diff options
| author | Greg Kurz <groug@kaod.org> | 2020-10-03 12:02:13 +0200 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2020-10-04 03:45:20 -0400 |
| commit | ab5122510b0a453c0ac898ec9952d38e80243ee7 (patch) | |
| tree | d645c482c4a211c0b1031c75d2590147462bd540 | |
| parent | 71878fa46c7e3b40fa7b3f1b6e4ba3f92f1ac359 (diff) | |
| download | linux-ab5122510b0a453c0ac898ec9952d38e80243ee7.tar.gz | |
vhost: Don't call log_access_ok() when using IOTLB
When the IOTLB device is enabled, the log_guest_addr that is passed by
userspace to the VHOST_SET_VRING_ADDR ioctl, and which is then written
to vq->log_addr, is a GIOVA. All writes to this address are translated
by log_user() to writes to an HVA, and then ultimately logged through
the corresponding GPAs in log_write_hva(). No logging will ever occur
with vq->log_addr in this case. It is thus wrong to pass vq->log_addr
and log_guest_addr to log_access_vq() which assumes they are actual
GPAs.
Introduce a new vq_log_used_access_ok() helper that only checks accesses
to the log for the used structure when there isn't an IOTLB device around.
Signed-off-by: Greg Kurz <groug@kaod.org>
Link: https://lore.kernel.org/r/160171933385.284610.10189082586063280867.stgit@bahia.lan
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | drivers/vhost/vhost.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 9d2c225fb518b..9ad45e1d27f0f 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1370,6 +1370,20 @@ bool vhost_log_access_ok(struct vhost_dev *dev) } EXPORT_SYMBOL_GPL(vhost_log_access_ok); +static bool vq_log_used_access_ok(struct vhost_virtqueue *vq, + void __user *log_base, + bool log_used, + u64 log_addr) +{ + /* If an IOTLB device is present, log_addr is a GIOVA that + * will never be logged by log_used(). */ + if (vq->iotlb) + return true; + + return !log_used || log_access_ok(log_base, log_addr, + vhost_get_used_size(vq, vq->num)); +} + /* Verify access for write logging. */ /* Caller should have vq mutex and device mutex */ static bool vq_log_access_ok(struct vhost_virtqueue *vq, @@ -1377,8 +1391,7 @@ static bool vq_log_access_ok(struct vhost_virtqueue *vq, { return vq_memory_access_ok(log_base, vq->umem, vhost_has_feature(vq, VHOST_F_LOG_ALL)) && - (!vq->log_used || log_access_ok(log_base, vq->log_addr, - vhost_get_used_size(vq, vq->num))); + vq_log_used_access_ok(vq, log_base, vq->log_used, vq->log_addr); } /* Can we start vq? */ @@ -1517,9 +1530,9 @@ static long vhost_vring_set_addr(struct vhost_dev *d, return -EINVAL; /* Also validate log access for used ring if enabled. */ - if ((a.flags & (0x1 << VHOST_VRING_F_LOG)) && - !log_access_ok(vq->log_base, a.log_guest_addr, - vhost_get_used_size(vq, vq->num))) + if (!vq_log_used_access_ok(vq, vq->log_base, + a.flags & (0x1 << VHOST_VRING_F_LOG), + a.log_guest_addr)) return -EINVAL; } |