David Riley
2019-Sep-10 20:06 UTC
[PATCH v3 2/2] drm/virtio: Use vmalloc for command buffer allocations.
Userspace requested command buffer allocations could be too large
to make as a contiguous allocation. Use vmalloc if necessary to
satisfy those allocations.
Signed-off-by: David Riley <davidriley at chromium.org>
---
drivers/gpu/drm/virtio/virtgpu_ioctl.c | 4 +-
drivers/gpu/drm/virtio/virtgpu_vq.c | 79 +++++++++++++++++++++++---
2 files changed, 73 insertions(+), 10 deletions(-)
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index ac60be9b5c19..a8732a8af766 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -195,7 +195,7 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device
*dev, void *data,
if (ret)
goto out_free;
- buf = memdup_user(u64_to_user_ptr(exbuf->command), exbuf->size);
+ buf = vmemdup_user(u64_to_user_ptr(exbuf->command), exbuf->size);
if (IS_ERR(buf)) {
ret = PTR_ERR(buf);
goto out_unresv;
@@ -230,7 +230,7 @@ static int virtio_gpu_execbuffer_ioctl(struct drm_device
*dev, void *data,
return 0;
out_memdup:
- kfree(buf);
+ kvfree(buf);
out_unresv:
ttm_eu_backoff_reservation(&ticket, &validate_list);
out_free:
diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c
b/drivers/gpu/drm/virtio/virtgpu_vq.c
index bf5a4a50b002..76cf2b9d5d1d 100644
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -154,7 +154,7 @@ static void free_vbuf(struct virtio_gpu_device *vgdev,
{
if (vbuf->resp_size > MAX_INLINE_RESP_SIZE)
kfree(vbuf->resp_buf);
- kfree(vbuf->data_buf);
+ kvfree(vbuf->data_buf);
kmem_cache_free(vgdev->vbufs, vbuf);
}
@@ -251,13 +251,54 @@ void virtio_gpu_dequeue_cursor_func(struct work_struct
*work)
wake_up(&vgdev->cursorq.ack_queue);
}
+/* Create sg_table from a vmalloc'd buffer. */
+static struct sg_table *vmalloc_to_sgt(char *data, uint32_t size, int *sg_ents)
+{
+ int ret, s, i;
+ struct sg_table *sgt;
+ struct scatterlist *sg;
+ struct page *pg;
+
+ if (WARN_ON(!PAGE_ALIGNED(data)))
+ return NULL;
+
+ sgt = kmalloc(sizeof(*sgt), GFP_KERNEL);
+ if (!sgt)
+ return NULL;
+
+ *sg_ents = DIV_ROUND_UP(size, PAGE_SIZE);
+ ret = sg_alloc_table(sgt, *sg_ents, GFP_KERNEL);
+ if (ret) {
+ kfree(sgt);
+ return NULL;
+ }
+
+ for_each_sg(sgt->sgl, sg, *sg_ents, i) {
+ pg = vmalloc_to_page(data);
+ if (!pg) {
+ sg_free_table(sgt);
+ kfree(sgt);
+ return NULL;
+ }
+
+ s = min_t(int, PAGE_SIZE, size);
+ sg_set_page(sg, pg, s, 0);
+
+ size -= s;
+ data += s;
+ }
+
+ return sgt;
+}
+
static int virtio_gpu_queue_ctrl_buffer_locked(struct virtio_gpu_device *vgdev,
- struct virtio_gpu_vbuffer *vbuf)
+ struct virtio_gpu_vbuffer *vbuf,
+ struct scatterlist *vout)
__releases(&vgdev->ctrlq.qlock)
__acquires(&vgdev->ctrlq.qlock)
{
struct virtqueue *vq = vgdev->ctrlq.vq;
- struct scatterlist *sgs[3], vcmd, vout, vresp;
+ struct scatterlist *sgs[3], vcmd, vresp;
int outcnt = 0, incnt = 0;
int ret;
@@ -268,9 +309,8 @@ static int virtio_gpu_queue_ctrl_buffer_locked(struct
virtio_gpu_device *vgdev,
sgs[outcnt + incnt] = &vcmd;
outcnt++;
- if (vbuf->data_size) {
- sg_init_one(&vout, vbuf->data_buf, vbuf->data_size);
- sgs[outcnt + incnt] = &vout;
+ if (vout) {
+ sgs[outcnt + incnt] = vout;
outcnt++;
}
@@ -305,7 +345,24 @@ static int virtio_gpu_queue_fenced_ctrl_buffer(struct
virtio_gpu_device *vgdev,
struct virtio_gpu_fence *fence)
{
struct virtqueue *vq = vgdev->ctrlq.vq;
+ struct scatterlist *vout = NULL, sg;
+ struct sg_table *sgt = NULL;
int rc;
+ int outcnt = 0;
+
+ if (vbuf->data_size) {
+ if (is_vmalloc_addr(vbuf->data_buf)) {
+ sgt = vmalloc_to_sgt(vbuf->data_buf, vbuf->data_size,
+ &outcnt);
+ if (!sgt)
+ return -ENOMEM;
+ vout = sgt->sgl;
+ } else {
+ sg_init_one(&sg, vbuf->data_buf, vbuf->data_size);
+ vout = &sg;
+ outcnt = 1;
+ }
+ }
again:
spin_lock(&vgdev->ctrlq.qlock);
@@ -318,7 +375,7 @@ static int virtio_gpu_queue_fenced_ctrl_buffer(struct
virtio_gpu_device *vgdev,
* to wait for free space, which can result in fence ids being
* submitted out-of-order.
*/
- if (vq->num_free < 3) {
+ if (vq->num_free < 2 + outcnt) {
spin_unlock(&vgdev->ctrlq.qlock);
wait_event(vgdev->ctrlq.ack_queue, vq->num_free >= 3);
goto again;
@@ -326,8 +383,14 @@ static int virtio_gpu_queue_fenced_ctrl_buffer(struct
virtio_gpu_device *vgdev,
if (hdr && fence)
virtio_gpu_fence_emit(vgdev, hdr, fence);
- rc = virtio_gpu_queue_ctrl_buffer_locked(vgdev, vbuf);
+ rc = virtio_gpu_queue_ctrl_buffer_locked(vgdev, vbuf, vout);
spin_unlock(&vgdev->ctrlq.qlock);
+
+ if (sgt) {
+ sg_free_table(sgt);
+ kfree(sgt);
+ }
+
return rc;
}
--
2.23.0.162.g0b9fbb3734-goog