12, VHOST_USER_SET_VRING_CALL = 13, VHOST_USER_SET_VRING_ERR = 14, + VHOST_USER_GET_PROTOCOL_FEATURES = 15, + VHOST_USER_SET_PROTOCOL_FEATURES = 16, VHOST_USER_MAX } VhostUserRequest; @@ -206,11 +210,13 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request, switch (msg_request) { case VHOST_USER_GET_FEATURES: + case VHOST_USER_GET_PROTOCOL_FEATURES: need_reply = 1; break; case VHOST_USER_SET_FEATURES: case VHOST_USER_SET_LOG_BASE: + case VHOST_USER_SET_PROTOCOL_FEATURES: msg.u64 = *((__u64 *) arg); msg.size = sizeof(m.u64); break; @@ -308,6 +314,7 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request, switch (msg_request) { case VHOST_USER_GET_FEATURES: + case VHOST_USER_GET_PROTOCOL_FEATURES: if (msg.size != sizeof(m.u64)) { error_report("Received bad msg size.\n"); return -1; @@ -333,10 +340,34 @@ static int vhost_user_call(struct vhost_dev *dev, unsigned long int request, static int vhost_user_init(struct vhost_dev *dev, void *opaque) { + unsigned long long features; + int err; + assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER); dev->opaque = opaque; + err = vhost_user_call(dev, VHOST_USER_GET_FEATURES, &features); + if (err < 0) { + return err; + } + + if (virtio_has_feature(features, VHOST_USER_F_PROTOCOL_FEATURES)) { + dev->backend_features |= 1ULL << VHOST_USER_F_PROTOCOL_FEATURES; + + err = vhost_user_call(dev, VHOST_USER_GET_PROTOCOL_FEATURES, &features); + if (err < 0) { + return err; + } + + dev->protocol_features = features & VHOST_USER_PROTOCOL_FEATURE_MASK; + err = vhost_user_call(dev, VHOST_USER_SET_PROTOCOL_FEATURES, + &dev->protocol_features); + if (err < 0) { + return err; + } + } + return 0; } diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index b8edb0f..798c8cc 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -41,6 +41,7 @@ struct vhost_dev { unsigned long long features; unsigned long long acked_features; unsigned long long backend_features; + unsigned long long protocol_features; bool started; bool log_enabled; vhost_log_chunk_t *log; -- 1.8.3.1