From 12bcbdca8ae9fcd5fec093e8ef5e70521e85e889 Mon Sep 17 00:00:00 2001 From: Christian Schoenebeck Date: Fri, 12 Jun 2026 20:22:52 +0200 Subject: [PATCH] 9pfs/virtio: implement response_buffer_size callback Add and implement the response_buffer_size callback for the virtio transport. Returns the actual current virtio response buffer size for the supplied PDU, which will be used as safety guard for limiting the response size when generating a 9p response. Link: https://lore.kernel.org/qemu-devel/5bbed2768f7a0da8fa2be183e75928c5d1ef691d.1781287774.git.qemu_oss@crudebyte.com Signed-off-by: Christian Schoenebeck --- hw/9pfs/virtio-9p-device.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/hw/9pfs/virtio-9p-device.c b/hw/9pfs/virtio-9p-device.c index 8c5d86cb66..50dc93091d 100644 --- a/hw/9pfs/virtio-9p-device.c +++ b/hw/9pfs/virtio-9p-device.c @@ -198,6 +198,15 @@ static size_t virtio_9p_msize_limit(V9fsState *s) return (VIRTQUEUE_MAX_SIZE - 2) * guestPageSize; } +static size_t virtio_9p_response_buffer_size(V9fsPDU *pdu) +{ + V9fsState *s = pdu->s; + V9fsVirtioState *v = container_of(s, V9fsVirtioState, state); + VirtQueueElement *elem = v->elems[pdu->idx]; + + return iov_size(elem->in_sg, elem->in_num); +} + static const V9fsTransport virtio_9p_transport = { .pdu_vmarshal = virtio_pdu_vmarshal, .pdu_vunmarshal = virtio_pdu_vunmarshal, @@ -205,6 +214,7 @@ static const V9fsTransport virtio_9p_transport = { .init_out_iov_from_pdu = virtio_init_out_iov_from_pdu, .push_and_notify = virtio_9p_push_and_notify, .msize_limit = virtio_9p_msize_limit, + .response_buffer_size = virtio_9p_response_buffer_size, }; static void virtio_9p_device_realize(DeviceState *dev, Error **errp)