[V3 PATCH 5/9] x86/hvm: pkeys, add functions to support PKRU access

[Huaitong Han <huaitong.han@intel.com>]

This patch adds functions to support PKRU access.

Signed-off-by: Huaitong Han <huaitong.han@intel.com>
---
 xen/include/asm-x86/processor.h | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 3f8411f..c345787 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -342,6 +342,26 @@ static inline void write_cr4(unsigned long val)
     asm volatile ( "mov %0,%%cr4" : : "r" (val) );
 }
 
+/* Macros for PKRU domain */
+#define PKRU_READ  (0)
+#define PKRU_WRITE (1)
+#define PKRU_ATTRS (2)
+
+/*
+ * PKRU defines 32 bits, there are 16 domains and 2 attribute bits per
+ * domain in pkru, pkeys is index to a defined domain, so the value of
+ * pte_pkeys * PKRU_ATTRS + R/W is offset of a defined domain attribute.
+ */
+static inline bool_t read_pkru_ad(unsigned int pkru, unsigned int pkey)
+{
+    return (pkru >> (pkey * PKRU_ATTRS + PKRU_READ)) & 1;
+}
+
+static inline bool_t read_pkru_wd(unsigned int pkru, unsigned int pkey)
+{
+    return (pkru >> (pkey * PKRU_ATTRS + PKRU_WRITE)) & 1;
+}
+
 /* Clear and set 'TS' bit respectively */
 static inline void clts(void) 
 {
-- 
2.4.3