From: Shannon Nelson shannon.nelson@amd.com
[ Upstream commit 55d8122f5cd62d5aaa225d7167dcd14a44c850b9 ]
Use the right structs for PACKED or split vqs when setting and getting the vring base.
Fixes: 4c8cf31885f6 ("vhost: introduce vDPA-based backend") Signed-off-by: Shannon Nelson shannon.nelson@amd.com Message-Id: 20230424225031.18947-3-shannon.nelson@amd.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Acked-by: Jason Wang jasowang@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vhost/vhost.c | 18 +++++++++++++----- drivers/vhost/vhost.h | 8 ++++++-- 2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 43c9770b86e5a..1a059b028c501 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1633,17 +1633,25 @@ long vhost_vring_ioctl(struct vhost_dev *d, unsigned int ioctl, void __user *arg r = -EFAULT; break; } - if (s.num > 0xffff) { - r = -EINVAL; - break; + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) { + vq->last_avail_idx = s.num & 0xffff; + vq->last_used_idx = (s.num >> 16) & 0xffff; + } else { + if (s.num > 0xffff) { + r = -EINVAL; + break; + } + vq->last_avail_idx = s.num; } - vq->last_avail_idx = s.num; /* Forget the cached index value. */ vq->avail_idx = vq->last_avail_idx; break; case VHOST_GET_VRING_BASE: s.index = idx; - s.num = vq->last_avail_idx; + if (vhost_has_feature(vq, VIRTIO_F_RING_PACKED)) + s.num = (u32)vq->last_avail_idx | ((u32)vq->last_used_idx << 16); + else + s.num = vq->last_avail_idx; if (copy_to_user(argp, &s, sizeof s)) r = -EFAULT; break; diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 790b296271f1e..5e17c4aa73745 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -85,13 +85,17 @@ struct vhost_virtqueue { /* The routine to call when the Guest pings us, or timeout. */ vhost_work_fn_t handle_kick;
- /* Last available index we saw. */ + /* Last available index we saw. + * Values are limited to 0x7fff, and the high bit is used as + * a wrap counter when using VIRTIO_F_RING_PACKED. */ u16 last_avail_idx;
/* Caches available index value from user. */ u16 avail_idx;
- /* Last index we used. */ + /* Last index we used. + * Values are limited to 0x7fff, and the high bit is used as + * a wrap counter when using VIRTIO_F_RING_PACKED. */ u16 last_used_idx;
/* Used flags */