By default svq vrings are placed in an anonymous memory map. As svqs will be leveraged to enable memory isolation in vhost-user, it is useful to be able to place the vrings in a shared isolation memory region.
Adds the option to specify vring placement by providing a vring base address before starting the svq. Signed-off-by: Connor Kite <[email protected]> --- hw/virtio/vhost-shadow-virtqueue.c | 69 ++++++++++++++++++++++++++++++++------ hw/virtio/vhost-shadow-virtqueue.h | 8 ++++- 2 files changed, 66 insertions(+), 11 deletions(-) diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c index 496e7e58a3..f54a61439a 100644 --- a/hw/virtio/vhost-shadow-virtqueue.c +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -812,6 +812,13 @@ size_t vhost_svq_device_area_size(const VhostShadowVirtqueue *svq) return ROUND_UP(used_size, qemu_real_host_page_size()); } +size_t vhost_svq_vring_total_size(VirtIODevice *vdev, VirtQueue *vq) +{ + VhostShadowVirtqueue svq; + svq.vring.num = virtio_queue_get_num(vdev, virtio_get_queue_index(vq)); + return vhost_svq_driver_area_size(&svq) + vhost_svq_device_area_size(&svq); +} + /** * Set a new file descriptor for the guest to kick the SVQ and notify for avail * @@ -842,6 +849,19 @@ void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd) } } +/** + * Set vring base address if using fixed locations + * + * @svq: Shadow Virtqueue + * @addr: Points to new base address + */ + + void vhost_svq_set_base_addr(VhostShadowVirtqueue *svq, void *addr) + { + svq->base_addr = addr; + } + + /** * Start the shadow virtqueue operation. * @@ -849,8 +869,10 @@ void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd) * @vdev: VirtIO device * @vq: Virtqueue to shadow * @iova_tree: Tree to perform descriptors translations + * + * Return 0 on success, -errno on failure */ -void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, +int vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, VirtQueue *vq, VhostIOVATree *iova_tree) { size_t desc_size; @@ -868,14 +890,27 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, svq->vring.num = virtio_queue_get_num(vdev, virtio_get_queue_index(vq)); svq->num_free = svq->vring.num; - svq->vring.desc = mmap(NULL, vhost_svq_driver_area_size(svq), - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, - -1, 0); desc_size = sizeof(vring_desc_t) * svq->vring.num; - svq->vring.avail = (void *)((char *)svq->vring.desc + desc_size); - svq->vring.used = mmap(NULL, vhost_svq_device_area_size(svq), - PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, - -1, 0); + if (svq->base_addr == NULL) { + svq->vring.desc = mmap(NULL, vhost_svq_driver_area_size(svq), + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, + -1, 0); + svq->vring.avail = (void *)((char *)svq->vring.desc + desc_size); + svq->vring.used = mmap(NULL, vhost_svq_device_area_size(svq), + PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, + -1, 0); + } else { + svq->vring.desc = (void *)svq->base_addr; + svq->vring.avail = (void *)((char *)svq->vring.desc + desc_size); + svq->vring.used = (void *)((char *)svq->base_addr + + vhost_svq_driver_area_size(svq)); + + if ((uint64_t)svq->vring.used + vhost_svq_device_area_size(svq) - 1 < + (uint64_t)svq->vring.desc) { + error_report("Invalid shadow vring location"); + return -ENOMEM; + } + } svq->desc_state = g_new0(SVQDescState, svq->vring.num); if (virtio_vdev_has_feature(svq->vdev, VIRTIO_F_IN_ORDER)) { svq->batch_last.id = VIRTIO_RING_NOT_IN_BATCH; @@ -884,6 +919,8 @@ void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, svq->desc_state[i].next = i + 1; } } + + return 0; } /** @@ -920,8 +957,19 @@ void vhost_svq_stop(VhostShadowVirtqueue *svq) } svq->vq = NULL; g_free(svq->desc_state); - munmap(svq->vring.desc, vhost_svq_driver_area_size(svq)); - munmap(svq->vring.used, vhost_svq_device_area_size(svq)); + + if (!svq->base_addr) { + munmap(svq->vring.desc, vhost_svq_driver_area_size(svq)); + munmap(svq->vring.used, vhost_svq_device_area_size(svq)); + } else{ + if (svq->vring.desc) { + memset(svq->vring.desc, 0, vhost_svq_driver_area_size(svq)); + } + if (svq->vring.used) { + memset(svq->vring.used, 0, vhost_svq_device_area_size(svq)); + } + } + event_notifier_set_handler(&svq->hdev_call, NULL); } @@ -940,6 +988,7 @@ VhostShadowVirtqueue *vhost_svq_new(const VhostShadowVirtqueueOps *ops, event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND); svq->ops = ops; svq->ops_opaque = ops_opaque; + svq->base_addr = NULL; return svq; } diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h index fd68319fb7..1e0cc9e5e4 100644 --- a/hw/virtio/vhost-shadow-virtqueue.h +++ b/hw/virtio/vhost-shadow-virtqueue.h @@ -150,6 +150,9 @@ typedef struct VhostShadowVirtqueue { /* Size of SVQ vring free descriptors */ uint16_t num_free; + + /* Location assigned to vrings if not in default anon memory map */ + void *base_addr; } VhostShadowVirtqueue; bool vhost_svq_valid_features(uint64_t features, Error **errp); @@ -169,8 +172,9 @@ void vhost_svq_get_vring_addr(const VhostShadowVirtqueue *svq, struct vhost_vring_addr *addr); size_t vhost_svq_driver_area_size(const VhostShadowVirtqueue *svq); size_t vhost_svq_device_area_size(const VhostShadowVirtqueue *svq); +size_t vhost_svq_vring_total_size(VirtIODevice *vdev, VirtQueue *vq); -void vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, +int vhost_svq_start(VhostShadowVirtqueue *svq, VirtIODevice *vdev, VirtQueue *vq, VhostIOVATree *iova_tree); void vhost_svq_stop(VhostShadowVirtqueue *svq); @@ -178,6 +182,8 @@ VhostShadowVirtqueue *vhost_svq_new(const VhostShadowVirtqueueOps *ops, void *ops_opaque); void vhost_svq_free(gpointer vq); +void vhost_svq_set_base_addr(VhostShadowVirtqueue *svq, void *addr); + G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostShadowVirtqueue, vhost_svq_free); #endif -- 2.43.0
