[PATCH 6/9] KVM: x86: Add static asserts to document connection b/w TSS structs and macros

[Sean Christopherson <seanjc@google.com>]

Add static asserts to sanity check the I/O permission map and TSS size
macros against tss_segment_32.  Alternatively, the macros could simply use
offsetof() and sizeof(), but having literal numbers makes it easier to
understand the bigger picture, and provides a good excuse for the sanity
checks.

Opportunistically add the necessary includes to make tss.h self sufficient.

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/kvm/tss.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/x86/kvm/tss.h b/arch/x86/kvm/tss.h
index 117bf8bec07d..55ced8975840 100644
--- a/arch/x86/kvm/tss.h
+++ b/arch/x86/kvm/tss.h
@@ -2,6 +2,10 @@
 #ifndef __TSS_SEGMENT_H
 #define __TSS_SEGMENT_H
 
+#include <linux/build_bug.h>
+#include <linux/stddef.h>
+#include <linux/types.h>
+
 struct tss_segment_32 {
 	u32 prev_task_link;
 	u32 esp0;
@@ -64,4 +68,7 @@ struct tss_segment_16 {
 #define RMODE_TSS_SIZE							\
 	(TSS_BASE_SIZE + TSS_REDIRECTION_SIZE + TSS_IOPB_SIZE + 1)
 
+static_assert(offsetof(struct tss_segment_32, io_map) == TSS_IOPB_BASE_OFFSET);
+static_assert(sizeof(struct tss_segment_32) == TSS_BASE_SIZE);
+
 #endif
-- 
2.55.0.rc0.799.gd6f94ed593-goog