On 2020/3/24 上午10:04, Li Qiang wrote:
P J P <ppan...@redhat.com <mailto:ppan...@redhat.com>> 于2020年3月23日周一
下午8:25写道:
From: Prasad J Pandit <p...@fedoraproject.org
<mailto:p...@fedoraproject.org>>
Define .can_receive routine to do sanity checks before receiving
packet data. And call qemu_flush_queued_packets to flush queued
packets once they are read in tulip_receive().
Suggested-by: Jason Wang <jasow...@redhat.com
<mailto:jasow...@redhat.com>>
Signed-off-by: Prasad J Pandit <p...@fedoraproject.org
<mailto:p...@fedoraproject.org>>
---
hw/net/tulip.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)
Update v6: merge earlier patch 2 & 3 into one
->
https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06868.html
diff --git a/hw/net/tulip.c b/hw/net/tulip.c
index fbe40095da..8d8c9519e7 100644
--- a/hw/net/tulip.c
+++ b/hw/net/tulip.c
@@ -229,6 +229,18 @@ static bool tulip_filter_address(TULIPState
*s, const uint8_t *addr)
return ret;
}
+static int
+tulip_can_receive(NetClientState *nc)
+{
+ TULIPState *s = qemu_get_nic_opaque(nc);
+
+ if (s->rx_frame_len || tulip_rx_stopped(s)) {
+ return false;
+ }
+
+ return true;
+}
+
static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf,
size_t size)
{
struct tulip_descriptor desc;
@@ -236,7 +248,7 @@ static ssize_t tulip_receive(TULIPState *s,
const uint8_t *buf, size_t size)
trace_tulip_receive(buf, size);
if (size < 14 || size > sizeof(s->rx_frame) - 4
- || s->rx_frame_len || tulip_rx_stopped(s)) {
+ || !tulip_can_receive(s->nic->ncs)) {
return 0;
}
@@ -275,6 +287,8 @@ static ssize_t tulip_receive(TULIPState *s,
const uint8_t *buf, size_t size)
tulip_desc_write(s, s->current_rx_desc, &desc);
tulip_next_rx_descriptor(s, &desc);
} while (s->rx_frame_len);
+
+ qemu_flush_queued_packets(qemu_get_queue(s->nic));
Hi Prasad ans Jason,
I want to know why here we need call 'qemu_flush_queued_packets'.
AFAICS, the other networking card emulation need no this.
Right, I thought we need this because rx_frame_len is checked in
tulip_can_receive().
But not I think it's unnecessary. According to kernel driver code, the
rx is not necessarily stopped when rx buffer is overrun, e.g,
tulip_rx_refill() only toggle the doorbell when chip is LC82C168. But
own emulation did DC21143.
This means using can_receive() is wrong.
So I think we can drop this patch.
Thanks for the checking and sorry for the wrong suggestion.
Thanks,
Li Qiang
return size;
}
@@ -288,6 +302,7 @@ static NetClientInfo net_tulip_info = {
.type = NET_CLIENT_DRIVER_NIC,
.size = sizeof(NICState),
.receive = tulip_receive_nc,
+ .can_receive = tulip_can_receive,
};
static const char *tulip_reg_name(const hwaddr addr)
--
2.25.1