KVM: nSVM: remove trailing padding for struct vmcb_control_area

Allow placing the VMCB structs on the stack or in other structs without
wasting too much space.  Add BUILD_BUG_ON as a quick safeguard against typos.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 6ece856..8a1f538 100644 (file)
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -96,7 +96,6 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
        u8 reserved_6[8];       /* Offset 0xe8 */
        u64 avic_logical_id;    /* Offset 0xf0 */
        u64 avic_physical_id;   /* Offset 0xf8 */
-       u8 reserved_7[768];
 };
 
 
@@ -203,8 +202,16 @@ struct __attribute__ ((__packed__)) vmcb_save_area {
        u64 last_excp_to;
 };
 
+
+static inline void __unused_size_checks(void)
+{
+       BUILD_BUG_ON(sizeof(struct vmcb_save_area) != 0x298);
+       BUILD_BUG_ON(sizeof(struct vmcb_control_area) != 256);
+}
+
 struct __attribute__ ((__packed__)) vmcb {
        struct vmcb_control_area control;
+       u8 reserved_control[1024 - sizeof(struct vmcb_control_area)];
        struct vmcb_save_area save;
 };