diff options
| -rw-r--r-- | drivers/net/xen-netback/netback.c | 11 | ||||
| -rw-r--r-- | drivers/xen/grant-table.c | 53 | ||||
| -rw-r--r-- | drivers/xen/xenbus/xenbus_client.c | 6 | ||||
| -rw-r--r-- | include/xen/grant_table.h | 12 |
4 files changed, 70 insertions, 12 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 682633bfe00f..05593d882023 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -635,9 +635,7 @@ static void xen_netbk_rx_action(struct xen_netbk *netbk) return; BUG_ON(npo.copy_prod > ARRAY_SIZE(netbk->grant_copy_op)); - ret = HYPERVISOR_grant_table_op(GNTTABOP_copy, &netbk->grant_copy_op, - npo.copy_prod); - BUG_ON(ret != 0); + gnttab_batch_copy(netbk->grant_copy_op, npo.copy_prod); while ((skb = __skb_dequeue(&rxq)) != NULL) { sco = (struct skb_cb_overlay *)skb->cb; @@ -1460,18 +1458,15 @@ static void xen_netbk_tx_submit(struct xen_netbk *netbk) static void xen_netbk_tx_action(struct xen_netbk *netbk) { unsigned nr_gops; - int ret; nr_gops = xen_netbk_tx_build_gops(netbk); if (nr_gops == 0) return; - ret = HYPERVISOR_grant_table_op(GNTTABOP_copy, - netbk->tx_copy_ops, nr_gops); - BUG_ON(ret); - xen_netbk_tx_submit(netbk); + gnttab_batch_copy(netbk->tx_copy_ops, nr_gops); + xen_netbk_tx_submit(netbk); } static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx) diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c index eea81cf8a2a5..3a567b15600b 100644 --- a/drivers/xen/grant-table.c +++ b/drivers/xen/grant-table.c @@ -38,6 +38,7 @@ #include <linux/vmalloc.h> #include <linux/uaccess.h> #include <linux/io.h> +#include <linux/delay.h> #include <linux/hardirq.h> #include <xen/xen.h> @@ -823,6 +824,52 @@ unsigned int gnttab_max_grant_frames(void) } EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); +/* Handling of paged out grant targets (GNTST_eagain) */ +#define MAX_DELAY 256 +static inline void +gnttab_retry_eagain_gop(unsigned int cmd, void *gop, int16_t *status, + const char *func) +{ + unsigned delay = 1; + + do { + BUG_ON(HYPERVISOR_grant_table_op(cmd, gop, 1)); + if (*status == GNTST_eagain) + msleep(delay++); + } while ((*status == GNTST_eagain) && (delay < MAX_DELAY)); + + if (delay >= MAX_DELAY) { + printk(KERN_ERR "%s: %s eagain grant\n", func, current->comm); + *status = GNTST_bad_page; + } +} + +void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count) +{ + struct gnttab_map_grant_ref *op; + + if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, batch, count)) + BUG(); + for (op = batch; op < batch + count; op++) + if (op->status == GNTST_eagain) + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, op, + &op->status, __func__); +} +EXPORT_SYMBOL_GPL(gnttab_batch_map); + +void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count) +{ + struct gnttab_copy *op; + + if (HYPERVISOR_grant_table_op(GNTTABOP_copy, batch, count)) + BUG(); + for (op = batch; op < batch + count; op++) + if (op->status == GNTST_eagain) + gnttab_retry_eagain_gop(GNTTABOP_copy, op, + &op->status, __func__); +} +EXPORT_SYMBOL_GPL(gnttab_batch_copy); + int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, struct gnttab_map_grant_ref *kmap_ops, struct page **pages, unsigned int count) @@ -836,6 +883,12 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, if (ret) return ret; + /* Retry eagain maps */ + for (i = 0; i < count; i++) + if (map_ops[i].status == GNTST_eagain) + gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, + &map_ops[i].status, __func__); + if (xen_feature(XENFEAT_auto_translated_physmap)) return ret; diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c index b3e146edb51d..bcf3ba4a6ec1 100644 --- a/drivers/xen/xenbus/xenbus_client.c +++ b/drivers/xen/xenbus/xenbus_client.c @@ -490,8 +490,7 @@ static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev, op.host_addr = arbitrary_virt_to_machine(pte).maddr; - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)) - BUG(); + gnttab_batch_map(&op, 1); if (op.status != GNTST_okay) { free_vm_area(area); @@ -572,8 +571,7 @@ int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, gnttab_set_map_op(&op, (unsigned long)vaddr, GNTMAP_host_map, gnt_ref, dev->otherend_id); - if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)) - BUG(); + gnttab_batch_map(&op, 1); if (op.status != GNTST_okay) { xenbus_dev_fatal(dev, op.status, diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h index 11e27c3af3cb..ba0d77529a29 100644 --- a/include/xen/grant_table.h +++ b/include/xen/grant_table.h @@ -189,4 +189,16 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, struct page **pages, unsigned int count, bool clear_pte); +/* Perform a batch of grant map/copy operations. Retry every batch slot + * for which the hypervisor returns GNTST_eagain. This is typically due + * to paged out target frames. + * + * Will retry for 1, 2, ... 255 ms, i.e. 256 times during 32 seconds. + * + * Return value in each iand every status field of the batch guaranteed + * to not be GNTST_eagain. + */ +void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count); +void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count); + #endif /* __ASM_GNTTAB_H__ */ |