From: Si-Wei Liu si-wei.liu@oracle.com
[ Upstream commit bc91df5c70ac720eca18bd1f4a288f2582713d3e ]
Using .compat_reset op from the previous patch, the buggy .reset behaviour can be kept as-is on older userspace apps, which don't ack the IOTLB_PERSIST backend feature. As this compatibility quirk is limited to those drivers that used to be buggy in the past, it won't affect change the behaviour or affect ABI on the setups with API compliant driver.
The separation of .compat_reset from the regular .reset allows vhost-vdpa able to know which driver had broken behaviour before, so it can apply the corresponding compatibility quirk to the individual driver whenever needed. Compared to overloading the existing .reset with flags, .compat_reset won't cause any extra burden to the implementation of every compliant driver.
[mst: squashed in two fixup commits]
Message-Id: 1697880319-4937-6-git-send-email-si-wei.liu@oracle.com Message-Id: 1698102863-21122-1-git-send-email-si-wei.liu@oracle.com Reported-by: Dragos Tatulea dtatulea@nvidia.com Tested-by: Dragos Tatulea dtatulea@nvidia.com Message-Id: 1698275594-19204-1-git-send-email-si-wei.liu@oracle.com Reported-by: Lei Yang leiyang@redhat.com Signed-off-by: Si-Wei Liu si-wei.liu@oracle.com Signed-off-by: Michael S. Tsirkin mst@redhat.com Tested-by: Lei Yang leiyang@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/vhost/vdpa.c | 20 ++++++++++++++++---- drivers/virtio/virtio_vdpa.c | 2 +- include/linux/vdpa.h | 7 +++++-- 3 files changed, 22 insertions(+), 7 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c index b43e8680eee8d..fb934a7e68bfb 100644 --- a/drivers/vhost/vdpa.c +++ b/drivers/vhost/vdpa.c @@ -210,13 +210,24 @@ static void vhost_vdpa_unsetup_vq_irq(struct vhost_vdpa *v, u16 qid) irq_bypass_unregister_producer(&vq->call_ctx.producer); }
-static int vhost_vdpa_reset(struct vhost_vdpa *v) +static int _compat_vdpa_reset(struct vhost_vdpa *v) { struct vdpa_device *vdpa = v->vdpa; + u32 flags = 0;
- v->in_batch = 0; + if (v->vdev.vqs) { + flags |= !vhost_backend_has_feature(v->vdev.vqs[0], + VHOST_BACKEND_F_IOTLB_PERSIST) ? + VDPA_RESET_F_CLEAN_MAP : 0; + } + + return vdpa_reset(vdpa, flags); +}
- return vdpa_reset(vdpa); +static int vhost_vdpa_reset(struct vhost_vdpa *v) +{ + v->in_batch = 0; + return _compat_vdpa_reset(v); }
static long vhost_vdpa_bind_mm(struct vhost_vdpa *v) @@ -295,7 +306,7 @@ static long vhost_vdpa_set_status(struct vhost_vdpa *v, u8 __user *statusp) vhost_vdpa_unsetup_vq_irq(v, i);
if (status == 0) { - ret = vdpa_reset(vdpa); + ret = _compat_vdpa_reset(v); if (ret) return ret; } else @@ -1272,6 +1283,7 @@ static void vhost_vdpa_cleanup(struct vhost_vdpa *v) vhost_vdpa_free_domain(v); vhost_dev_cleanup(&v->vdev); kfree(v->vdev.vqs); + v->vdev.vqs = NULL; }
static int vhost_vdpa_open(struct inode *inode, struct file *filep) diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c index 06ce6d8c2e004..8d63e5923d245 100644 --- a/drivers/virtio/virtio_vdpa.c +++ b/drivers/virtio/virtio_vdpa.c @@ -100,7 +100,7 @@ static void virtio_vdpa_reset(struct virtio_device *vdev) { struct vdpa_device *vdpa = vd_get_vdpa(vdev);
- vdpa_reset(vdpa); + vdpa_reset(vdpa, 0); }
static bool virtio_vdpa_notify(struct virtqueue *vq) diff --git a/include/linux/vdpa.h b/include/linux/vdpa.h index db1b0eaef4eb7..c287382b0a80b 100644 --- a/include/linux/vdpa.h +++ b/include/linux/vdpa.h @@ -481,14 +481,17 @@ static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev) return vdev->dma_dev; }
-static inline int vdpa_reset(struct vdpa_device *vdev) +static inline int vdpa_reset(struct vdpa_device *vdev, u32 flags) { const struct vdpa_config_ops *ops = vdev->config; int ret;
down_write(&vdev->cf_lock); vdev->features_valid = false; - ret = ops->reset(vdev); + if (ops->compat_reset && flags) + ret = ops->compat_reset(vdev, flags); + else + ret = ops->reset(vdev); up_write(&vdev->cf_lock); return ret; }