[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[Xen-devel] [PATCH 4/8] xenbus_client: Extend interface to support multi-page ring



Also bundle fixes for xen frontends and backends in this patch.

Signed-off-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Roger Pau Monne <roger.pau@xxxxxxxxxx>
Cc: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Cc: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
---
 drivers/block/xen-blkback/xenbus.c |   14 +-
 drivers/block/xen-blkfront.c       |    6 +-
 drivers/net/xen-netback/netback.c  |    4 +-
 drivers/net/xen-netfront.c         |    9 +-
 drivers/pci/xen-pcifront.c         |    5 +-
 drivers/xen/xen-pciback/xenbus.c   |   10 +-
 drivers/xen/xenbus/xenbus_client.c |  314 ++++++++++++++++++++++++++----------
 include/xen/xenbus.h               |   17 +-
 8 files changed, 270 insertions(+), 109 deletions(-)

diff --git a/drivers/block/xen-blkback/xenbus.c 
b/drivers/block/xen-blkback/xenbus.c
index 6398072..384ff24 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -122,7 +122,8 @@ static struct xen_blkif *xen_blkif_alloc(domid_t domid)
        return blkif;
 }
 
-static int xen_blkif_map(struct xen_blkif *blkif, unsigned long shared_page,
+static int xen_blkif_map(struct xen_blkif *blkif, int *shared_pages,
+                        int nr_pages,
                         unsigned int evtchn)
 {
        int err;
@@ -131,7 +132,8 @@ static int xen_blkif_map(struct xen_blkif *blkif, unsigned 
long shared_page,
        if (blkif->irq)
                return 0;
 
-       err = xenbus_map_ring_valloc(blkif->be->dev, shared_page, 
&blkif->blk_ring);
+       err = xenbus_map_ring_valloc(blkif->be->dev, shared_pages,
+                                    nr_pages, &blkif->blk_ring);
        if (err < 0)
                return err;
 
@@ -726,7 +728,7 @@ again:
 static int connect_ring(struct backend_info *be)
 {
        struct xenbus_device *dev = be->dev;
-       unsigned long ring_ref;
+       int ring_ref;
        unsigned int evtchn;
        unsigned int pers_grants;
        char protocol[64] = "";
@@ -767,14 +769,14 @@ static int connect_ring(struct backend_info *be)
        be->blkif->vbd.feature_gnt_persistent = pers_grants;
        be->blkif->vbd.overflow_max_grants = 0;
 
-       pr_info(DRV_PFX "ring-ref %ld, event-channel %d, protocol %d (%s) %s\n",
+       pr_info(DRV_PFX "ring-ref %d, event-channel %d, protocol %d (%s) %s\n",
                ring_ref, evtchn, be->blkif->blk_protocol, protocol,
                pers_grants ? "persistent grants" : "");
 
        /* Map the shared frame, irq etc. */
-       err = xen_blkif_map(be->blkif, ring_ref, evtchn);
+       err = xen_blkif_map(be->blkif, &ring_ref, 1, evtchn);
        if (err) {
-               xenbus_dev_fatal(dev, err, "mapping ring-ref %lu port %u",
+               xenbus_dev_fatal(dev, err, "mapping ring-ref %u port %u",
                                 ring_ref, evtchn);
                return err;
        }
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 96e9b00..12c9ebd 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -991,6 +991,7 @@ static int setup_blkring(struct xenbus_device *dev,
 {
        struct blkif_sring *sring;
        int err;
+       int grefs[1];
 
        info->ring_ref = GRANT_INVALID_REF;
 
@@ -1004,13 +1005,14 @@ static int setup_blkring(struct xenbus_device *dev,
 
        sg_init_table(info->sg, BLKIF_MAX_SEGMENTS_PER_REQUEST);
 
-       err = xenbus_grant_ring(dev, virt_to_mfn(info->ring.sring));
+       err = xenbus_grant_ring(dev, info->ring.sring,
+                               1, grefs);
        if (err < 0) {
                free_page((unsigned long)sring);
                info->ring.sring = NULL;
                goto fail;
        }
-       info->ring_ref = err;
+       info->ring_ref = grefs[0];
 
        err = xenbus_alloc_evtchn(dev, &info->evtchn);
        if (err)
diff --git a/drivers/net/xen-netback/netback.c 
b/drivers/net/xen-netback/netback.c
index de59098..98ccea9 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1665,7 +1665,7 @@ int xen_netbk_map_frontend_rings(struct xenvif *vif,
        int err = -ENOMEM;
 
        err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
-                                    tx_ring_ref, &addr);
+                                    &tx_ring_ref, 1, &addr);
        if (err)
                goto err;
 
@@ -1673,7 +1673,7 @@ int xen_netbk_map_frontend_rings(struct xenvif *vif,
        BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
 
        err = xenbus_map_ring_valloc(xenvif_to_xenbus_device(vif),
-                                    rx_ring_ref, &addr);
+                                    &rx_ring_ref, 1, &addr);
        if (err)
                goto err;
 
diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 7ffa43b..8bd75a1 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1501,6 +1501,7 @@ static int setup_netfront(struct xenbus_device *dev, 
struct netfront_info *info)
        struct xen_netif_tx_sring *txs;
        struct xen_netif_rx_sring *rxs;
        int err;
+       int grefs[1];
        struct net_device *netdev = info->netdev;
 
        info->tx_ring_ref = GRANT_INVALID_REF;
@@ -1524,13 +1525,13 @@ static int setup_netfront(struct xenbus_device *dev, 
struct netfront_info *info)
        SHARED_RING_INIT(txs);
        FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
 
-       err = xenbus_grant_ring(dev, virt_to_mfn(txs));
+       err = xenbus_grant_ring(dev, txs, 1, grefs);
        if (err < 0) {
                free_page((unsigned long)txs);
                goto fail;
        }
 
-       info->tx_ring_ref = err;
+       info->tx_ring_ref = grefs[0];
        rxs = (struct xen_netif_rx_sring *)get_zeroed_page(GFP_NOIO | 
__GFP_HIGH);
        if (!rxs) {
                err = -ENOMEM;
@@ -1540,12 +1541,12 @@ static int setup_netfront(struct xenbus_device *dev, 
struct netfront_info *info)
        SHARED_RING_INIT(rxs);
        FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
 
-       err = xenbus_grant_ring(dev, virt_to_mfn(rxs));
+       err = xenbus_grant_ring(dev, rxs, 1, grefs);
        if (err < 0) {
                free_page((unsigned long)rxs);
                goto fail;
        }
-       info->rx_ring_ref = err;
+       info->rx_ring_ref = grefs[0];
 
        err = xenbus_alloc_evtchn(dev, &info->evtchn);
        if (err)
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 966abc6..016a2bb 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -772,12 +772,13 @@ static int pcifront_publish_info(struct pcifront_device 
*pdev)
 {
        int err = 0;
        struct xenbus_transaction trans;
+       int grefs[1];
 
-       err = xenbus_grant_ring(pdev->xdev, virt_to_mfn(pdev->sh_info));
+       err = xenbus_grant_ring(pdev->xdev, pdev->sh_info, 1, grefs);
        if (err < 0)
                goto out;
 
-       pdev->gnt_ref = err;
+       pdev->gnt_ref = grefs[0];
 
        err = xenbus_alloc_evtchn(pdev->xdev, &pdev->evtchn);
        if (err)
diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 64b11f9..4655851 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -98,17 +98,17 @@ static void free_pdev(struct xen_pcibk_device *pdev)
        kfree(pdev);
 }
 
-static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int gnt_ref,
-                            int remote_evtchn)
+static int xen_pcibk_do_attach(struct xen_pcibk_device *pdev, int *gnt_ref,
+                              int nr_grefs, int remote_evtchn)
 {
        int err = 0;
        void *vaddr;
 
        dev_dbg(&pdev->xdev->dev,
                "Attaching to frontend resources - gnt_ref=%d evtchn=%d\n",
-               gnt_ref, remote_evtchn);
+               gnt_ref[0], remote_evtchn);
 
-       err = xenbus_map_ring_valloc(pdev->xdev, gnt_ref, &vaddr);
+       err = xenbus_map_ring_valloc(pdev->xdev, gnt_ref, nr_grefs, &vaddr);
        if (err < 0) {
                xenbus_dev_fatal(pdev->xdev, err,
                                "Error mapping other domain page in ours.");
@@ -172,7 +172,7 @@ static int xen_pcibk_attach(struct xen_pcibk_device *pdev)
                goto out;
        }
 
-       err = xen_pcibk_do_attach(pdev, gnt_ref, remote_evtchn);
+       err = xen_pcibk_do_attach(pdev, &gnt_ref, 1, remote_evtchn);
        if (err)
                goto out;
 
diff --git a/drivers/xen/xenbus/xenbus_client.c 
b/drivers/xen/xenbus/xenbus_client.c
index 1bac743..7c1bd49 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -54,14 +54,16 @@ struct xenbus_map_node {
                struct vm_struct *area; /* PV */
                struct page *page;     /* HVM */
        };
-       grant_handle_t handle;
+       grant_handle_t handle[XENBUS_MAX_RING_PAGES];
+       unsigned int   nr_handles;
 };
 
 static DEFINE_SPINLOCK(xenbus_valloc_lock);
 static LIST_HEAD(xenbus_valloc_pages);
 
 struct xenbus_ring_ops {
-       int (*map)(struct xenbus_device *dev, int gnt, void **vaddr);
+       int (*map)(struct xenbus_device *dev, int *gnt, int nr_gnts,
+                  void **vaddr);
        int (*unmap)(struct xenbus_device *dev, void *vaddr);
 };
 
@@ -357,17 +359,39 @@ static void xenbus_switch_fatal(struct xenbus_device 
*dev, int depth, int err,
 /**
  * xenbus_grant_ring
  * @dev: xenbus device
- * @ring_mfn: mfn of ring to grant
-
- * Grant access to the given @ring_mfn to the peer of the given device.  Return
- * 0 on success, or -errno on error.  On error, the device will switch to
+ * @vaddr: starting virtual address of the ring
+ * @nr_pages: number of pages to be granted
+ * @grefs: grant reference array to be filled in
+ *
+ * Grant access to the given @vaddr to the peer of the given device.
+ * Then fill in @grefs with grant references.  Return 0 on success, or
+ * -errno on error.  On error, the device will switch to
  * XenbusStateClosing, and the error will be saved in the store.
  */
-int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn)
+int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
+                     int nr_pages, int *grefs)
 {
-       int err = gnttab_grant_foreign_access(dev->otherend_id, ring_mfn, 0);
-       if (err < 0)
-               xenbus_dev_fatal(dev, err, "granting access to ring page");
+       int i;
+       int err;
+
+       for (i = 0; i < nr_pages; i++) {
+               unsigned long addr = (unsigned long)vaddr +
+                       (PAGE_SIZE * i);
+               err = gnttab_grant_foreign_access(dev->otherend_id,
+                                                 virt_to_mfn(addr), 0);
+               if (err < 0) {
+                       xenbus_dev_fatal(dev, err,
+                                        "granting access to ring page");
+                       goto fail;
+               }
+               grefs[i] = err;
+       }
+
+       return 0;
+
+fail:
+       for ( ; i >= 0; i--)
+               gnttab_end_foreign_access_ref(grefs[i], 0);
        return err;
 }
 EXPORT_SYMBOL_GPL(xenbus_grant_ring);
@@ -448,7 +472,8 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
 /**
  * xenbus_map_ring_valloc
  * @dev: xenbus device
- * @gnt_ref: grant reference
+ * @gnt_ref: grant reference array
+ * @nr_grefs: number of grant references
  * @vaddr: pointer to address to be filled out by mapping
  *
  * Based on Rusty Russell's skeleton driver's map_page.
@@ -459,51 +484,61 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
  * or -ENOMEM on error. If an error is returned, device will switch to
  * XenbusStateClosing and the error message will be saved in XenStore.
  */
-int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void 
**vaddr)
+int xenbus_map_ring_valloc(struct xenbus_device *dev, int *gnt_ref,
+                          int nr_grefs, void **vaddr)
 {
-       return ring_ops->map(dev, gnt_ref, vaddr);
+       return ring_ops->map(dev, gnt_ref, nr_grefs, vaddr);
 }
 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
 
 static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
-                                    int gnt_ref, void **vaddr)
+                                    int *gnt_ref, int nr_grefs, void **vaddr)
 {
-       struct gnttab_map_grant_ref op = {
-               .flags = GNTMAP_host_map | GNTMAP_contains_pte,
-               .ref   = gnt_ref,
-               .dom   = dev->otherend_id,
-       };
+       struct gnttab_map_grant_ref op;
        struct xenbus_map_node *node;
        struct vm_struct *area;
-       pte_t *pte;
+       pte_t *pte[XENBUS_MAX_RING_PAGES];
+       int i;
+       int err = GNTST_okay;
+       int vma_leaked; /* used in rollback */
 
        *vaddr = NULL;
 
+       if (nr_grefs > XENBUS_MAX_RING_PAGES)
+               return -EINVAL;
+
        node = kzalloc(sizeof(*node), GFP_KERNEL);
        if (!node)
                return -ENOMEM;
 
-       area = alloc_vm_area(PAGE_SIZE, &pte);
+       area = alloc_vm_area(PAGE_SIZE * nr_grefs, pte);
        if (!area) {
                kfree(node);
                return -ENOMEM;
        }
 
-       op.host_addr = arbitrary_virt_to_machine(pte).maddr;
-
-       if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
-               BUG();
-
-       if (op.status != GNTST_okay) {
-               free_vm_area(area);
-               kfree(node);
-               xenbus_dev_fatal(dev, op.status,
-                                "mapping in shared page %d from domain %d",
-                                gnt_ref, dev->otherend_id);
-               return op.status;
+       /* Issue hypercall for individual entry, rollback if error occurs. */
+       for (i = 0; i < nr_grefs; i++) {
+               op.flags = GNTMAP_host_map | GNTMAP_contains_pte;
+               op.ref   = gnt_ref[i];
+               op.dom   = dev->otherend_id;
+               op.host_addr = arbitrary_virt_to_machine(pte[i]).maddr;
+
+               if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
+                       BUG();
+
+               if (op.status != GNTST_okay) {
+                       err = op.status;
+                       xenbus_dev_fatal(dev, op.status,
+                                "mapping in shared page (%d/%d) %d from domain 
%d",
+                                i+1, nr_grefs, gnt_ref[i], dev->otherend_id);
+                       node->handle[i] = INVALID_GRANT_HANDLE;
+                       goto rollback;
+               } else
+                       node->handle[i] = op.handle;
        }
 
-       node->handle = op.handle;
+       node->nr_handles = nr_grefs;
        node->area = area;
 
        spin_lock(&xenbus_valloc_lock);
@@ -512,31 +547,73 @@ static int xenbus_map_ring_valloc_pv(struct xenbus_device 
*dev,
 
        *vaddr = area->addr;
        return 0;
+
+rollback:
+       vma_leaked = 0;
+       for ( ; i >= 0; i--) {
+               if (node->handle[i] != INVALID_GRANT_HANDLE) {
+                       struct gnttab_unmap_grant_ref unmap_op;
+                       unmap_op.dev_bus_addr = 0;
+                       unmap_op.host_addr =
+                               arbitrary_virt_to_machine(pte[i]).maddr;
+                       unmap_op.handle = node->handle[i];
+
+                       if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+                                                     &unmap_op, 1))
+                               BUG();
+
+                       if (unmap_op.status != GNTST_okay) {
+                               pr_alert("rollback mapping (%d/%d) %d from 
domain %d, err = %d",
+                                        i+1, nr_grefs, gnt_ref[i],
+                                        dev->otherend_id,
+                                        unmap_op.status);
+                               vma_leaked = 1;
+                       }
+                       node->handle[i] = INVALID_GRANT_HANDLE;
+               }
+       }
+
+       if (!vma_leaked)
+               free_vm_area(area);
+       else
+               pr_alert("leaking vm area %p size %d page(s)", area, nr_grefs);
+
+       kfree(node);
+
+       return err;
 }
 
 static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
-                                     int gnt_ref, void **vaddr)
+                                     int *gnt_ref, int nr_grefs, void **vaddr)
 {
        struct xenbus_map_node *node;
        int err;
        void *addr;
+       int vma_leaked;
 
        *vaddr = NULL;
 
+       if (nr_grefs > XENBUS_MAX_RING_PAGES)
+               return -EINVAL;
+
        node = kzalloc(sizeof(*node), GFP_KERNEL);
        if (!node)
                return -ENOMEM;
 
-       err = alloc_xenballooned_pages(1, &node->page, false /* lowmem */);
+       err = alloc_xenballooned_pages(nr_grefs, &node->page,
+                                      false /* lowmem */);
        if (err)
                goto out_err;
 
        addr = pfn_to_kaddr(page_to_pfn(node->page));
 
-       err = xenbus_map_ring(dev, gnt_ref, &node->handle, addr);
+       err = xenbus_map_ring(dev, gnt_ref, nr_grefs, node->handle,
+                             addr, &vma_leaked);
        if (err)
                goto out_err;
 
+       node->nr_handles = nr_grefs;
+
        spin_lock(&xenbus_valloc_lock);
        list_add(&node->next, &xenbus_valloc_pages);
        spin_unlock(&xenbus_valloc_lock);
@@ -545,7 +622,8 @@ static int xenbus_map_ring_valloc_hvm(struct xenbus_device 
*dev,
        return 0;
 
  out_err:
-       free_xenballooned_pages(1, &node->page);
+       if (!vma_leaked)
+               free_xenballooned_pages(nr_grefs, &node->page);
        kfree(node);
        return err;
 }
@@ -554,36 +632,75 @@ static int xenbus_map_ring_valloc_hvm(struct 
xenbus_device *dev,
 /**
  * xenbus_map_ring
  * @dev: xenbus device
- * @gnt_ref: grant reference
+ * @gnt_ref: grant reference array
+ * @nr_grefs: number of grant reference
  * @handle: pointer to grant handle to be filled
  * @vaddr: address to be mapped to
+ * @vma_leaked: cannot clean up a failed mapping, vma leaked
  *
- * Map a page of memory into this domain from another domain's grant table.
+ * Map pages of memory into this domain from another domain's grant table.
  * xenbus_map_ring does not allocate the virtual address space (you must do
- * this yourself!). It only maps in the page to the specified address.
+ * this yourself!). It only maps in the pages to the specified address.
  * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h)
  * or -ENOMEM on error. If an error is returned, device will switch to
- * XenbusStateClosing and the error message will be saved in XenStore.
+ * XenbusStateClosing and the last error message will be saved in XenStore.
  */
-int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
-                   grant_handle_t *handle, void *vaddr)
+int xenbus_map_ring(struct xenbus_device *dev, int *gnt_ref, int nr_grefs,
+                   grant_handle_t *handle, void *vaddr, int *vma_leaked)
 {
        struct gnttab_map_grant_ref op;
+       int i;
+       int err = GNTST_okay;
+
+       for (i = 0; i < nr_grefs; i++) {
+               unsigned long addr = (unsigned long)vaddr +
+                       (PAGE_SIZE * i);
+               gnttab_set_map_op(&op, (unsigned long)addr,
+                                 GNTMAP_host_map, gnt_ref[i],
+                                 dev->otherend_id);
+
+               if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref,
+                                             &op, 1))
+                       BUG();
+
+               if (op.status != GNTST_okay) {
+                       xenbus_dev_fatal(dev, op.status,
+                                "mapping in shared page (%d/%d) %d from domain 
%d",
+                                i+1, nr_grefs, gnt_ref[i], dev->otherend_id);
+                       handle[i] = INVALID_GRANT_HANDLE;
+                       goto rollback;
+               } else
+                       handle[i] = op.handle;
+       }
 
-       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();
+       return 0;
 
-       if (op.status != GNTST_okay) {
-               xenbus_dev_fatal(dev, op.status,
-                                "mapping in shared page %d from domain %d",
-                                gnt_ref, dev->otherend_id);
-       } else
-               *handle = op.handle;
+rollback:
+       *vma_leaked = 0;
+       for ( ; i >= 0; i--) {
+               if (handle[i] != INVALID_GRANT_HANDLE) {
+                       struct gnttab_unmap_grant_ref unmap_op;
+                       unsigned long addr = (unsigned long)vaddr +
+                               (PAGE_SIZE * i);
+                       gnttab_set_unmap_op(&unmap_op, (phys_addr_t)addr,
+                                           GNTMAP_host_map, handle[i]);
+
+                       if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+                                                     &unmap_op, 1))
+                               BUG();
+
+                       if (unmap_op.status != GNTST_okay) {
+                               pr_alert("rollback mapping (%d/%d) %d from 
domain %d, err = %d",
+                                        i+1, nr_grefs, gnt_ref[i],
+                                        dev->otherend_id,
+                                        unmap_op.status);
+                               *vma_leaked = 1;
+                       }
+                       handle[i] = INVALID_GRANT_HANDLE;
+               }
+       }
 
-       return op.status;
+       return err;
 }
 EXPORT_SYMBOL_GPL(xenbus_map_ring);
 
@@ -609,10 +726,11 @@ EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
 static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
 {
        struct xenbus_map_node *node;
-       struct gnttab_unmap_grant_ref op = {
-               .host_addr = (unsigned long)vaddr,
-       };
+       struct gnttab_unmap_grant_ref op[XENBUS_MAX_RING_PAGES];
        unsigned int level;
+       int i;
+       int last_error = GNTST_okay;
+       int vma_leaked;
 
        spin_lock(&xenbus_valloc_lock);
        list_for_each_entry(node, &xenbus_valloc_pages, next) {
@@ -631,22 +749,39 @@ static int xenbus_unmap_ring_vfree_pv(struct 
xenbus_device *dev, void *vaddr)
                return GNTST_bad_virt_addr;
        }
 
-       op.handle = node->handle;
-       op.host_addr = arbitrary_virt_to_machine(
-               lookup_address((unsigned long)vaddr, &level)).maddr;
+       for (i = 0; i < node->nr_handles; i++) {
+               unsigned long addr = (unsigned long)vaddr +
+                       (PAGE_SIZE * i);
+               op[i].dev_bus_addr = 0;
+               op[i].handle = node->handle[i];
+               op[i].host_addr = arbitrary_virt_to_machine(
+                       lookup_address((unsigned long)addr, &level)).maddr;
+       }
 
-       if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
+       if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, op,
+                                     node->nr_handles))
                BUG();
 
-       if (op.status == GNTST_okay)
+       vma_leaked = 0;
+       for (i = 0; i < node->nr_handles; i++) {
+               if (op[i].status != GNTST_okay) {
+                       last_error = op[i].status;
+                       vma_leaked = 1;
+                       xenbus_dev_error(dev, op[i].status,
+                                "unmapping page (%d/%d) at handle %d error %d",
+                                i+1, node->nr_handles, node->handle[i],
+                                op[i].status);
+               }
+       }
+
+       if (!vma_leaked)
                free_vm_area(node->area);
        else
-               xenbus_dev_error(dev, op.status,
-                                "unmapping page at handle %d error %d",
-                                node->handle, op.status);
+               pr_alert("leaking vm area %p size %d page(s)",
+                        node->area, node->nr_handles);
 
        kfree(node);
-       return op.status;
+       return last_error;
 }
 
 static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
@@ -673,10 +808,10 @@ static int xenbus_unmap_ring_vfree_hvm(struct 
xenbus_device *dev, void *vaddr)
                return GNTST_bad_virt_addr;
        }
 
-       rv = xenbus_unmap_ring(dev, node->handle, addr);
+       rv = xenbus_unmap_ring(dev, node->handle, node->nr_handles, addr);
 
        if (!rv)
-               free_xenballooned_pages(1, &node->page);
+               free_xenballooned_pages(node->nr_handles, &node->page);
        else
                WARN(1, "Leaking %p\n", vaddr);
 
@@ -687,7 +822,8 @@ static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device 
*dev, void *vaddr)
 /**
  * xenbus_unmap_ring
  * @dev: xenbus device
- * @handle: grant handle
+ * @handle: grant handle array
+ * @nr_handles: number of grant handles
  * @vaddr: addr to unmap
  *
  * Unmap a page of memory in this domain that was imported from another domain.
@@ -695,21 +831,33 @@ static int xenbus_unmap_ring_vfree_hvm(struct 
xenbus_device *dev, void *vaddr)
  * (see xen/include/interface/grant_table.h).
  */
 int xenbus_unmap_ring(struct xenbus_device *dev,
-                     grant_handle_t handle, void *vaddr)
+                     grant_handle_t *handle, int nr_handles,
+                     void *vaddr)
 {
        struct gnttab_unmap_grant_ref op;
+       int last_error = GNTST_okay;
+       int i;
+
+       for (i = 0; i < nr_handles; i++) {
+               unsigned long addr = (unsigned long)vaddr +
+                       (PAGE_SIZE * i);
+               gnttab_set_unmap_op(&op, (unsigned long)addr,
+                                   GNTMAP_host_map, handle[i]);
+               handle[i] = INVALID_GRANT_HANDLE;
+
+               if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref,
+                                             &op, 1))
+                       BUG();
+
+               if (op.status != GNTST_okay) {
+                       xenbus_dev_error(dev, op.status,
+                                "unmapping page (%d/%d) at handle %d error %d",
+                                i+1, nr_handles, handle[i], op.status);
+                       last_error = op.status;
+               }
+       }
 
-       gnttab_set_unmap_op(&op, (unsigned long)vaddr, GNTMAP_host_map, handle);
-
-       if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
-               BUG();
-
-       if (op.status != GNTST_okay)
-               xenbus_dev_error(dev, op.status,
-                                "unmapping page at handle %d error %d",
-                                handle, op.status);
-
-       return op.status;
+       return last_error;
 }
 EXPORT_SYMBOL_GPL(xenbus_unmap_ring);
 
diff --git a/include/xen/xenbus.h b/include/xen/xenbus.h
index 0a7515c..b7d9613 100644
--- a/include/xen/xenbus.h
+++ b/include/xen/xenbus.h
@@ -46,6 +46,11 @@
 #include <xen/interface/io/xenbus.h>
 #include <xen/interface/io/xs_wire.h>
 
+/* Max pages supported by multi-page ring in the backend */
+#define XENBUS_MAX_RING_PAGE_ORDER  2
+#define XENBUS_MAX_RING_PAGES       (1U << XENBUS_MAX_RING_PAGE_ORDER)
+#define INVALID_GRANT_HANDLE        (~0U)
+
 /* Register callback to watch this node. */
 struct xenbus_watch
 {
@@ -195,15 +200,17 @@ int xenbus_watch_pathfmt(struct xenbus_device *dev, 
struct xenbus_watch *watch,
                         const char *pathfmt, ...);
 
 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state 
new_state);
-int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
+int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
+                     int nr_gages, int *grefs);
 int xenbus_map_ring_valloc(struct xenbus_device *dev,
-                          int gnt_ref, void **vaddr);
-int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
-                          grant_handle_t *handle, void *vaddr);
+                          int *gnt_ref, int nr_grefs, void **vaddr);
+int xenbus_map_ring(struct xenbus_device *dev, int *gnt_ref, int nr_grefs,
+                   grant_handle_t *handle, void *vaddr, int *vma_leaked);
 
 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
 int xenbus_unmap_ring(struct xenbus_device *dev,
-                     grant_handle_t handle, void *vaddr);
+                     grant_handle_t *handle, int nr_handles,
+                     void *vaddr);
 
 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
 int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port);
-- 
1.7.10.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel


 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.