virtio: add vhost support for virtio devices

This patch adds a get_vhost() callback function for VirtIODevices that
returns the device's corresponding vhost_dev structure, if the vhost
device is running. This patch also adds a vhost_started flag for
VirtIODevices.

Previously, a VirtIODevice wouldn't be able to tell if its corresponding
vhost device was active or not.

Signed-off-by: Jonah Palmer <jonah.palmer@oracle.com>
Message-Id: <1648819405-25696-3-git-send-email-jonah.palmer@oracle.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

hw/block/vhost-user-blk.c

@@ -569,6 +569,12 @@ static void vhost_user_blk_instance_init(Object *obj)
                                   "/disk@0,0", DEVICE(obj));
 }
 
+static struct vhost_dev *vhost_user_blk_get_vhost(VirtIODevice *vdev)
+{
+    VHostUserBlk *s = VHOST_USER_BLK(vdev);
+    return &s->dev;
+}
+
 static const VMStateDescription vmstate_vhost_user_blk = {
     .name = "vhost-user-blk",
     .minimum_version_id = 1,
@@ -603,6 +609,7 @@ static void vhost_user_blk_class_init(ObjectClass *klass, void *data)
     vdc->get_features = vhost_user_blk_get_features;
     vdc->set_status = vhost_user_blk_set_status;
     vdc->reset = vhost_user_blk_reset;
+    vdc->get_vhost = vhost_user_blk_get_vhost;
 }
 
 static const TypeInfo vhost_user_blk_info = {

hw/display/vhost-user-gpu.c

@@ -565,6 +565,12 @@ vhost_user_gpu_device_realize(DeviceState *qdev, Error **errp)
     g->vhost_gpu_fd = -1;
 }
 
+static struct vhost_dev *vhost_user_gpu_get_vhost(VirtIODevice *vdev)
+{
+    VhostUserGPU *g = VHOST_USER_GPU(vdev);
+    return &g->vhost->dev;
+}
+
 static Property vhost_user_gpu_properties[] = {
     VIRTIO_GPU_BASE_PROPERTIES(VhostUserGPU, parent_obj.conf),
     DEFINE_PROP_END_OF_LIST(),
@@ -586,6 +592,7 @@ vhost_user_gpu_class_init(ObjectClass *klass, void *data)
     vdc->guest_notifier_pending = vhost_user_gpu_guest_notifier_pending;
     vdc->get_config = vhost_user_gpu_get_config;
     vdc->set_config = vhost_user_gpu_set_config;
+    vdc->get_vhost = vhost_user_gpu_get_vhost;
 
     device_class_set_props(dc, vhost_user_gpu_properties);
 }

hw/input/vhost-user-input.c

@@ -78,6 +78,12 @@ static void vhost_input_set_config(VirtIODevice *vdev,
     virtio_notify_config(vdev);
 }
 
+static struct vhost_dev *vhost_input_get_vhost(VirtIODevice *vdev)
+{
+    VHostUserInput *vhi = VHOST_USER_INPUT(vdev);
+    return &vhi->vhost->dev;
+}
+
 static const VMStateDescription vmstate_vhost_input = {
     .name = "vhost-user-input",
     .unmigratable = 1,
@@ -92,6 +98,7 @@ static void vhost_input_class_init(ObjectClass *klass, void *data)
     dc->vmsd = &vmstate_vhost_input;
     vdc->get_config = vhost_input_get_config;
     vdc->set_config = vhost_input_set_config;
+    vdc->get_vhost = vhost_input_get_vhost;
     vic->realize = vhost_input_realize;
     vic->change_active = vhost_input_change_active;
 }

hw/net/virtio-net.c

@@ -3620,6 +3620,14 @@ static bool dev_unplug_pending(void *opaque)
     return vdc->primary_unplug_pending(dev);
 }
 
+static struct vhost_dev *virtio_net_get_vhost(VirtIODevice *vdev)
+{
+    VirtIONet *n = VIRTIO_NET(vdev);
+    NetClientState *nc = qemu_get_queue(n->nic);
+    struct vhost_net *net = get_vhost_net(nc->peer);
+    return &net->dev;
+}
+
 static const VMStateDescription vmstate_virtio_net = {
     .name = "virtio-net",
     .minimum_version_id = VIRTIO_NET_VM_VERSION,
@@ -3722,6 +3730,7 @@ static void virtio_net_class_init(ObjectClass *klass, void *data)
     vdc->post_load = virtio_net_post_load_virtio;
     vdc->vmsd = &vmstate_virtio_net_device;
     vdc->primary_unplug_pending = primary_unplug_pending;
+    vdc->get_vhost = virtio_net_get_vhost;
 }
 
 static const TypeInfo virtio_net_info = {

hw/scsi/vhost-scsi.c

@@ -273,6 +273,13 @@ static void vhost_scsi_unrealize(DeviceState *dev)
     virtio_scsi_common_unrealize(dev);
 }
 
+static struct vhost_dev *vhost_scsi_get_vhost(VirtIODevice *vdev)
+{
+    VHostSCSI *s = VHOST_SCSI(vdev);
+    VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
+    return &vsc->dev;
+}
+
 static Property vhost_scsi_properties[] = {
     DEFINE_PROP_STRING("vhostfd", VirtIOSCSICommon, conf.vhostfd),
     DEFINE_PROP_STRING("wwpn", VirtIOSCSICommon, conf.wwpn),
@@ -307,6 +314,7 @@ static void vhost_scsi_class_init(ObjectClass *klass, void *data)
     vdc->get_features = vhost_scsi_common_get_features;
     vdc->set_config = vhost_scsi_common_set_config;
     vdc->set_status = vhost_scsi_set_status;
+    vdc->get_vhost = vhost_scsi_get_vhost;
     fwc->get_dev_path = vhost_scsi_common_get_fw_dev_path;
 }
 

hw/virtio/vhost-user-fs.c

@@ -276,6 +276,12 @@ static void vuf_device_unrealize(DeviceState *dev)
     fs->vhost_dev.vqs = NULL;
 }
 
+static struct vhost_dev *vuf_get_vhost(VirtIODevice *vdev)
+{
+    VHostUserFS *fs = VHOST_USER_FS(vdev);
+    return &fs->vhost_dev;
+}
+
 static const VMStateDescription vuf_vmstate = {
     .name = "vhost-user-fs",
     .unmigratable = 1,
@@ -313,6 +319,7 @@ static void vuf_class_init(ObjectClass *klass, void *data)
     vdc->set_status = vuf_set_status;
     vdc->guest_notifier_mask = vuf_guest_notifier_mask;
     vdc->guest_notifier_pending = vuf_guest_notifier_pending;
+    vdc->get_vhost = vuf_get_vhost;
 }
 
 static const TypeInfo vuf_info = {

hw/virtio/vhost-user-rng.c

@@ -247,6 +247,12 @@ static void vu_rng_device_unrealize(DeviceState *dev)
     vhost_user_cleanup(&rng->vhost_user);
 }
 
+static struct vhost_dev *vu_rng_get_vhost(VirtIODevice *vdev)
+{
+    VHostUserRNG *rng = VHOST_USER_RNG(vdev);
+    return &rng->vhost_dev;
+}
+
 static const VMStateDescription vu_rng_vmstate = {
     .name = "vhost-user-rng",
     .unmigratable = 1,
@@ -272,6 +278,7 @@ static void vu_rng_class_init(ObjectClass *klass, void *data)
     vdc->set_status = vu_rng_set_status;
     vdc->guest_notifier_mask = vu_rng_guest_notifier_mask;
     vdc->guest_notifier_pending = vu_rng_guest_notifier_pending;
+    vdc->get_vhost = vu_rng_get_vhost;
 }
 
 static const TypeInfo vu_rng_info = {

hw/virtio/vhost-vsock-common.c

@@ -258,6 +258,12 @@ void vhost_vsock_common_unrealize(VirtIODevice *vdev)
     virtio_cleanup(vdev);
 }
 
+static struct vhost_dev *vhost_vsock_common_get_vhost(VirtIODevice *vdev)
+{
+    VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev);
+    return &vvc->vhost_dev;
+}
+
 static Property vhost_vsock_common_properties[] = {
     DEFINE_PROP_ON_OFF_AUTO("seqpacket", VHostVSockCommon, seqpacket,
                             ON_OFF_AUTO_AUTO),
@@ -273,6 +279,7 @@ static void vhost_vsock_common_class_init(ObjectClass *klass, void *data)
     set_bit(DEVICE_CATEGORY_MISC, dc->categories);
     vdc->guest_notifier_mask = vhost_vsock_common_guest_notifier_mask;
     vdc->guest_notifier_pending = vhost_vsock_common_guest_notifier_pending;
+    vdc->get_vhost = vhost_vsock_common_get_vhost;
 }
 
 static const TypeInfo vhost_vsock_common_info = {

hw/virtio/vhost.c

@@ -1738,6 +1738,7 @@ int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev)
     /* should only be called after backend is connected */
     assert(hdev->vhost_ops);
 
+    vdev->vhost_started = true;
     hdev->started = true;
     hdev->vdev = vdev;
 
@@ -1810,7 +1811,7 @@ fail_vq:
 
 fail_mem:
 fail_features:
-
+    vdev->vhost_started = false;
     hdev->started = false;
     return r;
 }
@@ -1841,6 +1842,7 @@ void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
     }
     vhost_log_put(hdev, true);
     hdev->started = false;
+    vdev->vhost_started = false;
     hdev->vdev = NULL;
 }
 

hw/virtio/virtio-crypto.c

@@ -961,6 +961,15 @@ static bool virtio_crypto_guest_notifier_pending(VirtIODevice *vdev, int idx)
     return cryptodev_vhost_virtqueue_pending(vdev, queue, idx);
 }
 
+static struct vhost_dev *virtio_crypto_get_vhost(VirtIODevice *vdev)
+{
+    VirtIOCrypto *vcrypto = VIRTIO_CRYPTO(vdev);
+    CryptoDevBackend *b = vcrypto->cryptodev;
+    CryptoDevBackendClient *cc = b->conf.peers.ccs[0];
+    CryptoDevBackendVhost *vhost_crypto = cryptodev_get_vhost(cc, b, 0);
+    return &vhost_crypto->dev;
+}
+
 static void virtio_crypto_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -977,6 +986,7 @@ static void virtio_crypto_class_init(ObjectClass *klass, void *data)
     vdc->set_status = virtio_crypto_set_status;
     vdc->guest_notifier_mask = virtio_crypto_guest_notifier_mask;
     vdc->guest_notifier_pending = virtio_crypto_guest_notifier_pending;
+    vdc->get_vhost = virtio_crypto_get_vhost;
 }
 
 static void virtio_crypto_instance_init(Object *obj)

hw/virtio/virtio.c

@@ -3271,6 +3271,7 @@ void virtio_init(VirtIODevice *vdev, uint16_t device_id, size_t config_size)
 
     vdev->start_on_kick = false;
     vdev->started = false;
+    vdev->vhost_started = false;
     vdev->device_id = device_id;
     vdev->status = 0;
     qatomic_set(&vdev->isr, 0);

include/hw/virtio/virtio.h

@@ -22,6 +22,7 @@
 #include "standard-headers/linux/virtio_config.h"
 #include "standard-headers/linux/virtio_ring.h"
 #include "qom/object.h"
+#include "hw/virtio/vhost.h"
 
 /* A guest should never accept this.  It implies negotiation is broken. */
 #define VIRTIO_F_BAD_FEATURE		30
@@ -102,6 +103,7 @@ struct VirtIODevice
     bool started;
     bool start_on_kick; /* when virtio 1.0 feature has not been negotiated */
     bool disable_legacy_check;
+    bool vhost_started;
     VMChangeStateEntry *vmstate;
     char *bus_name;
     uint8_t device_endian;
@@ -160,6 +162,7 @@ struct VirtioDeviceClass {
     int (*post_load)(VirtIODevice *vdev);
     const VMStateDescription *vmsd;
     bool (*primary_unplug_pending)(void *opaque);
+    struct vhost_dev *(*get_vhost)(VirtIODevice *vdev);
 };
 
 void virtio_instance_init_common(Object *proxy_obj, void *data,