@@ -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);
}
@@ -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);
};
@@ -146,8 +146,22 @@ 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];
-
- return v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
+ int ret;
+
+ ret = v9fs_iov_vmarshal(elem->in_sg, elem->in_num, offset, 1, fmt, ap);
+ if (ret < 0) {
+ VirtIODevice *vdev = VIRTIO_DEVICE(v);
+
+ /* Any active PDU may try to send something back to the client without
+ * knowing if the transport is broken or not. This could result in
+ * MAX_REQ - 1 (ie, 127) extra error messages being printed.
+ */
+ if (!vdev->broken) {
+ 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 +170,52 @@ 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];
+ int ret;
- return v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
+ ret = v9fs_iov_vunmarshal(elem->out_sg, elem->out_num, offset, 1, fmt, ap);
+ if (ret < 0) {
+ VirtIODevice *vdev = VIRTIO_DEVICE(v);
+
+ 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;
@@ -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];
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 <groug@kaod.org> --- v4: - update changelog and add comment to explain why we check vdev->broken in virtio_pdu_vmarshal() - dropped uneeded vdev->broken check in virtio_pdu_vunmarshal() --- hw/9pfs/9p.c | 2 +- hw/9pfs/9p.h | 2 +- hw/9pfs/virtio-9p-device.c | 48 +++++++++++++++++++++++++++++++++++++++----- hw/9pfs/xen-9p-backend.c | 3 ++- 4 files changed, 47 insertions(+), 8 deletions(-)