[RFC PATCH 3/7] target/i386: Clarify the padding requirements of X86XSaveArea

[David Edmondson]

Replace the hard-coded size of offsets or structure elements with
defined constants or sizeof().

Signed-off-by: David Edmondson <david.edmondson@oracle.com>
---
 target/i386/cpu.h | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 1fb732f366..0bb365bddf 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1329,7 +1329,13 @@ typedef struct X86XSaveArea {
 
     /* AVX State: */
     XSaveAVX avx_state;
-    uint8_t padding[960 - 576 - sizeof(XSaveAVX)];
+
+    /* Ensure that XSaveBNDREG is properly aligned. */
+    uint8_t padding[XSAVE_BNDREG_OFFSET
+                    - sizeof(X86LegacyXSaveArea)
+                    - sizeof(X86XSaveHeader)
+                    - sizeof(XSaveAVX)];
+
     /* MPX State: */
     XSaveBNDREG bndreg_state;
     XSaveBNDCSR bndcsr_state;
-- 
2.30.2