[RFC PATCH 5/7] target/i386: Introduce AMD X86XSaveArea sub-union

[David Edmondson <david.edmondson@xxxxxxxxxx>]

AMD stores the pkru_state at a different offset to Intel.

Signed-off-by: David Edmondson <david.edmondson@xxxxxxxxxx>
---
 target/i386/cpu.h     | 17 +++++++++++++++--
 target/i386/kvm/kvm.c |  3 ++-
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index f1ce4e3008..99f0d5d851 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1319,7 +1319,8 @@ typedef struct XSavePKRU {
 #define XSAVE_OPMASK_OFFSET     0x440
 #define XSAVE_ZMM_HI256_OFFSET  0x480
 #define XSAVE_HI16_ZMM_OFFSET   0x680
-#define XSAVE_PKRU_OFFSET       0xa80
+#define XSAVE_INTEL_PKRU_OFFSET 0xa80
+#define XSAVE_AMD_PKRU_OFFSET   0x980
 
 typedef struct X86XSaveArea {
     X86LegacyXSaveArea legacy;
@@ -1348,6 +1349,16 @@ typedef struct X86XSaveArea {
             /* PKRU State: */
             XSavePKRU pkru_state;
         } intel;
+        struct {
+            /* Ensure that XSavePKRU is properly aligned. */
+            uint8_t padding[XSAVE_AMD_PKRU_OFFSET
+                            - sizeof(X86LegacyXSaveArea)
+                            - sizeof(X86XSaveHeader)
+                            - sizeof(XSaveAVX)];
+
+            /* PKRU State: */
+            XSavePKRU pkru_state;
+        } amd;
     };
 } X86XSaveArea;
 
@@ -1370,7 +1381,9 @@ QEMU_BUILD_BUG_ON(offsetof(X86XSaveArea, intel.hi16_zmm_state)
                   != XSAVE_HI16_ZMM_OFFSET);
 QEMU_BUILD_BUG_ON(sizeof(XSaveHi16_ZMM) != 0x400);
 QEMU_BUILD_BUG_ON(offsetof(X86XSaveArea, intel.pkru_state)
-                  != XSAVE_PKRU_OFFSET);
+                  != XSAVE_INTEL_PKRU_OFFSET);
+QEMU_BUILD_BUG_ON(offsetof(X86XSaveArea, amd.pkru_state)
+                  != XSAVE_AMD_PKRU_OFFSET);
 QEMU_BUILD_BUG_ON(sizeof(XSavePKRU) != 0x8);
 
 typedef enum TPRAccess {
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index 417776a635..9dd7db060d 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -2414,7 +2414,8 @@ ASSERT_OFFSET(XSAVE_BNDCSR_OFFSET, intel.bndcsr_state);
 ASSERT_OFFSET(XSAVE_OPMASK_OFFSET, intel.opmask_state);
 ASSERT_OFFSET(XSAVE_ZMM_HI256_OFFSET, intel.zmm_hi256_state);
 ASSERT_OFFSET(XSAVE_HI16_ZMM_OFFSET, intel.hi16_zmm_state);
-ASSERT_OFFSET(XSAVE_PKRU_OFFSET, intel.pkru_state);
+ASSERT_OFFSET(XSAVE_INTEL_PKRU_OFFSET, intel.pkru_state);
+ASSERT_OFFSET(XSAVE_AMD_PKRU_OFFSET, amd.pkru_state);
 
 static int kvm_put_xsave(X86CPU *cpu)
 {
-- 
2.30.2