[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH v5 3/5] virtio-9p: break device if buffers are m
From: |
Michael S. Tsirkin |
Subject: |
Re: [Qemu-devel] [PATCH v5 3/5] virtio-9p: break device if buffers are misconfigured |
Date: |
Fri, 30 Jun 2017 02:33:22 +0300 |
On Wed, Jun 28, 2017 at 10:44:30PM +0200, Greg Kurz wrote:
> The 9P protocol is transport agnostic: if the guest misconfigured the
> buffers, the best we can do is to set the broken flag on the device.
>
> Since virtio_pdu_vmarshal() may be called by several active PDUs, we
> check if the transport isn't broken already to avoid printing extra
> error messages.
>
> Signed-off-by: Greg Kurz <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
> ---
> v5: - use ssize_t variable in virtio_pdu_v[un]marshal()
> - drop remaining vdev->broken check (MST suggested to discuss calling
> virtio_error() when the device is already broken to a separate thread)
> ---
> hw/9pfs/9p.c | 2 +-
> hw/9pfs/9p.h | 2 +-
> hw/9pfs/virtio-9p-device.c | 40 ++++++++++++++++++++++++++++++++++++----
> hw/9pfs/xen-9p-backend.c | 3 ++-
> 4 files changed, 40 insertions(+), 7 deletions(-)
>
> diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c
> index 96d268334865..da0d6da65b45 100644
> --- a/hw/9pfs/9p.c
> +++ b/hw/9pfs/9p.c
> @@ -1664,7 +1664,7 @@ static void v9fs_init_qiov_from_pdu(QEMUIOVector *qiov,
> V9fsPDU *pdu,
> unsigned int niov;
>
> if (is_write) {
> - pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov);
> + pdu->s->transport->init_out_iov_from_pdu(pdu, &iov, &niov, size +
> skip);
> } else {
> pdu->s->transport->init_in_iov_from_pdu(pdu, &iov, &niov, size +
> skip);
> }
> diff --git a/hw/9pfs/9p.h b/hw/9pfs/9p.h
> index aac1b0b2ce3d..d1cfeaf10e4f 100644
> --- a/hw/9pfs/9p.h
> +++ b/hw/9pfs/9p.h
> @@ -363,7 +363,7 @@ struct V9fsTransport {
> void (*init_in_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
> unsigned int *pniov, size_t size);
> void (*init_out_iov_from_pdu)(V9fsPDU *pdu, struct iovec **piov,
> - unsigned int *pniov);
> + unsigned int *pniov, size_t size);
> void (*push_and_notify)(V9fsPDU *pdu);
> };
>
> diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c
> index 1a68c1622d3a..62650b0a6b99 100644
> --- a/hw/9pfs/virtio-9p-device.c
> +++ b/hw/9pfs/virtio-9p-device.c
> @@ -146,8 +146,16 @@ static ssize_t virtio_pdu_vmarshal(V9fsPDU *pdu, size_t
> offset,
> V9fsState *s = pdu->s;
> V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
> VirtQueueElement *elem = v->elems[pdu->idx];
> + ssize_t ret;
>
> - return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
> + ret = v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
> + if (ret < 0) {
> + VirtIODevice *vdev = VIRTIO_DEVICE(v);
> +
> + virtio_error(vdev, "Failed to encode VirtFS reply type %d",
> + pdu->id + 1);
> + }
> + return ret;
> }
>
> static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu, size_t offset,
> @@ -156,28 +164,52 @@ static ssize_t virtio_pdu_vunmarshal(V9fsPDU *pdu,
> size_t offset,
> V9fsState *s = pdu->s;
> V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
> VirtQueueElement *elem = v->elems[pdu->idx];
> + ssize_t ret;
> +
> + ret = v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt,
> ap);
> + if (ret < 0) {
> + VirtIODevice *vdev = VIRTIO_DEVICE(v);
>
> - return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt,
> ap);
> + virtio_error(vdev, "Failed to decode VirtFS request type %d",
> pdu->id);
> + }
> + return ret;
> }
>
> -/* The size parameter is used by other transports. Do not drop it. */
> static void virtio_init_in_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
> unsigned int *pniov, size_t size)
> {
> V9fsState *s = pdu->s;
> V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
> VirtQueueElement *elem = v->elems[pdu->idx];
> + size_t buf_size = iov_size(elem->in_sg, elem->in_num);
> +
> + if (buf_size < size) {
> + VirtIODevice *vdev = VIRTIO_DEVICE(v);
> +
> + virtio_error(vdev,
> + "VirtFS reply type %d needs %zu bytes, buffer has %zu",
> + pdu->id + 1, size, buf_size);
> + }
>
> *piov = elem->in_sg;
> *pniov = elem->in_num;
> }
>
> static void virtio_init_out_iov_from_pdu(V9fsPDU *pdu, struct iovec **piov,
> - unsigned int *pniov)
> + unsigned int *pniov, size_t size)
> {
> V9fsState *s = pdu->s;
> V9fsVirtioState *v = container_of(s, V9fsVirtioState, state);
> VirtQueueElement *elem = v->elems[pdu->idx];
> + size_t buf_size = iov_size(elem->out_sg, elem->out_num);
> +
> + if (buf_size < size) {
> + VirtIODevice *vdev = VIRTIO_DEVICE(v);
> +
> + virtio_error(vdev,
> + "VirtFS request type %d needs %zu bytes, buffer has
> %zu",
> + pdu->id, size, buf_size);
> + }
>
> *piov = elem->out_sg;
> *pniov = elem->out_num;
> diff --git a/hw/9pfs/xen-9p-backend.c b/hw/9pfs/xen-9p-backend.c
> index 922cc967be63..a82cf817fe45 100644
> --- a/hw/9pfs/xen-9p-backend.c
> +++ b/hw/9pfs/xen-9p-backend.c
> @@ -147,7 +147,8 @@ static ssize_t xen_9pfs_pdu_vunmarshal(V9fsPDU *pdu,
>
> static void xen_9pfs_init_out_iov_from_pdu(V9fsPDU *pdu,
> struct iovec **piov,
> - unsigned int *pniov)
> + unsigned int *pniov,
> + size_t size)
> {
> Xen9pfsDev *xen_9pfs = container_of(pdu->s, Xen9pfsDev, state);
> Xen9pfsRing *ring = &xen_9pfs->rings[pdu->tag % xen_9pfs->num_rings];
- [Qemu-devel] [PATCH v5 0/5] 9pfs: handle transport errors, Greg Kurz, 2017/06/28
- [Qemu-devel] [PATCH v5 1/5] virtio-9p: record element after sanity checks, Greg Kurz, 2017/06/28
- [Qemu-devel] [PATCH v5 2/5] virtio-9p: message header is 7-byte long, Greg Kurz, 2017/06/28
- [Qemu-devel] [PATCH v5 3/5] virtio-9p: break device if buffers are misconfigured, Greg Kurz, 2017/06/28
- [Qemu-devel] [PATCH v5 4/5] xen-9pfs: disconnect if buffers are misconfigured, Greg Kurz, 2017/06/28
- [Qemu-devel] [PATCH v5 5/5] 9pfs: handle transport errors in pdu_complete(), Greg Kurz, 2017/06/28