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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 5/8] netback: multi-page ring support
On Fri, Feb 15, 2013 at 04:00:06PM +0000, Wei Liu wrote:
Please a bit more description. Say which XenBus feature this
is using. And that probably means another patch to the Xen
tree to document this.
> Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
> ---
> drivers/net/xen-netback/common.h | 30 ++++++--
> drivers/net/xen-netback/interface.c | 46 +++++++++--
> drivers/net/xen-netback/netback.c | 73 ++++++++----------
> drivers/net/xen-netback/xenbus.c | 143
> +++++++++++++++++++++++++++++++++--
> 4 files changed, 229 insertions(+), 63 deletions(-)
>
> diff --git a/drivers/net/xen-netback/common.h
> b/drivers/net/xen-netback/common.h
> index 35d8772..f541ba9 100644
> --- a/drivers/net/xen-netback/common.h
> +++ b/drivers/net/xen-netback/common.h
> @@ -45,6 +45,12 @@
> #include <xen/grant_table.h>
> #include <xen/xenbus.h>
>
> +#define NETBK_MAX_RING_PAGE_ORDER XENBUS_MAX_RING_PAGE_ORDER
> +#define NETBK_MAX_RING_PAGES (1U << NETBK_MAX_RING_PAGE_ORDER)
> +
> +#define NETBK_MAX_TX_RING_SIZE XEN_NETIF_TX_RING_SIZE(NETBK_MAX_RING_PAGES)
> +#define NETBK_MAX_RX_RING_SIZE XEN_NETIF_RX_RING_SIZE(NETBK_MAX_RING_PAGES)
> +
> struct xen_netbk;
>
> struct xenvif {
> @@ -66,6 +72,8 @@ struct xenvif {
> /* The shared rings and indexes. */
> struct xen_netif_tx_back_ring tx;
> struct xen_netif_rx_back_ring rx;
> + unsigned int nr_tx_handles;
> + unsigned int nr_rx_handles;
>
> /* Frontend feature information. */
> u8 can_sg:1;
> @@ -105,15 +113,19 @@ static inline struct xenbus_device
> *xenvif_to_xenbus_device(struct xenvif *vif)
> return to_xenbus_device(vif->dev->dev.parent);
> }
>
> -#define XEN_NETIF_TX_RING_SIZE __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE)
> -#define XEN_NETIF_RX_RING_SIZE __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE)
> +#define XEN_NETIF_TX_RING_SIZE(_nr_pages) \
> + __CONST_RING_SIZE(xen_netif_tx, PAGE_SIZE * (_nr_pages))
> +#define XEN_NETIF_RX_RING_SIZE(_nr_pages) \
> + __CONST_RING_SIZE(xen_netif_rx, PAGE_SIZE * (_nr_pages))
>
> struct xenvif *xenvif_alloc(struct device *parent,
> domid_t domid,
> unsigned int handle);
>
> -int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
> - unsigned long rx_ring_ref, unsigned int evtchn);
> +int xenvif_connect(struct xenvif *vif,
> + unsigned long *tx_ring_ref, unsigned int tx_ring_order,
> + unsigned long *rx_ring_ref, unsigned int rx_ring_order,
> + unsigned int evtchn);
> void xenvif_disconnect(struct xenvif *vif);
>
> void xenvif_get(struct xenvif *vif);
> @@ -129,10 +141,12 @@ int xen_netbk_rx_ring_full(struct xenvif *vif);
> int xen_netbk_must_stop_queue(struct xenvif *vif);
>
> /* (Un)Map communication rings. */
> -void xen_netbk_unmap_frontend_rings(struct xenvif *vif);
> +void xen_netbk_unmap_frontend_rings(struct xenvif *vif, void *addr);
> int xen_netbk_map_frontend_rings(struct xenvif *vif,
> - grant_ref_t tx_ring_ref,
> - grant_ref_t rx_ring_ref);
> + void **addr,
> + int domid,
> + int *ring_ref,
> + unsigned int ring_ref_count);
>
> /* (De)Register a xenvif with the netback backend. */
> void xen_netbk_add_xenvif(struct xenvif *vif);
> @@ -158,4 +172,6 @@ void xenvif_carrier_off(struct xenvif *vif);
> /* Returns number of ring slots required to send an skb to the frontend */
> unsigned int xen_netbk_count_skb_slots(struct xenvif *vif, struct sk_buff
> *skb);
>
> +extern unsigned int MODPARM_netback_max_tx_ring_page_order;
> +extern unsigned int MODPARM_netback_max_rx_ring_page_order;
> #endif /* __XEN_NETBACK__COMMON_H__ */
> diff --git a/drivers/net/xen-netback/interface.c
> b/drivers/net/xen-netback/interface.c
> index db638e1..fa4d46d 100644
> --- a/drivers/net/xen-netback/interface.c
> +++ b/drivers/net/xen-netback/interface.c
> @@ -305,10 +305,16 @@ struct xenvif *xenvif_alloc(struct device *parent,
> domid_t domid,
> return vif;
> }
>
> -int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
> - unsigned long rx_ring_ref, unsigned int evtchn)
> +int xenvif_connect(struct xenvif *vif,
> + unsigned long *tx_ring_ref, unsigned int tx_ring_ref_count,
> + unsigned long *rx_ring_ref, unsigned int rx_ring_ref_count,
> + unsigned int evtchn)
> {
> int err = -ENOMEM;
> + void *addr;
> + struct xen_netif_tx_sring *txs;
> + struct xen_netif_rx_sring *rxs;
> + int tmp[NETBK_MAX_RING_PAGES], i;
>
> /* Already connected through? */
> if (vif->irq)
> @@ -316,15 +322,36 @@ int xenvif_connect(struct xenvif *vif, unsigned long
> tx_ring_ref,
>
> __module_get(THIS_MODULE);
>
> - err = xen_netbk_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
> + for (i = 0; i < tx_ring_ref_count; i++)
> + tmp[i] = tx_ring_ref[i];
> +
> + err = xen_netbk_map_frontend_rings(vif, &addr, vif->domid,
> + tmp, tx_ring_ref_count);
> if (err < 0)
> goto err;
>
> + txs = addr;
> + BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE * tx_ring_ref_count);
> + vif->nr_tx_handles = tx_ring_ref_count;
> +
> + for (i = 0; i < rx_ring_ref_count; i++)
> + tmp[i] = rx_ring_ref[i];
> +
> + err = xen_netbk_map_frontend_rings(vif, &addr, vif->domid,
> + tmp, rx_ring_ref_count);
> +
> + if (err < 0)
> + goto err_tx_unmap;
> +
> + rxs = addr;
> + BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE * rx_ring_ref_count);
> + vif->nr_rx_handles = rx_ring_ref_count;
> +
> err = bind_interdomain_evtchn_to_irqhandler(
> vif->domid, evtchn, xenvif_interrupt, 0,
> vif->dev->name, vif);
> if (err < 0)
> - goto err_unmap;
> + goto err_rx_unmap;
> vif->irq = err;
> disable_irq(vif->irq);
>
> @@ -340,8 +367,12 @@ int xenvif_connect(struct xenvif *vif, unsigned long
> tx_ring_ref,
> rtnl_unlock();
>
> return 0;
> -err_unmap:
> - xen_netbk_unmap_frontend_rings(vif);
> +err_rx_unmap:
> + xen_netbk_unmap_frontend_rings(vif, (void *)vif->rx.sring);
> + vif->nr_rx_handles = 0;
> +err_tx_unmap:
> + xen_netbk_unmap_frontend_rings(vif, (void *)vif->tx.sring);
> + vif->nr_tx_handles = 0;
> err:
> module_put(THIS_MODULE);
> return err;
> @@ -382,7 +413,8 @@ void xenvif_disconnect(struct xenvif *vif)
>
> unregister_netdev(vif->dev);
>
> - xen_netbk_unmap_frontend_rings(vif);
> + xen_netbk_unmap_frontend_rings(vif, (void *)vif->tx.sring);
> + xen_netbk_unmap_frontend_rings(vif, (void *)vif->rx.sring);
>
> free_netdev(vif->dev);
>
> diff --git a/drivers/net/xen-netback/netback.c
> b/drivers/net/xen-netback/netback.c
> index 98ccea9..644c760 100644
> --- a/drivers/net/xen-netback/netback.c
> +++ b/drivers/net/xen-netback/netback.c
> @@ -47,6 +47,19 @@
> #include <asm/xen/hypercall.h>
> #include <asm/xen/page.h>
>
> +unsigned int MODPARM_netback_max_rx_ring_page_order =
> NETBK_MAX_RING_PAGE_ORDER;
> +module_param_named(netback_max_rx_ring_page_order,
> + MODPARM_netback_max_rx_ring_page_order, uint, 0);
> +MODULE_PARM_DESC(netback_max_rx_ring_page_order,
> + "Maximum supported receiver ring page order");
> +
> +unsigned int MODPARM_netback_max_tx_ring_page_order =
> NETBK_MAX_RING_PAGE_ORDER;
> +module_param_named(netback_max_tx_ring_page_order,
> + MODPARM_netback_max_tx_ring_page_order, uint, 0);
> +MODULE_PARM_DESC(netback_max_tx_ring_page_order,
> + "Maximum supported transmitter ring page order");
> +
> +
These should also show up in Documentation/ABI/sysfs/stable/xen* something
But more importantly.. why not make the TX=RX order and just have one
option?
> struct pending_tx_info {
> struct xen_netif_tx_request req;
> struct xenvif *vif;
> @@ -59,7 +72,7 @@ struct netbk_rx_meta {
> int gso_size;
> };
>
> -#define MAX_PENDING_REQS 256
> +#define MAX_PENDING_REQS NETBK_MAX_TX_RING_SIZE
>
> /* Discriminate from any valid pending_idx value. */
> #define INVALID_PENDING_IDX 0xFFFF
> @@ -111,8 +124,8 @@ struct xen_netbk {
> * head/fragment page uses 2 copy operations because it
> * straddles two buffers in the frontend.
> */
> - struct gnttab_copy grant_copy_op[2*XEN_NETIF_RX_RING_SIZE];
> - struct netbk_rx_meta meta[2*XEN_NETIF_RX_RING_SIZE];
> + struct gnttab_copy grant_copy_op[2*NETBK_MAX_RX_RING_SIZE];
> + struct netbk_rx_meta meta[2*NETBK_MAX_RX_RING_SIZE];
> };
>
> static struct xen_netbk *xen_netbk;
> @@ -262,7 +275,8 @@ int xen_netbk_rx_ring_full(struct xenvif *vif)
> RING_IDX needed = max_required_rx_slots(vif);
>
> return ((vif->rx.sring->req_prod - peek) < needed) ||
> - ((vif->rx.rsp_prod_pvt + XEN_NETIF_RX_RING_SIZE - peek) <
> needed);
> + ((vif->rx.rsp_prod_pvt +
> + XEN_NETIF_RX_RING_SIZE(vif->nr_rx_handles) - peek) < needed);
> }
>
> int xen_netbk_must_stop_queue(struct xenvif *vif)
> @@ -657,7 +671,8 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk)
> __skb_queue_tail(&rxq, skb);
>
> /* Filled the batch queue? */
> - if (count + MAX_SKB_FRAGS >= XEN_NETIF_RX_RING_SIZE)
> + if (count + MAX_SKB_FRAGS >=
> + XEN_NETIF_RX_RING_SIZE(vif->nr_rx_handles))
> break;
> }
>
> @@ -1292,12 +1307,12 @@ static unsigned xen_netbk_tx_build_gops(struct
> xen_netbk *netbk)
> continue;
>
> if (vif->tx.sring->req_prod - vif->tx.req_cons >
> - XEN_NETIF_TX_RING_SIZE) {
> + XEN_NETIF_TX_RING_SIZE(vif->nr_tx_handles)) {
> netdev_err(vif->dev,
> "Impossible number of requests. "
> "req_prod %d, req_cons %d, size %ld\n",
> vif->tx.sring->req_prod, vif->tx.req_cons,
> - XEN_NETIF_TX_RING_SIZE);
> + XEN_NETIF_TX_RING_SIZE(vif->nr_tx_handles));
> netbk_fatal_tx_err(vif);
> continue;
> }
> @@ -1644,48 +1659,22 @@ static int xen_netbk_kthread(void *data)
> return 0;
> }
>
> -void xen_netbk_unmap_frontend_rings(struct xenvif *vif)
> +void xen_netbk_unmap_frontend_rings(struct xenvif *vif, void *addr)
> {
> - if (vif->tx.sring)
> - xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
> - vif->tx.sring);
> - if (vif->rx.sring)
> - xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
> - vif->rx.sring);
> + if (addr)
> + xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif), addr);
> }
>
> int xen_netbk_map_frontend_rings(struct xenvif *vif,
> - grant_ref_t tx_ring_ref,
> - grant_ref_t rx_ring_ref)
> + void **vaddr,
> + int domid,
> + int *ring_ref,
> + unsigned int ring_ref_count)
> {
> - void *addr;
> - struct xen_netif_tx_sring *txs;
> - struct xen_netif_rx_sring *rxs;
> -
> - int err = -ENOMEM;
> -
> - err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
> - &tx_ring_ref, 1, &addr);
> - if (err)
> - goto err;
> -
> - txs = (struct xen_netif_tx_sring *)addr;
> - BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
> + int err = 0;
>
> err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
> - &rx_ring_ref, 1, &addr);
> - if (err)
> - goto err;
> -
> - rxs = (struct xen_netif_rx_sring *)addr;
> - BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
> -
> - vif->rx_req_cons_peek = 0;
> -
> - return 0;
> -
> -err:
> - xen_netbk_unmap_frontend_rings(vif);
> + ring_ref, ring_ref_count, vaddr);
> return err;
> }
>
> diff --git a/drivers/net/xen-netback/xenbus.c
> b/drivers/net/xen-netback/xenbus.c
> index 65d14f2..1791807 100644
> --- a/drivers/net/xen-netback/xenbus.c
> +++ b/drivers/net/xen-netback/xenbus.c
> @@ -114,6 +114,33 @@ static int netback_probe(struct xenbus_device *dev,
> goto abort_transaction;
> }
>
> + /* Multi-page ring support */
> + if (MODPARM_netback_max_tx_ring_page_order >
> + NETBK_MAX_RING_PAGE_ORDER)
> + MODPARM_netback_max_tx_ring_page_order =
> + NETBK_MAX_RING_PAGE_ORDER;
> + err = xenbus_printf(xbt, dev->nodename,
> + "max-tx-ring-page-order",
> + "%u",
> + MODPARM_netback_max_tx_ring_page_order);
> + if (err) {
> + message = "writing max-tx-ring-page-order";
> + goto abort_transaction;
> + }
> +
> + if (MODPARM_netback_max_rx_ring_page_order >
> + NETBK_MAX_RING_PAGE_ORDER)
> + MODPARM_netback_max_rx_ring_page_order =
> + NETBK_MAX_RING_PAGE_ORDER;
> + err = xenbus_printf(xbt, dev->nodename,
> + "max-rx-ring-page-order",
> + "%u",
> + MODPARM_netback_max_rx_ring_page_order);
> + if (err) {
> + message = "writing max-rx-ring-page-order";
> + goto abort_transaction;
> + }
> +
> err = xenbus_transaction_end(xbt, 0);
> } while (err == -EAGAIN);
>
> @@ -392,22 +419,107 @@ static int connect_rings(struct backend_info *be)
> {
> struct xenvif *vif = be->vif;
> struct xenbus_device *dev = be->dev;
> - unsigned long tx_ring_ref, rx_ring_ref;
> unsigned int evtchn, rx_copy;
> int err;
> int val;
> + unsigned long tx_ring_ref[NETBK_MAX_RING_PAGES];
> + unsigned long rx_ring_ref[NETBK_MAX_RING_PAGES];
> + unsigned int tx_ring_order;
> + unsigned int rx_ring_order;
>
> err = xenbus_gather(XBT_NIL, dev->otherend,
> - "tx-ring-ref", "%lu", &tx_ring_ref,
> - "rx-ring-ref", "%lu", &rx_ring_ref,
> "event-channel", "%u", &evtchn, NULL);
> if (err) {
> xenbus_dev_fatal(dev, err,
> - "reading %s/ring-ref and event-channel",
> + "reading %s/event-channel",
> dev->otherend);
> return err;
> }
>
> + err = xenbus_scanf(XBT_NIL, dev->otherend, "tx-ring-order", "%u",
> + &tx_ring_order);
> + if (err < 0) {
> + tx_ring_order = 0;
> +
> + err = xenbus_scanf(XBT_NIL, dev->otherend, "tx-ring-ref", "%lu",
> + &tx_ring_ref[0]);
> + if (err < 0) {
> + xenbus_dev_fatal(dev, err, "reading %s/tx-ring-ref",
> + dev->otherend);
> + return err;
> + }
> + } else {
> + unsigned int i;
> +
> + if (tx_ring_order > MODPARM_netback_max_tx_ring_page_order) {
> + err = -EINVAL;
> + xenbus_dev_fatal(dev, err,
> + "%s/tx-ring-page-order too big",
> + dev->otherend);
> + return err;
> + }
> +
> + for (i = 0; i < (1U << tx_ring_order); i++) {
> + char ring_ref_name[sizeof("tx-ring-ref") + 2];
> +
> + snprintf(ring_ref_name, sizeof(ring_ref_name),
> + "tx-ring-ref%u", i);
> +
> + err = xenbus_scanf(XBT_NIL, dev->otherend,
> + ring_ref_name, "%lu",
> + &tx_ring_ref[i]);
> + if (err < 0) {
> + xenbus_dev_fatal(dev, err,
> + "reading %s/%s",
> + dev->otherend,
> + ring_ref_name);
> + return err;
> + }
> + }
> + }
> +
> + err = xenbus_scanf(XBT_NIL, dev->otherend, "rx-ring-order", "%u",
> + &rx_ring_order);
> + if (err < 0) {
> + rx_ring_order = 0;
> +
> + err = xenbus_scanf(XBT_NIL, dev->otherend, "rx-ring-ref", "%lu",
> + &rx_ring_ref[0]);
> + if (err < 0) {
> + xenbus_dev_fatal(dev, err, "reading %s/rx-ring-ref",
> + dev->otherend);
> + return err;
> + }
> + } else {
> + unsigned int i;
> +
> + if (rx_ring_order > MODPARM_netback_max_rx_ring_page_order) {
> + err = -EINVAL;
> + xenbus_dev_fatal(dev, err,
> + "%s/rx-ring-page-order too big",
> + dev->otherend);
> + return err;
> + }
> +
> + for (i = 0; i < (1U << rx_ring_order); i++) {
> + char ring_ref_name[sizeof("rx-ring-ref") + 2];
> +
> + snprintf(ring_ref_name, sizeof(ring_ref_name),
> + "rx-ring-ref%u", i);
> +
> + err = xenbus_scanf(XBT_NIL, dev->otherend,
> + ring_ref_name, "%lu",
> + &rx_ring_ref[i]);
> + if (err < 0) {
> + xenbus_dev_fatal(dev, err,
> + "reading %s/%s",
> + dev->otherend,
> + ring_ref_name);
> + return err;
> + }
> + }
> + }
> +
> err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
> &rx_copy);
> if (err == -ENOENT) {
> @@ -454,11 +566,28 @@ static int connect_rings(struct backend_info *be)
> vif->csum = !val;
>
> /* Map the shared frame, irq etc. */
> - err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref, evtchn);
> + err = xenvif_connect(vif, tx_ring_ref, (1U << tx_ring_order),
> + rx_ring_ref, (1U << rx_ring_order),
> + evtchn);
> if (err) {
> + /* construct 1 2 3 / 4 5 6 */
> + int i;
> + char txs[3 * (1U << MODPARM_netback_max_tx_ring_page_order)];
> + char rxs[3 * (1U << MODPARM_netback_max_rx_ring_page_order)];
> +
> + txs[0] = rxs[0] = 0;
> +
> + for (i = 0; i < (1U << tx_ring_order); i++)
> + snprintf(txs+strlen(txs), sizeof(txs)-strlen(txs)-1,
> + " %lu", tx_ring_ref[i]);
> +
> + for (i = 0; i < (1U << rx_ring_order); i++)
> + snprintf(rxs+strlen(rxs), sizeof(rxs)-strlen(rxs)-1,
> + " %lu", rx_ring_ref[i]);
> +
> xenbus_dev_fatal(dev, err,
> - "mapping shared-frames %lu/%lu port %u",
> - tx_ring_ref, rx_ring_ref, evtchn);
> + "mapping shared-frames%s /%s port %u",
> + txs, rxs, evtchn);
> return err;
> }
> return 0;
> --
> 1.7.10.4
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
>
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