linux-stable.git/drivers/vhost, branch v6.2

vhost-scsi: unbreak any layout for response

2023-01-27T11:18:41+00:00

Al Viro said:

"""
Since "vhost/scsi: fix reuse of &vq->iov[out] in response"
we have this:
                cmd->tvc_resp_iov = vq->iov[vc.out];
                cmd->tvc_in_iovs = vc.in;
combined with
                iov_iter_init(&iov_iter, ITER_DEST, &cmd->tvc_resp_iov,
                              cmd->tvc_in_iovs, sizeof(v_rsp));
in vhost_scsi_complete_cmd_work().  We used to have ->tvc_resp_iov
_pointing_ to vq->iov[vc.out]; back then iov_iter_init() asked to
set an iovec-backed iov_iter over the tail of vq->iov[], with
length being the amount of iovecs in the tail.

Now we have a copy of one element of that array.  Fortunately, the members
following it in the containing structure are two non-NULL kernel pointers,
so copy_to_iter() will not copy anything beyond the first iovec - kernel
pointer is not (on the majority of architectures) going to be accepted by
access_ok() in copyout() and it won't be skipped since the "length" (in
reality - another non-NULL kernel pointer) won't be zero.

So it's not going to give a guest-to-qemu escalation, but it's definitely
a bug.  Frankly, my preference would be to verify that the very first iovec
is long enough to hold rsp_size.  Due to the above, any users that try to
give us vq->iov[vc.out].iov_len < sizeof(struct virtio_scsi_cmd_resp)
would currently get a failure in vhost_scsi_complete_cmd_work()
anyway.
"""

However, the spec doesn't say anything about the legacy descriptor
layout for the respone. So this patch tries to not assume the response
to reside in a single separate descriptor which is what commit
79c14141a487 ("vhost/scsi: Convert completion path to use") tries to
achieve towards to ANY_LAYOUT.

This is done by allocating and using dedicate resp iov in the
command. To be safety, start with UIO_MAXIOV to be consistent with the
limitation that we advertise to the vhost_get_vq_desc().

Testing with the hacked virtio-scsi driver that use 1 descriptor for 1
byte in the response.

Reported-by: Al Viro 
Cc: Benjamin Coddington 
Cc: Nicholas Bellinger 
Fixes: a77ec83a5789 ("vhost/scsi: fix reuse of &vq->iov[out] in response")
Signed-off-by: Jason Wang 
Message-Id: <20230119073647.76467-1-jasowang@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Stefan Hajnoczi

vhost/net: Clear the pending messages when the backend is removed

2023-01-27T11:18:41+00:00

When the vhost iotlb is used along with a guest virtual iommu
and the guest gets rebooted, some MISS messages may have been
recorded just before the reboot and spuriously executed by
the virtual iommu after the reboot.

As vhost does not have any explicit reset user API,
VHOST_NET_SET_BACKEND looks a reasonable point where to clear
the pending messages, in case the backend is removed.

Export vhost_clear_msg() and call it in vhost_net_set_backend()
when fd == -1.

Signed-off-by: Eric Auger 
Suggested-by: Jason Wang 
Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API")
Message-Id: <20230117151518.44725-3-eric.auger@redhat.com>
Signed-off-by: Michael S. Tsirkin

vhost_vdpa: fix the crash in unmap a large memory

2022-12-28T10:28:11+00:00

While testing in vIOMMU, sometimes Guest will unmap very large memory,
which will cause the crash. To fix this, add a new function
vhost_vdpa_general_unmap(). This function will only unmap the memory
that saved in iotlb.

Call Trace:
[  647.820144] ------------[ cut here ]------------
[  647.820848] kernel BUG at drivers/iommu/intel/iommu.c:1174!
[  647.821486] invalid opcode: 0000 [#1] PREEMPT SMP PTI
[  647.822082] CPU: 10 PID: 1181 Comm: qemu-system-x86 Not tainted 6.0.0-rc1home_lulu_2452_lulu7_vhost+ #62
[  647.823139] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.15.0-29-g6a62e0cb0dfe-prebuilt.qem4
[  647.824365] RIP: 0010:domain_unmap+0x48/0x110
[  647.825424] Code: 48 89 fb 8d 4c f6 1e 39 c1 0f 4f c8 83 e9 0c 83 f9 3f 7f 18 48 89 e8 48 d3 e8 48 85 c0 75 59
[  647.828064] RSP: 0018:ffffae5340c0bbf0 EFLAGS: 00010202
[  647.828973] RAX: 0000000000000001 RBX: ffff921793d10540 RCX: 000000000000001b
[  647.830083] RDX: 00000000080000ff RSI: 0000000000000001 RDI: ffff921793d10540
[  647.831214] RBP: 0000000007fc0100 R08: ffffae5340c0bcd0 R09: 0000000000000003
[  647.832388] R10: 0000007fc0100000 R11: 0000000000100000 R12: 00000000080000ff
[  647.833668] R13: ffffae5340c0bcd0 R14: ffff921793d10590 R15: 0000008000100000
[  647.834782] FS:  00007f772ec90640(0000) GS:ffff921ce7a80000(0000) knlGS:0000000000000000
[  647.836004] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  647.836990] CR2: 00007f02c27a3a20 CR3: 0000000101b0c006 CR4: 0000000000372ee0
[  647.838107] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  647.839283] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  647.840666] Call Trace:
[  647.841437]  
[  647.842107]  intel_iommu_unmap_pages+0x93/0x140
[  647.843112]  __iommu_unmap+0x91/0x1b0
[  647.844003]  iommu_unmap+0x6a/0x95
[  647.844885]  vhost_vdpa_unmap+0x1de/0x1f0 [vhost_vdpa]
[  647.845985]  vhost_vdpa_process_iotlb_msg+0xf0/0x90b [vhost_vdpa]
[  647.847235]  ? _raw_spin_unlock+0x15/0x30
[  647.848181]  ? _copy_from_iter+0x8c/0x580
[  647.849137]  vhost_chr_write_iter+0xb3/0x430 [vhost]
[  647.850126]  vfs_write+0x1e4/0x3a0
[  647.850897]  ksys_write+0x53/0xd0
[  647.851688]  do_syscall_64+0x3a/0x90
[  647.852508]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  647.853457] RIP: 0033:0x7f7734ef9f4f
[  647.854408] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 76 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c8
[  647.857217] RSP: 002b:00007f772ec8f040 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
[  647.858486] RAX: ffffffffffffffda RBX: 00000000fef00000 RCX: 00007f7734ef9f4f
[  647.859713] RDX: 0000000000000048 RSI: 00007f772ec8f090 RDI: 0000000000000010
[  647.860942] RBP: 00007f772ec8f1a0 R08: 0000000000000000 R09: 0000000000000000
[  647.862206] R10: 0000000000000001 R11: 0000000000000293 R12: 0000000000000010
[  647.863446] R13: 0000000000000002 R14: 0000000000000000 R15: ffffffff01100000
[  647.864692]  
[  647.865458] Modules linked in: rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs v]
[  647.874688] ---[ end trace 0000000000000000 ]---

Cc: stable@vger.kernel.org
Fixes: 4c8cf31885f6 ("vhost: introduce vDPA-based backend")
Signed-off-by: Cindy Lu 
Message-Id: <20221219073331.556140-1-lulu@redhat.com>
Signed-off-by: Michael S. Tsirkin

vhost-vdpa: fix an iotlb memory leak

2022-12-28T10:28:10+00:00

Before commit 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB")
we called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during
release to free all the resources allocated when processing user IOTLB
messages through vhost_vdpa_process_iotlb_update().
That commit changed the handling of IOTLB a bit, and we accidentally
removed some code called during the release.

We partially fixed this with commit 037d4305569a ("vhost-vdpa: call
vhost_vdpa_cleanup during the release") but a potential memory leak is
still there as showed by kmemleak if the application does not send
VHOST_IOTLB_INVALIDATE or crashes:

  unreferenced object 0xffff888007fbaa30 (size 16):
    comm "blkio-bench", pid 914, jiffies 4294993521 (age 885.500s)
    hex dump (first 16 bytes):
      40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00  @sA.............
    backtrace:
      [<0000000087736d2a>] kmem_cache_alloc_trace+0x142/0x1c0
      [<0000000060740f50>] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa]
      [<0000000083e8e205>] vhost_chr_write_iter+0xc0/0x4a0 [vhost]
      [<000000008f2f414a>] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa]
      [<00000000de1cd4a0>] vfs_write+0x216/0x4b0
      [<00000000a2850200>] ksys_write+0x71/0xf0
      [<00000000de8e720b>] __x64_sys_write+0x19/0x20
      [<0000000018b12cbb>] do_syscall_64+0x3f/0x90
      [<00000000986ec465>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Let's fix this calling vhost_vdpa_iotlb_unmap() on the whole range in
vhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup()
since we need a valid v->vdev.mm in vhost_vdpa_pa_unmap().
vhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap()
on the whole range removes all the entries.

The kmemleak log reported was observed with a vDPA device that has `use_va`
set to true (e.g. VDUSE). This patch has been tested with both types of
devices.

Fixes: 037d4305569a ("vhost-vdpa: call vhost_vdpa_cleanup during the release")
Fixes: 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB")
Signed-off-by: Stefano Garzarella 
Message-Id: <20221109154213.146789-1-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin 
Acked-by: Jason Wang

vhost: fix range used in translate_desc()

2022-12-28T10:28:10+00:00

vhost_iotlb_itree_first() requires `start` and `last` parameters
to search for a mapping that overlaps the range.

In translate_desc() we cyclically call vhost_iotlb_itree_first(),
incrementing `addr` by the amount already translated, so rightly
we move the `start` parameter passed to vhost_iotlb_itree_first(),
but we should hold the `last` parameter constant.

Let's fix it by saving the `last` parameter value before incrementing
`addr` in the loop.

Fixes: a9709d6874d5 ("vhost: convert pre sorted vhost memory array to interval tree")
Acked-by: Jason Wang 
Signed-off-by: Stefano Garzarella 
Message-Id: <20221109102503.18816-3-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin

vringh: fix range used in iotlb_translate()

2022-12-28T10:28:10+00:00

vhost_iotlb_itree_first() requires `start` and `last` parameters
to search for a mapping that overlaps the range.

In iotlb_translate() we cyclically call vhost_iotlb_itree_first(),
incrementing `addr` by the amount already translated, so rightly
we move the `start` parameter passed to vhost_iotlb_itree_first(),
but we should hold the `last` parameter constant.

Let's fix it by saving the `last` parameter value before incrementing
`addr` in the loop.

Fixes: 9ad9c49cfe97 ("vringh: IOTLB support")
Acked-by: Jason Wang 
Signed-off-by: Stefano Garzarella 
Message-Id: <20221109102503.18816-2-sgarzare@redhat.com>
Signed-off-by: Michael S. Tsirkin

vhost/vsock: Fix error handling in vhost_vsock_init()

2022-12-28T10:28:10+00:00

A problem about modprobe vhost_vsock failed is triggered with the
following log given:

modprobe: ERROR: could not insert 'vhost_vsock': Device or resource busy

The reason is that vhost_vsock_init() returns misc_register() directly
without checking its return value, if misc_register() failed, it returns
without calling vsock_core_unregister() on vhost_transport, resulting the
vhost_vsock can never be installed later.
A simple call graph is shown as below:

 vhost_vsock_init()
   vsock_core_register() # register vhost_transport
   misc_register()
     device_create_with_groups()
       device_create_groups_vargs()
         dev = kzalloc(...) # OOM happened
   # return without unregister vhost_transport

Fix by calling vsock_core_unregister() when misc_register() returns error.

Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko")
Signed-off-by: Yuan Can 
Message-Id: <20221108101705.45981-1-yuancan@huawei.com>
Signed-off-by: Michael S. Tsirkin 
Reviewed-by: Stefano Garzarella 
Acked-by: Jason Wang

use less confusing names for iov_iter direction initializers

2022-11-25T18:01:55+00:00

READ/WRITE proved to be actively confusing - the meanings are
"data destination, as used with read(2)" and "data source, as
used with write(2)", but people keep interpreting those as
"we read data from it" and "we write data to it", i.e. exactly
the wrong way.

Call them ITER_DEST and ITER_SOURCE - at least that is harder
to misinterpret...

Signed-off-by: Al Viro

[vhost] fix 'direction' argument of iov_iter_{init,bvec}()

2022-11-25T18:01:21+00:00

READ means "data destination", WRITE - "data source".

Signed-off-by: Al Viro

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2022-10-10T21:02:53+00:00

Pull virtio updates from Michael Tsirkin:

 - 9k mtu perf improvements

 - vdpa feature provisioning

 - virtio blk SECURE ERASE support

 - fixes and cleanups all over the place

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  virtio_pci: don't try to use intxif pin is zero
  vDPA: conditionally read MTU and MAC in dev cfg space
  vDPA: fix spars cast warning in vdpa_dev_net_mq_config_fill
  vDPA: check virtio device features to detect MQ
  vDPA: check VIRTIO_NET_F_RSS for max_virtqueue_paris's presence
  vDPA: only report driver features if FEATURES_OK is set
  vDPA: allow userspace to query features of a vDPA device
  virtio_blk: add SECURE ERASE command support
  vp_vdpa: support feature provisioning
  vdpa_sim_net: support feature provisioning
  vdpa: device feature provisioning
  virtio-net: use mtu size as buffer length for big packets
  virtio-net: introduce and use helper function for guest gso support checks
  virtio: drop vp_legacy_set_queue_size
  virtio_ring: make vring_alloc_queue_packed prettier
  virtio_ring: split: Operators use unified style
  vhost: add __init/__exit annotations to module init/exit funcs