Commit 108a6481 authored by Cindy Lu's avatar Cindy Lu Committed by Michael S. Tsirkin
Browse files

vhost-vdpa: introduce vhost-vdpa backend 



Currently we have 2 types of vhost backends in QEMU: vhost kernel and
vhost-user. The above patch provides a generic device for vDPA purpose,
this vDPA device exposes to user space a non-vendor-specific configuration
interface for setting up a vhost HW accelerator, this patch set introduces
a third vhost backend called vhost-vdpa based on the vDPA interface.

Vhost-vdpa usage:

qemu-system-x86_64 -cpu host -enable-kvm \
    ......
    -netdev type=vhost-vdpa,vhostdev=/dev/vhost-vdpa-id,id=vhost-vdpa0 \
    -device virtio-net-pci,netdev=vhost-vdpa0,page-per-vq=on \

Signed-off-by: default avatarLingshan zhu <lingshan.zhu@intel.com>
Signed-off-by: default avatarTiwei Bie <tiwei.bie@intel.com>
Signed-off-by: default avatarCindy Lu <lulu@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Message-Id: <20200701145538.22333-14-lulu@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Acked-by: default avatarJason Wang <jasowang@redhat.com>
parent 38140cc4

configure

+21 −0
Original line number Diff line number Diff line
@@ -1575,6 +1575,10 @@ for opt do 
  ;;

  --enable-vhost-user) vhost_user="yes"

  ;;

  --disable-vhost-vdpa) vhost_vdpa="no"

  ;;

  --enable-vhost-vdpa) vhost_vdpa="yes"

  ;;

  --disable-vhost-kernel) vhost_kernel="no"

  ;;

  --enable-vhost-kernel) vhost_kernel="yes"
@@ -1883,6 +1887,7 @@ disabled with --disable-FEATURE, default is enabled if available: 
  vhost-crypto    vhost-user-crypto backend support

  vhost-kernel    vhost kernel backend support

  vhost-user      vhost-user backend support

  vhost-vdpa      vhost-vdpa kernel backend support

  spice           spice

  rbd             rados block device (rbd)

  libiscsi        iscsi support
@@ -2394,6 +2399,10 @@ test "$vhost_user" = "" && vhost_user=yes 
if test "$vhost_user" = "yes" && test "$mingw32" = "yes"; then

  error_exit "vhost-user isn't available on win32"

fi

test "$vhost_vdpa" = "" && vhost_vdpa=$linux

if test "$vhost_vdpa" = "yes" && test "$linux" != "yes"; then

  error_exit "vhost-vdpa is only available on Linux"

fi

test "$vhost_kernel" = "" && vhost_kernel=$linux

if test "$vhost_kernel" = "yes" && test "$linux" != "yes"; then

  error_exit "vhost-kernel is only available on Linux"
@@ -2422,6 +2431,11 @@ test "$vhost_user_fs" = "" && vhost_user_fs=$vhost_user 
if test "$vhost_user_fs" = "yes" && test "$vhost_user" = "no"; then

  error_exit "--enable-vhost-user-fs requires --enable-vhost-user"

fi

#vhost-vdpa backends

test "$vhost_net_vdpa" = "" && vhost_net_vdpa=$vhost_vdpa

if test "$vhost_net_vdpa" = "yes" && test "$vhost_vdpa" = "no"; then

  error_exit "--enable-vhost-net-vdpa requires --enable-vhost-vdpa"

fi



# OR the vhost-kernel and vhost-user values for simplicity

if test "$vhost_net" = ""; then
@@ -6936,6 +6950,7 @@ echo "vhost-scsi support $vhost_scsi" 
echo "vhost-vsock support $vhost_vsock"

echo "vhost-user support $vhost_user"

echo "vhost-user-fs support $vhost_user_fs"

echo "vhost-vdpa support $vhost_vdpa"

echo "Trace backends    $trace_backends"

if have_backend "simple"; then

echo "Trace output file $trace_file-<pid>"
@@ -7437,6 +7452,9 @@ fi 
if test "$vhost_net_user" = "yes" ; then

  echo "CONFIG_VHOST_NET_USER=y" >> $config_host_mak

fi

if test "$vhost_net_vdpa" = "yes" ; then

  echo "CONFIG_VHOST_NET_VDPA=y" >> $config_host_mak

fi

if test "$vhost_crypto" = "yes" ; then

  echo "CONFIG_VHOST_CRYPTO=y" >> $config_host_mak

fi
@@ -7452,6 +7470,9 @@ fi 
if test "$vhost_user" = "yes" ; then

  echo "CONFIG_VHOST_USER=y" >> $config_host_mak

fi

if test "$vhost_vdpa" = "yes" ; then

  echo "CONFIG_VHOST_VDPA=y" >> $config_host_mak

fi

if test "$vhost_user_fs" = "yes" ; then

  echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak

fi

docs/interop/index.rst

+1 −0
Original line number Diff line number Diff line
@@ -20,3 +20,4 @@ Contents: 
   qemu-ga

   vhost-user

   vhost-user-gpu

   vhost-vdpa

docs/interop/vhost-vdpa.rst

0 → 100644
+17 −0
Original line number Diff line number Diff line 
=====================

Vhost-vdpa Protocol

=====================



Introduction

=============

vDPA(Virtual data path acceleration) device is a device that uses

a datapath which complies with the virtio specifications with vendor

specific control path. vDPA devices can be both physically located on

the hardware or emulated by software.



This document describes the vDPA support in qemu



Here is the kernel commit here

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=4c8cf31885f69e86be0b5b9e6677a26797365e1d



TODO : More information will add later

hw/net/vhost_net.c

+12 −6
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
#include "net/net.h"

#include "net/tap.h"

#include "net/vhost-user.h"

#include "net/vhost-vdpa.h"



#include "standard-headers/linux/vhost_types.h"

#include "hw/virtio/virtio-net.h"
@@ -33,12 +34,6 @@ 
#include "hw/virtio/vhost.h"

#include "hw/virtio/virtio-bus.h"



struct vhost_net {

    struct vhost_dev dev;

    struct vhost_virtqueue vqs[2];

    int backend;

    NetClientState *nc;

};



/* Features supported by host kernel. */

static const int kernel_feature_bits[] = {
@@ -96,6 +91,11 @@ static const int *vhost_net_get_feature_bits(struct vhost_net *net) 
    case NET_CLIENT_DRIVER_VHOST_USER:

        feature_bits = user_feature_bits;

        break;

#ifdef CONFIG_VHOST_NET_VDPA

    case NET_CLIENT_DRIVER_VHOST_VDPA:

        feature_bits = vdpa_feature_bits;

        break;

#endif

    default:

        error_report("Feature bits not defined for this type: %d",

                net->nc->info->type);
@@ -443,6 +443,12 @@ VHostNetState *get_vhost_net(NetClientState *nc) 
        vhost_net = vhost_user_get_vhost_net(nc);

        assert(vhost_net);

        break;

#endif

#ifdef CONFIG_VHOST_NET_VDPA

    case NET_CLIENT_DRIVER_VHOST_VDPA:

        vhost_net = vhost_vdpa_get_vhost_net(nc);

        assert(vhost_net);

        break;

#endif

    default:

        break;

hw/net/virtio-net.c

+19 −0
Original line number Diff line number Diff line
@@ -43,6 +43,7 @@ 
#include "monitor/qdev.h"

#include "hw/pci/pci.h"

#include "net_rx_pkt.h"

#include "hw/virtio/vhost.h"



#define VIRTIO_NET_VM_VERSION    11
@@ -125,6 +126,8 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config) 
    VirtIONet *n = VIRTIO_NET(vdev);

    struct virtio_net_config netcfg;



    int ret = 0;

    memset(&netcfg, 0 , sizeof(struct virtio_net_config));

    virtio_stw_p(vdev, &netcfg.status, n->status);

    virtio_stw_p(vdev, &netcfg.max_virtqueue_pairs, n->max_queues);

    virtio_stw_p(vdev, &netcfg.mtu, n->net_conf.mtu);
@@ -138,6 +141,15 @@ static void virtio_net_get_config(VirtIODevice *vdev, uint8_t *config) 
    virtio_stl_p(vdev, &netcfg.supported_hash_types,

                 VIRTIO_NET_RSS_SUPPORTED_HASHES);

    memcpy(config, &netcfg, n->config_size);



    NetClientState *nc = qemu_get_queue(n->nic);

    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {

        ret = vhost_net_get_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,

                             n->config_size);

    if (ret != -1) {

        memcpy(config, &netcfg, n->config_size);

    }

    }

}



static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config)
@@ -153,6 +165,13 @@ static void virtio_net_set_config(VirtIODevice *vdev, const uint8_t *config) 
        memcpy(n->mac, netcfg.mac, ETH_ALEN);

        qemu_format_nic_info_str(qemu_get_queue(n->nic), n->mac);

    }



    NetClientState *nc = qemu_get_queue(n->nic);

    if (nc->peer->info->type == NET_CLIENT_DRIVER_VHOST_VDPA) {

        vhost_net_set_config(get_vhost_net(nc->peer), (uint8_t *)&netcfg,

                               0, n->config_size,

                        VHOST_SET_CONFIG_TYPE_MASTER);

      }

}



static bool virtio_net_started(VirtIONet *n, uint8_t status)