On Thu, Sep 17, 2015 at 03:12:55PM +0800, Jason Wang wrote:
>
>
> On 09/15/2015 03:10 PM, Yuanhan Liu wrote:
> > From: "Michael S. Tsirkin" <m...@redhat.com>
> >
> > 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.
> >
> > v2: leverage vhost_user_call for request handling -- Yuanhan Liu
> >
> > Signed-off-by: Michael S. Tsirkin <address@hidden>
> > Signed-off-by: Yuanhan Liu <yuanhan....@linux.intel.com>
> > ---
> > 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 5c1d11f..c864237 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 13677ac..43169a1 100644
> > --- a/hw/virtio/vhost-user.c
> > +++ b/hw/virtio/vhost-user.c
> > @@ -24,6 +24,8 @@
> > #include <linux/vhost.h>
> >
> > #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.");
> > 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)) {
>
> Need rebase to master. (And use virtio_has_feature() here).
Thanks. Will fix them in next version.
--yliu
