linux/debian/patches/bugfix/all/xen-netback-don-t-use-last-...

36 lines
1.4 KiB
Diff

From: David Vrabel <david.vrabel@citrix.com>
Date: Fri, 30 Oct 2015 15:16:01 +0000
Subject: [2/7] xen-netback: don't use last request to determine minimum Tx
credit
Origin: https://git.kernel.org/linus/0f589967a73f1f30ab4ac4dd9ce0bb399b4d6357
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.
CC: stable@vger.kernel.org
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>
---
drivers/net/xen-netback/netback.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -636,9 +636,7 @@ static void tx_add_credit(struct xenvif_
* 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(&queue->tx, queue->tx.req_cons)->size;
- max_burst = min(max_burst, 131072UL);
- max_burst = max(max_burst, queue->credit_bytes);
+ max_burst = max(131072UL, queue->credit_bytes);
/* Take care that adding a new chunk of credit doesn't wrap to zero. */
max_credit = queue->remaining_credit + queue->credit_bytes;