[v4][PATCH 2/9] xen:x86: define a new hypercall to get RMRR mappings

[Tiejun Chen <tiejun.chen@intel.com>]

We need this new hypercall to get RMRR mapping for VM.

Signed-off-by: Tiejun Chen <tiejun.chen@intel.com>
---
 xen/arch/x86/mm.c           | 71 +++++++++++++++++++++++++++++++++++++++++++++
 xen/include/public/memory.h | 37 ++++++++++++++++++++++-
 2 files changed, 107 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index d23cb3f..e0d6650 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -123,6 +123,7 @@
 #include <asm/setup.h>
 #include <asm/fixmap.h>
 #include <asm/pci.h>
+#include <asm/acpi.h>
 
 /* Mapping of the fixmap space needed early. */
 l1_pgentry_t __attribute__ ((__section__ (".bss.page_aligned")))
@@ -4842,6 +4843,76 @@ long arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         return rc;
     }
 
+    case XENMEM_reserved_device_memory_map:
+    {
+        struct xen_reserved_device_memory_map map;
+        XEN_GUEST_HANDLE(xen_reserved_device_memory_t) buffer;
+        XEN_GUEST_HANDLE_PARAM(xen_reserved_device_memory_t) buffer_param;
+        unsigned int i = 0;
+        static unsigned int nr_entries = 0;
+        static struct xen_reserved_device_memory *rmrr_map;
+        struct acpi_rmrr_unit *rmrr;
+
+        if ( copy_from_guest(&map, arg, 1) )
+            return -EFAULT;
+
+        if ( !nr_entries )
+            /* Currently we just need to cover RMRR. */
+            list_for_each_entry( rmrr, &acpi_rmrr_units, list )
+                nr_entries++;
+
+        if ( !nr_entries )
+                return -ENOENT;
+        else
+        {
+            if ( rmrr_map == NULL )
+            {
+                rmrr_map = xmalloc_array(xen_reserved_device_memory_t,
+                                         nr_entries);
+                if ( rmrr_map == NULL )
+                {
+                    return -ENOMEM;
+                }
+
+                list_for_each_entry( rmrr, &acpi_rmrr_units, list )
+                {
+                    rmrr_map[i].pfn = rmrr->base_address >> PAGE_SHIFT;
+                    rmrr_map[i].count = PAGE_ALIGN(rmrr->end_address -
+                                                   rmrr->base_address) /
+                                                   PAGE_SIZE;
+                    i++;
+                }
+            }
+        }
+
+        if ( map.nr_entries < nr_entries )
+        {
+            map.nr_entries =  nr_entries;
+            if ( copy_to_guest(arg, &map, 1) )
+                return -EFAULT;
+            return -ENOBUFS;
+        }
+
+        map.nr_entries =  nr_entries;
+        buffer_param = guest_handle_cast(map.buffer,
+                                         xen_reserved_device_memory_t);
+        buffer = guest_handle_from_param(buffer_param,
+                                         xen_reserved_device_memory_t);
+        if ( !guest_handle_okay(buffer, map.nr_entries) )
+            return -EFAULT;
+
+        for ( i = 0; i < map.nr_entries; ++i )
+        {
+            if ( copy_to_guest_offset(buffer, i, rmrr_map + i, 1) )
+                return -EFAULT;
+        }
+
+        if ( copy_to_guest(arg, &map, 1) )
+                return -EFAULT;
+
+        return 0;
+    }
+
     default:
         return subarch_memory_op(cmd, arg);
     }
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 2c57aa0..8481843 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -523,7 +523,42 @@ DEFINE_XEN_GUEST_HANDLE(xen_mem_sharing_op_t);
 
 #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
 
-/* Next available subop number is 26 */
+/*
+ * Some devices may reserve some range.
+ *
+ * Currently we just have RMRR
+ * - Reserved memory Region Reporting Structure,
+ * So returns the RMRR memory map as it was when the domain
+ * was started.
+ */
+#define XENMEM_reserved_device_memory_map   26
+struct xen_reserved_device_memory {
+    /* PFN of the current mapping of the page. */
+    xen_pfn_t pfn;
+    /* Number of the current mapping pages. */
+    xen_ulong_t count;
+};
+typedef struct xen_reserved_device_memory xen_reserved_device_memory_t;
+DEFINE_XEN_GUEST_HANDLE(xen_reserved_device_memory_t);
+
+struct xen_reserved_device_memory_map {
+    /*
+     * On call the number of entries which can be stored in buffer. On
+     * return the number of entries which have been stored in
+     * buffer.
+     */
+    unsigned int nr_entries;
+
+    /*
+     * Entries in the buffer are in the same format as
+     * xen_reserved_device_memory.
+     */
+    XEN_GUEST_HANDLE(void) buffer;
+};
+typedef struct xen_reserved_device_memory_map xen_reserved_device_memory_map_t;
+DEFINE_XEN_GUEST_HANDLE(xen_reserved_device_memory_map_t);
+
+/* Next available subop number is 27 */
 
 #endif /* __XEN_PUBLIC_MEMORY_H__ */
 
-- 
1.9.1