Re: [PATCH 07/11] vhost: convert vhost_umem_interval_tree to half closed intervals

Jason Wang
2019-10-10T05:49:29Z

On 2019/10/4 上午4:18, Davidlohr Bueso wrote:
> The vhost_umem interval tree really wants [a, b) intervals,
> not fully closed as currently. As such convert it to use the
> new interval_tree_gen.h, and also rename the 'last' endpoint
> in the node to 'end', which both a more suitable name for
> the half closed interval and also reduces the chances of some
> caller being missed.
>
> Cc: Michael S. Tsirkin" <mst@redhat.com>
> Cc: Jason Wang <jasowang@redhat.com>
> Cc: virtualization@lists.linux-foundation.org
> Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
> ---
> drivers/vhost/vhost.c | 19 +++++++++----------
> drivers/vhost/vhost.h | 4 ++--
> 2 files changed, 11 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index 36ca2cf419bf..80c3cca24dc7 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -28,7 +28,7 @@
> #include <linux/sort.h>
> #include <linux/sched/mm.h>
> #include <linux/sched/signal.h>
> -#include <linux/interval_tree_generic.h>
> +#include <linux/interval_tree_gen.h>
> #include <linux/nospec.h>
>
> #include "vhost.h"
> @@ -51,7 +51,7 @@ enum {
>
> INTERVAL_TREE_DEFINE(struct vhost_umem_node,
> rb, __u64, __subtree_last,
> - START, LAST, static inline, vhost_umem_interval_tree);
> + START, END, static inline, vhost_umem_interval_tree);
>
> #ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY
> static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)
> @@ -1034,7 +1034,7 @@ static int vhost_new_umem_range(struct vhost_umem *umem,
>
> node->start = start;
> node->size = size;
> - node->last = end;
> + node->end = end;
> node->userspace_addr = userspace_addr;
> node->perm = perm;
> INIT_LIST_HEAD(&node->link);
> @@ -1112,7 +1112,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
> }
> vhost_vq_meta_reset(dev);
> if (vhost_new_umem_range(dev->iotlb, msg->iova, msg->size,
> - msg->iova + msg->size - 1,
> + msg->iova + msg->size,
> msg->uaddr, msg->perm)) {
> ret = -ENOMEM;
> break;
> @@ -1126,7 +1126,7 @@ static int vhost_process_iotlb_msg(struct vhost_dev *dev,
> }
> vhost_vq_meta_reset(dev);
> vhost_del_umem_range(dev->iotlb, msg->iova,
> - msg->iova + msg->size - 1);
> + msg->iova + msg->size);
> break;
> default:
> ret = -EINVAL;
> @@ -1320,15 +1320,14 @@ static bool iotlb_access_ok(struct vhost_virtqueue *vq,
> {
> const struct vhost_umem_node *node;
> struct vhost_umem *umem = vq->iotlb;
> - u64 s = 0, size, orig_addr = addr, last = addr + len - 1;
> + u64 s = 0, size, orig_addr = addr, last = addr + len;
>
> if (vhost_vq_meta_fetch(vq, addr, len, type))
> return true;
>
> while (len > s) {
> node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
> - addr,
> - last);
> + addr, last);
> if (node == NULL || node->start > addr) {
> vhost_iotlb_miss(vq, addr, access);
> return false;
> @@ -1455,7 +1454,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
> region->guest_phys_addr,
> region->memory_size,
> region->guest_phys_addr +
> - region->memory_size - 1,
> + region->memory_size,
> region->userspace_addr,
> VHOST_ACCESS_RW))
> goto err;
> @@ -2055,7 +2054,7 @@ static int translate_desc(struct vhost_virtqueue *vq, u64 addr, u32 len,
> }
>
> node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
> - addr, addr + len - 1);
> + addr, addr + len);
> if (node == NULL || node->start > addr) {
> if (umem != dev->iotlb) {
> ret = -EFAULT;
> diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
> index e9ed2722b633..bb36cb9ed5ec 100644
> --- a/drivers/vhost/vhost.h
> +++ b/drivers/vhost/vhost.h
> @@ -53,13 +53,13 @@ struct vhost_log {
> };
>
> #define START(node) ((node)->start)
> -#define LAST(node) ((node)->last)
> +#define END(node) ((node)->end)
>
> struct vhost_umem_node {
> struct rb_node rb;
> struct list_head link;
> __u64 start;
> - __u64 last;
> + __u64 end;
> __u64 size;
> __u64 userspace_addr;
> __u32 perm;

Reviewed-by: Jason Wang <jasowang@redhat.com>