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Re: [Qemu-devel] [PATCH v6 6/8] Add vhost-user calls implementation
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v6 6/8] Add vhost-user calls implementation |
Date: |
Wed, 15 Jan 2014 11:14:14 +0200 |
On Tue, Jan 14, 2014 at 07:14:53PM +0100, Antonios Motakis wrote:
>
>
>
> On Tue, Jan 14, 2014 at 12:21 PM, Michael S. Tsirkin <address@hidden> wrote:
>
> On Mon, Jan 13, 2014 at 03:25:17PM +0100, Antonios Motakis wrote:
> > Each ioctl request of vhost-kernel has a vhost-user message equivalent,
> > which is sent over the control socket.
> >
> > The general approach is to copy the data from the supplied argument
> > pointer to a designated field in the message. If a file descriptor is
> > to be passed it will be placed in the fds array for inclusion in
> > the sendmsd control header.
> >
> > VHOST_SET_MEM_TABLE ignores the supplied vhost_memory structure and
> scans
> > the global ram_list for ram blocks with a valid fd field set. This would
> > be set when the -mem-path option with shared=on property is used.
> >
> > Signed-off-by: Antonios Motakis <address@hidden>
> > Signed-off-by: Nikolay Nikolaev <address@hidden>
>
> the name vhost-backend and vhost-user is unfortunate as you let some
> net specific stuff get in there.
>
>
> The vhost-net stuff here is not strictly necessary, so it can be removed. We
> don't need to set a TAP backend when using vhost-user.
>
Weird. It does not need a tap backend?
Why did you make this a tap option then?
>
> > ---
> > hw/virtio/vhost-backend.c | 147
> ++++++++++++++++++++++++++++++++++++++++++++--
> > 1 file changed, 143 insertions(+), 4 deletions(-)
> >
> > diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> > index 460ee02..8f98562 100644
> > --- a/hw/virtio/vhost-backend.c
> > +++ b/hw/virtio/vhost-backend.c
> > @@ -81,6 +81,39 @@ static VhostUserMsg m __attribute__ ((unused));
> > /* The version of the protocol we support */
> > #define VHOST_USER_VERSION (0x1)
> >
> > +static unsigned long int ioctl_to_vhost_user_request[VHOST_USER_MAX] =
> {
> > + -1, /* VHOST_USER_NONE */
> > + VHOST_GET_FEATURES, /* VHOST_USER_GET_FEATURES */
> > + VHOST_SET_FEATURES, /* VHOST_USER_SET_FEATURES */
> > + VHOST_SET_OWNER, /* VHOST_USER_SET_OWNER */
> > + VHOST_RESET_OWNER, /* VHOST_USER_RESET_OWNER */
> > + VHOST_SET_MEM_TABLE, /* VHOST_USER_SET_MEM_TABLE */
> > + VHOST_SET_LOG_BASE, /* VHOST_USER_SET_LOG_BASE */
> > + VHOST_SET_LOG_FD, /* VHOST_USER_SET_LOG_FD */
> > + VHOST_SET_VRING_NUM, /* VHOST_USER_SET_VRING_NUM */
> > + VHOST_SET_VRING_ADDR, /* VHOST_USER_SET_VRING_ADDR */
> > + VHOST_SET_VRING_BASE, /* VHOST_USER_SET_VRING_BASE */
> > + VHOST_GET_VRING_BASE, /* VHOST_USER_GET_VRING_BASE */
> > + VHOST_SET_VRING_KICK, /* VHOST_USER_SET_VRING_KICK */
> > + VHOST_SET_VRING_CALL, /* VHOST_USER_SET_VRING_CALL */
> > + VHOST_SET_VRING_ERR, /* VHOST_USER_SET_VRING_ERR */
> > + VHOST_NET_SET_BACKEND, /* VHOST_USER_NET_SET_BACKEND */
> > + -1 /* VHOST_USER_ECHO */
> > +};
> > +
> > +static VhostUserRequest vhost_user_request_translate(unsigned long int
> request)
> > +{
> > + VhostUserRequest idx;
> > +
> > + for (idx = 0; idx < VHOST_USER_MAX; idx++) {
> > + if (ioctl_to_vhost_user_request[idx] == request) {
> > + break;
> > + }
> > + }
> > +
> > + return (idx == VHOST_USER_MAX) ? VHOST_USER_NONE : idx;
> > +}
> > +
> > static int vhost_user_recv(int fd, VhostUserMsg *msg)
> > {
> > ssize_t r;
> > @@ -235,7 +268,10 @@ static int vhost_user_call(struct vhost_dev *dev,
> unsigned long int request,
> > {
> > int fd = dev->control;
> > VhostUserMsg msg;
> > - int result = 0;
> > + VhostUserRequest msg_request;
> > + RAMBlock *block = 0;
> > + struct vhost_vring_file *file = 0;
> > + int need_reply = 0;
> > int fds[VHOST_MEMORY_MAX_NREGIONS];
> > size_t fd_num = 0;
> >
> > @@ -245,20 +281,123 @@ static int vhost_user_call(struct vhost_dev *dev,
> unsigned long int request,
> > return 0;
> > }
> >
> > - msg.request = VHOST_USER_NONE;
> > + msg_request = vhost_user_request_translate(request);
> > + msg.request = msg_request;
> > msg.flags = VHOST_USER_VERSION;
> > msg.size = 0;
> >
> > switch (request) {
> > + case VHOST_GET_FEATURES:
> > + case VHOST_GET_VRING_BASE:
> > + need_reply = 1;
> > + break;
> > +
> > + case VHOST_SET_FEATURES:
> > + case VHOST_SET_LOG_BASE:
> > + msg.u64 = *((__u64 *) arg);
> > + msg.size = sizeof(m.u64);
> > + break;
> > +
> > + case VHOST_SET_OWNER:
> > + case VHOST_RESET_OWNER:
> > + break;
> > +
> > + case VHOST_SET_MEM_TABLE:
> > + QTAILQ_FOREACH(block, &ram_list.blocks, next)
> > + {
> > + if (block->fd > 0) {
> > + msg.memory.regions[fd_num].userspace_addr = (__u64)
> block->host;
> > + msg.memory.regions[fd_num].memory_size = block->length;
> > + msg.memory.regions[fd_num].guest_phys_addr = block->
> offset;
> > + fds[fd_num++] = block->fd;
> > + }
> > + }
> > +
> > + msg.memory.nregions = fd_num;
> > +
> > + if (!fd_num) {
> > + error_report("Failed initializing vhost-user memory map\n"
> > + "consider using -mem-path option\n");
> > + return -1;
> > + }
> > +
> > + msg.size = sizeof(m.memory.nregions);
> > + msg.size += sizeof(m.memory.padding);
> > + msg.size += fd_num * sizeof(VhostUserMemoryRegion);
> > +
> > + break;
> > +
> > + case VHOST_SET_LOG_FD:
> > + fds[fd_num++] = *((int *) arg);
> > + break;
> > +
> > + case VHOST_SET_VRING_NUM:
> > + case VHOST_SET_VRING_BASE:
> > + memcpy(&msg.state, arg, sizeof(struct vhost_vring_state));
> > + msg.size = sizeof(m.state);
> > + break;
> > +
> > + case VHOST_SET_VRING_ADDR:
> > + memcpy(&msg.addr, arg, sizeof(struct vhost_vring_addr));
> > + msg.size = sizeof(m.addr);
> > + break;
> > +
> > + case VHOST_SET_VRING_KICK:
> > + case VHOST_SET_VRING_CALL:
> > + case VHOST_SET_VRING_ERR:
> > + case VHOST_NET_SET_BACKEND:
> > + file = arg;
> > + msg.u64 = file->index;
> > + msg.size = sizeof(m.u64);
> > + if (file->fd > 0) {
> > + fds[fd_num++] = file->fd;
> > + }
> > + break;
> > default:
> > error_report("vhost-user trying to send unhandled ioctl\n");
> > return -1;
> > break;
> > }
> >
> > - result = vhost_user_send_fds(fd, &msg, fds, fd_num);
> > + if (vhost_user_send_fds(fd, &msg, fds, fd_num) < 0) {
> > + return -1;
> > + }
> >
> > - return result;
> > + if (need_reply) {
> > + if (vhost_user_recv(fd, &msg) < 0) {
> > + return -1;
> > + }
> > +
> > + if (msg_request != msg.request) {
> > + error_report("Received unexpected msg type."
> > + " Expected %d received %d\n",
> > + msg_request, msg.request);
> > + return -1;
> > + }
> > +
> > + switch (msg_request) {
> > + case VHOST_USER_GET_FEATURES:
> > + if (msg.size != sizeof(m.u64)) {
> > + error_report("Received bad msg size.\n");
> > + return -1;
> > + }
> > + *((__u64 *) arg) = msg.u64;
> > + break;
> > + case VHOST_USER_GET_VRING_BASE:
> > + if (msg.size != sizeof(m.state)) {
> > + error_report("Received bad msg size.\n");
> > + return -1;
> > + }
> > + memcpy(arg, &msg.state, sizeof(struct vhost_vring_state));
> > + break;
> > + default:
> > + error_report("Received unexpected msg type.\n");
> > + return -1;
> > + break;
> > + }
> > + }
> > +
> > + return 0;
> > }
> >
> > static int vhost_user_init(struct vhost_dev *dev, const char *devpath)
> > --
> > 1.8.3.2
> >
>
>
[Qemu-devel] [PATCH v6 7/8] Add new vhost-user netdev backend, Antonios Motakis, 2014/01/13
[Qemu-devel] [PATCH v6 8/8] Add vhost-user reconnection, Antonios Motakis, 2014/01/13
Re: [Qemu-devel] [PATCH v6 0/8] Vhost and vhost-net support for userspace based backends, Michael S. Tsirkin, 2014/01/14
Re: [Qemu-devel] [PATCH v6 0/8] Vhost and vhost-net support for userspace based backends, Michael S. Tsirkin, 2014/01/14