Alex Williamson wrote:
On Tue, 2009-02-03 at 14:56 -0600, Anthony Liguori wrote:
Alex Williamson wrote:
+ ctrl = elem.out_sg[0].iov_base;
+ status = elem.in_sg[elem.in_num - 1].iov_base;
This works only because we're dealing with uint8_ts but it's broken
elsewhere in virtio-net. iov_base is guest memory which means it may
have different endianness. We really should be using ldub_p() here.
+ *status = VIRTIO_NET_ERR;
And stb_p() here.
Thanks Anthony. So before I patch bomb again, I think this turns into
something like below. This makes the struct definitions less useful on
the backend side, but I'm not sure we can do anything about that. I
assume for u16s and u32s used in other parts of the interface, we'll
define those as little endian, which means the guest side driver
eventually needs a follow-up patch for big endian archs. Thanks,
Alex
qemu:virtio-net: Add a virtqueue for control commands from the guest
This will be used for RX mode, MAC table, VLAN table control, etc...
The control transaction consists of one or more "out" sg entries and
one or more "in" sg entries. The first out entry contains a header
defining the class and command. Additional out entries may provide
data for the command. A response via the ack entry is required
and the guest will typically be waiting for it.
Signed-off-by: Alex Williamson <alex.williamson@xxxxxx>
---
hw/virtio-net.c | 34 +++++++++++++++++++++++++++++++++-
hw/virtio-net.h | 18 ++++++++++++++++++
2 files changed, 51 insertions(+), 1 deletions(-)
diff --git a/hw/virtio-net.c b/hw/virtio-net.c
index 073f23a..7971f95 100644
--- a/hw/virtio-net.c
+++ b/hw/virtio-net.c
@@ -25,6 +25,7 @@ typedef struct VirtIONet
uint16_t status;
VirtQueue *rx_vq;
VirtQueue *tx_vq;
+ VirtQueue *ctrl_vq;
VLANClientState *vc;
QEMUTimer *tx_timer;
int tx_timer_active;
@@ -79,7 +80,9 @@ static void virtio_net_set_link_status(VLANClientState *vc)
static uint32_t virtio_net_get_features(VirtIODevice *vdev)
{
- uint32_t features = (1 << VIRTIO_NET_F_MAC) | (1 << VIRTIO_NET_F_STATUS);
+ uint32_t features = (1 << VIRTIO_NET_F_MAC) |
+ (1 << VIRTIO_NET_F_STATUS) |
+ (1 << VIRTIO_NET_F_CTRL_VQ);
return features;
}
@@ -91,6 +94,34 @@ static void virtio_net_set_features(VirtIODevice *vdev, uint32_t features)
n->mergeable_rx_bufs = !!(features & (1 << VIRTIO_NET_F_MRG_RXBUF));
}
+static void virtio_net_handle_ctrl(VirtIODevice *vdev, VirtQueue *vq)
+{
+ struct virtio_net_ctrl_hdr ctrl;
+ virtio_net_ctrl_ack status = VIRTIO_NET_ERR;
+ VirtQueueElement elem;
+
+ while (virtqueue_pop(vq, &elem)) {
+ if ((elem.in_num < 1) | (elem.out_num < 1)) {
+ fprintf(stderr, "virtio-net ctrl missing headers\n");
+ exit(1);
+ }
+
+ if (elem.out_sg[0].iov_len < sizeof(ctrl) ||
+ elem.out_sg[elem.in_num - 1].iov_len < sizeof(status)) {
+ fprintf(stderr, "virtio-net ctrl header not in correct element\n");
+ exit(1);
+ }
+
+ ctrl.class = ldub_p(elem.out_sg[0].iov_base);
+ ctrl.cmd = ldub_p(elem.out_sg[0].iov_base + sizeof(ctrl.class));
+
+ stb_p(elem.in_sg[elem.in_num - 1].iov_base, status);
+
+ virtqueue_push(vq, &elem, sizeof(status));
+ virtio_notify(vdev, vq);
+ }
+}
Yup, this looks right to me.
Regards,
Anthony Liguori
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