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authorDavid Vrabel <david.vrabel@citrix.com>2011-09-29 16:53:32 +0100
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2011-11-16 12:13:08 -0500
commitcd12909cb576d37311fe35868780e82d5007d0c8 (patch)
tree70ec60af4feb32087f542a838fe4dce8717f0cd6 /drivers/xen/xenbus
parent1ea6b8f48918282bdca0b32a34095504ee65bab5 (diff)
downloadvexpress-lsk-cd12909cb576d37311fe35868780e82d5007d0c8.tar.gz
xen: map foreign pages for shared rings by updating the PTEs directly
When mapping a foreign page with xenbus_map_ring_valloc() with the GNTTABOP_map_grant_ref hypercall, set the GNTMAP_contains_pte flag and pass a pointer to the PTE (in init_mm). After the page is mapped, the usual fault mechanism can be used to update additional MMs. This allows the vmalloc_sync_all() to be removed from alloc_vm_area(). Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> [v1: Squashed fix by Michal for no-mmu case] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Michal Simek <monstr@monstr.eu>
Diffstat (limited to 'drivers/xen/xenbus')
-rw-r--r--drivers/xen/xenbus/xenbus_client.c11
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c
index 81c3ce6b8bb..1906125eab4 100644
--- a/drivers/xen/xenbus/xenbus_client.c
+++ b/drivers/xen/xenbus/xenbus_client.c
@@ -35,6 +35,7 @@
#include <linux/vmalloc.h>
#include <linux/export.h>
#include <asm/xen/hypervisor.h>
+#include <asm/xen/page.h>
#include <xen/interface/xen.h>
#include <xen/interface/event_channel.h>
#include <xen/events.h>
@@ -436,19 +437,20 @@ EXPORT_SYMBOL_GPL(xenbus_free_evtchn);
int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void **vaddr)
{
struct gnttab_map_grant_ref op = {
- .flags = GNTMAP_host_map,
+ .flags = GNTMAP_host_map | GNTMAP_contains_pte,
.ref = gnt_ref,
.dom = dev->otherend_id,
};
struct vm_struct *area;
+ pte_t *pte;
*vaddr = NULL;
- area = alloc_vm_area(PAGE_SIZE);
+ area = alloc_vm_area(PAGE_SIZE, &pte);
if (!area)
return -ENOMEM;
- op.host_addr = (unsigned long)area->addr;
+ op.host_addr = arbitrary_virt_to_machine(pte).maddr;
if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
BUG();
@@ -527,6 +529,7 @@ int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
struct gnttab_unmap_grant_ref op = {
.host_addr = (unsigned long)vaddr,
};
+ unsigned int level;
/* It'd be nice if linux/vmalloc.h provided a find_vm_area(void *addr)
* method so that we don't have to muck with vmalloc internals here.
@@ -548,6 +551,8 @@ int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr)
}
op.handle = (grant_handle_t)area->phys_addr;
+ op.host_addr = arbitrary_virt_to_machine(
+ lookup_address((unsigned long)vaddr, &level)).maddr;
if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
BUG();