[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [RFC PATCH 02/13] xen-netback: xenbus feature persistent support
Checks for "feature-persistent" that indicates persistent grants support. Adds max_persistent_grants module param that specifies the max number of persistent grants, which if set to zero disables persistent grants. Signed-off-by: Joao Martins <joao.martins@xxxxxxxxx> --- drivers/net/xen-netback/common.h | 1 + drivers/net/xen-netback/netback.c | 5 +++++ drivers/net/xen-netback/xenbus.c | 13 +++++++++++++ 3 files changed, 19 insertions(+) diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index dd02386..e70ace7 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -378,6 +378,7 @@ extern bool separate_tx_rx_irq; extern unsigned int rx_drain_timeout_msecs; extern unsigned int rx_stall_timeout_msecs; extern unsigned int xenvif_max_queues; +extern unsigned int xenvif_max_pgrants; #ifdef CONFIG_DEBUG_FS extern struct dentry *xen_netback_dbg_root; diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 8df0a73..332e489 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -72,6 +72,11 @@ module_param_named(max_queues, xenvif_max_queues, uint, 0644); MODULE_PARM_DESC(max_queues, "Maximum number of queues per virtual interface"); +unsigned int xenvif_max_pgrants = XEN_NETIF_RX_RING_SIZE; +module_param_named(max_persistent_grants, xenvif_max_pgrants, int, 0644); +MODULE_PARM_DESC(max_persistent_grants, + "Maximum number of grants to map persistently"); + /* * This is the maximum slots a skb can have. If a guest sends a skb * which exceeds this limit it is considered malicious. diff --git a/drivers/net/xen-netback/xenbus.c b/drivers/net/xen-netback/xenbus.c index 3d8dbf5..766f7e5 100644 --- a/drivers/net/xen-netback/xenbus.c +++ b/drivers/net/xen-netback/xenbus.c @@ -331,6 +331,14 @@ static int netback_probe(struct xenbus_device *dev, goto fail; } + /* Persistent grants support. This is an optional feature. */ + err = xenbus_printf(XBT_NIL, dev->nodename, + "feature-persistent", "%d", xenvif_max_pgrants > 0); + if (err) { + message = "writing feature-persistent"; + goto abort_transaction; + } + /* * Split event channels support, this is optional so it is not * put inside the above loop. @@ -961,6 +969,11 @@ static int read_xenbus_vif_flags(struct backend_info *be) val = 0; vif->can_sg = !!val; + if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-persistent", + "%d", &val) < 0) + val = 0; + vif->persistent_grants = (xenvif_max_pgrants && !!val); + vif->gso_mask = 0; vif->gso_prefix_mask = 0; -- 2.1.3 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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