From: Mike Christie <michael.christie@oracle.com>
Date: Mon, 26 Jun 2023 18:23:03 -0500
Subject: vhost: add helper to parse userspace vring state/file
Patch-mainline: v6.5-rc1
Git-commit: cef25866f41c45a01a933adb032b0dcfb25b847a
References: jsc#PED-3311
The next patches add new vhost worker ioctls which will need to get a
vhost_virtqueue from a userspace struct which specifies the vq's index.
This moves the vhost_vring_ioctl code to do this to a helper so it can
be shared.
Signed-off-by: Mike Christie <michael.christie@oracle.com>
Message-Id: <20230626232307.97930-14-michael.christie@oracle.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/vhost/vhost.c | 29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -599,6 +599,27 @@ free_worker:
return NULL;
}
+static int vhost_get_vq_from_user(struct vhost_dev *dev, void __user *argp,
+ struct vhost_virtqueue **vq, u32 *id)
+{
+ u32 __user *idxp = argp;
+ u32 idx;
+ long r;
+
+ r = get_user(idx, idxp);
+ if (r < 0)
+ return r;
+
+ if (idx >= dev->nvqs)
+ return -ENOBUFS;
+
+ idx = array_index_nospec(idx, dev->nvqs);
+
+ *vq = dev->vqs[idx];
+ *id = idx;
+ return 0;
+}
+
/* Caller should have device mutex */
long vhost_dev_set_owner(struct vhost_dev *dev)
{
@@ -1618,21 +1639,15 @@ long vhost_vring_ioctl(struct vhost_dev
struct file *eventfp, *filep = NULL;
bool pollstart = false, pollstop = false;
struct eventfd_ctx *ctx = NULL;
- u32 __user *idxp = argp;
struct vhost_virtqueue *vq;
struct vhost_vring_state s;
struct vhost_vring_file f;
u32 idx;
long r;
- r = get_user(idx, idxp);
+ r = vhost_get_vq_from_user(d, argp, &vq, &idx);
if (r < 0)
return r;
- if (idx >= d->nvqs)
- return -ENOBUFS;
-
- idx = array_index_nospec(idx, d->nvqs);
- vq = d->vqs[idx];
if (ioctl == VHOST_SET_VRING_NUM ||
ioctl == VHOST_SET_VRING_ADDR) {