[RFC][PATCH 2/5] xen:x86: introduce 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               | 35 +++++++++++++++++++++++++++++++++++
 xen/arch/x86/x86_64/compat/mm.c |  8 ++++++++
 xen/include/public/memory.h     | 10 +++++++++-
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index d23cb3f..8176fd4 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -4769,6 +4769,41 @@ long arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         return 0;
     }
 
+    case XENMEM_RMRR_memory_map:
+    {
+        struct memory_map_context ctxt;
+        XEN_GUEST_HANDLE(e820entry_t) buffer;
+        XEN_GUEST_HANDLE_PARAM(e820entry_t) buffer_param;
+        unsigned int i;
+
+        rc = xsm_machine_memory_map(XSM_PRIV);
+        if ( rc )
+            return rc;
+
+        if ( copy_from_guest(&ctxt.map, arg, 1) )
+            return -EFAULT;
+        if ( ctxt.map.nr_entries < rmrr_e820.nr_map + 1 )
+            return -EINVAL;
+
+        buffer_param = guest_handle_cast(ctxt.map.buffer, e820entry_t);
+        buffer = guest_handle_from_param(buffer_param, e820entry_t);
+        if ( !guest_handle_okay(buffer, ctxt.map.nr_entries) )
+            return -EFAULT;
+
+        for ( i = 0, ctxt.n = 0, ctxt.s = 0; i < rmrr_e820.nr_map; ++i, ++ctxt.n )
+        {
+            if ( __copy_to_guest_offset(buffer, ctxt.n, rmrr_e820.map + i, 1) )
+                return -EFAULT;
+        }
+
+        ctxt.map.nr_entries = ctxt.n;
+
+        if ( __copy_to_guest(arg, &ctxt.map, 1) )
+            return -EFAULT;
+
+        return 0;
+    }
+
     case XENMEM_machphys_mapping:
     {
         struct xen_machphys_mapping mapping = {
diff --git a/xen/arch/x86/x86_64/compat/mm.c b/xen/arch/x86/x86_64/compat/mm.c
index 69c6195..c35d05d 100644
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -132,6 +132,14 @@ int compat_arch_memory_op(unsigned long cmd, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
     }
 
+    case XENMEM_RMRR_memory_map:
+    {
+        if ( copy_to_guest(arg, &rmrr_e820, 1) )
+            return -EFAULT;
+
+        return 0;
+    }
+
     case XENMEM_machphys_mapping:
     {
         struct domain *d = current->domain;
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 2c57aa0..e04c0a3 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -523,7 +523,15 @@ DEFINE_XEN_GUEST_HANDLE(xen_mem_sharing_op_t);
 
 #endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */
 
-/* Next available subop number is 26 */
+/*
+ * Returns the RMRR memory map as it was when the domain
+ * was started.
+ */
+#define XENMEM_RMRR_memory_map           26
+typedef struct e820map rmrr_e820_t;
+DEFINE_XEN_GUEST_HANDLE(rmrr_e820_t);
+
+/* Next available subop number is 27 */
 
 #endif /* __XEN_PUBLIC_MEMORY_H__ */
 
-- 
1.9.1