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Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() afte
From: |
Marc-André Lureau |
Subject: |
Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init() |
Date: |
Mon, 25 Jul 2016 08:45:52 -0400 (EDT) |
Hi
----- Original Message -----
> On 21.07.2016 11:57, Marc-André Lureau wrote:
> > From: Marc-André Lureau <address@hidden>
> >
> > vhost_net_init() calls vhost_dev_init() and in case of failure, calls
> > vhost_dev_cleanup() directly. However, the structure is already
> > partially cleaned on error. Calling vhost_dev_cleanup() again will call
> > vhost_virtqueue_cleanup() on already clean queues, and causing potential
> > double-close. Instead, adjust dev->nvqs and simplify vhost_dev_init()
> > code to not call vhost_virtqueue_cleanup() but vhost_dev_cleanup()
> > instead.
> >
> > Signed-off-by: Marc-André Lureau <address@hidden>
> > ---
> > hw/virtio/vhost.c | 13 ++++---------
> > 1 file changed, 4 insertions(+), 9 deletions(-)
> >
> > diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> > index 9400b47..c61302a 100644
> > --- a/hw/virtio/vhost.c
> > +++ b/hw/virtio/vhost.c
> > @@ -1047,7 +1047,8 @@ int vhost_dev_init(struct vhost_dev *hdev, void
> > *opaque,
> > for (i = 0; i < hdev->nvqs; ++i) {
> > r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i);
> > if (r < 0) {
> > - goto fail_vq;
> > + hdev->nvqs = i;
> > + goto fail;
> > }
> > }
> >
> > @@ -1104,19 +1105,13 @@ int vhost_dev_init(struct vhost_dev *hdev, void
> > *opaque,
> > memory_listener_register(&hdev->memory_listener,
> > &address_space_memory);
> > QLIST_INSERT_HEAD(&vhost_devices, hdev, entry);
> > return 0;
> > +
> > fail_busyloop:
> > while (--i >= 0) {
> > vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
> > }
> > - i = hdev->nvqs;
> > -fail_vq:
> > - while (--i >= 0) {
> > - vhost_virtqueue_cleanup(hdev->vqs + i);
> > - }
> > fail:
> > - r = -errno;
> > - hdev->vhost_ops->vhost_backend_cleanup(hdev);
> > - QLIST_REMOVE(hdev, entry);
> > + vhost_dev_cleanup(hdev);
> > return r;
> > }
> >
> >
>
> This patch introduces closing of zero fd on backend init failure or any
> other error before virtqueue_init loop because of calling
> 'vhost_virtqueue_cleanup()' on not initialized virtqueues.
>
> I'm suggesting following fixup:
>
> ----------------------------------------------------------------------
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 6175d8b..d7428c5 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1038,8 +1038,9 @@ int vhost_dev_init(struct vhost_dev *hdev, void
> *opaque,
> VhostBackendType backend_type, uint32_t busyloop_timeout)
> {
> uint64_t features;
> - int i, r;
> + int i, r, n_initialized_vqs;
>
> + n_initialized_vqs = 0;
> hdev->migration_blocker = NULL;
>
> r = vhost_set_backend_type(hdev, backend_type);
>
> @@ -1069,10 +1071,9 @@ int vhost_dev_init(struct vhost_dev *hdev, void
> *opaque,
> goto fail;
> }
>
> - for (i = 0; i < hdev->nvqs; ++i) {
> + for (i = 0; i < hdev->nvqs; ++i, ++n_initialized_vqs) {
> r = vhost_virtqueue_init(hdev, hdev->vqs + i, hdev->vq_index + i);
> if (r < 0) {
> - hdev->nvqs = i;
Isn't that assignment doing the same thing?
btw, thanks for the review
> goto fail;
> }
> }
> @@ -1136,6 +1137,7 @@ fail_busyloop:
> vhost_virtqueue_set_busyloop_timeout(hdev, hdev->vq_index + i, 0);
> }
> fail:
> + hdev->nvqs = n_initialized_vqs;
> vhost_dev_cleanup(hdev);
> return r;
> }
> ----------------------------------------------------------------------
>
> Best regards, Ilya Maximets.
>
- [Qemu-devel] [PATCH v5 01/31] misc: indentation, (continued)
- [Qemu-devel] [PATCH v5 01/31] misc: indentation, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 02/31] vhost-user: minor simplification, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 03/31] vhost: don't assume opaque is a fd, use backend cleanup, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 04/31] vhost: make vhost_log_put() idempotent, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 05/31] vhost: assert the log was cleaned up, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 06/31] vhost: fix cleanup on not fully initialized device, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 07/31] vhost: make vhost_dev_cleanup() idempotent, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 08/31] vhost-net: always call vhost_dev_cleanup() on failure, marcandre . lureau, 2016/07/21
- [Qemu-devel] [PATCH v5 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init(), marcandre . lureau, 2016/07/21
- Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init(), Ilya Maximets, 2016/07/25
- Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init(),
Marc-André Lureau <=
- Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init(), Ilya Maximets, 2016/07/25
- Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init(), Marc-André Lureau, 2016/07/25
- Re: [Qemu-devel] [v5, 09/31] vhost: fix calling vhost_dev_cleanup() after vhost_dev_init(), Ilya Maximets, 2016/07/25
[Qemu-devel] [PATCH v5 10/31] vhost: do not assert() on vhost_ops failure, marcandre . lureau, 2016/07/21
[Qemu-devel] [PATCH v5 11/31] vhost: add missing VHOST_OPS_DEBUG, marcandre . lureau, 2016/07/21
[Qemu-devel] [PATCH v5 12/31] vhost: use error_report() instead of fprintf(stderr, ...), marcandre . lureau, 2016/07/21
[Qemu-devel] [PATCH v5 13/31] qemu-char: fix qemu_chr_fe_set_msgfds() crash when disconnected, marcandre . lureau, 2016/07/21
[Qemu-devel] [PATCH v5 15/31] vhost-user: check qemu_chr_fe_set_msgfds() return value, marcandre . lureau, 2016/07/21
[Qemu-devel] [PATCH v5 14/31] vhost-user: call set_msgfds unconditionally, marcandre . lureau, 2016/07/21
[Qemu-devel] [PATCH v5 16/31] vhost-user: check vhost_user_{read, write}() return value, marcandre . lureau, 2016/07/21