| From | Willy Tarreau <> | Subject | [PATCH 3.10 034/319] xen-netback: don't use last request to determine minimum Tx credit | Date | Sun, 5 Feb 2017 20:20:21 +0100 |
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From: David Vrabel <david.vrabel@citrix.com>
commit 0f589967a73f1f30ab4ac4dd9ce0bb399b4d6357 upstream.
The last from guest transmitted request gives no indication about the minimum amount of credit that the guest might need to send a packet since the last packet might have been a small one.
Instead allow for the worst case 128 KiB packet.
This is part of XSA155.
Reviewed-by: Wei Liu <wei.liu2@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Willy Tarreau <w@1wt.eu> --- drivers/net/xen-netback/netback.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 1595f81..3e0907a 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -928,9 +928,7 @@ static void tx_add_credit(struct xenvif *vif) * Allow a burst big enough to transmit a jumbo packet of up to 128kB. * Otherwise the interface can seize up due to insufficient credit. */ - max_burst = RING_GET_REQUEST(&vif->tx, vif->tx.req_cons)->size; - max_burst = min(max_burst, 131072UL); - max_burst = max(max_burst, vif->credit_bytes); + max_burst = max(131072UL, vif->credit_bytes); /* Take care that adding a new chunk of credit doesn't wrap to zero. */ max_credit = vif->remaining_credit + vif->credit_bytes; -- 2.8.0.rc2.1.gbe9624a
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