xen: implement the privcmd user-space device

This device is only attached to priviledged domains, and allows the
toolstack to interact with Xen. The two functions of the privcmd
interface is to allow the execution of hypercalls from user-space, and
the mapping of foreign domain memory.

Sponsored by: Citrix Systems R&D

i386/include/xen/hypercall.h:
amd64/include/xen/hypercall.h:
 - Introduce a function to make generic hypercalls into Xen.

xen/interface/xen.h:
xen/interface/memory.h:
 - Import the new hypercall XENMEM_add_to_physmap_range used by
   auto-translated guests to map memory from foreign domains.

dev/xen/privcmd/privcmd.c:
 - This device has the following functions:
   - Allow user-space applications to make hypercalls into Xen.
   - Allow user-space applications to map memory from foreign domains,
     this is accomplished using the newly introduced hypercall
     (XENMEM_add_to_physmap_range).

xen/privcmd.h:
 - Public ioctl interface for the privcmd device.

x86/xen/hvm.c:
 - Remove declaration of hypercall_page, now it's declared in
   hypercall.h.

conf/files:
 - Add the privcmd device to the build process.

3 files changed, 92 insertions, 0 deletions

diff --git a/sys/xen/interface/memory.h b/sys/xen/interface/memory.h
index 86d02c8..cdb7a58 100644
--- a/sys/xen/interface/memory.h
+++ b/sys/xen/interface/memory.h
@@ -198,6 +198,14 @@ struct xen_machphys_mapping {
 typedef struct xen_machphys_mapping xen_machphys_mapping_t;
 DEFINE_XEN_GUEST_HANDLE(xen_machphys_mapping_t);
 
+#define XENMAPSPACE_shared_info  0 /* shared info page */
+#define XENMAPSPACE_grant_table  1 /* grant table page */
+#define XENMAPSPACE_gmfn         2 /* GMFN */
+#define XENMAPSPACE_gmfn_range   3 /* GMFN range, XENMEM_add_to_physmap only. */
+#define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another dom,
+                                    * XENMEM_add_to_physmap_range only.
+                                    */
+
 /*
  * Sets the GPFN at which a particular page appears in the specified guest's
  * pseudophysical address space.
@@ -248,6 +256,31 @@ DEFINE_XEN_GUEST_HANDLE(xen_remove_from_physmap_t);
 /*** REMOVED ***/
 /*#define XENMEM_translate_gpfn_list  8*/
 
+#define XENMEM_add_to_physmap_range 23
+struct xen_add_to_physmap_range {
+    /* IN */
+    /* Which domain to change the mapping for. */
+    domid_t domid;
+    uint16_t space; /* => enum phys_map_space */
+
+    /* Number of pages to go through */
+    uint16_t size;
+    domid_t foreign_domid; /* IFF gmfn_foreign */
+
+    /* Indexes into space being mapped. */
+    XEN_GUEST_HANDLE(xen_ulong_t) idxs;
+
+    /* GPFN in domid where the source mapping page should appear. */
+    XEN_GUEST_HANDLE(xen_pfn_t) gpfns;
+
+    /* OUT */
+
+    /* Per index error code. */
+    XEN_GUEST_HANDLE(int) errs;
+};
+typedef struct xen_add_to_physmap_range xen_add_to_physmap_range_t;
+DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_range_t);
+
 /*
  * Returns the pseudo-physical memory map as it was when the domain
  * was started (specified by XENMEM_set_memory_map).
diff --git a/sys/xen/interface/xen.h b/sys/xen/interface/xen.h
index b2f6c50..9425520 100644
--- a/sys/xen/interface/xen.h
+++ b/sys/xen/interface/xen.h
@@ -51,6 +51,7 @@ DEFINE_XEN_GUEST_HANDLE(void);
 
 DEFINE_XEN_GUEST_HANDLE(uint64_t);
 DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
+DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
 #endif
 
 /*
diff --git a/sys/xen/privcmd.h b/sys/xen/privcmd.h
new file mode 100644
index 0000000..a3cc4e1
--- /dev/null
+++ b/sys/xen/privcmd.h
@@ -0,0 +1,58 @@
+/******************************************************************************
+ * privcmd.h
+ * 
+ * Interface to /proc/xen/privcmd.
+ * 
+ * Copyright (c) 2003-2005, K A Fraser
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef __XEN_PRIVCMD_H__
+#define __XEN_PRIVCMD_H__
+
+struct ioctl_privcmd_hypercall
+{
+	unsigned long op; /* hypercall number */
+	unsigned long arg[5]; /* arguments */
+	long retval; /* return value */
+};
+
+struct ioctl_privcmd_mmapbatch {
+	int num;     /* number of pages to populate */
+	domid_t dom; /* target domain */
+	unsigned long addr;  /* virtual address */
+	const xen_pfn_t *arr; /* array of mfns */
+	int *err; /* array of error codes */
+};
+
+#define IOCTL_PRIVCMD_HYPERCALL					\
+	_IOWR('E', 0, struct ioctl_privcmd_hypercall)
+#define IOCTL_PRIVCMD_MMAPBATCH					\
+	_IOWR('E', 1, struct ioctl_privcmd_mmapbatch)
+
+#endif /* !__XEN_PRIVCMD_H__ */