[PATCH 09/23] ia64/xen: implement arch specific part of xen grant table.

Isaku Yamahata yamahata at valinux.co.jp
Tue Apr 8 21:50:16 PDT 2008


Xen implements grant tables which is for sharing pages with
guest domains.
This patch implements arch specific part of grant table initialization.
and xen_alloc_vm_area()/xen_free_vm_area() which are helper functions
for xen grant table.

Signed-off-by: Isaku Yamahata <yamahata at valinux.co.jp>
---
 arch/ia64/xen/Makefile             |    2 +-
 arch/ia64/xen/grant-table.c        |  155 ++++++++++++++++++++++++++++++++++++
 include/asm-ia64/xen/grant_table.h |   29 +++++++
 3 files changed, 185 insertions(+), 1 deletions(-)
 create mode 100644 arch/ia64/xen/grant-table.c
 create mode 100644 include/asm-ia64/xen/grant_table.h

diff --git a/arch/ia64/xen/Makefile b/arch/ia64/xen/Makefile
index ae08822..eb59563 100644
--- a/arch/ia64/xen/Makefile
+++ b/arch/ia64/xen/Makefile
@@ -2,4 +2,4 @@
 # Makefile for Xen components
 #
 
-obj-y := hypercall.o xencomm.o xcom_hcall.o
+obj-y := hypercall.o xencomm.o xcom_hcall.o grant-table.o
diff --git a/arch/ia64/xen/grant-table.c b/arch/ia64/xen/grant-table.c
new file mode 100644
index 0000000..777dd9a
--- /dev/null
+++ b/arch/ia64/xen/grant-table.c
@@ -0,0 +1,155 @@
+/******************************************************************************
+ * arch/ia64/xen/grant-table.c
+ *
+ * Copyright (c) 2006 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+
+#include <xen/interface/xen.h>
+#include <xen/interface/memory.h>
+#include <xen/grant_table.h>
+
+#include <asm/xen/hypervisor.h>
+
+struct vm_struct *xen_alloc_vm_area(unsigned long size)
+{
+	int order;
+	unsigned long virt;
+	unsigned long nr_pages;
+	struct vm_struct *area;
+
+	order = get_order(size);
+	virt = __get_free_pages(GFP_KERNEL, order);
+	if (virt == 0)
+		goto err0;
+	nr_pages = 1 << order;
+	scrub_pages(virt, nr_pages);
+
+	area = kmalloc(sizeof(*area), GFP_KERNEL);
+	if (area == NULL)
+		goto err1;
+
+	area->flags = VM_IOREMAP;
+	area->addr = (void *)virt;
+	area->size = size;
+	area->pages = NULL;
+	area->nr_pages = nr_pages;
+	area->phys_addr = 0;	/* xenbus_map_ring_valloc uses this field!  */
+
+	return area;
+
+err1:
+	free_pages(virt, order);
+err0:
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(xen_alloc_vm_area);
+
+void xen_free_vm_area(struct vm_struct *area)
+{
+	unsigned int order = get_order(area->size);
+	unsigned long i;
+	unsigned long phys_addr = __pa(area->addr);
+
+	/* This area is used for foreign page mappping.
+	 * So underlying machine page may not be assigned. */
+	for (i = 0; i < (1 << order); i++) {
+		unsigned long ret;
+		unsigned long gpfn = (phys_addr >> PAGE_SHIFT) + i;
+		struct xen_memory_reservation reservation = {
+			.nr_extents   = 1,
+			.address_bits = 0,
+			.extent_order = 0,
+			.domid        = DOMID_SELF
+		};
+		set_xen_guest_handle(reservation.extent_start, &gpfn);
+		ret = HYPERVISOR_memory_op(XENMEM_populate_physmap,
+					   &reservation);
+		BUG_ON(ret != 1);
+	}
+	free_pages((unsigned long)area->addr, order);
+	kfree(area);
+}
+EXPORT_SYMBOL_GPL(xen_free_vm_area);
+
+
+/****************************************************************************
+ * grant table hack
+ * cmd: GNTTABOP_xxx
+ */
+
+int arch_gnttab_map_shared(unsigned long *frames, unsigned long nr_gframes,
+			   unsigned long max_nr_gframes,
+			   struct grant_entry **__shared)
+{
+	*__shared = __va(frames[0] << PAGE_SHIFT);
+	return 0;
+}
+
+void arch_gnttab_unmap_shared(struct grant_entry *shared,
+			      unsigned long nr_gframes)
+{
+	/* nothing */
+}
+
+static void
+gnttab_map_grant_ref_pre(struct gnttab_map_grant_ref *uop)
+{
+	uint32_t flags;
+
+	flags = uop->flags;
+
+	if (flags & GNTMAP_host_map) {
+		if (flags & GNTMAP_application_map) {
+			printk(KERN_DEBUG
+			       "GNTMAP_application_map is not supported yet: "
+			       "flags 0x%x\n", flags);
+			BUG();
+		}
+		if (flags & GNTMAP_contains_pte) {
+			printk(KERN_DEBUG
+			       "GNTMAP_contains_pte is not supported yet: "
+			       "flags 0x%x\n", flags);
+			BUG();
+		}
+	} else if (flags & GNTMAP_device_map) {
+		printk("GNTMAP_device_map is not supported yet 0x%x\n", flags);
+		BUG();	/* not yet. actually this flag is not used. */
+	} else {
+		BUG();
+	}
+}
+
+int
+HYPERVISOR_grant_table_op(unsigned int cmd, void *uop, unsigned int count)
+{
+	if (cmd == GNTTABOP_map_grant_ref) {
+		unsigned int i;
+		for (i = 0; i < count; i++) {
+			gnttab_map_grant_ref_pre(
+				(struct gnttab_map_grant_ref *)uop + i);
+		}
+	}
+	return xencomm_hypercall_grant_table_op(cmd, uop, count);
+}
+
+EXPORT_SYMBOL(HYPERVISOR_grant_table_op);
diff --git a/include/asm-ia64/xen/grant_table.h b/include/asm-ia64/xen/grant_table.h
new file mode 100644
index 0000000..ebdf2ea
--- /dev/null
+++ b/include/asm-ia64/xen/grant_table.h
@@ -0,0 +1,29 @@
+/******************************************************************************
+ * include/asm-ia64/xen/grant_table.h
+ *
+ * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
+ *                    VA Linux Systems Japan K.K.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ */
+
+#ifndef _ASM_IA64_XEN_GRANT_TABLE_H
+#define _ASM_IA64_XEN_GRANT_TABLE_H
+
+struct vm_struct *xen_alloc_vm_area(unsigned long size);
+void xen_free_vm_area(struct vm_struct *area);
+
+#endif /* _ASM_IA64_XEN_GRANT_TABLE_H */
-- 
1.5.3



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