Re: Linux guest domain with two vnets , the dirty quick fix

[hyl]

1. add the debug code:
--- a/drivers/net/sunvnet.c
+++ b/drivers/net/sunvnet.c
@@ -540,6 +540,11 @@ static void vnet_event(void *arg, int event)
                }
                if (err == 0)
                        break;
+                {
+                  long stackdiff;
+                 viodbg(DATA, "** vio:%llx, vio->lp:%llx, stack:%llx\n",
+                                   &vio,     &vio->lp,     &stackdiff);
+                }
                viodbg(DATA, "TAG [%02x:%02x:%04x:%08x]\n",
                       msgbuf.tag.type,
                       msgbuf.tag.stype,

2. the output
from the below output, we see a re-enter to  vnet_event happend. the
vio-hardwre report 2 interrupt
for same packet/or msg( why?)

vio: ID[0] vnet_walk_rx start[00000009] end[00000008]
vio: ID[0] vio_walk_rx_one desc[02:00:0000003c:00000001:842800:800]
vio: ID[0] vio_walk_rx_one desc[01:00:00000000:00000001:845000:800]
vio: ID[0] ** vio:fffff8003f9cafa8, vio->lp:fffff8003ebf0008,
stack:fffff8003f9cafa0  << same ldc vio
vio: ID[0] ** vio:fffff8003f9cafa8, vio->lp:fffff8003ebf0008,
stack:fffff8003f9ccc     << with diffrent run stack
afa0
vio: ID[0] TAG [02:01:0042:0d4becc7]
vio: ID[0] TAG [02:01:0042:0d4becc7]
...........
vio: ID[0] vnet_walk_rx start[0000000a] end[00000009]
vio: ID[0] vio_walk_rx_one desc[02:00:0000003c:00000001:845000:800]
vio: ID[0] vio_walk_rx_one desc[02:00:0000003c:00000001:845000:800]
vio: ID[0] vio_walk_rx_one desc[01:00:00000000:00000001:847800:800]
vio: ID[0] vio_walk_rx_one desc[01:00:00000000:00000001:847800:800]
vio: ID[0] ** vio:fffff8003f9cb588, vio->lp:fffff8003ebf0008,
stack:fffff8003f9cb580
vio: ID[0] ** vio:fffff8003f9cb588, vio->lp:fffff8003ebf0008,
stack:fffff8003f9ccc


3. where need protection
the reason is :
static irqreturn_t ldc_rx(int irq, void *dev_id){

out:
	spin_unlock_irqrestore(&lp->lock, flags);
                                                                  <<
here run with out any lock
	send_events(lp, event_mask);

4. the dirty fix, welcome fain grained lock implementation suggestion: