Jason Wang
2022-Jan-28 06:56 UTC
[PATCH 06/31] vhost: Route guest->host notification through shadow virtqueue
? 2022/1/22 ??4:27, Eugenio P?rez ??:> At this moment no buffer forwarding will be performed in SVQ mode: Qemu > just forward the guest's kicks to the device. This commit also set up > SVQs in the vhost device. > > Host memory notifiers regions are left out for simplicity, and they will > not be addressed in this series.I wonder if it's better to squash this into patch 5 since it gives us a full guest->host forwarding.> > Signed-off-by: Eugenio P?rez <eperezma at redhat.com> > --- > include/hw/virtio/vhost-vdpa.h | 4 ++ > hw/virtio/vhost-vdpa.c | 122 ++++++++++++++++++++++++++++++++- > 2 files changed, 124 insertions(+), 2 deletions(-) > > diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h > index 3ce79a646d..009a9f3b6b 100644 > --- a/include/hw/virtio/vhost-vdpa.h > +++ b/include/hw/virtio/vhost-vdpa.h > @@ -12,6 +12,8 @@ > #ifndef HW_VIRTIO_VHOST_VDPA_H > #define HW_VIRTIO_VHOST_VDPA_H > > +#include <gmodule.h> > + > #include "hw/virtio/virtio.h" > #include "standard-headers/linux/vhost_types.h" > > @@ -27,6 +29,8 @@ typedef struct vhost_vdpa { > bool iotlb_batch_begin_sent; > MemoryListener listener; > struct vhost_vdpa_iova_range iova_range; > + bool shadow_vqs_enabled; > + GPtrArray *shadow_vqs; > struct vhost_dev *dev; > VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX]; > } VhostVDPA; > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c > index 6c10a7f05f..18de14f0fb 100644 > --- a/hw/virtio/vhost-vdpa.c > +++ b/hw/virtio/vhost-vdpa.c > @@ -17,12 +17,14 @@ > #include "hw/virtio/vhost.h" > #include "hw/virtio/vhost-backend.h" > #include "hw/virtio/virtio-net.h" > +#include "hw/virtio/vhost-shadow-virtqueue.h" > #include "hw/virtio/vhost-vdpa.h" > #include "exec/address-spaces.h" > #include "qemu/main-loop.h" > #include "cpu.h" > #include "trace.h" > #include "qemu-common.h" > +#include "qapi/error.h" > > /* > * Return one past the end of the end of section. Be careful with uint64_t > @@ -409,8 +411,14 @@ err: > > static void vhost_vdpa_host_notifiers_init(struct vhost_dev *dev) > { > + struct vhost_vdpa *v = dev->opaque; > int i; > > + if (v->shadow_vqs_enabled) { > + /* SVQ is not compatible with host notifiers mr */I guess there should be a TODO or FIXME here.> + return; > + } > + > for (i = dev->vq_index; i < dev->vq_index + dev->nvqs; i++) { > if (vhost_vdpa_host_notifier_init(dev, i)) { > goto err; > @@ -424,6 +432,17 @@ err: > return; > } > > +static void vhost_vdpa_svq_cleanup(struct vhost_dev *dev) > +{ > + struct vhost_vdpa *v = dev->opaque; > + size_t idx; > + > + for (idx = 0; idx < v->shadow_vqs->len; ++idx) { > + vhost_svq_stop(g_ptr_array_index(v->shadow_vqs, idx)); > + } > + g_ptr_array_free(v->shadow_vqs, true); > +} > + > static int vhost_vdpa_cleanup(struct vhost_dev *dev) > { > struct vhost_vdpa *v; > @@ -432,6 +451,7 @@ static int vhost_vdpa_cleanup(struct vhost_dev *dev) > trace_vhost_vdpa_cleanup(dev, v); > vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs); > memory_listener_unregister(&v->listener); > + vhost_vdpa_svq_cleanup(dev); > > dev->opaque = NULL; > ram_block_discard_disable(false); > @@ -507,9 +527,15 @@ static int vhost_vdpa_get_device_id(struct vhost_dev *dev, > > static int vhost_vdpa_reset_device(struct vhost_dev *dev) > { > + struct vhost_vdpa *v = dev->opaque; > int ret; > uint8_t status = 0; > > + for (unsigned i = 0; i < v->shadow_vqs->len; ++i) { > + VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i); > + vhost_svq_stop(svq); > + } > + > ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status); > trace_vhost_vdpa_reset_device(dev, status); > return ret; > @@ -639,13 +665,28 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev, > return ret; > } > > -static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev, > - struct vhost_vring_file *file) > +static int vhost_vdpa_set_vring_dev_kick(struct vhost_dev *dev, > + struct vhost_vring_file *file) > { > trace_vhost_vdpa_set_vring_kick(dev, file->index, file->fd); > return vhost_vdpa_call(dev, VHOST_SET_VRING_KICK, file); > } > > +static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev, > + struct vhost_vring_file *file) > +{ > + struct vhost_vdpa *v = dev->opaque; > + int vdpa_idx = vhost_vdpa_get_vq_index(dev, file->index); > + > + if (v->shadow_vqs_enabled) { > + VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, vdpa_idx); > + vhost_svq_set_svq_kick_fd(svq, file->fd); > + return 0; > + } else { > + return vhost_vdpa_set_vring_dev_kick(dev, file); > + } > +} > + > static int vhost_vdpa_set_vring_call(struct vhost_dev *dev, > struct vhost_vring_file *file) > { > @@ -653,6 +694,33 @@ static int vhost_vdpa_set_vring_call(struct vhost_dev *dev, > return vhost_vdpa_call(dev, VHOST_SET_VRING_CALL, file); > } > > +/** > + * Set shadow virtqueue descriptors to the device > + * > + * @dev The vhost device model > + * @svq The shadow virtqueue > + * @idx The index of the virtqueue in the vhost device > + */ > +static bool vhost_vdpa_svq_setup(struct vhost_dev *dev, > + VhostShadowVirtqueue *svq, > + unsigned idx) > +{ > + struct vhost_vring_file file = { > + .index = dev->vq_index + idx, > + }; > + const EventNotifier *event_notifier; > + int r; > + > + event_notifier = vhost_svq_get_dev_kick_notifier(svq);A question, any reason for making VhostShadowVirtqueue private? If we export it in .h we don't need helper to access its member like vhost_svq_get_dev_kick_notifier(). Note that vhost_dev is a public structure.> + file.fd = event_notifier_get_fd(event_notifier); > + r = vhost_vdpa_set_vring_dev_kick(dev, &file); > + if (unlikely(r != 0)) { > + error_report("Can't set device kick fd (%d)", -r); > + }I wonder whether or not we can generalize the logic here and vhost_vdpa_set_vring_kick(). There's nothing vdpa specific unless the vhost_ops->set_vring_kick().> + > + return r == 0; > +} > + > static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started) > { > struct vhost_vdpa *v = dev->opaque; > @@ -660,6 +728,13 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started) > > if (started) { > vhost_vdpa_host_notifiers_init(dev); > + for (unsigned i = 0; i < v->shadow_vqs->len; ++i) { > + VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i); > + bool ok = vhost_vdpa_svq_setup(dev, svq, i); > + if (unlikely(!ok)) { > + return -1; > + } > + } > vhost_vdpa_set_vring_ready(dev); > } else { > vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs); > @@ -737,6 +812,41 @@ static bool vhost_vdpa_force_iommu(struct vhost_dev *dev) > return true; > } > > +/** > + * Adaptor function to free shadow virtqueue through gpointer > + * > + * @svq The Shadow Virtqueue > + */ > +static void vhost_psvq_free(gpointer svq) > +{ > + vhost_svq_free(svq); > +}Any reason for such indirection? Can we simply use vhost_svq_free()? Thanks> + > +static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v, > + Error **errp) > +{ > + size_t n_svqs = v->shadow_vqs_enabled ? hdev->nvqs : 0; > + g_autoptr(GPtrArray) shadow_vqs = g_ptr_array_new_full(n_svqs, > + vhost_psvq_free); > + if (!v->shadow_vqs_enabled) { > + goto out; > + } > + > + for (unsigned n = 0; n < hdev->nvqs; ++n) { > + VhostShadowVirtqueue *svq = vhost_svq_new(); > + > + if (unlikely(!svq)) { > + error_setg(errp, "Cannot create svq %u", n); > + return -1; > + } > + g_ptr_array_add(v->shadow_vqs, svq); > + } > + > +out: > + v->shadow_vqs = g_steal_pointer(&shadow_vqs); > + return 0; > +} > + > static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp) > { > struct vhost_vdpa *v; > @@ -759,6 +869,10 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp) > dev->opaque = opaque ; > v->listener = vhost_vdpa_memory_listener; > v->msg_type = VHOST_IOTLB_MSG_V2; > + ret = vhost_vdpa_init_svq(dev, v, errp); > + if (ret) { > + goto err; > + } > > vhost_vdpa_get_iova_range(v); > > @@ -770,6 +884,10 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp) > VIRTIO_CONFIG_S_DRIVER); > > return 0; > + > +err: > + ram_block_discard_disable(false); > + return ret; > } > > const VhostOps vdpa_ops = {