From f51de24356e49e4dcb5095e87717065580912120 Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Tue, 8 Jul 2014 19:49:14 +0100 Subject: xen-netback: Adding debugfs "io_ring_qX" files This patch adds debugfs capabilities to netback. There used to be a similar patch floating around for classic kernel, but it used procfs. It is based on a very similar blkback patch. It creates xen-netback/[vifname]/io_ring_q[queueno] files, reading them output various ring variables etc. Writing "kick" into it imitates an interrupt happened, it can be useful to check whether the ring is just stalled due to a missed interrupt. Signed-off-by: Zoltan Kiss Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/net/xen-netback/common.h') diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 2532ce85d718..28c98229e95f 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -44,6 +44,7 @@ #include #include #include +#include typedef unsigned int pending_ring_idx_t; #define INVALID_PENDING_RING_IDX (~0U) @@ -224,6 +225,10 @@ struct xenvif { struct xenvif_queue *queues; unsigned int num_queues; /* active queues, resource allocated */ +#ifdef CONFIG_DEBUG_FS + struct dentry *xenvif_dbg_root; +#endif + /* Miscellaneous private stuff. */ struct net_device *dev; }; @@ -297,10 +302,16 @@ static inline pending_ring_idx_t nr_pending_reqs(struct xenvif_queue *queue) /* Callback from stack when TX packet can be released */ void xenvif_zerocopy_callback(struct ubuf_info *ubuf, bool zerocopy_success); +irqreturn_t xenvif_interrupt(int irq, void *dev_id); + extern bool separate_tx_rx_irq; extern unsigned int rx_drain_timeout_msecs; extern unsigned int rx_drain_timeout_jiffies; extern unsigned int xenvif_max_queues; +#ifdef CONFIG_DEBUG_FS +extern struct dentry *xen_netback_dbg_root; +#endif + #endif /* __XEN_NETBACK__COMMON_H__ */ -- cgit v1.2.3 From 3d1af1df9762e56e563e8fd088a1b4ce2bcfaf8b Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Mon, 4 Aug 2014 16:20:57 +0100 Subject: xen-netback: Using a new state bit instead of carrier This patch introduces a new state bit VIF_STATUS_CONNECTED to track whether the vif is in a connected state. Using carrier will not work with the next patch in this series, which aims to turn the carrier temporarily off if the guest doesn't seem to be able to receive packets. Signed-off-by: Zoltan Kiss Signed-off-by: David Vrabel Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org v2: - rename the bitshift type to "enum state_bit_shift" here, not in the next patch Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/net/xen-netback/common.h') diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 28c98229e95f..4a92fc19f410 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -198,6 +198,11 @@ struct xenvif_queue { /* Per-queue data for xenvif */ struct xenvif_stats stats; }; +enum state_bit_shift { + /* This bit marks that the vif is connected */ + VIF_STATUS_CONNECTED +}; + struct xenvif { /* Unique identifier for this interface. */ domid_t domid; @@ -220,6 +225,7 @@ struct xenvif { * frontend is rogue. */ bool disabled; + unsigned long status; /* Queues */ struct xenvif_queue *queues; -- cgit v1.2.3 From f34a4cf9c9b4fd35ba7f9a596cedb011879a1a4d Mon Sep 17 00:00:00 2001 From: Zoltan Kiss Date: Mon, 4 Aug 2014 16:20:58 +0100 Subject: xen-netback: Turn off the carrier if the guest is not able to receive Currently when the guest is not able to receive more packets, qdisc layer starts a timer, and when it goes off, qdisc is started again to deliver a packet again. This is a very slow way to drain the queues, consumes unnecessary resources and slows down other guests shutdown. This patch change the behaviour by turning the carrier off when that timer fires, so all the packets are freed up which were stucked waiting for that vif. Instead of the rx_queue_purge bool it uses the VIF_STATUS_RX_PURGE_EVENT bit to signal the thread that either the timeout happened or an RX interrupt arrived, so the thread can check what it should do. It also disables NAPI, so the guest can't transmit, but leaves the interrupts on, so it can resurrect. Only the queues which brought down the interface can enable it again, the bit QUEUE_STATUS_RX_STALLED makes sure of that. Signed-off-by: Zoltan Kiss Signed-off-by: David Vrabel Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: xen-devel@lists.xenproject.org Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) (limited to 'drivers/net/xen-netback/common.h') diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index 4a92fc19f410..ef3026f46a37 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -176,9 +176,9 @@ struct xenvif_queue { /* Per-queue data for xenvif */ struct xen_netif_rx_back_ring rx; struct sk_buff_head rx_queue; RING_IDX rx_last_skb_slots; - bool rx_queue_purge; + unsigned long status; - struct timer_list wake_queue; + struct timer_list rx_stalled; struct gnttab_copy grant_copy_op[MAX_GRANT_COPY_OPS]; @@ -200,7 +200,16 @@ struct xenvif_queue { /* Per-queue data for xenvif */ enum state_bit_shift { /* This bit marks that the vif is connected */ - VIF_STATUS_CONNECTED + VIF_STATUS_CONNECTED, + /* This bit signals the RX thread that queuing was stopped (in + * start_xmit), and either the timer fired or an RX interrupt came + */ + QUEUE_STATUS_RX_PURGE_EVENT, + /* This bit tells the interrupt handler that this queue was the reason + * for the carrier off, so it should kick the thread. Only queues which + * brought it down can turn on the carrier. + */ + QUEUE_STATUS_RX_STALLED }; struct xenvif { -- cgit v1.2.3 From a64bd934528e26e8956112e43a279fba2ee0634e Mon Sep 17 00:00:00 2001 From: Wei Liu Date: Tue, 12 Aug 2014 11:48:07 +0100 Subject: xen-netback: don't stop dealloc kthread too early Reference count the number of packets in host stack, so that we don't stop the deallocation thread too early. If not, we can end up with xenvif_free permanently waiting for deallocation thread to unmap grefs. Reported-by: Thomas Leonard Signed-off-by: Wei Liu Cc: Ian Campbell Cc: Zoltan Kiss Signed-off-by: David S. Miller --- drivers/net/xen-netback/common.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'drivers/net/xen-netback/common.h') diff --git a/drivers/net/xen-netback/common.h b/drivers/net/xen-netback/common.h index ef3026f46a37..d4eb8d2e9cb7 100644 --- a/drivers/net/xen-netback/common.h +++ b/drivers/net/xen-netback/common.h @@ -165,6 +165,7 @@ struct xenvif_queue { /* Per-queue data for xenvif */ u16 dealloc_ring[MAX_PENDING_REQS]; struct task_struct *dealloc_task; wait_queue_head_t dealloc_wq; + atomic_t inflight_packets; /* Use kthread for guest RX */ struct task_struct *task; @@ -329,4 +330,8 @@ extern unsigned int xenvif_max_queues; extern struct dentry *xen_netback_dbg_root; #endif +void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue, + struct sk_buff *skb); +void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue); + #endif /* __XEN_NETBACK__COMMON_H__ */ -- cgit v1.2.3