WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

[Xen-devel] [PATCH 1/6 v2] xenbus: Support HVM backends

Initial version lacked the list_del in xenbus_unmap_ring_vfree_hvm

-------------------------------------------------------->8

Add HVM implementations of xenbus_(map,unmap)_ring_v(alloc,free) so
that ring mappings can be done without using GNTMAP_contains_pte which
is not supported on HVM.

Signed-off-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
---
 drivers/xen/xenbus/xenbus_client.c |  155 +++++++++++++++++++++++++++++-------
 1 files changed, 125 insertions(+), 30 deletions(-)

diff --git a/drivers/xen/xenbus/xenbus_client.c 
b/drivers/xen/xenbus/xenbus_client.c
index 52bc57f..4b2fbcc 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -32,15 +32,26 @@
 
 #include <linux/slab.h>
 #include <linux/types.h>
+#include <linux/spinlock.h>
 #include <linux/vmalloc.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/page.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/event_channel.h>
+#include <xen/balloon.h>
 #include <xen/events.h>
 #include <xen/grant_table.h>
 #include <xen/xenbus.h>
 
+struct xenbus_map_node {
+       struct list_head next;
+       struct page *page;
+       grant_handle_t handle;
+};
+
+static DEFINE_SPINLOCK(xenbus_valloc_lock);
+static LIST_HEAD(xenbus_valloc_pages);
+
 const char *xenbus_strstate(enum xenbus_state state)
 {
        static const char *const name[] = {
@@ -419,21 +430,8 @@ int xenbus_free_evtchn(struct xenbus_device *dev, int port)
 EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
 
 
-/**
- * xenbus_map_ring_valloc
- * @dev: xenbus device
- * @gnt_ref: grant reference
- * @vaddr: pointer to address to be filled out by mapping
- *
- * Based on Rusty Russell's skeleton driver's map_page.
- * Map a page of memory into this domain from another domain's grant table.
- * xenbus_map_ring_valloc allocates a page of virtual address space, maps the
- * page to that address, and sets *vaddr to that 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.
- */
-int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void 
**vaddr)
+static int xenbus_map_ring_valloc_pv(struct xenbus_device *dev,
+                                     int gnt_ref, void **vaddr)
 {
        struct gnttab_map_grant_ref op = {
                .flags = GNTMAP_host_map | GNTMAP_contains_pte,
@@ -468,6 +466,64 @@ int xenbus_map_ring_valloc(struct xenbus_device *dev, int 
gnt_ref, void **vaddr)
        *vaddr = area->addr;
        return 0;
 }
+
+static int xenbus_map_ring_valloc_hvm(struct xenbus_device *dev,
+                                     int gnt_ref, void **vaddr)
+{
+       struct xenbus_map_node *node;
+       int err;
+       void *addr;
+
+       *vaddr = NULL;
+
+       node = kzalloc(sizeof(*node), GFP_KERNEL);
+       if (!node)
+               return -ENOMEM;
+
+       err = alloc_xenballooned_pages(1, &node->page, false);
+       if (err)
+               goto out_err;
+
+       addr = pfn_to_kaddr(page_to_pfn(node->page));
+
+       err = xenbus_map_ring(dev, gnt_ref, &node->handle, addr);
+       if (err)
+               goto out_err;
+
+       spin_lock(&xenbus_valloc_lock);
+       list_add(&node->next, &xenbus_valloc_pages);
+       spin_unlock(&xenbus_valloc_lock);
+
+       *vaddr = addr;
+       return 0;
+
+ out_err:
+       free_xenballooned_pages(1, &node->page);
+       kfree(node);
+       return err;
+}
+
+/**
+ * xenbus_map_ring_valloc
+ * @dev: xenbus device
+ * @gnt_ref: grant reference
+ * @vaddr: pointer to address to be filled out by mapping
+ *
+ * Based on Rusty Russell's skeleton driver's map_page.
+ * Map a page of memory into this domain from another domain's grant table.
+ * xenbus_map_ring_valloc allocates a page of virtual address space, maps the
+ * page to that address, and sets *vaddr to that 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.
+ */
+int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void 
**vaddr)
+{
+       if (xen_pv_domain())
+               return xenbus_map_ring_valloc_pv(dev, gnt_ref, vaddr);
+       else
+               return xenbus_map_ring_valloc_hvm(dev, gnt_ref, vaddr);
+}
 EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc);
 
 
@@ -509,20 +565,7 @@ int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
 }
 EXPORT_SYMBOL_GPL(xenbus_map_ring);
 
-
-/**
- * xenbus_unmap_ring_vfree
- * @dev: xenbus device
- * @vaddr: addr to unmap
- *
- * Based on Rusty Russell's skeleton driver's unmap_page.
- * Unmap a page of memory in this domain that was imported from another domain.
- * Use xenbus_unmap_ring_vfree if you mapped in your memory with
- * xenbus_map_ring_valloc (it will free the virtual address space).
- * Returns 0 on success and returns GNTST_* on error
- * (see xen/include/interface/grant_table.h).
- */
-int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
+static int xenbus_unmap_ring_vfree_pv(struct xenbus_device *dev, void *vaddr)
 {
        struct vm_struct *area;
        struct gnttab_unmap_grant_ref op = {
@@ -565,8 +608,60 @@ int xenbus_unmap_ring_vfree(struct xenbus_device *dev, 
void *vaddr)
 
        return op.status;
 }
-EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
 
+static int xenbus_unmap_ring_vfree_hvm(struct xenbus_device *dev, void *vaddr)
+{
+       int rv;
+       struct xenbus_map_node *node;
+       void *addr;
+
+       spin_lock(&xenbus_valloc_lock);
+       list_for_each_entry(node, &xenbus_valloc_pages, next) {
+               addr = pfn_to_kaddr(page_to_pfn(node->page));
+               if (addr == vaddr) {
+                       list_del(&node->next);
+                       goto found;
+               }
+       }
+       node = NULL;
+ found:
+       spin_unlock(&xenbus_valloc_lock);
+
+       if (!node) {
+               xenbus_dev_error(dev, -ENOENT,
+                                "can't find mapped virtual address %p", vaddr);
+               return -ENOENT;
+       }
+
+       rv = xenbus_unmap_ring(dev, node->handle, addr);
+
+       if (!rv)
+               free_xenballooned_pages(1, &node->page);
+
+       kfree(node);
+       return rv;
+}
+
+/**
+ * xenbus_unmap_ring_vfree
+ * @dev: xenbus device
+ * @vaddr: addr to unmap
+ *
+ * Based on Rusty Russell's skeleton driver's unmap_page.
+ * Unmap a page of memory in this domain that was imported from another domain.
+ * Use xenbus_unmap_ring_vfree if you mapped in your memory with
+ * xenbus_map_ring_valloc (it will free the virtual address space).
+ * Returns 0 on success and returns GNTST_* on error
+ * (see xen/include/interface/grant_table.h).
+ */
+int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
+{
+       if (xen_pv_domain())
+               return xenbus_unmap_ring_vfree_pv(dev, vaddr);
+       else
+               return xenbus_unmap_ring_vfree_hvm(dev, vaddr);
+}
+EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree);
 
 /**
  * xenbus_unmap_ring
-- 
1.7.6.4


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel

<Prev in Thread] Current Thread [Next in Thread>